WorldWideScience

Sample records for viable pre-combustion desulfurization

  1. Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

    Directory of Open Access Journals (Sweden)

    M. Zeki YILMAZOĞLU

    2010-02-01

    Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

  2. The Biocatalytic Desulfurization Project

    Energy Technology Data Exchange (ETDEWEB)

    David Nunn; James Boltz; Philip M. DiGrazia; Larry Nace

    2006-03-03

    The material in this report summarizes the Diversa technical effort in development of a biocatalyst for the biodesulfurization of Petro Star diesel as well as an economic report of standalone and combined desulfurization options, prepared by Pelorus and Anvil, to support and inform the development of a commercially viable process. We will discuss goals of the projected as originally stated and their modification as guided by parallel efforts to evaluate commercialization economics and process parameters. We describe efforts to identify novel genes and hosts for the generation of an optimal biocatalyst, analysis of diesel fuels (untreated, chemically oxidized and hydrotreated) for organosulfur compound composition and directed evolution of enzymes central to the biodesulfurization pathway to optimize properties important for their use in a biocatalyst. Finally we will summarize the challenges and issues that are central to successful development of a viable biodesulfurization process.

  3. JANNAF workshop on hazards due to pre-combustion behavior of high energy propellants

    Science.gov (United States)

    Boggs, T. L.

    1980-01-01

    Experimental results and hazards associated with the pre-combustion behavior of high energy propellants are discussed. Special attention was given to future needs for modeling and the problem of deflagration to detonation transition.

  4. Crude oil desulfurization

    Science.gov (United States)

    Kalvinskas, J. J.; Hsu, G. C.; Ernest, J. B. (Inventor)

    1982-01-01

    High sulfur crude oil is desulfurized by a low temperature (25-80 C.) chlorinolysis at ambient pressure in the absence of organic solvent or diluent but in the presence of water (water/oil=0.3) followed by a water and caustic wash to remove sulfur and chlorine containing reaction products. The process described can be practiced at a well site for the recovery of desulfurized oil used to generate steam for injection into the well for enhanced oil recovery.

  5. Pilot Testing of WRI'S Novel Mercury Control Technology by Pre-Combustion Thermal Treatment of Coal

    Energy Technology Data Exchange (ETDEWEB)

    Alan Bland; Jesse Newcomer; Kumar Sellakumar

    2008-08-17

    The challenges to the coal-fired power industry continue to focus on the emission control technologies, such as mercury, and plant efficiency improvements. An alternate approach to post-combustion control of mercury, while improving plant efficiency deals with Western Research Institute's (WRI)'s patented pre-combustion mercury removal and coal upgrading technology. WRI was awarded under the DOE's Phase III Mercury program, to evaluate the effectiveness of WRI's novel thermal pretreatment process to achieve >50% mercury removal, and at costs of <$30,000/lb of Hg removed. WRI has teamed with Etaa Energy, Energy and Environmental Research Center (EERC), Foster Wheeler North America Corp. (FWNA), and Washington Division of URS (WD-URS), and with project co-sponsors including Electric Power Research Institute (EPRI), Southern Company, Basin Electric Power Cooperative (BEPC), Montana-Dakota Utilities (MDU), North Dakota Industrial Commission (NDIC), Detroit Edison (DTE), and SaskPower to undertake this evaluation. The technical objectives of the project were structured in two phases: Phase I--coal selection and characterization, and bench-and PDU-scale WRI process testing and; and Phase II--pilot-scale pc combustion testing, design of an integrated boiler commercial configuration, its impacts on the boiler performance and the economics of the technology related to market applications. This report covers the results of the Phase I testing. The conclusion of the Phase I testing was that the WRI process is a technically viable technology for (1) removing essentially all of the moisture from low rank coals, thereby raising the heating value of the coal by about 30% for subbituminous coals and up to 40% for lignite coals, and (2) for removing volatile trace mercury species (up to 89%) from the coal prior to combustion. The results established that the process meets the goals of DOE of removing <50% of the mercury from the coals by pre-combustion methods

  6. Fluidized bed coal desulfurization

    Science.gov (United States)

    Ravindram, M.

    1983-01-01

    Laboratory scale experiments were conducted on two high volatile bituminous coals in a bench scale batch fluidized bed reactor. Chemical pretreatment and posttreatment of coals were tried as a means of enhancing desulfurization. Sequential chlorination and dechlorination cum hydrodesulfurization under modest conditions relative to the water slurry process were found to result in substantial sulfur reductions of about 80%. Sulfur forms as well as proximate and ultimate analyses of the processed coals are included. These studies indicate that a fluidized bed reactor process has considerable potential for being developed into a simple and economic process for coal desulfurization.

  7. Enzymatic desulfurization of coal

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1991-05-16

    The overall objective of this program was to investigate the feasibility of an enzymatic desulfurization process specifically intended for organic sulfur removal from coal. Toward that end, a series of specific objectives were defined: (1) establish the feasibility of (bio)oxidative pretreatment followed by biochemical sulfate cleavage for representative sulfur-containing model compounds and coals using commercially-available enzymes; (2) investigate the potential for the isolation and selective use of enzyme preparations from coal-utilizing microbial systems for desulfurization of sulfur-containing model compounds and coals; and (3) develop a conceptual design and economic analysis of a process for enzymatic removal of organic sulfur from coal. Within the scope of this program, it was proposed to carry out a portion of each of these efforts concurrently. (VC)

  8. Enzymatic desulfurization of coal

    Energy Technology Data Exchange (ETDEWEB)

    Marquis, J.K. (Boston Univ., MA (United States). School of Medicine); Kitchell, J.P. (Holometrix, Inc., Cambridge, MA (United States))

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  9. Fluidized bed desulfurization

    Science.gov (United States)

    Ravindram, M.; Kallvinskas, J. J. (Inventor)

    1985-01-01

    High sulfur content carbonaceous material, such as coal is desulfurized by continuous fluidized suspension in a reactor with chlorine gas, inert dechlorinating gas and hydrogen gas. A source of chlorine gas, a source of inert gas and a source of hydrogen gas are connected to the bottom inlet through a manifold and a heater. A flow controler operates servos in a manner to continuously and sequentially suspend coal in the three gases. The sulfur content is reduced at least 50% by the treatment.

  10. Microbial desulfurization of coal

    Science.gov (United States)

    Dastoor, M. N.; Kalvinskas, J. J.

    1978-01-01

    Experiments indicate that several sulfur-oxidizing bacteria strains have been very efficient in desulfurizing coal. Process occurs at room temperature and does not require large capital investments of high energy inputs. Process may expand use of abundant reserves of high-sulfur bituminous coal, which is currently restricted due to environmental pollution. On practical scale, process may be integrated with modern coal-slurry transportation lines.

  11. Coal desulfurization with iron pentacarbonyl

    Science.gov (United States)

    Hsu, G. C.

    1979-01-01

    Coal desulfurization with iron pentacarbonyl treatment under mild conditions removes up to eighty percent of organic sulfur. Preliminary tests on treatment process suggest it may be economical enough to encourage investigation of use for coal desulfurization. With mild operating conditions, process produces environmentally-acceptable clean coal at reasonable cost.

  12. Nanocarbons for Catalytic Desulfurization.

    Science.gov (United States)

    Gu, Qingqing; Lin, Yangming; Heumann, Saskia; Su, Dangsheng

    2017-08-24

    Nanocarbon catalysts are green and sustainable alternatives to metal-based catalysts for numerous catalytic transformations. The application of nanocarbons for environmental catalysis is an emerging research discipline and has undergone rapid development in recent years. In this focus review, we provide a critical analysis of state-of-the-art nanocarbon catalysts for three different catalytic desulfurization processes. In particular, we focus on the advantages and limitations as well as the reaction mechanisms of the nanocarbon catalysts at the molecular level. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and

  14. Evaluation of Dry Sorbent Injection Technology for Pre-Combustion CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Carl [URS Group, Inc., Austin, TX (United States); Steen, William [URS Group, Inc., Austin, TX (United States); Triana, Eugenio [URS Group, Inc., Austin, TX (United States); Machalek, Thomas [URS Group, Inc., Austin, TX (United States); Davila, Jenny [URS Group, Inc., Austin, TX (United States); Schmit, Claire [URS Group, Inc., Austin, TX (United States); Wang, Andrew [URS Group, Inc., Austin, TX (United States); Temple, Brian [URS Group, Inc., Austin, TX (United States); Lu, Yongqi [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Lu, Hong [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Zhang, Luzheng [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Ruhter, David [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Rostam-Abadi, Massoud [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Sayyah, Maryam [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Ito, Brandon [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States); Suslick, Kenneth [Illinois State Geological Survey - University of Illinois at Urbana-Champaign (United States)

    2013-09-30

    This document summarizes the work performed on Cooperative Agreement DE-FE0000465, “Evaluation of Dry Sorbent Technology for Pre-Combustion CO{sub 2} Capture,” during the period of performance of January 1, 2010 through September 30, 2013. This project involves the development of a novel technology that combines a dry sorbent-based carbon capture process with the water-gas-shift reaction for separating CO{sub 2} from syngas. The project objectives were to model, develop, synthesize and screen sorbents for CO{sub 2} capture from gasified coal streams. The project was funded by the DOE National Energy Technology Laboratory with URS as the prime contractor. Illinois Clean Coal Institute and The University of Illinois Urbana-Champaign were project co-funders. The objectives of this project were to identify and evaluate sorbent materials and concepts that were suitable for capturing carbon dioxide (CO{sub 2}) from warm/hot water-gas-shift (WGS) systems under conditions that minimize energy penalties and provide continuous gas flow to advanced synthesis gas combustion and processing systems. Objectives included identifying and evaluating sorbents that efficiently capture CO{sub 2} from a gas stream containing CO{sub 2}, carbon monoxide (CO), and hydrogen (H{sub 2}) at temperatures as high as 650 °C and pressures of 400-600 psi. After capturing the CO{sub 2}, the sorbents would ideally be regenerated using steam, or other condensable purge vapors. Results from the adsorption and regeneration testing were used to determine an optimal design scheme for a sorbent enhanced water gas shift (SEWGS) process and evaluate the technical and economic viability of the dry sorbent approach for CO{sub 2} capture. Project work included computational modeling, which was performed to identify key sorbent properties for the SEWGS process. Thermodynamic modeling was used to identify optimal physical properties for sorbents and helped down-select from the universe of possible sorbent

  15. Irradiation pretreatment for coal desulfurization

    Science.gov (United States)

    Hsu, G. C.

    1979-01-01

    Process using highly-penetrating nuclear radiation (Beta and Gamma radiation) from nuclear power plant radioactive waste to irradiate coal prior to conventional desulfurization procedures increases total extraction of sulfur.

  16. Pre-Combustion Carbon Capture by a Nanoporous, Superhydrophobic Membrane Contactor Process

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Howard; Zhou, S James; Ding, Yong; Bikson, Ben

    2012-03-31

    This report summarizes progress made during Phase I and Phase II of the project: "Pre-Combustion Carbon Capture by a Nanoporous, Superhydrophobic Membrane Contactor Process," under contract DE-FE-0000646. The objective of this project is to develop a practical and cost effective technology for CO{sub 2} separation and capture for pre-combustion coal-based gasification plants using a membrane contactor/solvent absorption process. The goals of this technology development project are to separate and capture at least 90% of the CO{sub 2} from Integrated Gasification Combined Cycle (IGCC) power plants with less than 10% increase in the cost of energy services. Unlike conventional gas separation membranes, the membrane contactor is a novel gas separation process based on the gas/liquid membrane concept. The membrane contactor is an advanced mass transfer device that operates with liquid on one side of the membrane and gas on the other. The membrane contactor can operate with pressures that are almost the same on both sides of the membrane, whereas the gas separation membranes use the differential pressure across the membrane as driving force for separation. The driving force for separation for the membrane contactor process is the chemical potential difference of CO{sub 2} in the gas phase and in the absorption liquid. This process is thus easily tailored to suit the needs for pre-combustion separation and capture of CO{sub 2}. Gas Technology Institute (GTI) and PoroGen Corporation (PGC) have developed a novel hollow fiber membrane technology that is based on chemically and thermally resistant commercial engineered polymer poly(ether ether ketone) or PEEK. The PEEK membrane material used in the membrane contactor during this technology development program is a high temperature engineered plastic that is virtually non-destructible under the operating conditions encountered in typical gas absorption applications. It can withstand contact with most of the common treating

  17. Enzymatic desulfurization of coal

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. (DynaGen, Inc., Cambridge, MA (United States)); Marquis, J.K. (Boston Univ., MA (United States). School of Medicine)

    1989-11-07

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to selectively catalyze oxidation at sulfur.

  18. Microbial desulfurization of dibenzothiophene

    Energy Technology Data Exchange (ETDEWEB)

    van Afferden, M.; Schacht, S.; Beyer, M.; Klein, J.

    1988-01-01

    Concerning the sulfur removal from coal before combustion there is considerable interest in microbial methods as pyrite oxidation and elimination of organically bound sulfur from coal. Using organic sulfur compounds relevant for coal the mechanism of desulfurization was investigated. The authors isolated a defined mixed culture (FODO) able to utilize dibenzothiophene as sole sulfur source for growth, while benzoate was used as carbon source. The mixed culture FODO consists of an Alcaligenes denitrificans subspecies and a Brevibacterium species. Two metabolites of the degradation and dibenzothiophene-5-dioxide. The subsequent degradation of dibenzothiophene-5-dioxide used as sole sulfur source results in a release of sulfate ions into the medium. The results suggest a sulfur specific oxidative mechanism for removal of sulfur from dibenzothiophene.

  19. Pre-combustion CO2 capture by transition metal ions embedded in phthalocyanine sheets.

    Science.gov (United States)

    Lü, Kun; Zhou, Jian; Zhou, Le; Chen, X S; Chan, Siew Hwa; Sun, Qiang

    2012-06-21

    Transition metal (TM) embedded two-dimensional phthalocyanine (Pc) sheets have been recently synthesized in experiments [M. Abel, S. Clair, O. Ourdjini, M. Mossoyan, and L. Porte, J. Am. Chem. Soc. 133, 1203 (2010)], where the transition metal ions are uniformly distributed in porous structures, providing the possibility of capturing gas molecules. Using first principles and grand canonical Monte Carlo simulations, TMPc sheets (TM = Sc, Ti, and Fe) are studied for pre-combustion CO(2) capture by considering the adsorptions of H(2)/CO(2) gas mixtures. It is found that ScPc sheet shows a good selectivity for CO(2), and the excess uptake capacity of single-component CO(2) on ScPc sheet at 298 K and 50 bar is found to be 2949 mg/g, larger than that of any other reported porous materials. Furthermore, electrostatic potential and natural bond orbital analyses are performed to reveal the underlying interaction mechanisms, showing that electrostatic interactions as well as the donation and back donation of electrons between the transition metal ions and the CO(2) molecules play a key role in the capture.

  20. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Steven E. Bonde; David Nunn

    2003-01-01

    During the first quarter of the Biological Desulfurization project several activities were pursued. A project kickoff meeting was held at the Diversa facility in San Diego, CA. Activities that were in process before the meeting and begun afterwards by Diversa Corporation and Petro Star Inc. include: Technology transfer in the form of information generated by Enchira to Diversa, the purchase and installation of equipment by Diversa, development of synthetic methods and preparation of organo-sulfur substrates for use in determining enzyme activities, production of extract via Petro Star's CED process, detailed analysis of Petro Star Inc. diesel and CED extract, and several activities in molecular biology. Diversa Corporation, in the area of molecular biology, engaged in several activities in support of the task list of the contract. These included: construction of a genomic library; development and utilization of a sequence-based gene discovery effort; a parallel discovery approach based on functional expression of enzymes with the ability to oxidize organosulfur compounds. Biodesulfurization genes have already been identified and are being sequenced and subcloned for expression in heterologous biological hosts. Diversa has evaluated and adapted assays developed by Enchira used to assess the activities of DBT and DBTO{sub 2} monooxygenases. Finally, Diversa personnel have developed two novel selection/screen strategies for the improvement of biocatalyst strains by directed evolution.

  1. Desulfurization apparatus and method

    Science.gov (United States)

    Rong, Charles; Jiang, Rongzhong; Chu, Deryn

    2013-06-18

    A method and system for desulfurization comprising first and second metal oxides; a walled enclosure having an inlet and an exhaust for the passage of gas to be treated; the first and second metal oxide being combinable with hydrogen sulfide to produce a reaction comprising a sulfide and water; the first metal oxide forming a first layer and the second metal oxide forming a second layer within the walled surroundings; the first and second layers being positioned so the first layer removes the bulk amount of the hydrogen sulfide from the treated gas prior to passage through the second layer, and the second layer removes substantially all of the remaining hydrogen sulfide from the treated gas; the first metal oxide producing a stoichiometrical capacity in excess of 500 mg sulfur/gram; the second metal oxide reacts with the hydrogen sulfide more favorably but has a stoichometrical capacity which is less than the first reactant; whereby the optimal amount by weight of the first and second metal oxides is achieved by utilizing two to three units by weight of the first metal oxide for every unit of the second metal oxide.

  2. A Low Cost, High Capacity Regenerable Sorbent for Pre-combustion CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Alptekin, Gokhan

    2012-09-30

    The overall objective of the proposed research is to develop a low cost, high capacity CO{sub 2} sorbent and demonstrate its technical and economic viability for pre-combustion CO{sub 2} capture. The specific objectives supporting our research plan were to optimize the chemical structure and physical properties of the sorbent, scale-up its production using high throughput manufacturing equipment and bulk raw materials and then evaluate its performance, first in bench-scale experiments and then in slipstream tests using actual coal-derived synthesis gas. One of the objectives of the laboratory-scale evaluations was to demonstrate the life and durability of the sorbent for over 10,000 cycles and to assess the impact of contaminants (such as sulfur) on its performance. In the field tests, our objective was to demonstrate the operation of the sorbent using actual coal-derived synthesis gas streams generated by air-blown and oxygen-blown commercial and pilot-scale coal gasifiers (the CO{sub 2} partial pressure in these gas streams is significantly different, which directly impacts the operating conditions hence the performance of the sorbent). To support the field demonstration work, TDA collaborated with Phillips 66 and Southern Company to carry out two separate field tests using actual coal-derived synthesis gas at the Wabash River IGCC Power Plant in Terre Haute, IN and the National Carbon Capture Center (NCCC) in Wilsonville, AL. In collaboration with the University of California, Irvine (UCI), a detailed engineering and economic analysis for the new CO{sub 2} capture system was also proposed to be carried out using Aspen PlusTM simulation software, and estimate its effect on the plant efficiency.

  3. Novel polymer membrane process for pre-combustion CO{sub 2} capture from coal-fired syngas

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, Tim [MTR Inc., Menlo Park, CA (United States)

    2011-09-14

    This final report describes work conducted for the Department of Energy (DOE NETL) on development of a novel polymer membrane process for pre-combustion CO{sub 2} capture from coalfired syngas (award number DE-FE0001124). The work was conducted by Membrane Technology and Research, Inc. (MTR) from September 15, 2009, through December 14, 2011. Tetramer Technologies, LLC (Tetramer) was our subcontract partner on this project. The National Carbon Capture Center (NCCC) at Wilsonville, AL, provided access to syngas gasifier test facilities. The main objective of this project was to develop a cost-effective membrane process that could be used in the relatively near-term to capture CO{sub 2} from shifted syngas generated by a coal-fired Integrated Gasification Combined Cycle (IGCC) power plant. In this project, novel polymeric membranes (designated as Proteus™ membranes) with separation properties superior to conventional polymeric membranes were developed. Hydrogen permeance of up to 800 gpu and H{sub 2}/CO{sub 2} selectivity of >12 was achieved using a simulated syngas mixture at 150°C and 50 psig, which exceeds the original project targets of 200 gpu for hydrogen permeance and 10 for H{sub 2}/CO{sub 2} selectivity. Lab-scale Proteus membrane modules (with a membrane area of 0.13 m{sup 2}) were also developed using scaled-up Proteus membranes and high temperature stable module components identified during this project. A mixed-gas hydrogen permeance of about 160 gpu and H{sub 2}/CO{sub 2} selectivity of >12 was achieved using a simulated syngas mixture at 150°C and 100 psig. We believe that a significant improvement in the membrane and module performance is likely with additional development work. Both Proteus membranes and lab-scale Proteus membrane modules were further evaluated using coal-derived syngas streams at the National Carbon Capture Center (NCCC). The results indicate that all module components, including the Proteus membrane, were stable under the field

  4. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Scott Collins; David Nunn

    2003-10-01

    The analysis of Petro Star diesel sulfur species is complete and a report is attached. Further analytical efforts will concentrate on characterization of diesel fuel, hydrodesulfurized to varying degrees, in order to determine sulfur species that may be problematic to hydrogen treatment and represent potential target substrates for biodesulfurization in a combined HDS-BDS process. Quotes have been received and are being considered for the partial treatment of Petro Star Inc. marine diesel fuel. Direction of research is changing slightly; economic analysis of the hyphenated--BDSHDS, BDS-CED--has shown the highest probability of success to be with a BDS-HDS process where the biodesulfurization precedes hydrodesulfurization. Thus, the microorganisms will be tailored to focus on those compounds that tend to be recalcitrant to hydrodesulfurization and decrease the severity of the hydrodesulfurization step. A separate, detailed justification for this change is being prepared. Research activities have continued in the characterization of the desulfurization enzymes from multiple sources. Genes for all DszA, -B, -C and -D enzymes (and homologs) have been cloned and expressed. Activity determinations, on a variety of substituted benzothiophene and dibenzothiophene substrates, have been carried out and continue. In addition, chemical synthesis efforts have been carried out to generate additional substrates for analytical standards and activity determinations. The generation of a GSSM mutant library of the ''Rhodococcus IGTS8 dszA'' gene has been completed and development of protocols for a high throughput screen to expand substrate specificity are nearing completion. In an effort to obtain improved hosts as biocatalyst, one hundred-thirty ''Rhodococcus'' and related strains are being evaluated for growth characteristics and other criteria deemed important for an optimal biocatalyst strain. We have also begun an effort to generate

  5. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    Science.gov (United States)

    Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

    2016-02-01

    Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

  6. Analysis of Combined Cycle Power Plants with Chemical Looping Reforming of Natural Gas and Pre-Combustion CO2 Capture

    Directory of Open Access Journals (Sweden)

    Shareq Mohd Nazir

    2018-01-01

    Full Text Available In this paper, a gas-fired combined cycle power plant subjected to a pre-combustion CO2 capture method has been analysed under different design conditions and different heat integration options. The power plant configuration includes the chemical looping reforming (CLR of natural gas (NG, water gas shift (WGS process, CO2 capture and compression, and a hydrogen fuelled combined cycle to produce power. The process is denoted as a CLR-CC process. One of the main parameters that affects the performance of the process is the pressure for the CLR. The process is analysed at different design pressures for the CLR, i.e., 5, 10, 15, 18, 25 and 30 bar. It is observed that the net electrical efficiency increases with an increase in the design pressure in the CLR. Secondly, the type of steam generated from the cooling of process streams also effects the net electrical efficiency of the process. Out of the five different cases including the base case presented in this study, it is observed that the net electrical efficiency of CLR-CCs can be improved to 46.5% (lower heating value of NG basis by producing high-pressure steam through heat recovery from the pre-combustion process streams and sending it to the Heat Recovery Steam Generator in the power plant.

  7. Coal desulfurization by aqueous chlorination

    Science.gov (United States)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K. (Inventor)

    1982-01-01

    A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 C to 500 C to form a non-caking, low-sulfur coal product.

  8. Environmental Performance of Hypothetical Canadian Pre-Combustion Carbon Dioxide Capture Processes Using Life-Cycle Techniques

    Directory of Open Access Journals (Sweden)

    Lakkana Piewkhaow

    2016-03-01

    Full Text Available The methodology of life-cycle assessment was applied in order to evaluate the environmental performance of a hypothetical Saskatchewan lignite-fueled Integrated Gasification Combined Cycle (IGCC electricity generation, with and without pre-combustion carbon dioxide (CO2 capture from a full life-cycle perspective. The emphasis here is placed on environmental performance associated with air contaminants of the comparison between IGCC systems (with and without CO2 capture and a competing lignite pulverized coal-fired electricity generating station in order to reveal which technology offers the most positive environmental effects. Moreover, ambient air pollutant modeling was also conducted by using American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD air dispersion modeling to determine the ground-level concentration of pollutants emitted from four different electricity generating stations. This study assumes that all stations are located close to Estevan. The results showed a significant reduction in greenhouse gas (GHG emissions and acidification potential by applying both post-combustion and pre-combustion CO2 capture processes. The GHG emissions were found to have reduced by 27%–86%, and IGCC systems were found to compare favorably to pulverized coal systems. However, in other environmental impact categories, there are multiple environmental trade-offs depending on the capture technology used. In the case of post-combustion capture, it was observed that the environmental impact category of eutrophication potential, summer smog, and ozone depletion increased due to the application of the CO2 capture process and the surface mining coal operation. IGCC systems, on the other hand, showed the same tendency as the conventional coal-fired electricity generation systems, but to a lesser degree. This is because the IGCC system is a cleaner technology that produces lower pollutant emission levels than the electricity

  9. Review of desulfurization process for biogas purification

    Science.gov (United States)

    Xiao, Cong; Ma, Yunqian; Ji, Dandan; Zang, Lihua

    2017-12-01

    Hydrogen sulfide (H2S) is a toxic and odorous compound present in biogas produced by the anaerobic digestion of biosolids and other organic materials. Elimination of H2S is necessary as it is extremely hazardous to human health, poisonous to process catalysts and corrosive to equipment. The desulfurization technology is an important part for efficient utilization of biogas. In this paper, the traditional wet and dry desulfurization technology for biogas was reviewed, and the new research progress of biological desulfurization technologies are also introduced.

  10. Oxidative desulfurization of tire pyrolysis oil

    Directory of Open Access Journals (Sweden)

    Ahmad Shahzad

    2016-01-01

    Full Text Available This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure and 50°C temperature for comparison of performance of various additives. The use of hydrogen peroxide-acetic acid mixture (10 wt.% was found more economical and effective in desulfurization and improvement of fuel properties of sample oils. The contribution of sulfuric acid in desulfurization and decreasing viscosity was also satisfactory but due to high price of concentrated sulfuric acid its use may not be economical. Calcium oxide and Fuller’s earth was not found to be effective in desulfurization. Results indicate that oxidative desulfurization could render tire pyrolysis oils suitable for blending as heating fuel.

  11. Energy and exergy analysis of chemical looping combustion technology and comparison with pre-combustion and oxy-fuel combustion technologies for CO2 capture

    OpenAIRE

    Mukherjee, Sanjay; Kumar, Prashant; Yang, Aidong; Fennell, Paul

    2015-01-01

    Abstract Carbon dioxide (CO2) emitted from conventional coal-based power plants is a growing concern for the environment. Chemical looping combustion (CLC), pre-combustion and oxy-fuel combustion are promising CO2 capture technologies which allow clean electricity generation from coal in an integrated gasification combined cycle (IGCC) power plant. This work compares the characteristics of the above three capture technologies to those of a conventional IGCC plant without CO2 capture. CLC tech...

  12. Method for desulfurization of coal

    Science.gov (United States)

    Kelland, D.R.

    1987-07-07

    A process and apparatus are disclosed for desulfurizing coal which removes sulfur in the inorganic and organic form by preferentially heating the inorganic iron sulfides in coal in a flowing gas to convert some of the inorganic iron sulfides from a pyrite form FeS[sub 2] to a troilite FeS form or a pyrrhotite form Fe[sub 1[minus]x]S and release some of the sulfur as a gaseous compound. The troilite and pyrrhotite forms are convenient catalyst for removing the organic sulfur in the next step, which is to react the coal with chemical agents such as alcohol, thus removing the organic sulfur as a liquid or a gas such as H[sub 2]S. The remaining inorganic sulfur is left in the predominantly higher magnetic form of pyrrhotite and is then removed by magnetic separation techniques. Optionally, an organic flocculant may be added after the organic sulfur has been removed and before magnetic separation. The flocculant attaches non-pyrite minerals with the pyrrhotite for removal by magnetic separation to reduce the ash-forming contents. 2 figs.

  13. Coal desulfurization by low-temperature chlorinolysis

    Science.gov (United States)

    Hsu, G. C.; Kalvinskas, J. J.; Ganguli, P. S.; Gavalas, G. R.

    1977-01-01

    Among the three principal methods for precombustion desulfurization of coal, which include physical depyriting, chemical desulfurization, and coal conversion to low-sulfur liquid and gaseous fuels, the potential of chemical methods looks promising in terms of both total sulfur removal and processing cost. The principal chemical methods for coal desulfurization involve treatment with either oxidizing agents or basic media at elevated temperature and pressure. A description is given of some recent experimental results which show the feasibility of removing sulfur, particularly organic sulfur, from high-sulfur coals by a simple method of low-temperature chlorinolysis followed by hydrolysis and dechlorination. The chemical feasibility of sulfur removal by chlorinolysis rather than the detailed engineering process is emphasized.

  14. Ultrasound-assisted oxidative desulfurization of bitumen

    Science.gov (United States)

    Kamal, Wan Mohamad Ikhwan bin Wan; Okawa, Hirokazu; Kato, Takahiro; Sugawara, Katsuyasu

    2017-07-01

    Bitumen contains a high percentage of sulfur (about 4.6 wt %). A hydrodesulfurization method is used to remove sulfur from bitumen. The drawback of this method is the requirement for a high temperature of >300 °C. Most of the sulfur in bitumen exists as thiophene. Oxidative desulfurization (ODS), involving oxidizing sulfur using H2O2, then removing it using NaOH, allows the removal of sulfur in thiophene at low temperatures. We removed sulfur from bitumen using ODS treatment under ultrasound irradiation, and 52% of sulfur was successfully removed. Additionally, the physical action of ultrasound assisted the desulfurization of bitumen, even at low H2O2 concentrations.

  15. Low-Cost Aqueous Coal Desulfurization

    Science.gov (United States)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K.

    1982-01-01

    Water-based process for desulfurizing coal not only eliminates need for costly organic solvent but removes sulfur more effectively than an earlier solvent-based process. New process could provide low-cost commercial method for converting high-sulfur coal into environmentally acceptable fuel.

  16. Managing Viable Knowledge

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Vriens, D.J.

    2002-01-01

    In this paper, Beer's Viable System Model (VSM) is applied to knowledge management. Based on the VSM, domains of knowledge are identified that an organization should possess to maintain its viability. The logic of the VSM is also used to support the diagnosis, design and implementation of the

  17. Preliminary evaluation of a process using plasma reactions to desulfurize heavy oils. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, P.W.; Miknis, F.P.

    1997-09-01

    Western Research Institute (WRI) has conducted exploratory experiments on the use of microwave-induced plasmas to desulfurize heavy oils. Batch mode experiments were conducted in a quartz reactor system using various reactive and nonreactive plasmas. In these experiments a high-sulfur asphalt was exposed to various plasmas, and the degree of conversion to distillate, gas, and solids was recorded. Products from selected experiments were analyzed to determine if the plasma exposure had resulted in a significant reduction in sulfur content. Exploratory experiments were conducted using reactive plasmas generated from hydrogen and methane and nonreactive plasmas generated from nitrogen. The effects of varying exposure duration, sample temperature, and location of the sample with respect to the plasma discharge were investigated. For comparative purposes two experiments were conducted in which the sample was heated under nitrogen with no plasma exposure. Distillates containing approximately 28% less sulfur than the feedstock represented the maximum desulfurization attained in the plasma experiments. It does not appear that plasma reactions using the simple configurations employed in this study represent a viable method for the desulfurization of heavy oils.

  18. [Performance of desulfurizing absorbent of roasted navajoite].

    Science.gov (United States)

    Chen, Fang; Yang, Chun-ping; Gan, Hai-ming; Wu, Ting; Chen, Hai-lin; Chen, Hong; Xu, Ke-hui; Xie, Geng-xin

    2010-04-01

    An innovative flue gas desulfurization (FGD) coupling process was proposed in this study to overcome the problems in wet-type limestone/lime processes which include fouling, clogging, and difficulty of selling the by-products and the problems in traditional process for vanadium extraction from navajoite ore such as excessive consumption of sulfuric acid and emissions of pollutants. The performance of a jet bubbling reactor (JBR) at pilot-scale was evaluated using navajoite ore produced in the process of extracting vanadium pentoxide as desulfurization absorbent. Results showed that navajoite ore slurry achieved better desulfurization performance than limestone slurry. When the inlet flue gas pressure drop was 3.0 kPa, the gas flow was about 2350 m3 x h(-1) and the pH of the navajoite ore slurry was higher than 4.5, the desulfurization efficiency was stable about 90%. The SO2 removal efficiency appeared to increase along with the increasing of absorbent cycle-index. The efficiency of the second circulation was improved 3.5% compared to the first circulation. After an operating duration of 40 minutes, the leaching rate of vanadium pentoxide was about 20%, and reached 60% when the by-products were leached with 5% dilute sulfuric acid for 10 hours. The by-product from this process not only could be used to produce vanadium pentoxide which is a valuable industrial product, but also could significantly overcome the pollution problem existing in the traditional refining process of vanadium pentoxide when navajoite ore is used as the feed material. This FGD process using roasted navajoite slurry as absorbent is environmental sound and cost-effective, and shows the potential for application in the field of flue gas desulfurization as well as hydrometallurgy.

  19. Modelling of a tubular membrane contactor for pre-combustion CO2 capture using ionic liquids: Influence of the membrane configuration, absorbent properties and operation parameters

    Directory of Open Access Journals (Sweden)

    Zhongde Dai

    2016-10-01

    Full Text Available A membrane contactor using ionic liquids (ILs as solvent for pre-combustion capture CO2 at elevated temperature (303–393 K and pressure (20 bar has been studied using mathematic model in the present work. A comprehensive two-dimensional (2D mass-transfer model was developed based on finite element method. The effects of liquid properties, membrane configurations, as well as operation parameters on the CO2 removal efficiency were systematically studied. The simulation results show that CO2 can be effectively removed in this process. In addition, it is found that the liquid phase mass transfer dominated the overall mass transfer. Membranes with high porosity and small thickness could apparently reduce the membrane resistance and thus increase the separation efficiency. On the other hand, the membrane diameter and membrane length have a relatively small influence on separation performance within the operation range. Keywords: CO2 capture, Pre-combustion, Membrane contactor, Ionic liquids, Modelling

  20. Synthesis of Deoxyglycosides by Desulfurization under UV Light.

    Science.gov (United States)

    Ge, Jian-Tao; Li, Ying-Ying; Tian, Jun; Liao, Rong-Zhen; Dong, Hai

    2017-07-07

    This study was performed to develop a highly efficient method whereby desulfurization could be completed in 0.5 h under ultraviolet light, at room temperature, and in the presence of trialkylphosphine. Using this method, deoxyglycosides could be produced from sulfur-containing glycosides in almost quantitative yields. The much higher reactivity of desulfurization with triethylphosphine versus that with triethylphosphite is also discussed.

  1. Magnesite base desulfurizer of metallurgical physical chemistry research

    Directory of Open Access Journals (Sweden)

    G. D. Liu

    2017-01-01

    Full Text Available This topic put carbon thermal vacuum method in combination with magnesium based desulfurization technology with magnesite reduction of magnesium vapor directly on hot metal desulphurization. This is a new type of desulfurization technology, the retrieval related literature at home and abroad was not reported in the recent ten years, according to the relationship between heat of desulfurizer preparation MgO style content can reach 50 %.It was found that the desulfurizer sample with 50 % MgO content was in accordance with the requirements, without adding flux, but its viscosity did not meet the requirements; adding 1 % flux (CaF2, the sample viscosity was significantly reduced, and about 1 400 °C sample viscosity suitable for hot metal pretreatment desulfurization.

  2. Enzymatic desulfurization of coal: Third quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    Marquis, Judith K. [School of Medicine, Boston Univ., MA (United States); Kitchell, Judith P. [Holometrix, Inc., Cambridge, Massachusetts (United States)

    1989-03-14

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ''model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix. In this quarter we obtained important results both with the development of our understanding of the enzyme reaction systems and also with the microbial work at Woods Hole. 12 figs., 11 tabs.

  3. Sorbent for use in hot gas desulfurization

    Science.gov (United States)

    Gasper-Galvin, Lee D.; Atimtay, Aysel T.

    1993-01-01

    A multiple metal oxide sorbent supported on a zeolite of substantially silicon oxide is used for the desulfurization of process gas streams, such as from a coal gasifier, at temperatures in the range of about 1200.degree. to about 1600.degree. F. The sorbent is provided by a mixture of copper oxide and manganese oxide and preferably such a mixture with molybdenum oxide. The manganese oxide and the molybdenum are believed to function as promoters for the reaction of hydrogen sulfide with copper oxide. Also, the manganese oxide inhibits the volatilization of the molybdenum oxide at the higher temperatures.

  4. Postligation-desulfurization: a general approach for chemical protein synthesis.

    Science.gov (United States)

    Ma, Jimei; Zeng, Jing; Wan, Qian

    2015-01-01

    Native chemical ligation, involving regioselective and chemoselective coupling of two unprotected peptide segments, enabled the synthesis of polypeptide with more than 200 amino acids. However, cysteine was indispensable in this synthetic technique in its initial format, which limited its further application. Thus, considerable effort has been put into breaking the restriction of cysteine-containing ligation. As a consequence, postligation-desulfurization, concerning thiol-mediated ligation followed by desulfurization, was developed. This review describes the development and recent progress on the chemical synthesis of peptides and proteins encompassing postligation-desulfurization at alanine, valine, lysine, threonine, leucine, proline, arginine, aspartic acid, glutamate, phenylalanine, glutamine, and tryptophan.

  5. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    Energy Technology Data Exchange (ETDEWEB)

    John G. Verkade

    1998-08-31

    The nonionic superbase P(MeNCH{sub 2}CH{sub 2}){sub 3}N (A) efficiently desulfurizes trisulfides to disulfides and monosulfides, disulfides to monosulfides, and propylene sulfide to propene. S=P(MeNCH{sub 2}CH{sub 2}){sub 3}N (B) was formed as the sulfur acceptor. P(NMe{sub 2}){sub 3} was a much poorer desulfurizing agent than A under the same reaction conditions. Thiocyanates and triphenylphosphine sulfide were also desulfurized with A, but N-(phenylthio)phthalimide formed [A-SP]{sup +} phthalimide in quantitative yield.

  6. Desulfurization of Saudi Arabian crudes by oxidation-extraction method.

    Science.gov (United States)

    Al Otaibi, Raja L; Liu, Dong; Hou, Xulian; Song, Linhua; Li, Qingyin; Li, Mengfei; Almigrin, Hamid O; Yan, Zifeng

    The oxidation-extraction desulfurization of Saudi Arabian crudes was conducted with hydrogen peroxide-acetic acid oxidation system. The selection of extractant, the optimization of oxidation-extraction conditions, and the exploration of desulfurization mechanism were studied. As DMF was used as the extractant, the optimal desulfurization rate of 35.11 % and oil recovery of 95 % were obtained at 70 °C with the molar ratio of peracetic acid to sulfur of 8:1, the molar ratio of acetic acid to hydrogen peroxide of 2:1 and the volume ratio of extractant to oil of 1:1. The desulfurization effect of different fractions in the treated Saudi Arabian crudes was found to obey the following order: gasoline-diesel fraction >VGO fraction >VR fraction, due to different types and structures of sulfur compounds. The oil quality was less affected and most sulfides were mainly extracted via DMF.

  7. Catalytic Desulfurization of Benzothiophene Using Keggin Type Polyoxometalates as Catalyst

    Directory of Open Access Journals (Sweden)

    Aldes Lesbani

    2015-01-01

    Full Text Available Performance of catalytic desulfurization of benzothiophen (BT was studied using polyoxometalates as catalyst. Polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40], have different heteroatom in Keggin structure and catalytic activities. Polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] have high crystallinity with homogeneous distribution particles. Desulfurization of BT using polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] resulted % conversion up to 99% for 3 h reaction time and at temperature 40 oC. Application of polyoxometalates H3[a-PW12O40] and H4[a-SiW12O40] for crude oil desulfurization showed % conversion of 4-88%. The main functional groups of polyoxometalates still retained after catalytic desulfurization indicated the stability of polyoxometalate compounds

  8. High Contacting Efficience Carrier Structures & Porcesses for Liquid Phase Regenerable Desulfurization of Logistic Fuels

    Science.gov (United States)

    2011-02-21

    Phase Regenerable Desulfurization of Logistic Fuels 5a. CONTRACT NUMBER Sb. GRANT NUMBER N00014-06-1-1165 6c. PROGRAM ELEMENT NUMBER 6. AUTHOR...developed and characterized. The adsorbent’s formulation, preparation procedure, desulfurization conditions and regeneration procedure have established and...enables novel process design for the logistic fuel desulfurization . 15. SUBJECT TERMS desulfurization , liquid fuel, silver, titania 16. SECURITY

  9. Desulfurization of Hydrocarbon Fuels at Ambient Conditions Using Supported Silver Oxide-Titania Sorbents

    Science.gov (United States)

    2010-12-13

    Desulfurization of Hydrocarbon Fuels at Ambient Conditions Using Supported Silver Oxide-Titania Sorbents by Sachin Appukuttan Nair...Philosophy Auburn, Alabama December 13, 2010 Keywords: Desulfurization , Silver, Titanium Oxide, Hydrocarbon Fuels, Adsorption, Dispersion...number. 1. REPORT DATE 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Desulfurization of Hydrocarbon Fuels

  10. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    Energy Technology Data Exchange (ETDEWEB)

    John G. Verkade

    2001-11-01

    Column chromatographic separation of the S=PBu{sub 3}/PBu{sub 3} product mixture followed by weighing the S=PBu{sub 3}, and by vacuum distillation of S=PBu{sub 3}/PBu{sub 3}mixture followed by gas chromatographic analysis are described. Effects of coal mesh size, pre-treatment with methanol Coal (S) + excess PR{sub 3} {yields} Coal + S=PR{sub 3}/PBu{sub 3} and sonication on sulfur removal by PBu{sub 3} revealed that particle size was not observed to affect desulfurization efficiency in a consistent manner. Coal pretreatment with methanol to induce swelling or the addition of a filter aid such as Celite reduced desulfurization efficiency of the PBu{sub 3} and sonication was no more effective than heating. A rationale is put forth for the lack of efficacy of methanol pretreatment of the coal in desulfurization runs with PBu{sub 3}. Coal desulfurization with PBu{sub 3} was not improved in the presence of miniscule beads of molten lithium or sodium as a desulfurizing reagent for SPBu{sub 3} in a strategy aimed at regenerating PBu{sub 3} inside coal pores. Although desulfurization of coals did occur in sodium solutions in liquid ammonia, substantial loss of coal mass was also observed. Of particular concern is the mass balance in the above reaction, a problem which is described in some detail. In an effort to solve this difficulty, a specially designed apparatus is described which we believe can solve this problem reasonably effectively. Elemental sodium was found to remove sulfur quantitatively from a variety of polycyclic organosulfur compounds including dibenzothiophene and benzothiophene under relatively mild conditions (150 C) in a hydrocarbon solvent without requiring the addition of a hydrogen donor. Lithium facilitates the same reaction at a higher temperature (254 C). Mechanistic pathways are proposed for these transformations. Curiously, dibenzothiophene and its corresponding sulfone was virtually quantitatively desulfurized in sodium solutions in liquid

  11. CONVERSION EXTRACTION DESULFURIZATION (CED) PHASE III

    Energy Technology Data Exchange (ETDEWEB)

    James Boltz

    2005-03-01

    This project was undertaken to refine the Conversion Extraction Desulfurization (CED) technology to efficiently and economically remove sulfur from diesel fuel to levels below 15-ppm. CED is considered a generic term covering all desulfurization processes that involve oxidation and extraction. The CED process first extracts a fraction of the sulfur from the diesel, then selectively oxidizes the remaining sulfur compounds, and finally extracts these oxidized materials. The Department of Energy (DOE) awarded Petro Star Inc. a contract to fund Phase III of the CED process development. Phase III consisted of testing a continuous-flow process, optimization of the process steps, design of a pilot plant, and completion of a market study for licensing the process. Petro Star and the Degussa Corporation in coordination with Koch Modular Process Systems (KMPS) tested six key process steps in a 7.6-centimeter (cm) (3.0-inch) inside diameter (ID) column at gas oil feed rates of 7.8 to 93.3 liters per hour (l/h) (2.1 to 24.6 gallons per hour). The team verified the technical feasibility with respect to hydraulics for each unit operation tested and successfully demonstrated pre-extraction and solvent recovery distillation. Test operations conducted at KMPS demonstrated that the oxidation reaction converted a maximum of 97% of the thiophenes. The CED Process Development Team demonstrated that CED technology is capable of reducing the sulfur content of light atmospheric gas oil from 5,000-ppm to less than 15-ppm within the laboratory scale. In continuous flow trials, the CED process consistently produced fuel with approximately 20-ppm of sulfur. The process economics study calculated an estimated process cost of $5.70 per product barrel. The Kline Company performed a marketing study to evaluate the possibility of licensing the CED technology. Kline concluded that only 13 refineries harbored opportunity for the CED process. The Kline study and the research team's discussions

  12. Desulfurization performance of azole-based ionic liquids

    Directory of Open Access Journals (Sweden)

    Liubei CHENG

    2017-10-01

    Full Text Available In order to study the addition of functional groups in ionic liquid anion and cation to achieve better absorbing of SO2, the 1,1,3,3-tetramethylguanidine triazole ( is synthesized using 1,1,3,3-tetramethylguanidine and triazole as raw materials. The desulfurization performance of the synthesized is systematically studied. The desulfurization performance and desulfurization mechanism of the are discussed. The results show that the has good performance of desulfurization and regeneration. At the atmospheric pressure, 1 mol of the absorbs 2.964 mol of SO2 at 20 ℃. With the increase of temperature, the desulfurization capacity of the decreases gradually. The molar absorption ratio increases with the increase of SO2 partial pressure, and under the conditions of 130 ℃, the desorption rate of the ionic liquid after saturated adsorption reaches over 95%. The mechanism investigation results show that the interaction of SO2 and is the combination of chemical absorption and physical absorption. The results have a certain reference value to improve the efficiency of flue gas treatment.

  13. Biogas desulfurization using autotrophic denitrification process.

    Science.gov (United States)

    Bayrakdar, Alper; Tilahun, Ebrahim; Calli, Baris

    2016-01-01

    The aim of this study was to evaluate the performance of an autotrophic denitrification process for desulfurization of biogas produced from a chicken manure digester. A laboratory scale upflow fixed bed reactor (UFBR) was operated for 105 days and fed with sodium sulfide or H2S scrubbed from the biogas and nitrate as electron donor and acceptor, respectively. The S/N ratio (2.5 mol/mol) of the feed solution was kept constant throughout the study. When the UFBR was fed with sodium sulfide solution with an influent pH of 7.7, about 95 % sulfide and 90 % nitrate removal efficiencies were achieved. However, the inlet of the UFBR was clogged several times due to the accumulation of biologically produced elemental sulfur particles and the clogging resulted in operational problems. When the UFBR was fed with the H2S absorbed from the biogas and operated with an influent pH of 8-9, around 98 % sulfide and 97 % nitrate removal efficiencies were obtained. In this way, above 95 % of the H2S in the biogas was removed as elemental sulfur and the reactor effluent was reused as scrubbing liquid without any clogging problem.

  14. Electric-Field-Driven Direct Desulfurization.

    Science.gov (United States)

    Borca, Bogdana; Michnowicz, Tomasz; Pétuya, Rémi; Pristl, Marcel; Schendel, Verena; Pentegov, Ivan; Kraft, Ulrike; Klauk, Hagen; Wahl, Peter; Gutzler, Rico; Arnau, Andrés; Schlickum, Uta; Kern, Klaus

    2017-05-23

    The ability to elucidate the elementary steps of a chemical reaction at the atomic scale is important for the detailed understanding of the processes involved, which is key to uncover avenues for improved reaction paths. Here, we track the chemical pathway of an irreversible direct desulfurization reaction of tetracenothiophene adsorbed on the Cu(111) closed-packed surface at the submolecular level. Using the precise control of the tip position in a scanning tunneling microscope and the electric field applied across the tunnel junction, the two carbon-sulfur bonds of a thiophene unit are successively cleaved. Comparison of spatially mapped molecular states close to the Fermi level of the metallic substrate acquired at each reaction step with density functional theory calculations reveals the two elementary steps of this reaction mechanism. The first reaction step is activated by an electric field larger than 2 V nm(-1), practically in absence of tunneling electrons, opening the thiophene ring and leading to a transient intermediate. Subsequently, at the same threshold electric field and with simultaneous injection of electrons into the molecule, the exergonic detachment of the sulfur atom is triggered. Thus, a stable molecule with a bifurcated end is obtained, which is covalently bound to the metallic surface. The sulfur atom is expelled from the vicinity of the molecule.

  15. Copper-based sorbents for hot coal gas desulfurization systems

    Energy Technology Data Exchange (ETDEWEB)

    Abbasian, J.; Slimane, R.B.; Zarnegar, M.K. [Inst. of Gas Technology, Des Plaines, IL (United States)] [and others

    1997-07-01

    High-temperature coal gas desulfurization has been recognized as essential in the development of emerging power generation technologies such as the Integrated Gasification Combined Cycle (IGCC), aiming to improve both the efficiency and environmental performance of power generation from coal. Hot gas desulfurization may be accomplished by using regenerable mixed metal oxides sorbents which can reduce the H{sub 2}S content of the coal gas to a few ppmv over many sulfidation/regeneration cycles. The focus of much of the current research on hot gas desulfurization has been on the use of zinc-based sorbents. Although these sorbents have been the subject of extensive pilot-scale and process development work, zinc-based sorbents have been shown to suffer from sulfate formation and zinc volatilization, leading to sorbent degradation over multicycle use, increasing sorbent replacement costs and the overall cost of hot gas desulfurization processes. A novel copper-chromite sorbent has been developed at IGT for hot coal gas desulfurization under the sponsorship of the Illinois Clean Coal Institute (ICCI). Results obtained so far indicate that this sorbent, in granular form (i.e., CuCr-29), has a much higher attrition resistance compared to the commercial granular zinc titanate sorbent, as well as excellent desulfurization efficiency. Furthermore, unlike most zinc titanate sorbents, the reactivity of IGT`s CuCr-29 sorbent gradually and consistently improved during the 20 cycles tested. The sorbent preparation techniques developed at IGT have been applied to produce highly reactive and attrition resistant sorbent pellets for moving-bed applications.

  16. Nano-magnetic particles as multifunctional microreactor for deep desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xinai; Yao, Dongdong [Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China); Li, Hong [College of Environment and Chemical Engineering, Xi' an Polytechnic University, Xi' an 710048 (China); Yang, Juxiang [Department of Chemistry, Xi' an University of Arts and Science, Xi' an 710065 (China); Hu, Daodao, E-mail: daodaohu@snnu.edu.cn [Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi' an 710062 (China)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer An easy-separated amphiphilic catalyst with small size was prepared for deep desulfurization. Black-Right-Pointing-Pointer The effects of several factors on desulfurization reactivity were systematically investigated. Black-Right-Pointing-Pointer The catalyst demonstrates high performance in the deep desulfurization. Black-Right-Pointing-Pointer The material could make integration of micro-reactor and micro-extractor into one system. - Abstract: Oxidation of dibenzothiophene with hydrogen peroxide using a recyclable amphiphilic catalyst has been studied. The catalyst was synthesized by surfacely covering magnetic silica nanospheres (MSN) with the complexes between 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (AEM) and phosphotungstic acid (PTA). The morphology and components of the composite material were characterized by TEM, EDX, XPS, FT-IR, and VSM, respectively. The effects of several factors on desulfurization reactivity were systematically investigated. The results showed that the composite nanospheres have core/shell structure with the properties of amphiphilicity and superparamagnetism. The composite nanospheres have high catalytic activity in the oxidation of dibenzothiophene to corresponding sulfones by hydrogen peroxide under mild reaction conditions. The sulfur level could be lowered from 487 ppm to less than 0.8 ppm under optimal conditions. Additionally, the amphiphilic catalyst and the oxidized product could be simultaneously separated from medium by external magnetism, and the recovered composite material could be recycled for three times with almost constant activity.

  17. Mechanical, Hygric and Thermal Properties of Flue Gas Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    P. Tesárek

    2004-01-01

    Full Text Available The reference measurements of basic mechanical, thermal and hygric parameters of hardened flue gas desulfurization gypsum are carried out. Moisture diffusivity, water vapor diffusion coefficient, thermal conductivity, volumetric heat capacity and linear thermal expansion coefficient are determined with the primary aim of comparison with data obtained for various types of modified gypsum in the future. 

  18. CURRENT STATUS OF ADVACATE PROCESS FOR FLUE GAS DESULFURIZATION

    Science.gov (United States)

    The following report discusses current bench- and pilot-plant advances in preparation of ADVAnced siliCATE (ADVACATE) calcium silicate sorbentsfor flue gas desulfurization. It also discusses current bench- and pilot-plant advances in sorbent preparation. Fly ash was ground in a l...

  19. Ralstonia eutropha as a biocatalyst for desulfurization of dibenzothiophene.

    Science.gov (United States)

    Dejaloud, Azita; Vahabzadeh, Farzaneh; Habibi, Alireza

    2017-07-01

    The potential of Ralstonia eutropha as a biocatalyst for desulfurization of dibenzothiophene (DBT) was studied in growing and resting cell conditions. The results of both conditions showed that sulfur was removed from DBT which accompanied by the formation of 2-hydroxybiphenyl (2-HBP). In growing cell experiments, glucose was used as an energy supplying substrate in initial concentrations of 55 mM (energy-limited) and 111 mM (energy-sufficient). The growing cell behaviors were quantitatively described using the logistic equation and maintenance concept. The results indicated that 2-HBP production was higher for the energy-sufficient cultures, while the values of the specific growth rate and the maintenance coefficient for these media were lower than those of the energy-limited cultures. Additionally, the kinetic studies showed that the half-saturation constant for the energy-limited cultures was 2 times higher than the energy-sufficient ones where the inhibition constant (0.08 mM) and the maximum specific DBT desulfurization rate (0.002 mmol gcell(-1) h(-1)) were almost constant. By defining desulfurizing capacity (D DBT) including both the biomass concentration and time to reach a particular percentage of DBT conversion, the best condition for desulfurizing cell was determined at 23% gcell L(-1) h(-1) which corresponded with the resting cells that were harvested at the mid-exponential growth phase.

  20. Core-in-shell sorbent for hot coal gas desulfurization

    Science.gov (United States)

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  1. Theoretical study of the catalytic desulfurization mechanism of ...

    African Journals Online (AJOL)

    The desulfurization process of compounds implicates two steps. The first step is the adsorption process on the catalytic site and the second, the breaking of the carbon-heteroatom bond leading to the heteroatom elimination. The adsorption process of thiiren have been studied and published in previous works. The results ...

  2. Workshop on sulfur chemistry in flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.E. Jr.

    1980-05-01

    The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

  3. Mechanistic analysis of ultrasound assisted enzymatic desulfurization of liquid fuels using horseradish peroxidase.

    Science.gov (United States)

    Bhasarkar, Jaykumar; Borah, Arup Jyoti; Goswami, Pranab; Moholkar, Vijayanand S

    2015-11-01

    This study has attempted to gain physical insight into ultrasound-assisted enzymatic desulfurization using system comprising horseradish peroxidase enzyme and dibenzothiophene (DBT). Desulfurization pathway (comprising DBT-sulfoxide and DBT-sulfone as intermediates and 4-methoxy benzoic acid as final product) has been established with GC-MS analysis. Intrinsic fluorescence and circular dichroism spectra of ultrasound-treated enzyme reveal conformational changes in secondary structure (reduction in α-helix and β-conformations and increase in random coil content) leading to enhancement in activity. Concurrent analysis of desulfurization profiles, Arrhenius and thermodynamic parameters, and simulations of cavitation bubble dynamics reveal that strong micro-convection generated by sonication enhances enzyme activity and desulfurization kinetics. Parallel oxidation of DBT by radicals generated from transient cavitation gives further boost to desulfurization kinetics. However, random motion of enzyme molecules induced by shock waves reduces frequency factor and limits the ultrasonic enhancement of enzymatic desulfurization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    Science.gov (United States)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-10-28

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

  5. Test and Characterization of Some Zeolite Supported Gas Phase Desulfurization Sorbents

    Science.gov (United States)

    2009-06-01

    Test and Characterization of Some Zeolite Supported Gas Phase Desulfurization Sorbents by Charles Rong, Deryn Chu, and John Hopkins ARL...20783-1197 ARL-TR-4859 June 2009 Test and Characterization of Some Zeolite Supported Gas Phase Desulfurization Sorbents Charles Rong...Characterization of Some Zeolite Supported Gas Phase Desulfurization Sorbents 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 6

  6. Application and Development Trend of Flue Gas Desulfurization (FGD) Process: A Review

    OpenAIRE

    Rehan Jamil; Li Ming; Irfan Jamil; Rizwan Jamil

    2013-01-01

    In 1927, the limestone desulfurization process was first applied in the Barthes and Bansside Power Plants (total 120MW) beside the Thames River in UK to protect high-rise building in London. Up to now, over 10 desulfurization processes have been launched and applied. Based on the desulfurizing agent being used, there include calcium process (limestone/lime), ammonia process, magnesium process, sodium process, alkali alumina process, copper oxide/zinc process, active carbon process, ammonium d...

  7. Effect of Silicon on Desulfurization of Aluminum-killed Steels

    Science.gov (United States)

    Roy, Debdutta

    Recent reports have suggested that silicon has a beneficial effect on the rate of desulfurization of Al-killed steel. This effect is difficult to understand looking at the overall desulfurization reaction which does not include silicon. However an explanation is proposed by taking into account the (SiO2)/[Si] equilibrium in which some Al reaching the slag-metal interface is used in reducing the SiO2 in the slag. This reaction can be suppressed to some extent if the silicon content of the metal is increased and in doing so, more Al will be available at the slag-metal interface for the desulfurization reaction and this would increase the rate of the desulfurization reaction. A model was developed, assuming the rates are controlled by mass transfer, taking into account the coupled reactions of the reduction of silica, and other unstable oxides, namely iron oxide and manganese oxide, in the slag and desulfurization reaction in the steel by aluminum. The model predicts that increasing silicon increases the rate and extent of desulfurization. Plant data was analyzed to obtain rough estimates of ladle desulfurization rates and also used to validate the model predictions. Experiments have been conducted on a kilogram scale of material in an induction furnace to test the hypothesis. The major conclusions of the study are as follows: The rate and extent of desulfurization improve with increasing initial silicon content in the steel; the effect diminishes at silicon contents higher than approximately 0.2% and with increasing slag basicity. This was confirmed with kilogram-scale laboratory experiments. The effects of the silicon content in the steel (and of initial FeO and MnO in the slag) largely arise from the dominant effects of these reactions on the equilibrium aluminum content of the steel: as far as aluminum consumption or pick-up is concerned, the Si/SiO2 reaction dominates, and desulfurization has only a minor effect on aluminum consumption. The rate is primarily

  8. Mathematical Model of Hot Metal Desulfurization by Powder Injection

    Directory of Open Access Journals (Sweden)

    Yolanda Cepeda Rodríguez

    2012-01-01

    Full Text Available Although there have been a numerous number of studies on mathematical model of hot metal desulfurization by deep injection of calcium carbide, the research field as a whole is not well integrated. This paper presents a model that takes into account the kinetics, thermodynamics, and transport processes to predict the sulfur levels in the hot metal throughout a blow. The model could be utilized to assess the influence of the treatment temperature, rate of injection, gas flow rate, and initial concentration of sulfur on the desulfurization kinetics. In the second part of this paper an analysis of the industrial data for injection of calcium carbide using this model is described. From a mathematical model that describes the characteristics of a system, it is possible to predict the behavior of the variables involved in the process, resulting in savings of time and money. Discretization is realized through the finite difference method combined with interpolation in the border domain by Taylor series.

  9. Simple biogas desulfurization by microaeration - Full scale experience.

    Science.gov (United States)

    Jeníček, P; Horejš, J; Pokorná-Krayzelová, L; Bindzar, J; Bartáček, J

    2017-08-01

    Hydrogen sulfide in biogas is common problem during anaerobic treatment of wastewater with high sulfate concentration (breweries, distilleries, etc.) and needs to be removed before biogas utilization. Physico-chemical desulfurization methods are energetically demanding and expensive compare to biochemical methods. Microaeration, i.e. dosing of small amount of air, is suitable and cost effective biochemical method of sulfide oxidation to elemental sulfur. It has been widely used in biogas plants, but its application in anaerobic reactors for wastewater treatment has been rarely studied or tested. The lack of full-scale experience with microaeration in wastewater treatment plants has been overcome by evaluating the results of seven microaerobic digesters in central Europe. The desulfurization efficiency has been more than 90% in most of the cases. Moreover, microaeration improved the degradability of COD and volatile suspended solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Mass Transfer Model of Desulfurization in the Electroslag Remelting Process

    Science.gov (United States)

    Hou, Dong; Jiang, Zhou-Hua; Dong, Yan-Wu; Li, Yang; Gong, Wei; Liu, Fu-Bin

    2017-06-01

    Experimental and theoretical studies have been carried out to investigate the effects of the slag on desulfurization during the electroslag remelting (ESR) process with a focus of developing a mass transfer model to understand the mechanism of desulfurization. Stainless steel 1Cr21Ni5Ti was used as the electrode and remelted with two different kinds of slags using a 50-kg ESR furnace. The contents of sulfur along the axial direction of product ingots were analyzed. It was found that the sulfur content of 350 ppm in the electrode is reduced to 71 to 95 ppm in the ingot by remelting with the slag containing 5 wt pct of CaO, and lowered more to 47 to 59 ppm with another slag having 20 wt pct CaO. On the basis of the penetration and film theories, the theoretical model developed in this work well elucidates the kinetics of desulfurization revealing the mechanism of sulfur transfer during the ESR process. The calculation results obtained from the model agree well with the experimental results. The model indicates that when sulfur content in electrode is given, there is a corresponding minimum value of sulfur content in the ingot due to the kinetics limit. This lowest sulfur content cannot be further reduced even with increasing L S (sulfur distribution coefficient between metal and slag phases) or decreasing sulfur content in the slag. Constant addition of extra amount of CaO to the molten slag with the increase of sulfur content in the slag during the remelting process can improve the macrosegregation of sulfur distributed along the axial direction of ESR ingots. Since the rate-determining steps of the sulfur mass transfer lie in the metal phase, adding calcium as deoxidizer can change mass transfer of sulfur and thus promote desulfurization further during the ESR process.

  11. Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization

    Science.gov (United States)

    Abin-Fuentes, Andres; Mohamed, Magdy El-Said; Wang, Daniel I. C.

    2013-01-01

    Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubating Rhodococcus erythropolis IGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 μM with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC50s) for DszA, DszB, and DszC were measured to be 60 ± 5 μM, 110 ± 10 μM, and 50 ± 5 μM, respectively. The fact that the IC50s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation. PMID:24096431

  12. Numerical simulation of flow in the wet scrubber for desulfurization

    Directory of Open Access Journals (Sweden)

    Novosád Jan

    2015-01-01

    Full Text Available This article deals with numerical simulation of flow and chemical reactions in absorber for desulfurization of flue-gas. The objective of the work is the investigation of effect of different nozzles types and their placement in spray layers. These nozzles distribute lime suspension into flue gas stream. The research includes two types of nozzles and four different arrangements of nozzles and spray layers. Conclusion describes the effect of nozzle types and their arrangements on the suspension concentration in absorber.

  13. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    Energy Technology Data Exchange (ETDEWEB)

    John G. Verkade

    1998-02-28

    The reactions of dialkyl mono- and disulfides and functionalized alkylthio compounds with sodium in refluxing hydrocarbon solvent (tetradecane, mesitylene or toluene) resulted in sulfur-free products in very high yields. Greater than 95% sulfur removal was observed when dialkyl mono or polysulfides were treated with Na in liquid ammonia. Polycyclic aromatic sulfur heterocycles were only moderately desulfurized under these conditions while phenylthio derivatives gave thiophenol as the major product and dithiophenols as the minor products.

  14. The mechanism of coal gas desulfurization by iron oxide sorbents.

    Science.gov (United States)

    Lin, Yi-Hsing; Chen, Yen-Chiao; Chu, Hsin

    2015-02-01

    This study aims to understand the roles of hydrogen and carbon monoxide during the desulfurization process in a coal gasification system that H2S of the syngas was removed by Fe2O3/SiO2 sorbents. The Fe2O3/SiO2 sorbents were prepared by incipient wetness impregnation. Through the breakthrough experiments and Fourier transform infrared spectroscopy analyses, the overall desulfurization mechanism of the Fe2O3/SiO2 sorbents was proposed in this study. The results show that the major reaction route is that Fe2O3 reacts with H2S to form FeS, and the existence of CO and H2 in the simulated gas significantly affects equilibrium concentrations of H2S and COS. The formation of COS occurs when the feeding gas is blended with CO and H2S, or CO2 and H2S. The pathways in the formation of products from the desulfurization process by the reaction of Fe2O3 with H2S have been successfully established. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Molecular biological enhancement of coal desulfurization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krawiec, S.

    1994-12-31

    During the period from 1986 through 1993 the prospect of bacterial desulfurization of fossil fuel was transformed from a theoretically appealing concept to a demonstrable laboratory phenomenon. Results from several laboratories confirmed that there was not one but, rather, several metabolic bases of selectively removing sulfur from the carbon frame of sulfur-containing organic compounds characteristic of fossil fuels. Results in this report relate solely to the so-called ``4S`` pathway (named for the four sulfur-containing compounds in the sequence: (l) dibenzothiophene [DBT] {yields} (2) dibenzothiophene sulfoxide [DBTO] {yields} (3) dibenzosulfone [DBTO{sup 2}] {yields} (4) dibenzosulfonate {yields} monohydroxybiphenyl [OH-BP] + SO{sub 4}{sup =}. [An additional desulfurized product, biphenyl, has been hypothesized and another, o,o{prime}-biphenyl, observed.]) The following subjects are discussed: isolating bacteria with a DbtS{sup +} phenotype; confirming the production of a desulfurized product; determining the identity of the isolates; determining the growth characteristics of the isolates in batch and continuous cultures; determining the kinetics and yields of product in batch and continuous cultures.

  16. Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

    Directory of Open Access Journals (Sweden)

    Dezhi Shao

    2015-01-01

    Full Text Available This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain.

  17. Viable Syntax: Rethinking Minimalist Architecture

    Directory of Open Access Journals (Sweden)

    Ken Safir

    2010-03-01

    Full Text Available Hauser et al. (2002 suggest that the human language faculty emerged as a genetic innovation in the form of what is called here a ‘keystone factor’—a single, simple, formal mental capability that, interacting with the pre-existing faculties of hominid ancestors, caused a cascade of effects resulting in the language faculty in modern humans. They take Merge to be the keystone factor, but instead it is posited here that Merge is the pre-existing mechanism of thought made viable by a principle that permits relations interpretable at the interfaces to be mapped onto c-command. The simplified minimalist architecture proposed here respects the keystone factor as closely as possible, but is justified on the basis of linguistic analyses it makes available, including a relativized intervention theory applicable across Case, scope, agreement, selection and linearization, a derivation of the A/A’-distinction from Case theory, and predictions such as why in situ wh-interpretation is island-insensitive, but susceptible to intervention effects.

  18. Global evaluation of mass transfer effects: In-duct injection flue gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.A.; Newton, G.H.; Kramlich, J.C.; Payne, R.

    1990-09-30

    Sorbent injection is a low capital cost, low operating cost approach to SO{sub 2} control targeted primarily at older boilers for which conventional fuel gas desulfurization is not economically viable. Duct injection is one variation of this concept in which the sorbent, either a dry powder or a slurry, is injected into the cooler regions of the boiler, generally downstream of the air heaters. The attractiveness of duct injection is tied to the fact that it avoids much of the boiler heat transfer equipment and thus has minimal impact of boiler performance. Both capital and operating cost are low. This program has as its objectives three performance related issues to address: (1) experimentally identify limits on sorbent performance. (2) identify and test sorbent performance enhancement strategies. (3) develop a compute model of the duct injection process. Two major tasks are described: a laboratory-scale global experiment and development of process model. Both are aimed at understanding and quantifying the rate-limiting processes which control SO{sub 2} capture by lime slurry during boiler duct injection. 29 refs., 35 figs., 4 tabs.

  19. Use of Flue Gas Desulfurization (FGD) Gypsum as a Heavy Metal Stabilizer in Contaminated Soils

    Science.gov (United States)

    Flue Gas Desulfurization (FGD) gypsum is a synthetic by-product generated from the flue gas desulfurization process in coal power plants. It has several beneficial applications such as an ingredient in cement production, wallboard production and in agricultural practice as a soil...

  20. Inhibition of carbon disulfide on bio-desulfurization in the process of ...

    African Journals Online (AJOL)

    Biological desulfurization is a novel technology for the removal of hydrogen sulfide from some biogas or sour gas, in which there are always a certain amounts of carbon disulfide together with much hydrogen sulfide. Nowadays, carbon disulfide is found to have negative effect on the biological desulfurization, but seldom ...

  1. Investigation on the relationship between the fine particle emission and crystallization characteristics of gypsum during wet flue gas desulfurization process.

    Science.gov (United States)

    Pan, Danping; Wu, Hao; Yang, Linjun

    2017-05-01

    The relationship between the fine particles emitted after desulfurization and gypsum crystals in the desulfurization slurry was investigated, and the crystallization characteristics varying with the operation parameters and compositions of the desulfurization slurry were discussed. The results showed that the fine particles generated during the desulfurization process were closely related to the crystal characteristics in the desulfurization slurry by comparison of their morphology and elements. With the higher proportion of fine crystals in the desulfurization slurry, the number concentration of fine particles after desulfurization was increased and their particle sizes were smaller, indicating that the optimization of gypsum crystallization was beneficial for the reduction of the fine particle emission. The lower pH value and an optimal temperature of the desulfurization slurry were beneficial to restrain the generation of fine crystals in the desulfurization slurry. In addition, the higher concentrations of the Fe(3+) ions and the F(-) ions in the desulfurization slurry both promoted the generation of fine crystals with corresponding change of the morphology and the effect of the Fe(3+) ions was more obvious. With the application of the desulfurization synergist additive, it was beneficial for the inhibition of fine crystals while the thinner crystals were generated. Copyright © 2016. Published by Elsevier B.V.

  2. Molecular biological enhancement of coal desulfurization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krawiec, S.

    1995-01-01

    Fresh isolates of bacteria presumptively identified as R. erythropolis unequivocally have a DbtS{sup +} phenotype. The production of OH-BP from either DBT or DBTO{sub 2} was confirmed by difference spectroscopy, HPLC, and mass spectrometry. The temperature, pH, and means of supplying the thiophenic or sulfonic sole source of sulfur were optimized. The maximal rate of growth of the organism, its affinity for sulfone, and the extent to which substrate was converted to product were determined by using batch, fed batch, and continuous cultures. For strain N1-36, the maximum specific growth rate was 0.235 hr{sup -1} which corresponds to a minimal generation time of 2.95 hr. The K{sub s} was estimated to be 0.39 {mu}M. With 100 {mu}M DBT as the sole sulfur source, approximately 40 {mu}M OH-BP are produced (after 40 hr of growth); with 100 {mu}M DBTO{sub 2} as the sole sulfur source, approximately 70 {mu}M OH-BP are produced (after 40 hr of growth). The desulfurization activity is repressed by SO{sub 4}{sup =} OH-BP does not serve as a carbon source. The DbtS{sup +} phenotype of the R. erythropolis isolates is stable and discrete. The isolates selectively remove sulfur from DBT, a compound which models a refractory form of organic sulfur in compounds characteristic of fossil fuels. The desulfurization occurs with no oxidation of carbon-carbon bonds. The stability and specificity (along with genetic regulation) indicate that microbial desulfurization in a real phenomenon in which a noxious element is removed without significantly affecting the calorific value of the substrate. Additional characterization (and optimization) would provide the basis of a very important form of fossil fuel beneficiation.

  3. Methods, systems, and devices for deep desulfurization of fuel gases

    Science.gov (United States)

    Li, Liyu [Richland, WA; King, David L [Richland, WA; Liu, Jun [Richland, WA; Huo, Qisheng [Richland, WA

    2012-04-17

    A highly effective and regenerable method, system and device that enables the desulfurization of warm fuel gases by passing these warm gasses over metal-based sorbents arranged in a mesoporous substrate. This technology will protect Fischer-Tropsch synthesis catalysts and other sulfur sensitive catalysts, without drastic cooling of the fuel gases. This invention can be utilized in a process either alone or alongside other separation processes, and allows the total sulfur in such a gas to be reduced to less than 500 ppb and in some instances as low as 50 ppb.

  4. Influence of addition of alkali metal compounds to calcium carbonate on desulfurization characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Ichiro; Saito, Katsuhiro; Murakami, Takahiro

    1999-07-01

    Limestone is currently supplied as a desulfurizer into bubbling and circulating fluidized bed coal combustors since both combustors are operated at the temperature ranged from 1,073 to 1,173 K, where limestone can be calcined and sulfurized optimally. In the practical boilers, however, the limestone particles are fed to the combustor excessively since the utilization efficiency of CaO produced by the calcination of limestone is low. On the other hand, many kinds of sea-shell are clarified as one of industrial wastes, and also consist of CaCO{sub 3} similar to limestone. Therefore it would be possible for wasted sea-shell to be applied to one of the desulfurizers. In this case the CO{sub 2} produced by calcination of the shell is fixed and recycled naturally in obedience to the ecological law. From this viewpoint, desulfurization characteristics of wasted sea shell have been already studied fundamentally by using a thermobalance as compared with the results obtained by limestone. The results obtained by this study are summarized as follows. (1) The desulfurization activity for wasted sea-shell is much higher than that for limestone. (2) Even if the alkali metal compounds are partially removed from the sea shell, the desulfurization efficiency does not change. (3) The desulfurization activity can be enhanced by adding alkali metal compounds to limestone. Sodium compounds are more effective on the desulfurization efficiency than potassium compounds. Sodium chloride is the best agent among them.

  5. Enhanced desulfurizing flotation of coal using sonoelectrochemical method.

    Science.gov (United States)

    Zhang, Hong-Xi; Hou, Xiao-Yang; Xu, Shi-Xun; Li, Zhi-Long; Yu, Hai-Feng; Shen, Xue-Hua

    2013-09-01

    Enhanced desulfurizing flotation of low sulfur coal was investigated using sonoelectrochemical method. The supporting electrolyte used in this process was sodium chloride and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature, sonoelectrolytic time and coal sample granulometry. The optimal experimental conditions achieved for anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature and sonoelectrolytic time are 1.7 mol L(-1), 5.1×10(-3) mol L(-1), 10 V, 70 °C, 50 min achieved for a -0.18 mm coal sample. Optimal conditions cause a sulfur reduction of up to 69.4%. The raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, ash as well as moisture are partially removed. The combination of high sulfur reduction, high yield, as well as high ash reduction was obtained in the newly developed method of enhanced flotation by sonoelectrochemistry. Ultrasound irradiation promotes electron transfer efficiency and increases clean coal yield. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  6. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in

  7. Pure Quantum Interpretations Are not Viable

    Science.gov (United States)

    Schmelzer, I.

    2011-02-01

    Pure interpretations of quantum theory, which throw away the classical part of the Copenhagen interpretation without adding new structure to its quantum part, are not viable. This is a consequence of a non-uniqueness result for the canonical operators.

  8. Synthesis and application of different phthalocyanine molecular sieve catalyst for oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Na; Li, Siwen; Wang, Jinyi; Zhang, Ronglan [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Material Science, Northwest University, Xi’an 710069, Shaanxi (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Gao, Ruimin [Research Institute of Shaanxi Yanchang Petroleum Group Corp. Ltd., Xi’an 710075 (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Zhao, Jianshe, E-mail: jszhao@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Material Science, Northwest University, Xi’an 710069, Shaanxi (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China); Wang, Junlong [Research Institute of Shaanxi Yanchang Petroleum Group Corp. Ltd., Xi’an 710075 (China); Composites Research Institute, Weinan Normal University, Weinan 714000 (China)

    2015-05-15

    M{sub 2}(PcAN){sub 2} (M=Fe, Co, Ni, Cu, Zn and Mn) anchored onto W-HZSM-5 (M{sub 2}(PcAN){sub 2}–W-HZSM-5) or the M{sub 2}(PcTN){sub 2} doping W-HZSM-5 (M{sub 2}(PcTN){sub 2}/W-HZSM-5) were prepared and their catalytic performances were tested for oxidative desulfurization in the presence of oxygen. Thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT) were considered as sulfur compounds. Among zeolite-based catalysts, the Cu{sub 2}(PcAN){sub 2}–W-HZSM-5 and Cu{sub 2}(PcTN){sub 2}/W-HZSM-5 showed superior desulfurization performance and the activity of selectivity followed the order: T>BT>DBT. The effects of phthalocyanine concentration were studied by UV–Vis and calcination temperature was obtained by TG-DSC for Cu{sub 2}(PcTN){sub 2}/W-HZSM-5. Catalysts were characterized by EA, IR, XRD, SEM, TEM, ICP, and N{sub 2} adsorption. Reaction time, temperature and the amount of catalyst were investigated as the important parameters for optimization of the reaction. Furthermore, a possible process of oxidative desulfurization and the reaction products were proposed. - Graphical abstract: The ODS reaction schematic shows the reaction mechanism of ultra-deep desulfurization. The sulfur compounds are oxidized to their corresponding sulfoxides or sulfones through the use of oxygen and catalysts. The reaction process of ultra-deep desulfurization. - Highlights: • A kind of novel catalyst for deep desulfurization was synthesized. • Cu{sub 2}(PcAN){sub 2}–W-HZSM-5 exhibits excellent catalytic performance for desulfurization. • The reaction conditions that affect desulfurization efficiency are investigated. • The reaction process of model sulfur compounds is proposed.

  9. Characteristics of dibenzothiophene desulfurization by Rhodococcus erythropolis R1 and its Dsz-negative mutant

    Directory of Open Access Journals (Sweden)

    Zahra Etemadifar

    2014-01-01

    Full Text Available Introduction: Biodesulfurization is used as a selective method for lowering the sulfur content of petroleum products. Materials and methods: A sulfur-oxidation bacterial strain named Rhodococcus erythropolis R1 (NCBI GenBank Accession No. GU570564 was used in this study for desulfurization of dibenzothiophene (DBT. Results: The induced culture of strain R1 was able to produce 2-hydroxybiphenyl (2- HBP from DBT followed 4S pathway without further degrading carbon backbone. This process confirmed by gas chromatography (GC analysis. The specific activity of DBT desulfurization by R1 was 45 µM (g dry wt-1 h-1. The addition of Tween 80 as surfactant and glycerol as carbon source determines a 100% rate of DBT-desulfurization during 3 days. The heavy plasmid detected in R1 strain carries dsz genes responsible for biodesulfurization of DBT that was shown by PCR reaction. The mutant strains which had lost this plasmid also had lost desulfurization phenotype. Both mutant and wild strain were sensitive to high concentration of 2-HBP and some antibiotics. Discussion and conclusion: Strain R1 desulfurize DBT through the sulfur-specific degradation pathway or 4S pathway with the selective cleavage of carbon-sulfur (C-S bonds without reducing the energy content. Addition of surfactant enhanced the desulfurization of DBT by increasing its bioavailability and also could improve the growth and desulfurization rate. The location of desulfurization genes was on a heavy plasmid in strain R1. Based on the results of this study, R. erythropolis R1 could serve as a model system for efficient biodesulfurization of petroleum oil without reducing the energy value.

  10. New reagents for coal desulfurization. Final technical report, September 1, 1990--August 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, D.H.; Kalembasa, S.; Olson, D.; Wang, S.; Warfel, L.

    1991-12-31

    The primary goal of this project was development and exploration of potential new desulfurization reagents for the removal of ``organic sulfur`` from Illinois coals by mild chemical methods. Potential new desulfurization reagents were investigated using organic sulfur compounds of the types thought to be present in coals. Reagents included low-valent metal complexes based on nickel and on iron as well as possible Single Electron Transfer reagents. Soluble coal extracts served as second generation model compounds during this reagent development project.

  11. Adsorptive desulfurization of kerosene and diesel oil by Zn impregnated montmorollonite clay

    Directory of Open Access Journals (Sweden)

    Waqas Ahmad

    2017-05-01

    Full Text Available In the present research work, desulfurization of kerosene and diesel oil has been carried out by selective adsorption through metals impregnated montmorollonite clay (MMT. Different metals were impregnated on MMT by wet impregnation method which included Fe, Cr, Ni, Co, Mn, Pb, Zn and Ag. The adsorption study was carried out in batch operation initially for 1 h time and at room temperature (25 °C. The results show that high desulfurization was brought about by Zn-MMT. In the case of kerosene highest desulfurization of 76% and in the case of diesel maximum desulfurization of 77% was achieved with adsorption through Zn-MMT. Conditions were also optimized for the desulfurization process. Highest yield of desulfurization was obtained at 1-h stirring period, at room temperature (25 °C and using oil to adsorbent ratio of 20:1.5. Under optimized conditions the adsorbent was found to adsorb about 81% of DBT from the model oil containing 1000 ppm DBT dissolved in cyclohexane. EDX, Surface characterization and SEM analysis of the adsorbents used in the study were conducted to evaluate their mineralogical nature and textural behavior. Results show that the surface area, pore size and pore volume of the MMT has been found to be increased many fold with Zn impregnation. Also the surface morphology of the MMT has also been improved with Zn impregnation.

  12. A novel semidry flue gas desulfurization process with the magnetically fluidized bed reactor.

    Science.gov (United States)

    Zhang, Qi; Gui, Keting

    2009-09-15

    The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO(2) removal. Results showed that SO(2) removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field intensity can make the surface morphology on the surface of the ferromagnetic particles loose and enhance the oxidation of S(IV), hence reducing the liquid phase mass transfer resistance of the slurry droplets and increasing desulfurization reaction rate, respectively. Therefore, the desulfurization efficiency increased obviously with the increase of DC field intensity.

  13. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Berggren, M.H.; Jha, M.C.

    1989-10-01

    AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

  14. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    Energy Technology Data Exchange (ETDEWEB)

    John G. Verkade

    1997-08-31

    Remarkably mild conditions have been discovered for quantitative sulfur removal from dibenzothiophene and other organosulfur systems using relatively cheap elemental sodium. The project objectives are: (1) Optimize the coal desulfurization reaction with respect to time, temperature, coal type and the R groups (including R = H), and also on extraction, impregnation and sonication conditions; (2) Optimize the conditions for the HDS reaction (which allows the PR{sub 3} to function as an HDS catalyst for coal) with respect to R group, temperature, pressure, H{sub 2} gas flow rate and inert solvent presence; (3) Determine the product(s) and the pathway of the novel redox reaction that appears to quantitatively remove sulfur from dibenzothiophene (DBT) when R = Bu when FeCl{sub 3} is used as a catalyst; (4) Impregnate sulfur-laden coals with Fe{sup 3+} to ascertain if the PR{sub 3} desulfurization rate increases; (5) Determine the nature of the presently unextractable phosphorus compounds formed in solid coals by PR{sub 3}; (6) Explore the efficacy of PR{sub 3}/Fe{sup 3+} in removing sulfur from petroleum feedstocks, heavy ends (whether solid or liquid), coal tar and discarded tire rubber; (7) Explore the possibility of using water-soluble PR{sub 3} compounds and Fe{sup 3+} to remove sulfur from petroleum feedstocks and heavy ends in order to remove the SPR{sub 3} (and Fe{sup 3+} catalyst) by water extraction (for subsequent HDS of the SPR{sub 3}); and (8) Explore the possibility of using solid-supported PR{sub 3} compounds (plus Fe{sup 3+} catalyst) to remove sulfur from petroleum feedstocks and heavy ends in order to keep the oil and the SPR{sub 3} (formed in the reaction) in easily separable phases.

  15. GRANULATION AND BRIQUETTING OF SOLID PRODUCTS FROM FLUE GAS DESULFURIZATION

    Directory of Open Access Journals (Sweden)

    Jan J. Hycnar

    2015-11-01

    Full Text Available Most flue gas desulfurization products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water, and soil. Among many approaches to utilization of this waste, the process of agglomeration using granulation or briquetting has proved very effective. Using desulfurization products a new material of aggregate characteristics has been acquired, and this material is resistant to water and wind erosion as well as to the conditions of transportation and storage. The paper presents the results of industrial trials granulation and briquetting of calcium desulphurization products. The granulation of a mixture of phosphogypsum used with fly ash (in the share 1:5. The resulting granules characterized by a compressive strength of 41.6 MPa, the damping resistance of 70% and 14.2% abrasion. The granulate was used for the production of cement mix. The produced concrete mortar have a longer setting and hardening time, as compared to the traditional ash and gypsum mortar, and have a higher or comparable flexural and compressive strength during hardening. Briquetting trials made of a product called synthetic gypsum or rea-gypsum both in pure form and with the addition of 5% and 10% of the limestone dust. Briquettes have a high initial strength and resistance to abrasion. The values ​​of these parameters increased after 72 hours of seasoning. It was found that higher hardiness of briquettes with rea-gypsum was obtained with the impact of atmospheric conditions and higher resistance to elution of water-soluble components in comparison to ash briquettes.

  16. Using Generic Examples to Make Viable Arguments

    Science.gov (United States)

    Adams, Anne E.; Ely, Rob; Yopp, David

    2017-01-01

    The twenty-first century has seen an increased call to train students to craft mathematical arguments. The third of the Common Core's (CCSS) Standards for Mathematical Practice (SMP 3) (CCSSI 2010) calls for all mathematically proficient students to "construct viable arguments" to support the truth of their ideas and to "critique…

  17. P-B Desulfurization: An Enabling Method for Protein Chemical Synthesis and Site-Specific Deuteration.

    Science.gov (United States)

    Jin, Kang; Li, Tianlu; Chow, Hoi Yee; Liu, Han; Li, Xuechen

    2017-11-13

    Cysteine-mediated native chemical ligation is a powerful method for protein chemical synthesis. Herein, we report an unprecedentedly mild system (TCEP/NaBH4 or TCEP/LiBEt3 H; TCEP=tris(2-carboxyethyl)phosphine) for chemoselective peptide desulfurization to achieve effective protein synthesis via the native chemical ligation-desulfurization approach. This method, termed P-B desulfurization, features usage of common reagents, simplicity of operation, robustness, high yields, clean conversion, and versatile functionality compatibility with complex peptides/proteins. In addition, this method can be used for incorporating deuterium into the peptides after cysteine desulfurization by running the reaction in D2 O buffer. Moreover, this method enables the clean desulfurization of peptides carrying post-translational modifications, such as phosphorylation and crotonylation. The effectiveness of this method has been demonstrated by the synthesis of the cyclic peptides dichotomin C and E and synthetic proteins, including ubiquitin, γ-synuclein, and histone H2A. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Radiation-induced desulfurization of Arabian crude oil and straight-run diesel

    Energy Technology Data Exchange (ETDEWEB)

    Basfar, A.A., E-mail: abasfar@kacst.edu.sa [Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442 (Saudi Arabia); Mohamed, K.A. [Radiation Technology Center, Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442 (Saudi Arabia)

    2011-11-15

    Radiation-induced desulfurization of four types of Arabian crude oils (heavy, medium, light and extra light) and straight-run diesel (SRD) was investigated over the range of 10-200 kGy. Results show that gamma radiation processing at absorbed doses up to 200 kGy without further treatment is not sufficient for desulfurization. However, the combination of gamma-irradiation with other physical/chemical processes (i.e. L/L extraction, adsorption and oxidation) may be capable of removing considerable levels of sulfur compounds in the investigated products. Currently, this approach of combined radiation/physical/chemical processes is under investigation. The findings of these attempts will be reported in the future. - Highlights: > Irradiation effect on desulfurization in Arabian crude oils and straight-run diesel was investigated. > No noticeable changes in sulfur content after irradiation up to 200 kGy were observed. > Stricter regulations on sulfur levels in fuels motivate search for improved desulfurization processes. > Limited investigations on radiation-induced desulfurization of oil products are conducted.

  19. Deep desulfurization of full range and low boiling diesel streams from Kuwait Lower Fars heavy crude

    Energy Technology Data Exchange (ETDEWEB)

    Marafi, A.; Al-Hindi, A.; Stanislaus, A. [Petroleum and Refining Department, Petroleum Research and Studies Center, Kuwait Institute for Scientific Research (Kuwait)

    2007-09-15

    Information on feed quality and, in particular, various types of sulfur compounds present in the diesel (gas oil) fractions produced form different crudes and their HDS reactivities under different operating conditions are of a great value for the optimization and economics of the deep HDS process. This paper deals with deep desulfurization of gas oils obtained from a new heavy Kuwaiti crude, namely, Lower Fars (LF) which will be processed in the future at Kuwaiti refineries. Comparative studies were carried out to examine the extent of deep HDS, and the quality of diesel product using two gas oil feeds with different boiling ranges. The results revealed that the full range diesel feed stream produced from the LF crude was very difficult to desulfurize due to its low quality caused by high aromatics content (low feed saturation) together with the presence of high concentrations of organic nitrogen compounds and sterically hindered alkyl DBTs. The low-boiling range gas oil showed better desulfurization compared with the full range gas oil, however, deep desulfurization to 50 ppm sulfur was not achieved even at a temperature as high as 380 C for both feeds. The desulfurized diesel product from the low-boiling gas-oil feed was better in quality with respect to the S, N and PNA contents and cetane index than the full-range gas-oil feed. (author)

  20. [Difference in acclimation of Acidithiobacillus ferrooxidans by various substrates and its effect on coal desulfurization efficiency].

    Science.gov (United States)

    Zhang, De-Wei; Zhou, Li-Xiang; Yang, Xin-Ping; Wang, Shi-Mei

    2011-01-01

    In this study, Acidithiobacillus ferrooxidans LX5 was cultured in 9K medium with pyrite and ferrous sulfate as the substrates. Results showed that the number of A. ferrooxidans LX5 acclimated by pyrite for 20 d was 3.0 x 10(7) cell/mL in the liquid, and the oxidation activity to pyrite was stronger. A. ferrooxidans LX5 cultured for 48 h was 1.0 x 10(8) cell/mL in medium with FeSO4. Extracellular polymeric substance (EPS) produced from A. ferrooxidans LX5 acclimated by pyrite was 2 395 microg/(10(10) cells) three times as much as that cultured with FeSO4. A high-sulfur coal desulfurization experiment were carried out with A. ferrooxidans LX5 domesticated respectively in medium with ferrous sulfate and pyrite. The results showed that the coal desulfurization rate was up to 72.4% after bioleaching for 13 d by A. ferrooxidans LX5 acclimated by pyrite, at the same time, the desulfurization rate was only 47.2% with A. ferrooxidans LX5 cultured with ferrous sulfate and reached 65.8% in 20 d. Therefore, the desulfurization efficiency can be improved of coal and shorten the desulfurization time when A. ferrooxidans LX5 acclimated with pyrite as the substrate.

  1. Multi-objective optimization of oxidative desulfurization in a sono-photochemical airlift reactor.

    Science.gov (United States)

    Behin, Jamshid; Farhadian, Negin

    2017-09-01

    Response surface methodology (RSM) was employed to optimize ultrasound/ultraviolet-assisted oxidative desulfurization in an airlift reactor. Ultrasonic waves were incorporated in a novel-geometry reactor to investigate the synergistic effects of sono-chemistry and enhanced gas-liquid mass transfer. Non-hydrotreated kerosene containing sulfur and aromatic compounds was chosen as a case study. Experimental runs were conducted based on a face-centered central composite design and analyzed using RSM. The effects of two categorical factors, i.e., ultrasound and ultraviolet irradiation and two numerical factors, i.e., superficial gas velocity and oxidation time were investigated on two responses, i.e., desulfurization and de-aromatization yields. Two-factor interaction (2FI) polynomial model was developed for the responses and the desirability function associate with overlay graphs was applied to find optimum conditions. The results showed enhancement in desulfurization ability corresponds to more reduction in aromatic content of kerosene in each combination. Based on desirability approach and certain criteria considered for desulfurization/de-aromatization, the optimal desulfurization and de-aromatization yields of 91.7% and 48% were obtained in US/UV/O3/H2O2 combination, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Roles of Electrolyte Characterization on Bauxite Electrolysis Desulfurization with Regeneration and Recycling

    Science.gov (United States)

    Gong, Xuzhong; Wang, Zhi; Zhuang, Siyuan; Wang, Dong; Wang, Yuhua; Wang, Mingyong

    2017-02-01

    The recycling of NaCl used as supporting electrolyte for bauxite electrolysis was carried out in this study. The electrolyte was regenerated by adding anhydrous CaCl2 into the solution after filtration, and effects of electrolyte characterization on bauxite electrolysis were examined by observing the change in desulfurization ratio and cell voltage. The results indicated that the desulfurization ratio increased with increasing recycling times of electrolyte. In the meantime, the increase in recycling times has led to the decrease in pH value as well as the increase in Fe ion concentration in the electrolyte, which were the main reasons for the increase in the desulfurization ratio with increasing recycling of electrolyte. The pH value of electrolyte after second electrolysis was lower than 1.5, and the desulfurization ratio increased obviously due to the increase in Fe3+ concentration and suppression of jarosite formation. The increase in Ca2+ concentration did not apparently change desulfurization ratio and anode surface activity. However, with Ca2+ addition, the cathode surface was covered by CaSO4·nH2O, thus resulting in the increase of cell voltage.

  3. Simultaneous desulfurization and denitrification by microwave reactor with ammonium bicarbonate and zeolite.

    Science.gov (United States)

    Wei, Zaishan; Lin, Zhehang; Niu, Hejingying; He, Haiming; Ji, Yongfeng

    2009-03-15

    Microwave reactor with ammonium bicarbonate (NH(4)HCO(3)) and zeolite was set up to study the simultaneous removal of sulfur dioxide (SO(2)) and nitrogen oxides (NO(x)) from flue gas. The results showed that the microwave reactor filled with NH(4)HCO(3) and zeolite could reduce SO(2) to sulfur with the best desulfurization efficiency of 99.1% and reduce NO(x) to nitrogen with the best NO(x) purifying efficiency of 86.5%. Microwave desulfurization and denitrification effect of the experiment using ammonium bicarbonate and zeolite together is much higher than that using ammonium bicarbonate or zeolite only. NO(x) concentration has little effect on denitrification but has no influence on desulfurization, SO(2) concentration has no effect on denitrification. The optimal microwave power and empty bed residence time (EBRT) on simultaneous desulfurization and dentrification are 211-280 W and 0.315 s, respectively. The mechanism for microwave reduced desulfurization and denitrification can be described as the microwave-induced catalytic reduction reaction between SO(2), NO(x) and ammonium bicarbonate with zeolite being the catalyst and microwave absorbent.

  4. Use of Green Mussel Shell as a Desulfurizer in the Blending of Low Rank Coal-Biomass Briquette Combustion

    Directory of Open Access Journals (Sweden)

    Mahidin Mahidin

    2016-08-01

    Full Text Available Calcium oxide-based material is available abundantly and naturally. A potential resource of that material comes from marine mollusk shell such as clams, scallops, mussels, oysters, winkles and nerites. The CaO-based material has exhibited a good performance as the desulfurizer oradsorbent in coal combustion in order to reduce SO2 emission. In this study, pulverized green mussel shell, without calcination, was utilized as the desulfurizer in the briquette produced from a mixture of low rank coal and palm kernel shell (PKS, also known as bio-briquette. The ratio ofcoal to PKS in the briquette was 90:10 (wt/wt. The influence of green mussel shell contents and combustion temperature were examined to prove the possible use of that materialas a desulfurizer. The ratio of Ca to S (Ca = calcium content in desulfurizer; S = sulfur content in briquette werefixed at 1:1, 1.25:1, 1.5:1, 1.75:1, and 2:1 (mole/mole. The burning (or desulfurization temperature range was 300-500 °C; the reaction time was 720 seconds and the air flow rate was 1.2 L/min. The results showed that green mussel shell can be introduced as a desulfurizer in coal briquette or bio-briquette combustions. The desulfurization process using that desulfurizer exhibited the first order reaction and the highest average efficiency of 84.5%.

  5. Enhanced adsorptive desulfurization with flexible metal-organic frameworks in the presence of diethyl ether and water.

    Science.gov (United States)

    Khan, Nazmul Abedin; Yoon, Ji Woong; Chang, Jong-San; Jhung, Sung Hwa

    2016-07-05

    Several metal-organic frameworks (MOFs) were employed in adsorptive desulfurization in the presence of oxygen-containing compounds (OCCs). Unlike conventional MOFs and activated carbon, flexible MOFs with a MIL-53 topology showed remarkable performances for the desulfurization in the presence of OCCs.

  6. Monotone viable trajectories for functional differential inclusions

    Science.gov (United States)

    Haddad, Georges

    This paper is a study on functional differential inclusions with memory which represent the multivalued version of retarded functional differential equations. The main result gives a necessary and sufficient equations. The main result gives a necessary and sufficient condition ensuring the existence of viable trajectories; that means trajectories remaining in a given nonempty closed convex set defined by given constraints the system must satisfy to be viable. Some motivations for this paper can be found in control theory where F( t, φ) = { f( t, φ, u)} uɛU is the set of possible velocities of the system at time t, depending on the past history represented by the function φ and on a control u ranging over a set U of controls. Other motivations can be found in planning procedures in microeconomics and in biological evolutions where problems with memory do effectively appear in a multivalued version. All these models require viability constraints represented by a closed convex set.

  7. Optimisation of Experimental Conditions for Ex-Bed Desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J. M.; Ruiz, E.; Otero, J.

    2010-12-22

    This report compiles the results of the work conducted by CIEMAT for Task 6.3 Sulfur and Nitrogen Compounds Abatement of the FLEXGAS project Near Zero Emission Advanced Fluidized Bed Gasification, which has been carried out with financial support from the Research Fund for Coal and Steel, RFCR-CT-2007-00005. The assignment of CIEMAT in Task 6.3 has dealt with the experimental study of ex-bed desulfurization at high temperature and high pressure. Based on a review of the state of the art, a zinc oxide sorbent was chosen as a promising candidate for bulk sulfur removal in highly reducing gases such as those from coal and waste oxygen gasification or for a polishing stage in low sulfur content gases, which is typically the case in biomass gasification gases. The work accomplished has included the study of the sulfidation and regeneration stages in order to determine successful operating conditions and the assessment of the long term performance of the sorbent over subsequent sulfidation and regeneration cycles. (Author) 36 refs.

  8. CFD and CHD in random packing columns with seawater desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Mei-Shan [Southeast Univ., Nanjing (China). College of Civil Engineering; Wang, Shi-He; Wang, Xiao-Ming [State Power Environmental Protection Research Institute, Nanjing (China); Guo, Ming-Chun [Shanghai Huolin engineering Plastics Co., Ltd., Shanghai (China)

    2013-07-01

    By the volume average method, gas-liquid two-phase flow CFD and CHT model is established to describe the random packing column in seawater desulfurization. By numerical calculation, the flow velocity, porosity distribution, pressure distribution and temperature distribution of seawater are obtained. Pressure loss and the outlet temperature of seawater are compared with experimental data, the prediction results and experimental results are well consistent, is exactly the same trend. Analyzing the results of calculation, a significant ''wall flow'' phenomena was found, and the reason of its formation is that the porosity of filler near the wall is significantly higher than in the middle region. Analyzing the distribution of seawater temperature, it is found that the distribution of seawater temperature is more uniform on the top of column, the seawater temperature near the wall fluctuated and were gradually more uniform towards the center of the column. Along the direction of the column from top to bottom, the seawater temperature gradually decreased, and the degree of fluctuations gradually reduced and basically does not change at half of the column, which indicated that the heat exchange between the gas and liquid has been basically completed.

  9. Characterization of flue gas desulfurization particulates in equalization basins

    Energy Technology Data Exchange (ETDEWEB)

    Meg M. Iannacone; James W. Castle; John H. Rodgers Jr. [Clemson University, Clemson, SC (United States). Department of Environmental Engineering and Earth Sciences

    2009-09-15

    Particulates in pilot-scale flue gas desulfurization (FGD) scrubber water were characterized by powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and size analysis based on Stokes' Law after settling in an equalization basin of a pilot-scale constructed wetland treatment system. Three sources were interpreted for specific particle types identified in samples analyzed: FGD wet scrubbing processes, coal combustion byproducts, and uncombusted material from coal. Gypsum (CaSO{sub 4}.2H{sub 2}O) from the FGD scrubbing process comprises 95% of the particulates. Iron oxide particles and cenospheres in the particulate samples are interpreted as coal combustion products. Particles interpreted as originating from unburned coal contain carbon and metals including Zn and Fe. The most abundant elements in the particulates analyzed are O, C, Ca, S, Fe, and Si, with maximum mean content of individual elements ranging from 13% to 70% among particle types. Less abundant elements include Al, K, Mg, Ti, and Mo, with maximum mean content from 0.1% to 3.8%. 41 refs., 5 figs., 5 tabs.

  10. Microbial communities associated with wet flue gas desulfurization systems

    Science.gov (United States)

    Brown, Bryan P.; Brown, Shannon R.; Senko, John M.

    2012-01-01

    Flue gas desulfurization (FGD) systems are employed to remove SOx gasses that are produced by the combustion of coal for electric power generation, and consequently limit acid rain associated with these activities. Wet FGDs represent a physicochemically extreme environment due to the high operating temperatures and total dissolved solids (TDS) of fluids in the interior of the FGD units. Despite the potential importance of microbial activities in the performance and operation of FGD systems, the microbial communities associated with them have not been evaluated. Microbial communities associated with distinct process points of FGD systems at several coal-fired electricity generation facilities were evaluated using culture-dependent and -independent approaches. Due to the high solute concentrations and temperatures in the FGD absorber units, culturable halothermophilic/tolerant bacteria were more abundant in samples collected from within the absorber units than in samples collected from the makeup waters that are used to replenish fluids inside the absorber units. Evaluation of bacterial 16S rRNA genes recovered from scale deposits on the walls of absorber units revealed that the microbial communities associated with these deposits are primarily composed of thermophilic bacterial lineages. These findings suggest that unique microbial communities develop in FGD systems in response to physicochemical characteristics of the different process points within the systems. The activities of the thermophilic microbial communities that develop within scale deposits could play a role in the corrosion of steel structures in FGD systems. PMID:23226147

  11. Economic assessment of advanced flue gas desulfurization processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bierman, G. R.; May, E. H.; Mirabelli, R. E.; Pow, C. N.; Scardino, C.; Wan, E. I.

    1981-09-01

    This report presents the results of a project sponsored by the Morgantown Energy Technology Center (METC). The purpose of the study was to perform an economic and market assessment of advanced flue gas desulfurization (FGD) processes for application to coal-fired electric utility plants. The time period considered in the study is 1981 through 1990, and costs are reported in 1980 dollars. The task was divided into the following four subtasks: (1) determine the factors affecting FGD cost evaluations; (2) select FGD processes to be cost-analyzed; (3) define the future electric utility FGD system market; and (4) perform cost analyses for the selected FGD processes. The study was initiated in September 1979, and separate reports were prepared for the first two subtasks. The results of the latter two subtasks appear only in this final reprot, since the end-date of those subtasks coincided with the end-date of the overall task. The Subtask 1 report, Criteria and Methods for Performing FGD Cost Evaluations, was completed in October 1980. A slightly modified and condensed version of that report appears as appendix B to this report. The Subtask 2 report, FGD Candidate Process Selection, was completed in January 1981, and the principal outputs of that subtask appear in Appendices C and D to this report.

  12. Enhancement of Oxidative Desulfurization Performance over UiO-66(Zr) by Titanium Ion Exchange.

    Science.gov (United States)

    Ye, Gan; Qi, Hui; Li, Xiaolin; Leng, Kunyue; Sun, Yinyong; Xu, Wei

    2017-07-19

    Oxidative desulfurization is considered to be one of the most promising methods for producing ultra-low-sulfur fuels because it can effectively remove refractory sulfur-containing aromatic compounds under mild conditions. In this work, the oxidative desulfurization performance over UiO-66(Zr) is greatly enhanced by Ti ion exchange. This strategy is not only efficient for UiO-66(Zr) with crystal defects but also for UiO-66(Zr) with high crystallinity. In particular, the performance of UiO-66(Zr) with high crystallinity in the oxidative desulfurization of dibenzothiophene can be improved more than 11-fold, which can be mainly attributed to the introduction of active Ti sites. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Theoretical study of the catalytic desulfurization mechanism of thiiren and its methyl derivative

    Directory of Open Access Journals (Sweden)

    L.O. Olatunji

    2003-06-01

    Full Text Available The desulfurization process of compounds implicates two steps. The first step is the adsorption process on the catalytic site and the second, the breaking of the carbon-heteroatom bond leading to the heteroatom elimination. The adsorption process of thiiren have been studied and published in previous works. The results obtained on MoS3H3+ and MoS4H4 have shown that the adsorption of this molecule was very good on the two and three anionic vacancies sites based on molybdenum. In the present study, we have carried out the adsorption according to vertical and horizontal geometries of dihydrothiiren, methylthiiren, and methyldihydrothiiren, and the desulfurization of all these molecules including thiiren molecule. The results obtained have shown that, the desulfurization of thiiren and its methyl derivate pass through the hydrogenation of the aromatic ring on the two types of catalytic sites.

  14. Evaluation of sulfur-reducing microorganisms for organic desulfurization. [Pyrococcus furiosus

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K.W.

    1991-01-01

    Because of substantial portion of the sulfur in Illinois coal is organic, microbial desulfurization of sulfidic and thiophenic functionalities could hold great potential for completing pyritic sulfur removal. We are testing the hypothesis that organic sulfur can be reductively removed as H{sub 2}S through the activities of anaerobic microorganisms. Our objectives for this year include the following: (1) To obtain cultures that will reductively desulfurize thiophenic model compounds. In addition to crude oil enrichments begun last year, we sampled municipal sewage sludge. (2) To continue to work toward optimizing the activity of the DBDS-reducing cultures obtained during the previous year. (3) To expand coal desulfurization work to include other coals including Illinois Basin Coal 101 and a North Dakota lignite, which might be more susceptible to the dibenzyldisulfide reducing cultures due to its lower rank. (4) To address the problem of sulfide sorption, by investigating the sorption capacity of coals in addition to Illinois Basin Coal 108.

  15. Biochemical mechanisms for the desulfurization of coal-relevant organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Afferden, M. van; Tappe, D.; Beyer, M.; Trueper, H.G.; Klein, J. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany))

    1993-12-01

    Two microbial strains ([ital Brevibacterium] sp. DO, [ital Pseudomonas aeruginosa] OS1) were isolated for their ability to desulfurize dibenzothiophene (DBT) and benzyl methyl sulfide (BMS). Enrichment was achieved by a sulfur-selective screening system using the model compounds as the sole source of sulfur for bacterial growth. [ital Brevibacterium] sp. DO utilizes DBT as a sole source of sulfur, carbon and energy for growth, whereas [ital Pseudomonas aeruginosa] OS1 metabolizes BMS to only a small extent under sulfur-selective conditions. Investigations of the regulation of enzymes involved in the desulfurization of coal-relevant sulfur compounds indicate that in nature at least two mechanisms exist: 'carbon regulation' and 'sulfur regulation'. The biochemical mechanisms leading to the desulfurization of BMS and DBT are similar. The sulfur atom of both compounds is initially oxidized to the corresponding sulfone, and cleavage of the C-S bond proceeds via the formation of a chemically unstable hemimercaptal (S-oxidized form) by oxidation of the carbon atom adjacent to the sulfur atom. These results indicate that oxidation of sulfur to its highest oxidation state may be the precondition for the oxidative cleavage of the covalent C-S bonds. By isotope-labelling experiments using [sup 18]O[sub 2], the initial enzymes were identified as sulfoxygenases that use molecular oxygen. Cleavage of the C-S bond of DBT and BMS leads to the formation of organic sulfinic acids as intermediates. With DBT the sulfinic acid is desulfurized probably by hydrolysis; this results in the formation of sulfite and benzoate. The desulfurization of BMS proceeds by sulfonic acid-oxidation. The applicability of these biochemical mechanisms to the microbial desulfurization of coal is discussed. 39 refs., 10 figs., 2 tabs.

  16. Basic tests of in-furnace desulfurization in a circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Fujima, Y.; Ichimura, S.; Ohshima, K.

    1986-01-01

    This paper reports a study of the relation between lime reactivity and the desulfurization efficiency achieved in a circulating fluidized bed equipped with lime injection. Theoretical calculations were made of the reaction between Ca and SO/sub 2/, based on the assumption that this reaction takes place in a dilute zone. The required reaction time for Ca particles was found to coincide closely with the residence time of particles in a dilute bed. The authors give an equation relating percentage desulfurization with the Ca particle circulation rate. 4 refs., 6 figs.

  17. Application of Pt/CdS for the Photocatalytic Flue Gas Desulfurization

    Directory of Open Access Journals (Sweden)

    Xiulan Song

    2012-01-01

    Full Text Available A photocatalytic flue gas desulfurization technology was designed to control emissions of SO2 from the combustion of fossil fuels. With the photocatalytic technology, we cannot only achieve the purpose of solving the problem of SO2 emissions but also realize the desire of hydrogen production from water. CdS loaded with Pt were selected as the model photocatalyst for the photocatalytic flue gas desulfurization. The factors influencing the rate of hydrogen production and ammonia sulfite solution oxidation were detected.

  18. Effect of Slag Chemistry on the Desulfurization Kinetics in Secondary Refining Processes

    Science.gov (United States)

    Kang, Jin Gyu; Shin, Jae Hong; Chung, Yongsug; Park, Joo Hyun

    2017-08-01

    Desulfurization behavior was investigated based on a wide slag composition and working temperature range. Moreover, the rate-controlling step (RCS) for desulfurization with regard to the ladle-refining conditions and the transition of the RCS by changing the slag composition was systematically discussed. The desulfurization ratio reached an equilibrium value within approximately 15 minutes irrespective of the CaO/Al2O3 (=C/A = 1.3 to 1.9) and CaO/SiO2 (=C/S = 3.8 to 6.3) ratios. However, the desulfurization behavior of less basic slags (C/A = 1.1 or C/S = 1.9) exhibited a relatively sluggish [S]-decreasing rate as a function of time. The equilibrium S partition ratio increased with an increase in slag basicity (C/A and C/S ratio), not only due to an increase in sulfide capacity but also due to a decrease in oxygen activity in the molten steel. There was a good correlation between the calculated and measured S partition ratios at various slag compositions. However, the measured S partition ratio increased by adding 5 pct CaF2, followed by a constant value. Multiphase slag exhibited a relatively slow desulfurization rate compared to that of fully liquid slag, possibly due to a decrease in the effective liquid slag volume, interfacial reaction area, and a relatively slow slag initial melting rate due to a high melting point. The activation energy of the desulfurization process was estimated to be 58.7 kJ/mol, from which it was proposed that the desulfurization reaction of molten steel via CaO-Al2O3-SiO2-MgO-CaF2 ladle slag was generally controlled by the mass transfer of sulfur in the metal phase. However, there was a transitional period associated with the rate-controlling mechanism due to a change in the physicochemical properties of the slag. For slag with a viscosity greater than about 1.1 dPa·s and an equilibrium S partition ratio lower than about 400, the overall mass-transfer coefficient was affected by the slag properties. Hence, it was theoretically and

  19. Performance of a Wet Flue Gas Desulfurization Pilot Plant under Oxy-Fuel Conditions

    DEFF Research Database (Denmark)

    Hansen, Brian Brun; Fogh, Folmer; Knudsen, Niels Ole

    2011-01-01

    Oxy-fuel firing is a promising technology that should enable the capture and storage of anthropogenic CO2 emissions from large stationary sources such as power plants and heavy industry. However, this new technology has a high energy demand for air separation and CO2 compression and storage...... desulfurization (FGD) process under operating conditions corresponding to oxy-fuel firing. The most important output parameters were the overall degree of desulfurization and the residual limestone concentration in the gypsum slurry. Pilot-scale experiments quantified that the introduction of a flue gas with 90...

  20. Air-spore in Cartagena, Spain: viable and non-viable sampling methods.

    Science.gov (United States)

    Elvira-Rendueles, Belen; Moreno, Jose; Garcia-Sanchez, Antonio; Vergara, Nuria; Martinez-Garcia, Maria Jose; Moreno-Grau, Stella

    2013-01-01

    In the presented study the airborne fungal spores of the semiarid city of Cartagena, Spain, are identified and quantified by means of viable or non-viable sampling methods. Airborne fungal samples were collected simultaneously using a filtration method and a pollen and particle sampler based on the Hirst methodology. This information is very useful for elucidating geographical patterns of hay fever and asthma. The qualitative results showed that when the non-viable methodology was employed, Cladosporium, Ustilago, and Alternaria were the most abundant spores identified in the atmosphere of Cartagena, while the viable methodology showed that the most abundant taxa were: Cladosporium, Penicillium, Aspergillus and Alternaria. The quantitative results of airborne fungal spores identified by the Hirst-type air sampler (non-viable method), showed that Deuteromycetes represented 74% of total annual spore counts, Cladosporium being the major component of the fungal spectrum (62.2%), followed by Alternaria (5.3%), and Stemphylium (1.3%). The Basidiomycetes group represented 18.9% of total annual spore counts, Ustilago (7.1%) being the most representative taxon of this group and the second most abundant spore type. Ascomycetes accounted for 6.9%, Nectria (2.3%) being the principal taxon. Oomycetes (0.2%) and Zygomycestes and Myxomycestes (0.06%) were scarce. The prevailing species define our bioaerosol as typical of dry air. The viable methodology was better at identifying small hyaline spores and allowed for the discrimination of the genus of some spore types. However, non-viable methods revealed the richness of fungal types present in the bioaerosol. Thus, the use of both methodologies provides a more comprehensive characterization of the spore profile.

  1. Parejas viables que perduran en el tiempo

    OpenAIRE

    Juan José Cuervo Rodríguez

    2013-01-01

    El presente artículo científico presenta resultados del proceso llevado a cabo en el proyecto de investigación docente "Mecanismos de autorregulación en parejas viables que perduran en el tiempo". Se soporta en una mirada compleja de la psicología basada en una epistemología de la construcción. En el ámbito metodológico, se inscribe en los estudios de terapia familiar desde una perspectiva de la comunicación humana como un todo integrado. Participaron nueve parejas. Los criterios de inclusión...

  2. Catalytic oxidative desulfurization of liquid hydrocarbon fuels using air

    Science.gov (United States)

    Sundararaman, Ramanathan

    Conventional approaches to oxidative desulfurization of liquid hydrocarbons involve use of high-purity, expensive water soluble peroxide for oxidation of sulfur compounds followed by post-treatment for removal of oxidized sulfones by extraction. Both are associated with higher cost due to handling, storage of oxidants and yield loss with extraction and water separation, making the whole process more expensive. This thesis explores an oxidative desulfurization process using air as an oxidant followed by catalytic decomposition of sulfones thereby eliminating the aforementioned issues. Oxidation of sulfur compounds was realized by a two step process in which peroxides were first generated in-situ by catalytic air oxidation, followed by catalytic oxidation of S compounds using the peroxides generated in-situ completing the two step approach. By this technique it was feasible to oxidize over 90% of sulfur compounds present in real jet (520 ppmw S) and diesel (41 ppmw S) fuels. Screening of bulk and supported CuO based catalysts for peroxide generation using model aromatic compound representing diesel fuel showed that bulk CuO catalyst was more effective in producing peroxides with high yield and selectivity. Testing of three real diesel fuels obtained from different sources for air oxidation over bulk CuO catalyst showed different level of effectiveness for generating peroxides in-situ which was consistent with air oxidation of representative model aromatic compounds. Peroxides generated in-situ was then used as an oxidant to oxidize sulfur compounds present in the fuel over MoO3/SiO2 catalyst. 81% selectivity of peroxides for oxidation of sulfur compounds was observed on MoO3/SiO2 catalyst at 40 °C and under similar conditions MoO3/Al2O3 gave only 41% selectivity. This difference in selectivity might be related to the difference in the nature of active sites of MoO3 on SiO2 and Al2O 3 supports as suggested by H2-TPR and XRD analyses. Testing of supported and bulk Mg

  3. Adsorptive desulfurization and denitrogenation using metal-organic frameworks.

    Science.gov (United States)

    Ahmed, Imteaz; Jhung, Sung Hwa

    2016-01-15

    With the increasing worldwide demand for energy, utilization of fossil fuels is increasing proportionally. Additionally, new and unconventional energy sources are also being utilized at an increasing rate day-by-day. These sources, along with some industrial processes, result in the exposal of several sulfur- and nitrogen-containing compounds (SCCs and NCCs, respectively) to the environment, and the exposure is one of the greatest environmental threats in the recent years. Although, several methods were established for the removal of these pollutants during the last few decades, recent advancements in adsorptive desulfurization and denitrogenation (ADS and ADN, respectively) with metal-organic frameworks (MOFs) make this the most promising and remarkable method. Therefore, many research groups are currently involved with ADS and ADN with MOFs, and the results are improving gradually by modifying the MOF adsorbents according to several specific adsorption mechanisms. In this review, ADS and ADN studies are thoroughly discussed for both liquid-phase and gas-phase adsorption. The MOF modification procedures, which are important for improved adsorption, are also described. To improve the knowledge among the scientific community, it is very important to understand the detailed chemistry and mechanism involved in a chemical process, which also creates the possibility and pathway for further developments in research and applications. Therefore, the mechanisms related to the adsorption procedures are also discussed in detail. From this review, it can be expected that the scientific community will obtain an understanding of the current state of ADS and ADN, their importance, and some encouragement and insight to take the research knowledge base to a higher level. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Kinetic behaviour of iron oxide sorbent in hot gas desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Y.G. Pan; J.F. Perales; E. Velo; L. Puigjaner [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Chemical Engineering

    2005-06-01

    Although a number of reports on sorbents containing ZnO for H{sub 2}S removal from coal-derived gases can be found in the literature, it is shown in our study that a special sorbent containing Fe{sub 2}O{sub 3}{center_dot}FeO (SFO) with minor promoters (Al{sub 2}O{sub 3}, K{sub 2}O, and CaO) as the main active species is more attractive for both sulfidation and regeneration stages, also under economic considerations. This paper presents the kinetic behaviour of SFO in a hot gas desulfurization process using a thermogravimetric analysis under isothermal condition in the operating range between 500 and 800{sup o}C. The gas stream was N{sub 2} with a 2% wt of H{sub 2}S. Experiences carried out on sorbent sulfidation with SFO (particle sizes in the range of 0.042-0.12 mm) indicate that the sorbent sulfidation capacity sharply increases with temperature in the range of 500-600{sup o}C. It is also shown that the sample weight reaches its maximum absorption capacity, near saturation, at 600{sup o}C so that it makes no sense to increase the sulfidation temperature from this point. To make a comparison between SFO and a zinc titanate based sorbent, a set of sulfidation tests was carried out at 600{sup o}C during 7200 s using the same sieve range for both sorbents between 42 and 90 m. Results show that the sulfidation capacity of SFO is 1.9 times higher than that of zinc titanate. 11 refs., 8 figs., 1 tab.

  5. PRODUCTION OF CONSTRUCTION AGGREGATES FROM FLUE GAS DESULFURIZATION SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Through a cooperative agreement with DOE, the Research and Development Department of CONSOL Inc. (CONSOL R and D) is teaming with SynAggs, Inc. and Duquesne Light to design, construct, and operate a 500 lb/h continuous pilot plant to produce road construction aggregate from a mixture of wet flue gas desulfurization (FGD) sludge, fly ash, and other components. The proposed project is divided into six tasks: (1) Project Management; (2) Mix Design Evaluation; (3) Process Design; (4) Construction; (5) Start-Up and Operation; and (6) Reporting. In this quarter, Tasks 1 and 2 were completed. A project management plan (Task 1) was issued to DOE on October 22, 1998 . The mix design evaluation (Task 2) with Duquesne Light Elrama Station FGD sludge and Allegheny Power Hatfields Ferry Station fly ash was completed. Eight semi-continuous bench-scale tests were conducted to examine the effects of mix formulation on aggregate properties. A suitable mix formulation was identified to produce aggregates that meet specifications of the American Association of State High Transport Officials (AASHTO) as Class A aggregate for use in highway construction. The mix formulation was used in designing the flow sheet of the pilot plant. The process design (Task 3) is approximately 80% completed. Equipment was evaluated to comply with design requirements. The design for the curing vessel was completed by an outside engineering firm. All major equipment items for the pilot plant, except the curing vessel, were ordered. Pilot plant construction (Task 4) was begun in October. The Hazardous Substance Plan was issued to DOE. The Allegheny County (PA) Heat Department determined that an air emission permit is not required for operation of the pilot plant.

  6. Desulfurization of dibenzothiophene (DBT) by a novel strain Lysinibacillus sphaericus DMT-7 isolated from diesel contaminated soil.

    Science.gov (United States)

    Bahuguna, Ashutosh; Lily, Madhuri K; Munjal, Ashok; Singh, Ravindra N; Dangwal, Koushalya

    2011-01-01

    A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene (DBT) was isolated from diesel contaminated soil. The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7 (NCBI GenBank Accession No. GQ496620) using 16S rDNA gene sequence analysis. The desulfurized product of DBT, 2-hydroxybiphenyl (2HBP), was identified and confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively. The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr, exponentially increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT. However, further growth resulted into DBT degradation. The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization pathway of DMT-7. In addition, Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole source of sulfur such as benzothiophene, 3,4-benzo DBT, 4,6-dimethyl DBT, and 4,6-dibutyl DBT. Therefore, Lysinibacillus sphaericus DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol.

  7. Enzymatic isolation of viable human odontoblasts.

    Science.gov (United States)

    Cuffaro, H M; Pääkkönen, V; Tjäderhane, L

    2016-05-01

    To improve an enzymatic method previously used for isolation of rat odontoblasts to isolate viable mature human odontoblasts. Collagenase I, collagenase I/hyaluronidase mixture and hyaluronidase were used to extract mature human odontoblasts from the pulp chamber. Detachment of odontoblasts from dentine was determined with field emission scanning electron microscopy (FESEM) and to analyse the significance of differences in tubular diameter, and the t-test was used. MTT-reaction was used to analyse cell viability, and nonparametric Kruskal-Wallis and Mann-Whitney post hoc tests were used to analyse the data. Immunofluorescent staining of dentine sialoprotein (DSP), aquaporin-4 (AQP4) and matrix metalloproteinase-20 (MMP-20) and quantitative PCR (qPCR) of dentine sialophosphoprotein (DSPP) were used to confirm the odontoblastic nature of the cells. MTT-reaction and FESEM demonstrated collagenase I/hyaluronidase resulted in more effective detachment and higher viability than collagenase I alone. Hyaluronidase alone was not able to detach odontoblasts. Immunofluorescence revealed the typical odontoblastic-morphology with one process, and DSP, AQP4 and MMP-20 were detected. Quantitative PCR of DSPP confirmed that the isolated cells expressed this odontoblast-specific gene. The isolation of viable human odontoblasts was successful. The cells demonstrated morphology typical for odontoblasts and expressed characteristic odontoblast-type genes and proteins. This method will enable new approaches, such as apoptosis analysis, for studies using fully differentiated odontoblasts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Numerical Study on the Effect of Electrode Polarity on Desulfurization in Direct Current Electroslag Remelting Process

    Science.gov (United States)

    Wang, Qiang; Liu, Yu; Wang, Fang; Li, Guangqiang; Li, Baokuan; Qiao, Wenwei

    2017-10-01

    In order to clarify the influence of electrode polarity on desulfurization in direct current (DC) electroslag remelting process, a transient three-dimensional coupled mathematical model has been established. The finite volume method was invoked to simultaneously solve the mass, momentum, energy, and species conservation equations. The Joule heating and Lorentz force were fully coupled through calculating Maxwell's equations with the assistance of the magnetic potential vector. The motion of the metal-slag interface was described by using the volume of fluid approach. An auxiliary metallurgical kinetics module was introduced to determine the thermochemical and the electrochemical reaction rates. A reasonable agreement between the measured data and the simulated results are observed. A longer time and a larger area for the desulfurization can be provided by the metal pool-slag interface when compared with the metal droplet-slag interface. The electrochemical transfer rate at the metal pool-slag interface is positive in the DC reverse polarity (DCRP) remelting, while in the DC straight polarity (DCSP) remelting, the electrochemical transfer rate is negative at this interface. The desulfurization progress in the DCSP remelting thus is fall behind that in the DCRP remelting. The desulfurization rate of the DCRP remelting is around 70 pct and the rate of the DCSP remelting is about 40 pct.

  9. Feasibility Study of Commercial Sorbent in Coal-derived Syngas Desulfurization Field.

    Czech Academy of Sciences Publication Activity Database

    Chien, H.-Y.; Chyou, Y.-P.; Svoboda, Karel

    2015-01-01

    Roč. 6, č. 4 (2015), s. 236-242 ISSN 2078-0737 R&D Projects: GA ČR GC14-09692J Grant - others:MOST(TW) NSC 103-2923-E-042A-001 -MY3 Institutional support: RVO:67985858 Keywords : gasification * desulfurization * sorbent Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  10. Synthesis, characterization and application of 1-butyl-3-methylimidazolium tetrafluoroborate for extractive desulfurization of liquid fuel

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2016-07-01

    Full Text Available In the present paper the experimental data of extractive desulfurization of liquid fuel using 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF4 have been presented. The data of FTIR, 1H NMR and 13C NMR have been discussed for the molecular confirmation of synthesized [BMIM]BF4. Further, the thermal properties, conductivity, solubility, and viscosity analysis of the [BMIM]BF4 were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of ionic liquid without regeneration on dibenzothiophene removal of liquid fuel were presented. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 73.02% for mass ratio of 1:1 in 30 min at 30 °C under the mild reaction conditions. The ionic liquids could be reused four times without a significant decrease in activity. Also, the desulfurizations of real fuels, multistage extraction were presented. The data and results provided in the present paper explore the significant insights of imidazoled ILs for extractive desulfurization of liquid fuels.

  11. Extractive Deep Desulfurization of Liquid Fuels Using Lewis-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2013-01-01

    Full Text Available A new class of green solvents, known as ionic liquids (ILs, has recently been the subject of intensive research on the extractive desulfurization of liquid fuels because of the limitation of traditional hydrodesulfurization method. In present work, eleven Lewis acid ionic liquids were synthesized and employed as promising extractants for deep desulfurization of the liquid fuel containing dibenzothiophene (DBT to test the desulfurization efficiency. [Bmim]Cl/FeCl3 was the most promising ionic liquid and performed the best among studied ionic liquids under the same operating conditions. It can remove dibenzothiophene from the model liquid fuel in the single-stage extraction process with the maximum desulfurization efficiency of 75.6%. It was also found that [Bmim]Cl/FeCl3 may be reused without regeneration with considerable extraction efficiency of 47.3%. Huge saving on energy can be achieved if we make use of this ionic liquids behavior in process design, instead of regenerating ionic liquids after every time of extraction.

  12. Facile Fabrication of AgCl Nanoparticles and Their Application in Adsorptive Desulfurization.

    Science.gov (United States)

    Li, Yan-Hua; Tan, Peng; Liu, Xiao-Qin; Zu, Dan-Dan; Huang, Chun-Ling; Sun, Lin-Bing

    2015-06-01

    Adsorption via π-complexation is highly promising for selective removal of aromatic sulfur from transportation fuels. Because adsorbents play a crucial role in the process of desulfurization, the development of efficient adsorbents attracts increasing attention recently. In the present study, AgCl nanoparticles were employed as π-complexation adsorbents for adsorptive desulfurization, for the first time. A facile strategy for the fabrication of AgCI nanoparticles was designed in aqueous phase with the assistance of surfactant (namely, cetyltrimethylammonium chloride). The present strategy avoids the use of cosurfactant and oil phase that is compulsory for the traditional microemulsion method. As a result, the synthetic system is greatly simplified and the synthetic controllability is improved. By adjusting the reaction temperature, both size and morphology of AgCl nanoparticles can be well controlled. We also demonstrate that the obtained AgCI nanoparticles are active in adsorptive desulfurization, and the adsorption capacity can be well correlated with the particle size of AgCl. The high accessibility of active Ag(I) sites in AgCl nanoparticles is believed to be responsible for the good adsorptive desulfurization capacity. The present study may open a way for the development of new, efficient adsorbents based on nanoparticles.

  13. COMPARISON OF WEST GERMAN AND U.S. FLUE GAS DESULFURIZATION AND SELECTIVE CATALYTIC REDUCTION COSTS

    Science.gov (United States)

    The report documents a comparison of the actual cost retrofitting flue gas desulfurization (FGD) and selective catalytic reduction (SCR) on Federal Republic of German (FRG) boilers to cost estimating procedures used in the U.S. to estimate the retrofit of these controls on U.S. b...

  14. DEVELOPMENT OF INFRARED METHODS FOR CHARACTERIZATION OF INORGANIC SULFUR SPECIES RELATED TO INJECTION DESULFURIZATION PROCESSES

    Science.gov (United States)

    Current methods designed to control and reduce the amount of sulfur dioxide emitted into the atmosphere from coal-fired power plants and factories rely upon the reaction between SO2 and alkaline earth compounds and are called flue gas desulfurization (FGD) processes. Of these met...

  15. Investigation Of A Mercury Speciation Technique For Flue Gas Desulfurization Materials

    Science.gov (United States)

    Most of the synthetic gypsum generated from wet flue gas desulfurization (FGD) scrubbers is currently being used for wallboard production. Because oxidized mercury is readily captured by the wet FGD scrubber, and coal-fired power plants equipped with wet scrubbers desire to bene...

  16. Preferential desulfurization of dibenzyl sulfide by an isolated Gordonia sp. IITR100.

    Science.gov (United States)

    Ahmad, Abrar; Chauhan, Ashok Kumar; Kushwaha, Hari Narayan; Javed, Saleem; Kumar, Ashwani

    2015-06-01

    Several organosulfur compounds are present in the crude oil, and are required to be removed before its processing into transport fuel. For this reason, biodesulfurization of thiophenic compounds has been studied extensively. However, studies on the sulfide compounds are scarce. In this paper, we describe desulfurization of a model sulfidic compound, dibenzyl sulfide (DBS) by an isolated Gordonia sp. IITR100. The reaction was accompanied with the formation of metabolites dibenzyl sulfoxide, dibenzyl sulfone and benzoic acid. Studies with recombinant E. coli revealed that enzyme DszC of this isolate metabolizes DBS into dibenzyl sulfoxide and dibenzyl sulfone, but the reaction downstream to it is mediated by some enzyme other than its DszA. In reactions where DBS and dibenzothiophene (DBT) were present together, both IITR100 and recombinant E. coli exhibited preference for the desulfurization of DBS over DBT. The newly identified capability of IITR100 for desulfurization of both thiophenic and sulfidic compounds suggests its potential use in improved desulfurization of petroleum fractions.

  17. L-proline-based deep eutectic solvents (DESs) for deep catalytic oxidative desulfurization (ODS) of diesel.

    Science.gov (United States)

    Hao, Lingwan; Wang, Meiri; Shan, Wenjuan; Deng, Changliang; Ren, Wanzhong; Shi, Zhouzhou; Lü, Hongying

    2017-10-05

    A series of L-proline-based DESs was prepared through an atom economic reaction between L-proline (L-Pro) and four different kinds of organic acids. The DESs were characterized by Fourier transform infrared spectroscopy (FT-IR), H nuclear magnetic resonance (1HNMR), cyclic voltammogram (CV) and the Hammett method. The synthesized DESs were used for the oxidative desulfurization and the L-Pro/p-toluenesultonic acid (L-Pro/p-TsOH) system shows the highest catalytic activity that the removal of dibenzothiophene (DBT) reached 99% at 60°C in 2h, which may involve the dual activation of the L-Pro/p-TsOH. The acidity of four different L-proline-based DESs was measured and the results show that it could not simply conclude that the correlation between the acidity of DESs and desulfurization capability was positive or negative. The electrochemical measurements evidences and recycling experiment indicate a good stability performance of L-Pro/p-TsOH in desulfurization. This work will provide a novel and potential method for the deep oxidation desulfurization. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. A modeling and experimental study of flue gas desulfurization in a dense phase tower.

    Science.gov (United States)

    Chang, Guanqin; Song, Cunyi; Wang, Li

    2011-05-15

    We used a dense phase tower as the reactor in a novel semi-dry flue gas desulfurization process to achieve a high desulfurization efficiency of over 95% when the Ca/S molar ratio reaches 1.3. Pilot-scale experiments were conducted for choosing the parameters of the full-scale reactor. Results show that with an increase in the flue gas flow rate the rate of the pressure drop in the dense phase tower also increases, however, the rate of the temperature drop decreases in the non-load hot gas. We chose a water flow rate of 0.6 kg/min to minimize the approach to adiabatic saturation temperature difference and maximize the desulfurization efficiency. To study the flue gas characteristics under different processing parameters, we simulated the desulfurization process in the reactor. The simulated data matched very well with the experimental data. We also found that with an increase in the Ca/S molar ratio, the differences between the simulation and experimental data tend to decrease; conversely, an increase in the flue gas flow rate increases the difference; this may be associated with the surface reactions caused by collision, coalescence and fragmentation between the dispersed phases. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Mercury isotope fractionation during transfer from post-desulfurized seawater to air.

    Science.gov (United States)

    Huang, Shuyuan; Lin, Kunning; Yuan, Dongxing; Gao, Yaqin; Sun, Lumin

    2016-12-15

    Samples of dissolved gaseous mercury (DGM) in the post-desulfurized seawater discharged from a coal-fired power plant together with samples of gaseous elemental mercury (GEM) over the post-desulfurized seawater surface were collected and analyzed to study the mercury isotope fractionation during transfer from post-desulfurized seawater to air. Experimental results showed that when DGM in the seawater was converted to GEM in the air, the δ202Hg and Δ199Hg values were changed, ranging from -2.98 to -0.04‰ and from -0.31 to 0.64‰, respectively. Aeration played a key role in accelerating the transformation of DGM to GEM, and resulted in light mercury isotopes being more likely to be enriched in the GEM. The ratio Δ199Hg/Δ201Hg was 1.626 in all samples, suggesting that mercury mass independent fractionation occurred owing to the nuclear volume effect during the transformation. In addition, mass independent fractionation of mercury even isotopes was found in the GEM above the post-desulfurized seawater surface in the aeration pool. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Roots of success: cultivating viable community forestry

    Energy Technology Data Exchange (ETDEWEB)

    MacQueen, Duncan

    2009-05-15

    Is community forestry emerging from the shadows? The evidence shows that locally controlled enterprises can be economically viable, and often build on stronger social and environmental foundations than the big private-sector players. Certainly this is an industry in need of a shakeup. Many forests have become flashpoints where agro-industry, large-scale logging concerns and conservation interests clash, while forest-dependent communities are left out in the cold. Meanwhile, governments – driven by concerns over the climate impacts of deforestation – are having to gear up for legal, sustainable forestry production. Community forestry could be crucial to solving many of these challenges. By building on local core capabilities and developing strategic partnerships, they are forging key new business models that could transform the sector.

  1. Experimental study on the stability of the ClHgSO3(-) in desulfurization wastewater.

    Science.gov (United States)

    Huang, Yu; Chen, Yu; Guo, Xin; Zheng, Chu-Guang

    2017-07-01

    Wet flue gas desulfurization technologies have received much concern for their superior performance on co-controlling the acid gases and mercury. However, high concentrations of mercury-containing desulfurization wastewater, which discharge from wet flue gas desulfurization system regularly, have received researchers' attention since it might generate the risk of secondary pollution. In this paper, the species of mercuric complexes in the desulfurization wastewater was investigated. It speculated that ClHgSO3(-) might determine the residual rate of Hg(2+) in the desulfurization wastewater. Besides, the stability of ClHgSO3(-) on the condition of various wastewater features was also evaluated. The experiment revealed that the high temperature and high pH level promoted the decomposition of ClHgSO3(-). SO3(2-) could restrain the decomposition of ClHgSO3(-) gently; the Hg(2+) residual rate was determined by the new mercury complexes which compounded by Hg(2+) and SO3(2-). The decrease of SO4(2-) and increase of Ca(2+) concentrations could also stimulate the stability of ClHgSO3(-) in wastewater. Cu(2+) and Fe(2+) disturbed the stability of complexes for their catalysis and reduction activities. The study proposed that the ClHgSO3(-) probably decomposes and releases Hg(0) in two pathways. Furthermore, changes of the water's features could disturb the balance of Hg(2+)-Cl(-)-SO3(2-) systems, which might stimulate the decomposition of ClHgSO3.

  2. Spray-dry desulfurization of flue gas from heavy oil combustion.

    Science.gov (United States)

    Scala, Fabrizio; Lancia, Amedeo; Nigro, Roberto; Volpicelli, Gennaro

    2005-01-01

    An experimental investigation on sulfur dioxide removal in a pilot-scale spray dryer from the flue gas generated by combustion of low-sulfur (S) heavy oil is reported. A limewater slurry was sprayed through an ultrasonic two-fluid atomizer in the spray-dry chamber, and the spent sorbent was collected downstream in a pulse-jet baghouse together with fly ash. Flue gas was sampled at different points to measure the desulfurization efficiency after both the spray-dry chamber and the baghouse. Parametric tests were performed to study the effect of the following variables: gas inlet temperature, difference between gas outlet temperature and adiabatic saturation temperature, lime-to-S ratio, and average size of lime particles in the slurry. Results indicated that spray drying is an effective technology for the desulfurization of low-S fuel oil flue gas, provided operating conditions are chosen carefully. In particular, the lowest gas inlet and outlet temperatures compatible with baghouse operation should be selected, as should a sufficiently high lime-to-S ratio. The attainment of a small lime particle size in the slurry is critical for obtaining a high desulfurization efficiency. A previously presented spray-dry flue gas desulfurization model was used to simulate the pilot-scale desulfurization tests, to check the ability of the model to predict the S capture data and its usefulness as a design tool, minimizing the need for pilot-scale experimentation. Comparison between model and experimental results was fairly good for the whole range of calcium/S ratios considered.

  3. Enumeration of viable and non-viable larvated Ascaris eggs with quantitative PCR.

    Science.gov (United States)

    Raynal, Maria; Villegas, Eric N; Nelson, Kara L

    2012-12-01

    The goal of this study was to further develop an incubation-quantitative polymerase chain reaction (qPCR) method for quantifying viable Ascaris eggs by characterizing the detection limit and number of template copies per egg, determining the specificity of the method, and testing the method with viable and inactivated larvated eggs. The number of template copies per cell was determined by amplifying DNA from known numbers of eggs at different development stages; the value was estimated to be 32 copies. The specificity of the method was tested against a panel of bacteria, fungi, protozoa and helminths, and no amplification was found with non-target DNA. Finally, fully larvated eggs were inactivated by four different treatments: 254 nm ultraviolet light, 2,000 ppm NH(3)-N at pH 9, moderate heat (48 °C) and high heat (70 °C). Concentrations of treated eggs were measured by direct microscopy and incubation-qPCR. The qPCR signal decreased following all four treatments, and was in general agreement with the decrease in viable eggs determined by microscopy. The incubation-qPCR method for enumerating viable Ascaris eggs is a promising approach that can produce results faster than direct microscopy, and may have benefits for applications such as assessing biosolids.

  4. Polymerase chain reaction-based discrimination of viable from non-viable Mycoplasma gallisepticum

    Directory of Open Access Journals (Sweden)

    Ching Giap Tan

    2014-02-01

    Full Text Available The present study was based on the reverse transcription polymerase chain reaction (RT-PCR of the 16S ribosomal nucleic acid (rRNA of Mycoplasma for detection of viable Mycoplasma gallisepticum. To determine the stability of M. gallisepticum 16S rRNA in vitro, three inactivation methods were used and the suspensions were stored at different temperatures. The 16S rRNA of M. gallisepticum was detected up to approximately 20–25 h at 37 °C, 22–25 h at 16 °C, and 23–27 h at 4 °C. The test, therefore, could detect viable or recently dead M. gallisepticum (< 20 h. The RT-PCR method was applied during an in vivo study of drug efficacy under experimental conditions, where commercial broiler-breeder eggs were inoculated with M. gallisepticum into the yolk. Hatched chicks that had been inoculated in ovo were treated with Macrolide 1. The method was then applied in a flock of day 0 chicks with naturally acquired vertical transmission of M. gallisepticum, treated with Macrolide 2. Swabs of the respiratory tract were obtained for PCR and RT-PCR evaluations to determine the viability of M. gallisepticum. This study proved that the combination of both PCR and RT-PCR enables detection and differentiation of viable from non-viable M. gallisepticum.

  5. Assessment of the desulfurization of FCC vacuum gasoil and light cycle oil using ionic liquid 1-butyl-3-methylimidazolium octylsulfate

    National Research Council Canada - National Science Library

    Sefoka, Ramogohlo E; Mulopo, Jean

    2017-01-01

    ... ([BMIM][OcSO4]) for the desulfurization of the fluid catalytic cracking diesel fuels. The IL was found to be effective in the selective removal of sulfur from FCC light cycle oil than from the FCC vacuum gasoil stream...

  6. Mechanistic and chiroptical studies on the desulfurization of epidithiodioxopiperazines reveal universal retention of configuration at the bridgehead carbon atoms.

    Science.gov (United States)

    Cherblanc, Fanny L; Lo, Ya-Pei; Herrebout, Wouter A; Bultinck, Patrick; Rzepa, Henry S; Fuchter, Matthew J

    2013-12-06

    The stereochemistry of the desulfurization products of chiral natural and synthetic 3,6-epidithiodiketopiperazines (ETPs) is specified inconsistently in the literature. Qualitative mechanisms have been put forward to explain apparently divergent stereochemical pathways, but the quantitative feasibility of such mechanistic pathways has not been assessed. We report a computational study revealing that desulfurization of ETPs should occur universally with retention of configuration. While the majority of stereochemically assigned and reassigned cases fit this model, until now desulfurization of the synthetic gliotoxin analogue shown has remained assigned as proceeding via inversion of configuration. Through detailed chiroptical studies comparing experimentally obtained optical rotation values, electronic circular dichroism spectra, and vibrational circular dichroism spectra to their computationally simulated counterparts as well as chemical derivatization studies, we have unambiguously demonstrated that contrary to its current assignment in the literature, the desulfurization of this synthetic ETP also proceeds with retention of configuration.

  7. Pressurized fluidized-bed hydroretorting of Eastern oil shales -- Sulfur control. Topical report for Subtask 3.1, In-bed sulfur capture tests; Subtask 3.2, Electrostatic desulfurization; Subtask 3.3, Microbial desulfurization and denitrification

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, M.J.; Abbasian, J.; Akin, C.; Lau, F.S.; Maka, A.; Mensinger, M.C.; Punwani, D.V.; Rue, D.M. [Institute of Gas Technology, Chicago, IL (United States); Gidaspow, D.; Gupta, R.; Wasan, D.T. [Illinois Inst. of Tech., Chicago, IL (United States); Pfister, R.M.: Krieger, E.J. [Ohio State Univ., Columbus, OH (United States)

    1992-05-01

    This topical report on ``Sulfur Control`` presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). The objective of the task on In-Bed Sulfur Capture was to determine the effectiveness of different sorbents (that is, limestone, calcined limestone, dolomite, and siderite) for capturing sulfur (as H{sub 2}S) in the reactor during hydroretorting. The objective of the task on Electrostatic Desulfurization was to determine the operating conditions necessary to achieve a high degree of sulfur removal and kerogen recovery in IIT`s electrostatic separator. The objectives of the task on Microbial Desulfurization and Denitrification were to (1) isolate microbial cultures and evaluate their ability to desulfurize and denitrify shale, (2) conduct laboratory-scale batch and continuous tests to improve and enhance microbial removal of these components, and (3) determine the effects of processing parameters, such as shale slurry concentration, solids settling characteristics, agitation rate, and pH on the process.

  8. The Conceptual Mechanism for Viable Organizational Learning Based on Complex System Theory and the Viable System Model

    Science.gov (United States)

    Sung, Dia; You, Yeongmahn; Song, Ji Hoon

    2008-01-01

    The purpose of this research is to explore the possibility of viable learning organizations based on identifying viable organizational learning mechanisms. Two theoretical foundations, complex system theory and viable system theory, have been integrated to provide the rationale for building the sustainable organizational learning mechanism. The…

  9. Deletion of ultraconserved elements yields viable mice

    Energy Technology Data Exchange (ETDEWEB)

    Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A.; Rubin, Edward M.

    2007-07-15

    Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.

  10. Is Greenberg's "Macro-Carib" viable?

    Directory of Open Access Journals (Sweden)

    Spike Gildea

    Full Text Available In his landmark work Language in the Americas, Greenberg (1987 proposed that Macro-Carib was one of the major low-level stocks of South America, which together with Macro-Panoan and Macro-Ge-Bororo were claimed to comprise the putative Ge-Pano-Carib Phylum. His Macro-Carib includes the isolates Andoke and Kukura, and the Witotoan, Peba-Yaguan, and Cariban families. Greenberg's primary evidence came from person-marking paradigms in individual languages, plus scattered words from individual languages collected into 79 Macro-Carib 'etymologies' and another 64 Amerind 'etymologies'. The goal of this paper is to re-evaluate Greenberg's Macro-Carib claim in the light of the much more extensive and reliable language data that has become available largely since 1987. Based on full person-marking paradigms for Proto-Cariban, Yagua, Bora and Andoke, we conclude that Greenberg's morphological claims are unfounded. For our lexical comparison, we created lexical lists for Proto-Cariban, Proto-Witotoan, Yagua and Andoke, for both Greenberg's 143 putative etymologies and for the Swadesh 100 list. From both lists, a total of 23 potential cognates were found, but no consonantal correspondences were repeated even once. We conclude that our greatly expanded and improved database does not provide sufficient evidence to convince the skeptic that the Macro-Carib hypothesis is viable

  11. Economically viable large-scale hydrogen liquefaction

    Science.gov (United States)

    Cardella, U.; Decker, L.; Klein, H.

    2017-02-01

    The liquid hydrogen demand, particularly driven by clean energy applications, will rise in the near future. As industrial large scale liquefiers will play a major role within the hydrogen supply chain, production capacity will have to increase by a multiple of today’s typical sizes. The main goal is to reduce the total cost of ownership for these plants by increasing energy efficiency with innovative and simple process designs, optimized in capital expenditure. New concepts must ensure a manageable plant complexity and flexible operability. In the phase of process development and selection, a dimensioning of key equipment for large scale liquefiers, such as turbines and compressors as well as heat exchangers, must be performed iteratively to ensure technological feasibility and maturity. Further critical aspects related to hydrogen liquefaction, e.g. fluid properties, ortho-para hydrogen conversion, and coldbox configuration, must be analysed in detail. This paper provides an overview on the approach, challenges and preliminary results in the development of efficient as well as economically viable concepts for large-scale hydrogen liquefaction.

  12. Effect of KOH activation in the desulfurization process of activated carbon prepared by sewage sludge & corn straw.

    Science.gov (United States)

    Zeng, Fan; Liao, Xiaofeng; Hu, Hui; Liao, Li

    2017-12-07

    Series sludge-straw based activated carbons were prepared by sewage sludge and corn straw with potassium hydroxide activation, and the desulfurization performance of activated carbons were studied. To obtain the best desulfurization performance, the optimum ratio between the raw materials and the activator was investigated. The results showed that as the mass ratio of sewage sludge, corn straw and potassium hydroxide was 3:7:2, the activated carbon obtained the best breakthrough and saturation sulfur sorption capacity, which were 12.38 and 5.74 times of sample prepared by the non-activated raw materials, respectively. The appropriate KOH could improve the microporosity and alkaline groups, meanwhile reduce the lactone groups, which were all beneficial to their desulfurization performance. The chemical adsorption process of desulfurization can be simplified to four main steps, and the main desulfurization products are elemental sulfur and sulfate. Implication Sewage sludge (SS) and corn straw (CS) both were great production, wide distribution, readily available in China. Much attention has been paid on how to deal with them effectively. Based on the environment protection idea of waste treatment with waste and resource recycling, low-cost adsorbents were prepared by them. The proposed method can be expanded to the municipal solid waste recycling programs and renewable energy plan. Thus, proceed with the study of prepared AC by SS and straw as a carbon-based dry desulfurization agent could obtain huge social, economical and environmental benefits.

  13. Parejas viables que perduran en el tiempo

    Directory of Open Access Journals (Sweden)

    Juan José Cuervo Rodríguez

    2013-01-01

    Full Text Available El presente artículo científico presenta resultados del proceso llevado a cabo en el proyecto de investigación docente "Mecanismos de autorregulación en parejas viables que perduran en el tiempo". Se soporta en una mirada compleja de la psicología basada en una epistemología de la construcción. En el ámbito metodológico, se inscribe en los estudios de terapia familiar desde una perspectiva de la comunicación humana como un todo integrado. Participaron nueve parejas. Los criterios de inclusión fueron: cinco o más años de convivencia, participación voluntaria, no presentar (ni haber presentado problemáticas especiales que ameriten intervención psicoterapéutica y la obtención de un porcentaje significativo en el uso de estrategias de comunicación asertiva en la resolución de conflictos. El método general utilizado fue el análisis de la comunicación en tarea de conversación. Los principales hallazgos señalan una estrecha relación entre el contexto de desarrollo de las parejas, la emergencia de códigos comunicacionales propios y la posibilidad de perdurar en el tiempo; también, se resalta el tipo de comunicación asertiva o constructiva, la construcción de valores como el respeto y la aceptación de las diferencias, y el deseo por vivir y construir bienestar común, como elementos constitutivos de su identidad como pareja.

  14. Investigation of organic desulfurization additives affecting the calcium sulfate crystals formation

    Directory of Open Access Journals (Sweden)

    Lv Lina

    2017-01-01

    Full Text Available In the study, the optimal experimental conditions for gypsum crystals formation were 323 K, 300 rpm stirring speed. The major impurities of Mg2+, Al3+ and Fe3+ were found to inhibit calcium sulfate crystals formation. Fe3+ caused the strongest inhibition, followed by Mg2+ and Al3+. The influence of desulfurization additives on the gypsum crystals formation was explored with the properties of moisture content, particle size distribution and crystal morphology. The organic desulfurization additives of adipic acid, citric acid, sodium citrate and benzoic acid were investigated. Citric acid and sodium citrate were found to improve the quality of gypsum. Moisture contents were reduced by more than 50%, gypsum particle sizes were respectively enlarged by 9.1 and 22.8%, induction time extended from 4.3 (blank to 5.3 and 7.8 min, and crystal morphology trended to be thicker.

  15. The Desulfurization of Magnetite Ore by Flotation with a Mixture of Xanthate and Dixanthogen

    Directory of Open Access Journals (Sweden)

    Jun Yu

    2016-07-01

    Full Text Available The contamination of sulfur emanating from pyrrhotite in magnetite concentrates has been a problem in iron ore processing. This study utilized froth flotation to float pyrrhotite away from magnetite using collectors of xanthate and dixanthogen. It was found that xanthate or dixanthogen alone could not achieve selective separation between pyrrhotite and magnetite in flotation. A high loss of magnetite was obtained with xanthate, while a low desulfurization degree was obtained with dixanthogen. It was interesting that a high desulfurization ratio was achieved with little loss of magnetite when xanthate was mixed with dixanthogen as the collector. The synergistic effect of the mixed collector on pyrrhotite was studied by electrokinectic studies and FTIR measurements. It was found that xanthate was the anchor on pyrrhotite and determined its selectivity against magnetite, while dixanthogen associated with xanthate, enhancing its hydrophobicity. This study provides new insights into the separation of iron minerals.

  16. FBC desulfurization process using coal with low sulfur content, high oxidizing conditions and metamorphic limestones

    Directory of Open Access Journals (Sweden)

    S. R. Bragança

    2009-06-01

    Full Text Available A metamorphic limestone and a dolomite were employed as SO2 sorbents in the desulfurization of gas from coal combustion. The tests were performed in a fluidized bed reactor on a bench and pilot scale. Several parameters such as bed temperature, sorbent type, and sorbent particle size at different Ca/S molar ratios were analyzed. These parameters were evaluated for the combustion of coal with low-sulfur/high-ash content, experimental conditions of high air excess and high O2 level in fluidization air. Under these conditions, typical of furnaces, few published data can be found. In this work, a medium level of desulfurization efficiency (~60% for Ca/S = 2 was obtained.

  17. Gas-exfoliated porous monolayer boron nitride for enhanced aerobic oxidative desulfurization performance

    Science.gov (United States)

    Wu, Yingcheng; Wu, Peiwen; Chao, Yanhong; He, Jing; Li, Hongping; Lu, Linjie; Jiang, Wei; Zhang, Beibei; Li, Huaming; Zhu, Wenshuai

    2018-01-01

    Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ∼98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

  18. Desulfurization of gas tailings in the petroleum industry; Dessulfuracao de efluentes gasosos na industria petrolifera

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, Edwin A.; Ribeiro, Eduardo D.L. [Minas Gerais Univ., Belo Horizonte, MG (Brazil)

    1993-12-31

    A review of the main gas-stream desulfurization processes, as applied to the petroleum industry, is presented during this work. Technology in actual use for decontamination of natural gas and tail gas in oil refineries, in terms of H{sub 2} S removal, is also discussed. Main processes for oxidized-sulphur gases removal in gas tailings of this industry are described. (author). 6 figs., 2 tabs., 16 refs.

  19. Enzymatic desulfurization of coal. Second quarterly report, October 1--December 15, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Marquis, J.K. [Boston Univ., MA (United States). School of Medicine; Kitchell, J.P. [Holometrix, Inc., Cambridge, MA (United States)

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  20. Biocatalytic desulfurization of thiophenic compounds and crude oil by newly isolated bacteria

    Science.gov (United States)

    Mohamed, Magdy El-Said; Al-Yacoub, Zakariya H.; Vedakumar, John V.

    2015-01-01

    Microorganisms possess enormous highly specific metabolic activities, which enable them to utilize and transform nearly every known chemical class present in crude oil. In this context, one of the most studied biocatalytic processes is the biodesulfurization (BDS) of thiophenic sulfur-containing compounds such as benzothiophene (BT) and dibenzothiophene (DBT) in crude oils and refinery streams. Three newly isolated bacterial strains, which were affiliated as Rhodococcus sp. strain SA11, Stenotrophomonas sp. strain SA21, and Rhodococcus sp. strain SA31, were enriched from oil contaminated soil in the presence of DBT as the sole S source. GC-FID analysis of DBT-grown cultures showed consumption of DBT, transient formation of DBT sulfone (DBTO2) and accumulation of 2-hydroxybiphenyl (2-HBP). Molecular detection of the plasmid-borne dsz operon, which codes for the DBT desulfurization activity, revealed the presence of dszA, dszB, and dszC genes. These results point to the operation of the known 4S pathway in the BDS of DBT. The maximum consumption rate of DBT was 11 μmol/g dry cell weight (DCW)/h and the maximum formation rate of 2-HBP formation was 4 μmol/g DCW/h. Inhibition of both cell growth and DBT consumption by 2-HBP was observed for all isolates but SA11 isolate was the least affected. The isolated biocatalysts desulfurized other model DBT alkylated homologs. SA11 isolate was capable of desulfurizing BT as well. Resting cells of SA11 exhibited 10% reduction in total sulfur present in heavy crude oil and 18% reduction in total sulfur present in the hexane-soluble fraction of the heavy crude oil. The capabilities of the isolated bacteria to survive and desulfurize a wide range of S compounds present in crude oil are desirable traits for the development of a robust BDS biocatalyst to upgrade crude oils and refinery streams. PMID:25762990

  1. Study on optimum technological conditions of ore sintering flue gas desulfurization by using poor manganese

    Science.gov (United States)

    Li, H. Y.; Li, S. E.; Long, Z. G.; Wu, F. Z.; Cui, T. M.; Zhou, X. Z.

    2017-11-01

    Orthogonal experiments were conducted to study the effect of each single factor on the desulfurization rate and leaching rate of Mn2+ to obtain improved process parameters. The results showed that the use of pyrolusite flue gas and the process method of by-product MnSO4 can not only effectively remove the sulfur in the gas, thereby controlling environmental pollution, but can also recover sulfur.

  2. Enhanced pervaporative desulfurization by polydimethylsiloxane membranes embedded with silver/silica core-shell microspheres.

    Science.gov (United States)

    Cao, Ruijian; Zhang, Xiongfei; Wu, Hong; Wang, Jingtao; Liu, Xiaofei; Jiang, Zhongyi

    2011-03-15

    Pervaporative desulfurization based on membrane technology provides a promising alternative for removal of sulfur substances (as represented by thiophene) in fluid catalytic cracking (FCC) gasoline. The present study focused on the performance enhancement of polydimethylsiloxane (PDMS) membrane by incorporation of core-shell structured silver/silica microspheres. A silane coupling agent, N-[3-(trimethoxysily)propyl]-ethylenediamine (TSD), was used to chelate the Ag(+) via its amino groups and attach the silver seeds onto the silica surface via condensation of its methoxyl groups. The resultant microspheres were characterized by Zeta-positron annihilation lifetime spectroscopy (ZetaPALS), inductively coupled plasmaoptical emission spectrophotometer (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Ag(+)/SiO(2)-PDMS composite membranes were prepared by blending PDMS with the as-synthesized silver/silica microspheres. PALS analysis was used to correlate the apparent fractional free volume with permeation flux. The sorption selectivity towards thiophene was enhanced after incorporation of silver/silica microspheres due to the π-complexation between the silver on the microsphere surface and the thiophene molecules. The pervaporative desulfurization performance of the composite membrane was investigated using thiophene/n-octane mixture as a model gasoline. The composite membrane exhibited an optimum desulfurization performance with a permeation flux of 7.76 kg/(m(2)h) and an enrichment factor of 4.3 at the doping content of 5%. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Experimental Study on Hot Metal Desulfurization Using Sintered Red Mud-Based Flux

    Science.gov (United States)

    Li, Fengshan; Zhang, Yanling; Guo, Zhancheng

    2017-09-01

    This research presents the results of laboratory and pilot-scale tests conducted on the use of sintered red mud (RM)-based flux in the hot metal desulfurization (HMD) process. Al2O3/Na2O in RM can decrease the melting point of lime-based slag and can work as a flux in the HMD process. Good slag fluidity was observed throughout the process, and high desulfurization rates ( 80%) with a low final S content (<0.02%) were experimentally obtained when the RM:CaO ratio was between 1.2:1 and 2.4:1. The pilot-scale test results indicated that a desulfurization rate as high as 91% and a S content <0.0099% could be acquired when RM:lime = 1:1, verifying the feasibility of using sintered RM-based flux in HMD. The data obtained provide important information for promoting the large-scale application of sintered RM in steelmaking.

  4. Desulfurization of chemical waste gases and flue gases with economic utilization of air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, K.; Wischnewski, W.

    1983-09-01

    The technological state of recovery of sulfur dioxide from waste and flue gases in the GDR is discussed. Two examples of plants are presented: a pyrosulfuric acid plant in Coswig, recovering sulfur dioxide from gases by absorption with sodium hydroxide, followed by catalytic oxidation to sulfur trioxide, and a plant for waste sulfuric acid recovery from paraffin refining, where the diluted waste acid is sprayed into a furnace and recovered by an ammonium-sulfite-bisulfite solution from the combustion gas (with 4 to 10% sulfur dioxide content). Investment and operation costs as well as profits of both plants are given. Methods employed for power plant flue gas desulfurization in major industrial countries are further assessed: about 90% of these methods uses wet flue gas scrubbing with lime. In the USA flue gas from 25,000 MW of power plant capacity is desulfurized. In the USSR, a 35,000 m/sup 3//h trial plant at Severo-Donetzk is operating using lime, alkali and magnesite. At the 150 MW Dorogobush power plant in the USSR a desulfurization plant using a cyclic ammonia process is under construction.

  5. Preparation of Ag/TiO2-zeolite adsorbents, their desulfurization performance, and benzothiophene adsorption isotherms

    Science.gov (United States)

    Song, Hua; Yang, Gang; Song, Hua-Lin; Wang, Deng; Wang, Xue-Qin

    2017-02-01

    A series of Ag/TiO2-NaY (TY) composite adsorbents were successfully prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, BET, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. The effects of TiO2 and Ag contents on the structure and desulfurization performance of NaY zeolite were studied. The results show that anatase phase is the main form of TiO2 in AgTY adsorbent, and the Y-zeolite framework remained unchanged. AgTY with 6 wt % of Ag and 50 wt % of TiO2 exhibited the best desulfurization performance with the effluent volume of 63.2 mL/g at 10 mg/L sulfur breakthrough level (desulfurization rate of 95%). The benzothiophene (BT) removal performance of the various adsorbents follows the order: NaY < TiO2 < TY-50 < AgTY-50-6. The equilibrium data were modeled by Langmuir and Freundlich equations. The Langmuir model can describe well the adsorption isotherms of BT over AgTY.

  6. Surface acidity effects of Al-SBA-15 mesoporous materials on adsorptive desulfurization.

    Science.gov (United States)

    Meng, Xiuhong; Wang, Yuan; Duan, Linhai; Qin, Yucai; Yu, Wenguang; Wang, Qiang; Dong, Shiwei; Ruan, Yanjun; Wang, Haiyan; Song, Lijuan

    2014-09-01

    SBA-15 and Aluminum-substituted SBA-15 with Si/Al molar ratio 10 (Al-SBA-15(10)) mesoporous materials were directly synthesized by a hydrolysis approach and characterized by a powder X-ray diffraction (XRD), N2 physisorption analysis and Fourier transform infrared (FTIR) etc. The relative number of hydroxyl groups was investigated by in situ FTIR systematically. The acid type and acid strength of the adsorbents were monitord by FTIR at 423 K and 673 K, respectively, utilizing pyridine as a probe. Desulfurization performances of the adsorbents were investigated via static adsorption experiment. Gas chromatography-sulfur chemiluminescence detector (GC-SCD) was employed to detect the sulfur compounds in model fuels before and after treated by the adsorbents. The calcined Al-SBA-15(10) material shows well-ordered hexagonal mesostructure and strong Lewis acid sites (L acid) and weak Brönsted acid sites (B acid). The number of hydroxy on the surface of the Al-SBA-15(10) is more than that of SBA-15, which is beneficial to further modifications such as spontaneous monolayer dispersion. Desulfurization performance of the adsorbents is affected by surface acidity of adsorbents and the constituent of model fuels (olefins, arene, etc.). The thiophene and olefins adsorbed on the B acid site of the adsorbent may occur subsequently alkylation reactions, which may block the pores of the adsorbents and thus cause the reduction of desulfurization capacity.

  7. A multicomponent assembly approach for the design of deep desulfurization heterogeneous catalysts.

    Science.gov (United States)

    Xu, Yanqi; Xuan, Weimin; Zhang, Mengmeng; Miras, Haralampos N; Song, Yu-Fei

    2016-12-06

    Deep desulfurization is a challenging task and global efforts are focused on the development of new approaches for the reduction of sulfur-containing compounds in fuel oils. In this work, we have proposed a new design strategy for the development of deep desulfurization heterogeneous catalysts. Based on the adopted design strategy, a novel composite material of polyoxometalate (POM)-based ionic liquid-grafted layered double hydroxides (LDHs) was synthesized by an exfoliation/grafting/assembly process. The structural properties of the as-prepared catalyst were characterized using FT-IR, XRD, TG, NMR, XPS, BET, SEM and HRTEM. The heterogeneous catalyst exhibited high activity in deep desulfurization of DBT (dibenzothiophene), 4,6-DMDBT (4,6-dimethyldibenzothiophene) and BT (benzothiophene) at 70 °C in 25, 30 and 40 minutes, respectively. The catalyst can be easily recovered and reused at least ten times without obvious decrease of its catalytic activity. Such excellent sulfur removal ability as well as the cost efficiency of the novel heterogeneous catalyst can be attributed to the rational design, where the spatial proximity of the substrate and the active sites, the immobilization of ionic liquid onto the LDHs via covalent bonding and the recyclability of the catalyst are carefully considered.

  8. Controlling Peptide Self-Assembly through a Native Chemical Ligation/Desulfurization Strategy.

    Science.gov (United States)

    Rasale, Dnyaneshwar B; Konda, Maruthi; Biswas, Sagar; Das, Apurba K

    2016-03-18

    Self-assembled peptides were synthesized by using a native chemical ligation (NCL)/desulfurization strategy that maintained the chemical diversity of the self-assembled peptides. Herein, we employed oxo-ester-mediated NCL reactions to incorporate cysteine, a cysteine-based dipeptide, and a sterically hindered unnatural amino acid (penicillamine) into peptides. Self-assembly of the peptides resulted in the formation of self-supporting gels. Microscopy analysis indicated the formation of helical nanofibers, which were responsible for the formation of gel matrices. The self-assembly of the ligated peptides was governed by covalent and non-covalent interactions, as confirmed by FTIR, CD, fluorescence spectroscopy, and MS (ESI) analyses. Peptide disassembly was induced by desulfurization reactions with tris(2-carboxyethyl)phosphine (TCEP) and glutathione at 80 °C. Desulfurization reactions of the ligated peptides converted the Cys and penicillamine functionalities into Ala and Val moieties, respectively. The self-supporting gels showed significant shear-thinning and thixotropic properties. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Catalytic Emulsion Based on Janus Nanosheets for Ultra-Deep Desulfurization.

    Science.gov (United States)

    Xia, Lixin; Zhang, Hairan; Wei, Zhichao; Jiang, Yi; Zhang, Ling; Zhao, Jie; Zhang, Junhui; Dong, Li; Li, Erni; Ruhlmann, Laurent; Zhang, Qian

    2017-02-03

    Catalytic Janus nanosheets were synthesized by using an anion-exchange reaction between heteropolyacids (HPAs) and the modified ionic-liquid (IL) moieties of Janus nanosheets. Their morphology and surface properties were characterized by using SEM, energy-dispersive spectroscopy (EDS), FTIR spectroscopy, and X-ray photoelectron spectroscopy (XPS) studies. Because of their inherent Janus structure, the nanosheets exhibited good amphipathic character with ILs and oil to form a stable ILs-in-oil emulsion. Therefore, these Janus nanosheets can be used as both emulsifiers and catalysts to perform emulsive desulfurization. During this process, sulfur-containing compounds at the interface could be easily oxidized and efficiently removed from a model oil. Application of this Janus emulsion brings an efficient, useful, and green procedure to the desulfurization process. Compared with the desulfurization catalyzed by using HPAs in a conventional two-phase system, the sulfur removal of dibenzothiophene (DBT) achieved in a Janus emulsion system was improved from 68 to 97 % within 1.5 h. Moreover, this emulsion system could be demulsified easily by simple centrifugation to recover both the nanosheets and the ILs. Owing to the good structural stability of the Janus nanosheets, the sulfur removal efficiency of DBT could still reach 99.9 % after the catalytic nanosheets had been recycled at least six times. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Desulfurization with Thialkalivibrio versutus immobilized on magnetic nanoparticles modified with 3-aminopropyltriethoxysilane.

    Science.gov (United States)

    Mu, Tingzhen; Zhao, Jixiang; Guan, Yueping; Tian, Jiangnan; Yang, Maohua; Guo, Chen; Xing, Jianmin

    2017-06-01

    Thialkalivibrio versutus D301 cells were immobilized on Fe3O4 nanoparticles (NPs) synthesized by an improved chemical coprecipitation method and modified with 3-aminopropyltriethoxysilane (APTES), then the immobilized cells were used in sulfur oxidation. The prepared Fe3O4-APTES NPs had a narrow size distribution (10 ± 2 nm) and were superparamagnetic, with a saturation magnetization of 60.69 emu/g. Immobilized cells had a saturation magnetization of 34.95 emu/g and retained superparamagnetism. The optimum conditions for cell immobilization were obtained at pH 9.5 and 1 M Na(+). The immobilization capacity of Fe3O4-APTES NPs was 7.15 g DCW/g-NPs that was 2.3-fold higher than that of Fe3O4 NPs. The desulfurization efficiency of the immobilized cells was close to 100%, having the same sulfur oxidation capacity as free cells. Further, the immobilized cells could be reused at least eight times, retaining more than 85% of their desulfurization efficiency. Immobilization of cells with the modified magnetic NPs efficiently increased cell controllability, have no effect on their desulfurization activity and could be effectively used in large-scale industrial applications.

  11. Illuminate the active sites of γ-FeOOH for low-temperature desulfurization

    Science.gov (United States)

    Shen, Lijuan; Cao, Yanning; Du, Zhongjie; Zhao, Wentao; Lin, Ke; Jiang, Lilong

    2017-12-01

    FeOOH has been explored as a promising adsorbent for low-temperature H2S adsorption. However, the nature of the active sites toward the desulfurization has remained elusive. Here, a series of γ-FeOOH is prepared with well-defined lath-like and rod-like shapes by adjusting the pH value of the reaction system. The two shapes of γ-FeOOH have identical bulk structures but expose different distributions of surface OH groups, namely singly (tbnd FeOH, sbnd OH), doubly (tbnd Fe2OH, μsbnd OH), and triply coordinated (tbnd Fe3OH, μ3sbnd OH) hydroxyls, allowing us to investigate the geometrical-site-dependent desulfurization activity of γ-FeOOH at molecular-scale level. Following a thorough analysis by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and in situ Fourier transform infrared spectroscopy (In situ FT-IR), we demonstrate that singly hydroxyl (tbnd FeOH, sbnd OH) site is responsible for H2S adsorption, which acts as the active site for low-temperature desulfurization.

  12. Oxidation desulfurization of fuel using pyridinium-based ionic liquids as phase-transfer catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong; Zhang, Juan

    2010-12-15

    In this work, several ionic liquids based on pyridinium cations are prepared. The ionic liquids are employed as phase-transfer catalysts (PTCs) for phase-transfer catalytic oxidation of dibenzothiophene (DBT) dissolved in n-octane. The partition coefficients of DBT between ionic liquids and n-octane are investigated. Then H{sub 2}O{sub 2}-formic acid is used as an oxidant and ionic liquids are used as PTCs. The reaction turns to be heterogeneous and desulfurization rate of DBT increased apparently. When IL ([BPy]HSO{sub 4}) is used as PTC, and the condition are: temperature is 60 C, time is 60 min, H{sub 2}O{sub 2}/sulfur molar ratio (O/S) is 4, the desulfurization rate reaches the maximum (93.3%), and the desulfurization of the real gasoline is also investigated, 87.7% of sulfur contents are removed under optima reaction conditions. The PTC [BPy]HSO{sub 4} can be recycled for five times without significant decrease in activity. (author)

  13. Enhanced pervaporative desulfurization by polydimethylsiloxane membranes embedded with silver/silica core-shell microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Cao Ruijian; Zhang Xiongfei [Key Laboratory for Green Chemical Technology, Ministry of Education of China, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Wu Hong, E-mail: wuhong2000@gmail.com [Key Laboratory for Green Chemical Technology, Ministry of Education of China, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072 (China); Wang Jingtao; Liu Xiaofei [Key Laboratory for Green Chemical Technology, Ministry of Education of China, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Jiang Zhongyi [Key Laboratory for Green Chemical Technology, Ministry of Education of China, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2011-03-15

    Pervaporative desulfurization based on membrane technology provides a promising alternative for removal of sulfur substances (as represented by thiophene) in fluid catalytic cracking (FCC) gasoline. The present study focused on the performance enhancement of polydimethylsiloxane (PDMS) membrane by incorporation of core-shell structured silver/silica microspheres. A silane coupling agent, N-[3-(trimethoxysily)propyl]-ethylenediamine (TSD), was used to chelate the Ag{sup +} via its amino groups and attach the silver seeds onto the silica surface via condensation of its methoxyl groups. The resultant microspheres were characterized by Zeta-positron annihilation lifetime spectroscopy (ZetaPALS), inductively coupled plasmaoptical emission spectrophotometer (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Ag{sup +}/SiO{sub 2}-PDMS composite membranes were prepared by blending PDMS with the as-synthesized silver/silica microspheres. PALS analysis was used to correlate the apparent fractional free volume with permeation flux. The sorption selectivity towards thiophene was enhanced after incorporation of silver/silica microspheres due to the {pi}-complexation between the silver on the microsphere surface and the thiophene molecules. The pervaporative desulfurization performance of the composite membrane was investigated using thiophene/n-octane mixture as a model gasoline. The composite membrane exhibited an optimum desulfurization performance with a permeation flux of 7.76 kg/(m{sup 2} h) and an enrichment factor of 4.3 at the doping content of 5%.

  14. Deep-desulfurization of the petroleum diesel using the heterogeneous carboxyl functionalized poly-ionic liquid

    Directory of Open Access Journals (Sweden)

    Kamlesh Rudreshwar Balinge

    2016-12-01

    Full Text Available Acidic carboxyl functionalized poly(ionic liquid (CFPIL has been synthesized and characterized by various techniques like FT-NMR, Fourier transform infrared spectroscopy (FTIR. In this work, deep oxidative desulfurization of model oil (thiophene dissolved in iso-octane by CFPIL catalyst was carried out in presence of 30 wt% H2O2 solution as an oxidant. The effects of the hydrogen peroxide, amount of CFPIL, temperature-time and recyclability are scrutinized systematically. It was found that the effective molar proportion of H2O2 to sulfur was 4:1 at 70 °C in 180 min with 0.6 g catalyst, removing 100% thiophene from model oil. This method has shown high efficiency for the removal of thiophene, which is difficult to remove from the oil than benzothiophene and dibenzothiophene. Additionally, an oxidative desulfurization mechanism has been proposed according to the experimental results. This catalytic system by CFPIL offers advantages such as higher efficiency, low amount of ionic liquid, simple work up for separating oil from the catalyst and ease of recycling. This protocol inclines to show that diesel fuels in industry can be purified to sulfur-free or ultra-low sulfur fuels by further deep oxidative desulfurization with CFPILs after hydrodesulfurization.

  15. Development of economical and high efficient desulfurization process using low rank coal; Teitankadotan wo mochiita ankana kokoritsu datsuryuho no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takarada, Y.; Kato, K.; Kuroda, M.; Nakagawa, N. [Gunma University, Gunma (Japan). Faculty of Engineering; Roman, M. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-02-01

    Experiment reveals the characteristics of low rank coal serving as a desulfurizing material in fluidized coal bed reactor with oxygen-containing functional groups exchanged with Ca ions. This effort aims at identifying inexpensive Ca materials and determining the desulfurizing characteristics of Ca-carrying brown coal. A slurry of cement sludge serving as a Ca source and low rank coal is agitated for the exchange of functional groups and Ca ions, and the desulfurizing characteristics of the Ca-carrying brown coal is determined. The Ca-carrying brown coal and high-sulfur coal char is mixed and incinerated in a fluidized bed reactor, and it is found that a desulfurization rate of 75% is achieved when the Ca/S ratio is 1 in the desulfurization of SO2. This rate is far higher than the rate obtained when limestone or cement sludge without preliminary treatment is used as a desulfurizer. Next, Ca-carrying brown coal and H2S are caused to react upon each other in a fixed bed reactor, and then it is found that desulfurization characteristics are not dependent on the diameter of the Ca-carrying brown coal grain, that the coal is different from limestone in that it stays quite active against H2S for long 40 minutes after the start of the reaction, and that CaO small in crystal diameter is dispersed in quantities into the char upon thermal disintegration of Ca-carrying brown coal to cause the coal to say quite active. 5 figs.

  16. A Green Desulfurization Technique: Utilization of Flue Gas SO2 to Produce H2 via a Photoelectrochemical Process Based on Mo-Doped BiVO4

    Directory of Open Access Journals (Sweden)

    Jin Han

    2017-12-01

    Full Text Available A green photoelectrochemical (PEC process with simultaneous SO2 removal and H2 production has attracted an increasing attention. The proposed process uses flue gas SO2 to improve H2 production. The improvement of the efficiency of this process is necessary before it can become industrial viable. Herein, we reported a Mo modified BiVO4 photocatalysts for a simultaneous SO2 removal and H2 production. And the PEC performance could be significantly improved with doping and flue gas removal. The evolution rate of H2 and removal of SO2 could be enhanced by almost three times after Mo doping as compared with pristine BiVO4. The enhanced H2 production and SO2 removal is attributed to the improved bulk charge carrier transportation after Mo doping, and greatly enhanced oxidation reaction kinetics on the photoanode due to the formation of SO32− after SO2 absorption by the electrolyte. Due to the utilization of SO2 to improve the production of H2, the proposed PEC process may become a profitable desulfurization technique.

  17. Proteomics and Metabolomics Analyses to Elucidate the Desulfurization Pathway of Chelatococcus sp.

    Directory of Open Access Journals (Sweden)

    Naba K Bordoloi

    Full Text Available Desulfurization of dibenzothiophene (DBT and alkylated DBT derivatives present in transport fuel through specific cleavage of carbon-sulfur (C-S bonds by a newly isolated bacterium Chelatococcus sp. is reported for the first time. Gas chromatography-mass spectrometry (GC-MS analysis of the products of DBT degradation by Chelatococcus sp. showed the transient formation of 2-hydroxybiphenyl (2-HBP which was subsequently converted to 2-methoxybiphenyl (2-MBP by methylation at the hydroxyl group of 2-HBP. The relative ratio of 2-HBP and 2-MBP formed after 96 h of bacterial growth was determined at 4:1 suggesting partial conversion of 2-HBP or rapid degradation of 2-MBP. Nevertheless, the enzyme involved in this conversion process remains to be identified. This production of 2-MBP rather than 2-HBP from DBT desulfurization has a significant metabolic advantage for enhancing the growth and sulfur utilization from DBT by Chelatococcus sp. and it also reduces the environmental pollution by 2-HBP. Furthermore, desulfurization of DBT derivatives such as 4-M-DBT and 4, 6-DM-DBT by Chelatococcus sp. resulted in formation of 2-hydroxy-3-methyl-biphenyl and 2-hydroxy -3, 3/- dimethyl-biphenyl, respectively as end product. The GC and X-ray fluorescence studies revealed that Chelatococcus sp. after 24 h of treatment at 37°C reduced the total sulfur content of diesel fuel by 12% by per gram resting cells, without compromising the quality of fuel. The LC-MS/MS analysis of tryptic digested intracellular proteins of Chelatococcus sp. when grown in DBT demonstrated the biosynthesis of 4S pathway desulfurizing enzymes viz. monoxygenases (DszC, DszA, desulfinase (DszB, and an NADH-dependent flavin reductase (DszD. Besides, several other intracellular proteins of Chelatococcus sp. having diverse biological functions were also identified by LC-MS/MS analysis. Many of these enzymes are directly involved with desulfurization process whereas the other enzymes

  18. Fructophilic behaviour of Gordonia alkanivorans strain 1B during dibenzothiophene desulfurization process.

    Science.gov (United States)

    Alves, Luís; Paixão, Susana M

    2014-01-25

    Biodesulfurization (BDS) aims at the removal of recalcitrant sulfur from fossil fuels at mild operating conditions with the aid of microorganisms. These microorganisms can remove sulfur from dibenzothiphene (DBT), a model compound, or other polycyclic aromatic used as sulfur source, making BDS an easy and environmental friendly process. Gordonia alkanivorans strain 1B has been described as a desulfurizing bacterium, able to desulfurize DBT to 2-hydroxybiphenyl (2-HBP), the final product of the 4S pathway, using d-glucose as carbon source. However, both cell growth and desulfurization can be largely affected by the nutrient composition of the growth medium, due to cofactor requirements of many enzymes involved in the BDS biochemical pathway. In this study, the main goal was to investigate the influence of several sugars, as carbon source, on the growth and DBT desulfurization ability of G. alkanivorans strain 1B. The results of desulfurization tests showed that the lowest values for the growth rate (0.025 hour(-1)) and for the overall 2-HBP production rate (1.80 μm/hour) by the strain 1B were obtained in glucose grown cultures. When using sucrose, the growth rate increase exhibited by strain 1B led to a higher biomass productivity, which induced a slightly increase in the 2-HBP production rate (1.91 μm/hour), conversely in terms of 2-HBP specific production rate (q2-HBP) the value obtained was markedly lower (0.718 μmol/g/hour in sucrose versus 1.22 μmol/g/hour in glucose). When a mixture of glucose and fructose was used as carbon source, strain 1B reached a value of q2-HBP=1.90 μmol/g/hour, close to that in fructose (q2-HBP=2.12 μmol/g/hour). The highest values for both cell growth (μ=0.091 hour(-1)) and 2-HPB production (9.29μm/hour) were obtained when strain 1B was desulfurizing DBT in the presence of fructose as the only carbon source, indicating a fructophilic behaviour by this bacterium. This fact is in agreement with the highest value of biomass

  19. Visible-light photoredox-catalyzed desulfurization of thiol- and disulfide-containing amino acids and small peptides.

    Science.gov (United States)

    Lee, Myungmo; Neukirchen, Saskia; Cabrele, Chiara; Reiser, Oliver

    2017-07-01

    A scalable protocol for the desulfurization of cysteine by using visible light, the photocatalyst Ir(dF(CF3 )ppy)2 (dtb-bpy)PF6 and triethylphosphite under biphasic reaction conditions has been developed. The loading of the catalyst can be as low as 0.01 mol%, which can be efficiently removed during the workup (≤0.3 ppm), giving rise to the corresponding desulfurized product in high yields. This method has been applied also to cystine, penicillamine, and reduced and oxidized glutathione. The desulfurization has been found to be pH sensitive, with an optimal pH value of 6.5 and 7.0 for the cysteine derivatives and glutathione, respectively. In addition, during the desulfurization of a decapeptide containing cysteine and methionine, concurrent oxidation of the two sulfur-containing residues to disulfide and sulfoxide has been observed. Therefore, whereas the presented protocol allows a straightforward visible light-mediated desulfurization of simple thiols by using very low catalyst loading and a cost-effective trialkylphosphite as thiyl radical trapping agent, its application to complex substrates needs to be carefully validated. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  20. [Effects of desulfurization waste on calcium distribution, Ca(2+)-ATPase activity, and antioxidant characteristics of rice leaf under alkali stress].

    Science.gov (United States)

    Mao, Gui-Lian; Xu, Xing; Zeng, Jin; Yue, Zi-Hui; Yang, Shu-Juan

    2012-02-01

    To approach the action mechanisms of desulfurization waste on alleviating alkali stress-induced injury of rice, a pot experiment was conducted to study the variations of leaf total calcium content, calcium distribution, plasma membrane Ca(2+)-ATPase activity, and reactive oxygen content of rice seedlings under alkali stress after the application of desulfurization waste. In the control, a few calcium particulates scattered in the cell wall and chloroplasts, while applying desulfurization waste or CaSO4 increased the calcium particulates in the plasma membrane, intercellular space, cell wall, and vacuole significantly. With the increasing application rate of desulfurization waste or CaSO4, the leaf total calcium content increased, Ca(2+)-ATPase activity in plasma membrane and tonoplast presented an increasing trend, plasma membrane relative permeability, MDA content, and O2 production rate decreased, and SOD and POD activities increased. The desulfurization waste could relieve the alkali stress to rice in some extent, and the main reactive compound in the waste could be CaSO4.

  1. Asouzu's Complementary Ontology as a Foundation for a Viable ...

    African Journals Online (AJOL)

    This paper on “Asouzu's Complementary Ontology as a foundation for a viable Ethic of the Environment”, posits that an ethic of the environment can be seen as viable if it considers the whole of reality as ontologically relevant. This point of view would free environmental ethics of anthropocentric bias and its attendant ...

  2. Separation of viable and non-viable tomato (Solanum lycopersicum L.) seeds using single seed near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Shrestha, Santosh; Deleuran, Lise Christina; Gislum, René

    2017-01-01

    -viable tomato seeds of two cultivars using chemometrics. The data exploration were performed by principal component analysis (PCA). Subsequently, viable and non-viable seeds were classified by partial least squares-discriminant analysis (PLS-DA) and interval PLS-DA (iPLS-DA). The indication of clustering...... of viable and non-viable seeds were observed in the PCA of each cultivar and the pooled samples. However, the PCA did not exhibit a pattern of separation among the early, normal and late germinated tomato seeds. The NIR spectral regions of 1160–1170, 1383–1397, 1647–1666, 1860–1884 and 1915–1940 nm were...... identified as important for classification of viable and non-viable tomato seeds by iPLS-DA. The sensitivity i.e. ability to correctly identify the positive samples and specificity i.e. ability to reject the negative samples of the (iPLS-DA) model on identified spectral regions for prediction of viable...

  3. Interaction between Ni and HZSM-5 in aromatization-enhanced reactive adsorption desulfurization catalysts for FCC gasoline upgrading.

    Science.gov (United States)

    Zhao, Jinchong; Zhang, Lulu; She, Nannan; Liu, Yunqi; Chai, Yongming; Liu, Chenguang

    A compound catalyst (RA) consisted of Ni, ZnO and HZSM-5 with functions of reactive adsorption desulfurization (RADS) and olefin aromatization for fluid catalytic cracking (FCC) gasoline upgrading was prepared. X-ray powder diffraction (XRD), temperature-programmed reduction and low-temperature N2 adsorption were used to characterize the properties of the catalysts. Performance evaluation by FCC gasoline was carried out, and the result showed that the catalyst RA performed well in desulfurization and aromatization. For comparison, RADS catalyst (represented by DS) consisted of Ni and ZnO and aromatization catalyst (represented by Ar) consisted of HZSM-5 were prepared, respectively. They were combined in different ways to help investigating interaction between Ni and HZSM-5. Performance evaluated by FCC gasoline showed that catalyst RA performed best in desulfurization with a slight octane number loss. Interaction between Ni and HZSM-5 is a significant factor which influences the performance of the catalyst.

  4. Synthesis of l- and d-Ubiquitin by One-Pot Ligation and Metal-Free Desulfurization.

    Science.gov (United States)

    Huang, Yi-Chao; Chen, Chen-Chen; Gao, Shuai; Wang, Ye-Hai; Xiao, Hua; Wang, Feng; Tian, Chang-Lin; Li, Yi-Ming

    2016-05-23

    Native chemical ligation combined with desulfurization has become a powerful strategy for the chemical synthesis of proteins. Here we describe the use of a new thiol additive, methyl thioglycolate, to accomplish one-pot native chemical ligation and metal-free desulfurization for chemical protein synthesis. This one-pot strategy was used to prepare ubiquitin from two or three peptide segments. Circular dichroism spectroscopy and racemic protein X-ray crystallography confirmed the correct folding of ubiquitin. Our results demonstrate that proteins synthesized chemically by streamlined 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis coupled with a one-pot ligation-desulfurization strategy can supply useful molecules with sufficient purity for crystallographic studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Evaluation of sulfur-reducing microorganisms for organic desulfurization. Final technical report, September 1, 1990--August 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Miller, K.W.

    1991-12-31

    Because of substantial portion of the sulfur in Illinois coal is organic, microbial desulfurization of sulfidic and thiophenic functionalities could hold great potential for completing pyritic sulfur removal. We are testing the hypothesis that organic sulfur can be reductively removed as H{sub 2}S through the activities of anaerobic microorganisms. Our objectives for this year include the following: (1) To obtain cultures that will reductively desulfurize thiophenic model compounds. In addition to crude oil enrichments begun last year, we sampled municipal sewage sludge. (2) To continue to work toward optimizing the activity of the DBDS-reducing cultures obtained during the previous year. (3) To expand coal desulfurization work to include other coals including Illinois Basin Coal 101 and a North Dakota lignite, which might be more susceptible to the dibenzyldisulfide reducing cultures due to its lower rank. (4) To address the problem of sulfide sorption, by investigating the sorption capacity of coals in addition to Illinois Basin Coal 108.

  6. Microwave-Assisted Adsorptive Desulfurization of Model Diesel Fuel Using Synthesized Microporous Rare Earth Metal-Doped Zeolite Y

    Directory of Open Access Journals (Sweden)

    N. Salahudeen

    2015-06-01

    Full Text Available The microwave-assisted adsorptive desulfurization of model fuel (thiophene in n-heptane was investigated using a synthesized rare earth metal-doped zeolite Y (RE Y. Crystallinity of the synthesized zeolite was 89.5%, the silicon/aluminium (Si/Al molar ratio was 5.2, the Brunauer–Emmett–Teller (BET surface area was 980.9 m2/g, and the pore volume and diameter was 0.3494 cm3/g and 1.425 nm, respectively. The results showed that the microwave reactor could be used to enhance the adsorptive desulfurization process with best efficiency of 75% at reaction conditions of 100 °C and 15 minutes. The high desulfurization effect was likely due to the higher efficiency impact of microwave energy in the interaction between sulfur in thiophene and HO-La(OSiAl.

  7. Desulfurization activity and reusability of magnetite nanoparticle-coated Rhodococcus erythropolis FMF and R. erythropolis IGTS8 bacterial cells.

    Science.gov (United States)

    Bardania, Hassan; Raheb, Jamshid; Mohammad-Beigi, Hossein; Rasekh, Behnam; Arpanaei, Ayyoob

    2013-01-01

    The application of Fe3 O4 nanoparticles to the separation of desulfurizing bacterial cells and their influence on the desulfurization activity and reusability of the two bacterial strains Rhodococcus erythropolis FMF and R. erythropolis IGTS8 were investigated. Magnetite nanoparticles were synthesized via the reverse coprecipitation method. Transmission electron microscopy (TEM) images showed that the magnetite nanoparticles had sizes of 5.35 ± 1.13 (F1 nanoparticles) and 8.74 ± 1.18 nm (F2 nanoparticles) when glycine was added during the synthesis of nanoparticles and when it was absent from the reaction mixture, respectively. Glycine was added after the synthesis of both F1 and F2 nanoparticles to stabilize the nanoparticle dispersion. TEM images of cells treated with magnetite nanoparticles indicated that F1 nanoparticles were immobilized on the surface of bacterial cells more evenly than the F2 nanoparticles. Desulfurization activities of the F1 magnetite nanoparticle-coated R. erythropolis FMF and R. erythropolis IGTS8 cells (with sulfur-removal percentage values of 70 ± 4 and 73 ± 3, respectively), as examined with the spectrophotometric Gibbs assay (based on dibenzothiophene degradation and sulfur-removal percentage), were not significantly different from those for the free bacterial cells (67 ± 3 and 69 ± 4, respectively). These results indicate that magnetite nanoparticles cannot affect the desulfurization activity of cells examined in this work. Isolation of bacterial cells from the suspension using a magnet and evaluation of desulfurization activity of separated cells showed that Fe3 O4 nanoparticles can provide a high-efficiency recovery of bacterial cells from a suspension, with the reused magnetite nanoparticle-coated bacterial cells being able to maintain their desulfurization activity efficiently. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  8. Advanced fuel gas desulfurization (AFGD) demonstration project. Technical progress report No. 19, July 1, 1994--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The {open_quotes}Advanced Flue Gas Desulfurization (AFGD) Demonstration Project{close_quotes} is a $150.5 million cooperative effort between the U.S. Department of Energy and Pure Air, a general partnership of Air Products and Chemicals, Inc. and Mitsubishi Heavy Industries America, Inc. The AFGD process is one of several alternatives to conventional flue gas desulfurization (FGD) being demonstrated under the Department of Energy`s Clean Coal Technology Demonstration Program. The AFGD demonstration project is located at the Northern Indiana Public Service Company`s Bailly Generating Station, about 12 miles northeast of Gary, Indiana.

  9. Influence of Fe loadings on desulfurization performance of activated carbon treated by nitric acid.

    Science.gov (United States)

    Guo, Jia-Xiu; Shu, Song; Liu, Xiao-Li; Wang, Xue-Jiao; Yin, Hua-Qiang; Chu, Ying-Hao

    2017-02-01

    A series of Fe supported on activated carbon treated by nitric acid are prepared by incipient wetness impregnation with ultrasonic assistance and characterized by N2 adsorption-desorption, X-ray diffraction, Fourier transform infrared spectrum and X-ray photoelectron spectroscopy. It has shown that Fe loadings significantly influence the desulfurization activity. Fe/NAC5 exhibits an excellent removal ability of SO2, corresponding to breakthrough sulfur capacity of 323 mg/g. With the increasing Fe loadings, the generated Fe3O4 and Fe2SiO4 increase, but Fe2(SO4)3 is observed after desulfurization. Fe/NAC1 has a Brunauer-Emmett-Teller (BET) surface area of 925 m(2)/g with micropore surface area of 843 m(2)/g and total pore volume of 0.562 cm(3)/g including a micropore volume of 0.300 cm(3)/g. With the increasing Fe loadings, BET surface area and micropore volume decrease, and those of Fe/NAC10 decrease to 706 m(2)/g and 0.249 cm(3)/g. The Fe loadings influence the pore-size distribution, and SO2 adsorption mainly reacts in micropores at about 0.70 nm. C=O and C-O are observed for all samples before SO2 removal. After desulfurization, the C-O stretching is still detected, but the C=O stretching vibration of carbonyl groups disappears. The stretching of S-O or S=O in sulfate is observed at 592 cm(-1) for the used sample, proving that the existence of [Formula: see text].

  10. Phytane from chemolytic analysis of modern marine sediments: A product of desulfurization or not?

    Science.gov (United States)

    Prahl, F. G.; Pinto, L. A.; Sparrow, M. A.

    1996-03-01

    A set of modern marine sediments was analyzed to evaluate the role of sulfurization as a mechanism for biomarker preservation during early diagenesis. The set consisted of sediments accumulating within various oxic to anoxic depositional environments. Raney nickel treatment of the polar fraction of total extractable lipids (pTEL) from each sample yielded 3,7,11,15-tetramethylhexadecane ('phytane') as the dominant product, accompanied in several cases by minor levels of C 27, C 28, and C 29 5 α/ β(H)-steranes, n-C 31 alkane, and β-carotane. Although others have ascribed such products to a desulfurization reaction, our work reveals significant production of phytane from the action of Raney nickel on the esterified side chain of chlorophyll. Results suggest that catalytic dehydration/hydrogenation of chlorophyll accounts for ~50 and ~4% of the Raney nickel phytane (rnPhy) yield measured in suboxic sediments from the Washington shelf and anoxic sediments from Saanich Inlet, respectively. If 8-20% of the pheopigment detected in the suboxic sediments and all of the pheopigment detected in the anoxic sediment exists as pheophytin, the catalytic dehydration/hydrogenation process would account for 100 and 50%, respectively, of the observed rnPhy yield. The collective findings from our work underscore the necessity to exercise extreme caution when interpreting the geochemical significance of hydrocarbon products from Raney nickel treatment of pTEL from sediments. Despite the organic chemical fact that Raney nickel is a well-known desulfurizing agent, desulfurization cannot be assigned necessarily as the source of hydrocarbons generated by the action of this reagent on complex lipid extracts from sediments, particularly those from modern environments.

  11. Adsorptive desulfurization with CPO-27/MOF-74: an experimental and computational investigation.

    Science.gov (United States)

    Van de Voorde, Ben; Hezinová, Markéta; Lannoeye, Jeroen; Vandekerkhove, Annelies; Marszalek, Bartosz; Gil, Barbara; Beurroies, Isabelle; Nachtigall, Petr; De Vos, Dirk

    2015-04-28

    By combining experimental adsorption isotherms, microcalorimetric data, infrared spectroscopy and quantum chemical calculations the adsorption behaviour of the CPO-27/MOF-74 series (Ni, Co, Mg, Cu, and Zn) in the desulfurization of fuels is evaluated. The results show a clear influence of the metal ion on the adsorption capacity and affinity for S-heterocyclic compounds, with CPO-27(Ni) being the best performing material both in terms of capacity and affinity. The microcalorimetric data and infrared spectroscopy confirm the high affinity of CPO-27(Ni) for thiophene and similar compounds, while the computational data reveal that the origin of this outstanding adsorption performance is the strong sulfur-metal interaction.

  12. Viable Cell Culture Banking for Biodiversity Characterization and Conservation.

    Science.gov (United States)

    Ryder, Oliver A; Onuma, Manabu

    2018-02-15

    Because living cells can be saved for indefinite periods, unprecedented opportunities for characterizing, cataloging, and conserving biological diversity have emerged as advanced cellular and genetic technologies portend new options for preventing species extinction. Crucial to realizing the potential impacts of stem cells and assisted reproductive technologies on biodiversity conservation is the cryobanking of viable cell cultures from diverse species, especially those identified as vulnerable to extinction in the near future. The advent of in vitro cell culture and cryobanking is reviewed here in the context of biodiversity collections of viable cell cultures that represent the progress and limitations of current efforts. The prospects for incorporating collections of frozen viable cell cultures into efforts to characterize the genetic changes that have produced the diversity of species on Earth and contribute to new initiatives in conservation argue strongly for a global network of facilities for establishing and cryobanking collections of viable cells.

  13. Status of METC investigations of coal gas desulfurization at high temperature. [Zinc ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, G.

    1984-03-01

    This report documents the continuing effort at the US Department of Energy/Morgantown Energy Technology Center (METC) to develop a hot-gas desulfurization process for coal-derived gas, primarily for application to molten carbonate fuel cells. Metal oxide sorbents were tested on lab-scale test equipment, and it was determined that scale-up of the process was warranted. A larger, skid-mounted test unit was therefore designed, constructed, and installed on a sidestream of the DOE/METC fixed-bed gasifier. A first series of tests was conducted during Gasifier Run 101. These tests served to shake down the test unit, and provide data on the performance of the test unit operating on coal-derived gas. Overall, the process operated well on fixed-bed, air-blown gasifier gas. Sulfur levels in exit dry gas were reduced to less than 10 ppM. Regeneration appears to restore the sulfur-removing capacity of the sorbent. Sorbent integrity was maintained during the test period, which incorporated three sulfidations. It is recommended that treatment of the regeneration offgas be investigated, and that testing and development of a system to reduce the sulfur in this gas to elemental sulfur be initiated. In addition, it is suggested that a multiple reactor system be planned for continuous operation, to allow for long-term tests of downstream users of desulfurized gas. 7 references, 18 figures, 9 tables.

  14. The Stability of Lubricant Oil Acidity of Biogas Fuelled Engine due to Biogas Desulfurization

    Science.gov (United States)

    Gde Tirta Nindhia, Tjokorda; Wayan Surata, I.; Wardana, Ari

    2017-05-01

    This research is established for the purpose of the understanding the stability of the acidity of lubricant oil in biogas fuelled engine due to the absence of hydrogen sulfide (H2S). As was recognized that other than Methane (CH4), there are also other gas impurities in the biogas such as carbon dioxide (CO2), hydrogen sulfide (H2S), moisture (H2O) and ammonia (NH3). Due to H2S contents in the biogas fuel, the engine was found failure. This is caused by corrosion in the combustion chamber due to increase of lubricant acidity. To overcome this problem in practical, the lubricant is increased the pH to basic level with the hope will be decrease to normal value after several time use. Other method is by installing pH measurement sensor in the engine lubricant so that when lubricant is known turn to be acid, then lubricant replacement should be done. In this research, the effect of biogas desulfurization down to zero level to the acidity of lubricant oil in the four stroke engine was carried out with the hope that neutral lubrication oil to be available during running the engine. The result indicates that by eliminating H2S due desulfurization process, effect on stability and neutrality of pH lubricant. By this method the engine safety can be obtained without often replacement the lubricant oil.

  15. Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuna, E-mail: zhangshujuan@tust.edu.cn [College of Textile Engineering, Zhejiang Industry Polytechnic College, Shaoxing 312000 (China); Zhang, Shujuan [College of Science, Tianjin University of Science and Technology, Tianjin 300457 (China); Song, Limin, E-mail: tjpu2012@sohu.com [College of Environment and Chemical Engineering and State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China); Wu, Xiaoqing [Institute of Composite Materials and Ministry of Education Key Laboratory of Advanced Textile Composite Materials, Tianjin Polytechnic University, Tianjin 300387 (China); Fang, Sheng, E-mail: songlmnk@sohu.com [College of Environment and Chemical Engineering and State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin 300387 (China)

    2014-05-01

    Graphical abstract: Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance. - Highlights: • Three-dimensional Ni{sub 2}P has been prepared using foam nickel as a template. • The microstructures interconnected and formed sponge-like porous networks. • Three-dimensional Ni{sub 2}P shows superior hydrodesulfurization activity. - Abstract: Three-dimensional microstructured nickel phosphide (Ni{sub 2}P) was fabricated by the reaction between foam nickel (Ni) and phosphorus red. The as-prepared Ni{sub 2}P samples, as interconnected networks, maintained the original mesh structure of foamed nickel. The crystal structure and morphology of the as-synthesized Ni{sub 2}P were characterized by X-ray diffraction, scanning electron microscopy, automatic mercury porosimetry and X-ray photoelectron spectroscopy. The SEM study showed adjacent hollow branches were mutually interconnected to form sponge-like networks. The investigation on pore structure provided detailed information for the hollow microstructures. The growth mechanism for the three-dimensionally structured Ni{sub 2}P was postulated and discussed in detail. To investigate its catalytic properties, SiO{sub 2} supported three-dimensional Ni{sub 2}P was prepared successfully and evaluated for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). DBT molecules were mostly hydrogenated and then desulfurized by Ni{sub 2}P/SiO{sub 2}.

  16. Land application uses for dry flue gas desulfurization by-products: Phase 3

    Energy Technology Data Exchange (ETDEWEB)

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.

    1999-01-31

    New flue gas desulfurization (FGD) scrubbing technologies create a dry, solid by-product material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Generally, dry FGD by-products are treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing. Provided the environmental impacts are socially and scientifically acceptable, beneficial uses via recycling can provide economic benefits to both the producer and the end user of the FGD. A study titled ''Land Application Uses for Dry Flue Gas Desulfurization By-Products'' was initiated in December, 1990 to develop and demonstrate large volume, beneficial uses of FGD by-products. Phase 1 and Phase 2 reports have been published by the Electric Power Research Institute (EPRI), Palo Alto, CA. Phase 3 objectives were to demonstrate, using field studies, the beneficial uses of FGD by-products (1) as an amendment material on agricultural lands and on abandoned surface coal mine land, (2) as an engineering material for soil stabilization and raid repair, and (3) to assess the environmental and economic impacts of such beneficial uses. Application of dry FGD by-product to three soils in place of agricultural limestone increased alfalfa (Medicago sativa L.) and corn (Zea may L.) yields. No detrimental effects on soil and plant quality were observed.

  17. Thermostabilization of desulfurization enzymes from Rhodococcos sp. IGTS8. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    John J. Kilbane II

    2000-12-15

    The objective of this project was to develop thermophilic cultures capable of expressing the desulfurization (dsz) operon of Rhodococcus sp. IGTS8. The approaches taken in this project included the development of plasmid and integrative expression vectors that function well in Thermus thermophilus, the cloning of Rhodococcus dsz genes in Thermus expression vectors, and the isolation of bacterial cultures that express the dsz operon at thermophilic temperatures. This project has resulted in the development of plasmid and integrative expression vectors for use in T. thermophilus. The dsz genes have been expressed at moderately thermophilic temperatures (52 C) in Mycobacterium phlei and at temperatures as high as 72 C in T. thermophilus. The tools and methods developed in this project will be generally useful for the expression of heterologous genes in Thermus. Key developments in the project have been the isolation of a Mycobacterium phlei culture capable of expressing the desulfurization operon at 52 C, development of plasmid and integrative expression vectors for Thermus thermophilus, and the development of a host-vector system based on the malate dehydrogenase gene that allows plasmids to be stably maintained in T. thermophilus and provides a convenient reporter gene for the accurate quantification of gene expression. Publications have been prepared regarding each of these topics; these preprints are included.

  18. Oxidative desulfurization of model diesel via dual activation by a protic ionic liquid.

    Science.gov (United States)

    Lü, Hongying; Wang, Shunan; Deng, Changliang; Ren, Wanzhong; Guo, Baocun

    2014-08-30

    A novel and green carboxylate-anion-based protic ionic liquid (PIL), [Hnmp]HCOO, was prepared through a simple and atom economic neutralization reaction between N-methyl-2-pyrrolidonium (NMP) and formic acids. Both FT-IR spectra and (1)H NMR confirmed its simple salt structure. [Hnmp]HCOO exhibited so high catalytic activity that the dibenzothiophene (DBT) removal reached 99% at 50°C in 3h under conditions of VPIL/Vmodel oil=1:10 and H2O2/DBT (O/S, molar ratio)=5. The catalytic oxidation reactivity of S-compounds was found to be in the order of DBT>4,6-dimethyldibenzothiophene (4,6-DMDBT)>benzothiophene (BT). The investigation on mechanism showed that oxidative desulfurization was realized through dual activation of PIL. Moreover, [Hnmp]HCOO can be recycled for five times with an unnoticeable decrease in desulfurization activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Desulfurization of Cysteine-Containing Peptides Resulting from Sample Preparation for Protein Characterization by MS

    Science.gov (United States)

    Wang, Zhouxi; Rejtar, Tomas; Zhou, Zhaohui Sunny; Karger, Barry L.

    2010-01-01

    In this paper, we have examined two cysteine modifications resulting from sample preparation for protein characterization by MS: (1) a previously observed conversion of cysteine to dehydroalanine, now found in the case of disulfide mapping and (2) a novel modification corresponding to conversion of cysteine to alanine. Using model peptides, the conversion of cysteine to dehydroalanine via β-elimination of a disulfide bond was seen to result from the conditions of typical tryptic digestion (37 °C, pH 7.0– 9.0) without disulfide reduction and alkylation.. Furthermore, the surprising conversion of cysteine to alanine was shown to occur by heating cysteine containing peptides in the presence of a phosphine (TCEP). The formation of alanine from cysteine, investigated by performing experiments in H2O or D2O, suggested a radical-based desulfurization mechanism unrelated to β-elimination. Importantly, an understanding of the mechanism and conditions favorable for cysteine desulfurization provides insight for the establishment of improved sample preparation procedures of protein analysis. PMID:20049891

  20. Ultrasound-assisted oxidative desulfurization and denitrogenation of liquid hydrocarbon fuels: A critical review.

    Science.gov (United States)

    Ja'fari, Mahsa; Ebrahimi, Seyedeh Leila; Khosravi-Nikou, Mohammad Reza

    2018-01-01

    Nowadays, a continuously worldwide concern for development of process to produce ultra-low sulfur and nitrogen fuels have been emerged. Typical hydrodesulfurization and hydrodenitrogenation technology deals with important difficulties such as high pressure and temperature operating condition, failure to treat some recalcitrant compounds and limitations to meet the stringent environmental regulations. In contrary an advanced oxidation process that is ultrasound assisted oxidative desulfurization and denitrogenation satisfies latest environmental regulations in much milder conditions with more efficiency. The present work deals with a comprehensive review on findings and development in the ultrasound assisted oxidative desulfurization and denitrogenation (UAOD) during the last decades. The role of individual parameters namely temperature, residence time, ultrasound power and frequency, pH, initial concentration and types of sulfur and nitrogen compounds on the efficiency are described. What's more another treatment properties that is role of phase transfer agent (PTA) and solvents of extraction step, reaction kinetics, mechanism of the ultrasound, fuel properties and recovery in UAOD are reviewed. Finally, the required future works to mature this technology are suggested. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A potassium tert-butoxide and hydrosilane system for ultra-deep desulfurization of fuels

    Science.gov (United States)

    Toutov, Anton A.; Salata, Mike; Fedorov, Alexey; Yang, Yun-Fang; Liang, Yong; Cariou, Renan; Betz, Kerry N.; Couzijn, Erik P. A.; Shabaker, John W.; Houk, Kendall N.; Grubbs, Robert H.

    2017-02-01

    Hydrodesulfurization (HDS) is the process by which sulfur-containing impurities are removed from petroleum streams, typically using a heterogeneous, sulfided transition metal catalyst under high H2 pressures and temperatures. Although generally effective, a major obstacle that remains is the desulfurization of highly refractory sulfur-containing heterocycles, such as 4,6-dimethyldibenzothiophene (4,6-Me2DBT), which are naturally occurring in fossil fuels. Homogeneous HDS strategies using well-defined molecular catalysts have been designed to target these recalcitrant S-heterocycles; however, the formation of stable transition metal sulfide complexes following C-S bond activation has largely prevented catalytic turnover. Here we show that a robust potassium (K) alkoxide (O)/hydrosilane (Si)-based ('KOSi') system efficiently desulfurizes refractory sulfur heterocycles. Subjecting sulfur-rich diesel (that is, [S] ∼ 10,000 ppm) to KOSi conditions results in a fuel with [S] ∼ 2 ppm, surpassing ambitious future governmental regulatory goals set for fuel sulfur content in all countries.

  2. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor.

    Science.gov (United States)

    Montebello, Andrea M; Mora, Mabel; López, Luis R; Bezerra, Tercia; Gamisans, Xavier; Lafuente, Javier; Baeza, Mireia; Gabriel, David

    2014-09-15

    Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H2S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130s, H2S loading rate of 52gS-H2Sm(-3)h(-1) and pH 2.50-2.75. The EBRT reduction showed that the critical EBRT was 75s and the maximum EC 100gS-H2Sm(-3)h(-1). Stepwise increases of the inlet H2S concentration up to 10,000 ppmv lead to a maximum EC of 220gS-H2Sm(-3)h(-1). The H2S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70-80% of the total H2S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H2S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H2S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Desulfurization of 4-methyl dibenzothiophene using titanium supported Keggin type polyoxometalate

    Science.gov (United States)

    Lesbani, Aldes; Anggraini, Ana; Mohadi, Risfidian; Rohendi, Dedi; Said, Muhammad

    2017-03-01

    Titanium supported Keggin type polyoxometalate H5PV2Mo10O40.nH2O has been prepared using tetra isopropyl orthotitanate by sol-gel method and microemulsion to form H5PV2Mo10O40/TiO2. Compound H5PV2Mo10O40.nH2O/TiO2 was characterized using FTTR spectroscopy, X-Ray analysis, and acidity measurement. FTTR spectrum showed that all vibration of titanium and polyoxometalate were appeared in H5PV2Mo10O40.nH2O/TiO2 with decreasing crystallinity. The acidity of H5PV2Mo10O40.nH2O/TiO2 was higher than H5PV2Mo10O40.nH2O. Desulfurization of 4-methyl dibenzothiophene (4-MDBT) using H5PV2Mo10O40.nH2O/TiO2 as catalyst resulted conversion of 4-MDBT was 99% and higher than desulfurization using H5PV2Mo10O40.nH2O under mild conditions.

  4. Effects of foaming and antifoaming agents on the performance of a wet flue gas desulfurization pilot plant

    DEFF Research Database (Denmark)

    Qin, Siqiang; Hansen, Brian Brun; Kiil, Søren

    2014-01-01

    Foaming is a common phenomenon in industrial processes, including wet flue gas desulfurization (FGD) plants. A systemic investigation of the influence of two foaming agents, sodium dodecyl sulphate (SDS) and egg white albumin (protein), and two commercial antifoams on a wet FGD pilot plant...

  5. Synthesis, Characterization and Application of 1-Butyl-3 Methylimidazolium Chloride as Green Material for Extractive Desulfurization of Liquid Fuel

    Directory of Open Access Journals (Sweden)

    Swapnil A. Dharaskar

    2013-01-01

    Full Text Available The possible application of imidazolium ionic liquids as energy-efficient green material for extractive deep desulfurization of liquid fuel has been investigated. 1-Butyl-3-methylimidazolium chloride [BMIM]Cl was synthesized by nucleophilic substitution reaction of n-methylimidazolium and 1-chlorobutane. Molecular structures of the ILs were confirmed by FTIR, 1H-NMR, and 13C-NMR. The thermal properties, conductivity, solubility, water content and viscosity analysis of [BMIM]Cl were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of IL without regeneration on dibenzothiophene removal of liquid fuel were presented. In the extractive desulfurization process, the removal of dibenzothiophene in n-dodecane using [BMIM]Cl was 81% with mass ratio of 1 : 1, in 30 min at 30°C under the mild reaction conditions. Also, desulfurization of real fuels with IL and multistage extraction were studied. The results of this work might offer significant insights in the perceptive use of imidazoled ILs as energy-efficient green material for extractive deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency.

  6. Mercury emission and plant uptake of trace elements during early stage of soil amendment using flue gas desulfurization materials.

    Science.gov (United States)

    A pilot-scale field study was carried out to investigate the distribution of Hg and other selected elements in the three potential mitigation pathways, i.e., emission to ambient air, uptake by surface vegetation (i.e., grass), and rainfall infiltration, after flue gas desulfurization (FGD) material ...

  7. Desulfurization characteristics of rapidly hydrated sorbents with various adhesive carrier particles for a semidry CFB-FGD system.

    Science.gov (United States)

    You, Changfu; Li, Yuan

    2013-03-19

    Semidry flue gas desulfurization (FGD) experiments were conducted using rapidly hydrated sorbents with four different adhesive carrier particles: circulation ash from a circulating fluidized bed boiler (CFBB circulation ash), fly ash from the first electrical field of the electrostatic precipitator of a circulating fluidized bed boiler (CFBB ESP ash), fly ash from a chain boiler (chain boiler ash), and river sand smaller than 1 mm. The influences of various adhesive carrier particles and operating conditions on the desulfurization characteristics of the sorbents were investigated, including sprayed water, reaction temperature, and the ratio of calcium to sulfur (Ca/S). The experimental results indicated that the rapidly hydrated sorbents had better desulfurization characteristics by using adhesive carrier particles which possessed better pore, adhesion, and fluidization characteristics. The desulfurization efficiency of the system increased as the reaction temperature decreased, it improved from 35% to 90% as the mass flow rate of the sprayed water increased from 0 to 10 kg/h, and it increased from 65.6% to 82.7% as Ca/S increased from 1.0 to 2.0. Based on these findings, a new semidry circulating fluidized bed (CFB)-FGD system using rapidly hydrated sorbent was developed. Using the rapidly hydrated sorbent, this system uses a cyclone separator instead of an ESP or a bag filter to recycle the sorbent particles, thereby decreasing the system flow resistance, saving investment and operating costs of the solids collection equipment.

  8. Structural Elucidation of DNA-Protein Crosslinks Using Reductive Desulfurization and Liquid Chromatography-Tandem Mass Spectrometry

    Science.gov (United States)

    Wickramaratne, Susith

    2014-01-01

    Structural characterization of DNA-protein crosslinks involving cysteine using reductive desulfurization in combination with liquid chromatography-tandem mass spectrometry is highlighted. The novel approach was used to identify hydrolytically stable DNA-protein lesions involving alkylguanine DNA alkyltransferase (AGT). PMID:24436288

  9. Synthesis, characterization and application of 1-butyl-3 methylimidazolium chloride as green material for extractive desulfurization of liquid fuel.

    Science.gov (United States)

    Dharaskar, Swapnil A; Varma, Mahesh N; Shende, Diwakar Z; Yoo, Chang Kyoo; Wasewar, Kailas L

    2013-01-01

    The possible application of imidazolium ionic liquids as energy-efficient green material for extractive deep desulfurization of liquid fuel has been investigated. 1-Butyl-3-methylimidazolium chloride [BMIM]Cl was synthesized by nucleophilic substitution reaction of n-methylimidazolium and 1-chlorobutane. Molecular structures of the ILs were confirmed by FTIR, (1)H-NMR, and (13)C-NMR. The thermal properties, conductivity, solubility, water content and viscosity analysis of [BMIM]Cl were carried out. The effects of reaction time, reaction temperature, sulfur compounds, and recycling of IL without regeneration on dibenzothiophene removal of liquid fuel were presented. In the extractive desulfurization process, the removal of dibenzothiophene in n-dodecane using [BMIM]Cl was 81% with mass ratio of 1 : 1, in 30 min at 30°C under the mild reaction conditions. Also, desulfurization of real fuels with IL and multistage extraction were studied. The results of this work might offer significant insights in the perceptive use of imidazoled ILs as energy-efficient green material for extractive deep desulfurization of liquid fuels as it can be reused without regeneration with considerable extraction efficiency.

  10. High H2O-resistance CaO-MnOx/MSU-H sorbents for hot coal gas desulfurization.

    Science.gov (United States)

    Xia, Hong; Liu, Bingsi

    2017-02-15

    A series of xMnyCa/MSU-H sorbents with various Mn/Ca molar ratio were first designed and synthesized with a sol-gel method. The desulfurization performance of the new sorbent was investigated at 600-800°C in hot coal gas. 90Mn10Ca/MSU-H exhibited better desulfurization performance at 750°C with a breakthrough sulfur capacity (BSC) of 18.69g S/100g sorbent compared to other supported Mn-based sorbents (13.2g S/100g sorbent) in similar desulfurization condition, and strong durability in multiple sulfidation-regeneration cycles using oxidation/reduction regeneration method which resolved the scientific issue of that CaSO4 is hardly decomposed to CaO. The introduction of Ca species effectively promoted the dispersion of active constituents, which improved the desulfurization activity. More importantly, 90Mn10Ca/MSU-H showed excellent H2O-resistance ability due to the fact that CaO enhanced the sorption of H2O. Moreover, the utilization of MSU-H with large pore size and excellent thermal stability effectively assured fast mass-transfer and confined the migration of active particles, which led to long lifetime stability of sorbents. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Impact of Leaching Conditions on Constituents Release from Flue Gas Desulfurization Gypsum (FGDG) and FGDG-Soil Mixture

    Science.gov (United States)

    The interest in using Flue Gas Desulfurization Gypsum(FGDG) has increased recently. This study evaluates the leaching characteristics of trace elements in "modern" FGDG (produced after fly ash removal) and FGDG-mixed soil (SF) under different environmental conditions using rece...

  12. Deep desulfurization by amphiphilic lanthanide-containing polyoxometalates in ionic-liquid emulsion systems under mild conditions.

    Science.gov (United States)

    Xu, Junhua; Zhao, Shen; Ji, Yuanchun; Song, Yu-Fei

    2013-01-07

    Amphiphilic lanthanide-containing polyoxometalates (POMs) were prepared by surfactant encapsulation. Investigation of these lanthanide-containing POMs in oxidative desulfurization (ODS) showed that highly efficient deep desulfurization could be achieved in only 14 min with 100% conversion of dibenzothiophene under mild conditions by using (DDA)(9)LaW(10)/[omim]PF(6) (DDA=dimethyldioctadecylammonium, omim=1-octyl-3-methyl-imidazolium) in the presence of H(2) O(2) . Furthermore, deep desulfurization proceeds smoothly in model oil with an S content as low as 50 ppm. A scaled-up experiment in which the volume of model oil was increased from 5 to 1000 mL with S content of 1000 ppm indicated that about 99% sulfur removal can be achieved in 40 mins in an ionic-liquid emulsion system. To the best of our knowledge, the (DDA)(9)LaW(10)/[omim]PF(6) catalyst system with H(2)O(2) as oxidant is one of the most efficient desulfurization systems reported so far. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A green surfactant-assisted synthesis of hierarchical TS-1 zeolites with excellent catalytic properties for oxidative desulfurization.

    Science.gov (United States)

    Du, Shuting; Li, Fen; Sun, Qiming; Wang, Ning; Jia, Mingjun; Yu, Jihong

    2016-02-25

    Hierarchical TS-1 zeolites with uniform intracrystalline mesopores have been successfully synthesized through the hydrothermal method by using the green and cheap surfactant Triton X-100 as the mesoporous template. The resultant materials exhibit remarkably enhanced catalytic activity in oxidative desulfurization reactions compared to the conventional TS-1 zeolite.

  14. Experimental design for the optimization of propidium monoazide treatment to quantify viable and non-viable bacteria in piggery effluents.

    Science.gov (United States)

    Desneux, Jérémy; Chemaly, Marianne; Pourcher, Anne-Marie

    2015-08-16

    Distinguishing between viable and dead bacteria in animal and urban effluents is a major challenge. Among existing methods, propidium monoazide (PMA)-qPCR is a promising way to quantify viable cells. However, its efficiency depends on the composition of the effluent, particularly on total suspended solids (TSS)) and on methodological parameters. The aim of this study was evaluate the influence of three methodological factors (concentration of PMA, incubation time and photoactivation time) on the efficiency of PMA-qPCR to quantify viable and dead cells of Listeria monocytogenes used as a microorganism model, in two piggery effluents (manure and lagoon effluent containing 20 and 0.4 TSS g.kg(-1), respectively). An experimental design strategy (Doehlert design and desirability function) was used to identify the experimental conditions to achieve optimal PMA-qPCR results. The quantification of viable cells of L. monocytogenes was mainly influenced by the concentration of PMA in the manure and by the duration of photoactivation in the lagoon effluent. Optimal values differed with the matrix: 55 μM PMA, 5 min incubation and 56 min photoactivation for manure and 20 μM PMA, 20 min incubation and 30 min photoactivation for lagoon effluent. Applied to five manure and four lagoon samples, these conditions resulted in satisfactory quantification of viable and dead cells. PMA-qPCR can be used on undiluted turbid effluent with high levels of TSS, provided preliminary tests are performed to identify the optimal conditions.

  15. THERMODYNAMIC AND KINETIC PARAMETERS OF MIXTURES DESULFURIZING THE MADE WITH CaO, MgO, SiO2 AND CaF2

    Directory of Open Access Journals (Sweden)

    Felipe Nylo de Aguiar

    2012-09-01

    Full Text Available This paper presents an analysis of the kinetics and thermodynamics of marble residue mixtures utilisation on desulfurization of pig iron. The desulfurization was carried out using lime, marble residue, fluorite and pig iron. Different mixtures of these materials were added into a bath of pig iron at 1,450°C. Metal samples were collected via vacuum samplers at times of 5, 10, 15, 20 and 30 minutes, in order to check the variation of sulfur content. Based on the results of chemical analysis of the metal and the desulfurizer mixture, the sulfide capacity of mixtures, the sulfur partition coefficient and the sulfur mass transport coefficient values were calculated.The results show the technical feasibility of using marble waste as desulfurizer agent.

  16. Experimental study and mechanism analysis of modified limestone by red mud for improving desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hongtao; Han, Kuihua; Niu, Shengli; Lu, Chunmei; Liu, Mengqi; Li, Hui [Shandong Univ., Jinan (China). School of Energy and Power Engineering

    2013-07-01

    Red mud is a type of solid waste generated during alumina production from bauxite, and how to dispose and utilize red mud in a large scale is yet a question with no satisfied answer. This paper attempts to use red mud as a kind of additive to modify the limestone. The enhancement of the sulfation reaction of limestone by red mud (two kinds of Bayer process red mud and one kind of sintering process red mud) are studied by a tube furnace reactor. The calcination and sulfation process and kinetics are investigated in a thermogravimetric (TG) analyzer. The results show that red mud can effectively improve the desulfurization performance of limestone in the whole temperature range (1,073-1,373K). Sulfur capacity of limestone (means quality of SO{sub 2} which can be retained by 100mg of limestone) can be increased by 25.73, 7.17 and 15.31% while the utilization of calcium can be increased from 39.68 to 64.13%, 60.61 and 61.16% after modified by three kinds of red mud under calcium/metallic element (metallic element described here means all metallic elements which can play a catalytic effect on the sulfation process, including the Na, K, Fe, Ti) ratio being 15, at the temperature of 1,173K. The structure of limestone modified by red mud is interlaced and tridimensional which is conducive to the sulfation reaction. The phase composition analysis measured by XRD of modified limestone sulfated at high temperature shows that there are correspondingly more sulphates for silicate and aluminate complexes of calcium existing in the products. Temperature, calcium/metallic element ratio and particle diameter are important factors as for the sulfation reaction. The optimum results can be obtained as calcium/metallic element ratio being 15. Calcination characteristic of limestone modified by red mud shows a migration to lower temperature direction. The enhancement of sulfation by doping red mud is more pronounced once the product layer has been formed and consequently the promoting

  17. Aerobic desulfurization of biogas by acidic biotrickling filtration in a randomly packed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Montebello, Andrea M.; Mora, Mabel; López, Luis R.; Bezerra, Tercia [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gamisans, Xavier [Department of Mining Engineering and Natural Resources, Universitat Politècnica de Catalunya, Bases de Manresa 61-73, 08240 Manresa (Spain); Lafuente, Javier [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Baeza, Mireia [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Gabriel, David, E-mail: david.gabriel@uab.cat [Department of Chemical Engineering, School of Engineering, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2014-09-15

    Highlights: • Desulfurization of high loads of H{sub 2}S is feasible by acidic biotrickling filtration. • Robustness of the process is demonstrated in the long-term (550 d). • Biosulfur to sulfate oxidation under H{sub 2}S starvation was successfully performed. • Lower sulfate production found at acidic pH compared to that at neutral pH. • Plastic material is recommended for long-term acidic biotrickling filtration. - Abstract: Biotrickling filters for biogas desulfurization still must prove their stability and robustness in the long run under extreme conditions. Long-term desulfurization of high loads of H{sub 2}S under acidic pH was studied in a lab-scale aerobic biotrickling filter packed with metallic Pall rings. Reference operating conditions at steady-state corresponded to an empty bed residence time (EBRT) of 130 s, H{sub 2}S loading rate of 52 g S–H{sub 2}S m{sup −3} h{sup −1} and pH 2.50–2.75. The EBRT reduction showed that the critical EBRT was 75 s and the maximum EC 100 g S–H{sub 2}S m{sup −3} h{sup −1}. Stepwise increases of the inlet H{sub 2}S concentration up to 10,000 ppm{sub v} lead to a maximum EC of 220 g S–H{sub 2}S m{sup −3} h{sup −1}. The H{sub 2}S removal profile along the filter bed indicated that the first third of the filter bed was responsible for 70–80% of the total H{sub 2}S removal. The oxidation rate of solid sulfur accumulated inside the bioreactor during periodical H{sub 2}S starvation episodes was verified under acidic operating conditions. The performance under acidic pH was comparable to that under neutral pH in terms of H{sub 2}S removal capacity. However, bioleaching of the metallic packing used as support and chemical precipitation of sulfide/sulfur salts occurred.

  18. The search for viable local government system in Nigeria: an ...

    African Journals Online (AJOL)

    The history of the Nigerian local government system has been one long episode of trails and errors aimed at achieving viable local government institution without much success. Local government in the country began its long series of reforms from the colonial period when the colonial government attempted to ...

  19. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for polymerase chain ...

  20. Comment: Towards a Viable Local Government Structure in Nigeria ...

    African Journals Online (AJOL)

    Local governments are principally established for development at the grassroots and they must be structured in a manner that makes them viable and capable of achieving this purpose. The objective of this comment is to appraise the current local government structure under the Nigerian constitutional framework with a view ...

  1. Cultivation and multiplication of viable axenic Trypanosoma vivax in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... Cultivation and multiplication of viable axenic. Trypanosoma vivax in vitro and in vivo. O. A. Idowu, A. B. Idowu, C. F. Mafiana and S. O. Sam-Wobo*. Parasitology Laboratory, Department of Biological Sciences, University of Agriculture, Abeokuta, Nigeria. Accepted 13 April, 2006. Trypanosoma vivax was ...

  2. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    DRINIE

    2003-04-02

    Apr 2, 2003 ... A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for ...

  3. High speed flow cytometric separation of viable cells

    Science.gov (United States)

    Sasaki, Dennis T.; Van den Engh, Gerrit J.; Buckie, Anne-Marie

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  4. Plant and soil responses to field-applied flue gas desulfurization residue

    Energy Technology Data Exchange (ETDEWEB)

    Sloan, J.J.; Dowdy, R.H.; Dolan, M.S.; Rehm, G.W. [University of Minnesota, St. Paul, MN (United States). Dept. of Soil, Water and Climate, USDA-ARS

    1999-01-01

    The objective of this study was to document the availability of flue gas desulfurization (FGD) residue-borne boron (B), sulfur (S), and molybdenum (Mo) for alfalfa (Medicago sativa L.) uptake when applied at agronomic rates to marginally B deficient soils. The FGD residue was applied at rates of 0, 0.46 and 3.75 Mg ha{sup -1} on a silt loam soil immediately prior to alfalfa seeding. Alfalfa yields were unaffected by these rates of residue applications, but shoot concentrations of B and S in the second cutting, and B, S and Mo in the third cutting were increased by residue applications. Hence, FGD residue is a readily available B source, particularly later in the growing season when native soil B availability decreased. 31 refs., 3 figs., 3 tabs.

  5. Microbial desulfurization of gasoline by free whole-cells of Rhodococcus erythropolis XP.

    Science.gov (United States)

    Yu, Bo; Ma, Cuiqing; Zhou, Wenjuan; Wang, Ying; Cai, Xiaofeng; Tao, Fei; Zhang, Quan; Tong, Mingyou; Qu, Jingyao; Xu, Ping

    2006-05-01

    Rhodococcus erythropolis XP could grow well with condensed thiophenes, mono-thiophenic compounds and mercaptans present in gasoline. Rhodococcus erythropolis XP was also capable of efficiently degrading the condensed thiophenes in resting cell as well as biphasic reactions in which n-octane served as a model oil phase. Free whole cells of R. erythropolis XP were adopted to desulfurize fluid catalytic cracking (FCC) and straight-run (SR) gasoline oils. About 30% of the sulfur content of FCC gasoline and 85% of sulfur in SR gasoline were reduced, respectively. Gas chromatography analysis with atomic emission detection also showed depletion of sulfur compounds in SR gasoline. Rhodococcus erythropolis XP could partly resist the toxicity of gasoline and had an application potential to biodesulfurization of gasoline.

  6. A novel [Bmim]PW/HMS catalyst with high catalytic performance for the oxidative desulfurization process

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Ling; Luo, Guangqing; Kang, Lihua; Zhu, Mingyuan; Dai, Bin [Shihezi University, Shihezi (China)

    2013-02-15

    To effectively reduce the sulfur content in model fuel, [Bmim]PW/HMS catalyst was synthesized through impregnating the hexagonal mesoporous silica (HMS) support by phosphotungstic acid (HPW) and ionic liquid [Bmim] HSO{sub 4}. Physical structure characterizations of the catalysts showed that HMS retained mesoporous structure, and [Bmim] PW was well dispersed on the support of HMS. The catalytic activity of the [Bmim]PW/HMS was evaluated in the oxidative desulfurization process, and the optimal reaction conditions including loading of the catalysts, reaction temperature, catalyst amount, O/S (H{sub 2}O{sub 2}/sulfur) molar ratio and agitation speed were investigated. Under the optimal reaction conditions, the conversion of benzothiophene (BT), dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (4, 6-DMDBT) could reach 79%, 98%, 88%, respectively.

  7. Enzymatic desulfurization of coal. Fifth quarterly report, June 16--September 15, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. [DynaGen, Inc., Cambridge, MA (United States); Marquis, J.K. [Boston Univ., MA (United States). School of Medicine

    1989-11-07

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to selectively catalyze oxidation at sulfur.

  8. PET-modified red mud as catalysts for oxidative desulfurization reactions.

    Science.gov (United States)

    do Prado, Nayara T; Heitmann, Ana P; Mansur, Herman S; Mansur, Alexandra A; Oliveira, Luiz C A; de Castro, Cinthia S

    2017-07-01

    This work describes the synthesis of catalysts based on red mud/polyethylene terephthalate (PET) composites and their subsequent heat treatment under N2 atmosphere. The materials were characterized by scanning electron microscopy (SEM), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG) analysis and N2 adsorption/desorption. The catalysts were evaluated in the oxidative desulfurization reaction of dibenzothiophene (DBT) in a biphasic system. The results indicated that the PET impregnation on red mud increased the affinity of the catalyst with the nonpolar phase (fuel), in which the contaminant was dissolved, allowing a higher conversion (up to 80%) and selectivity to the corresponding dibenzothiophene sulfone. The sulfone compound is more polar than DBT and diffused into the polar solvent as indicated by the data obtained via gas chromatography-mass spectrometry (GC-MS). Copyright © 2017. Published by Elsevier B.V.

  9. Screening of active metals for reactive adsorption desulfurization adsorbent using density functional theory

    Science.gov (United States)

    Wang, Lei; Zhao, Liang; Xu, Chunming; Wang, Yuxian; Gao, Jinsen

    2017-03-01

    To explore characteristics of active metals for reactive adsorption desulfurization (RADS) technology, the adsorption of thiophene on M (100) (M = Cr, Mo, Co, Ni, Cu, Au, and Ag) surfaces was systematically studied by density functional theory with vdW correction (DFT + D3). We found that, in all case, the most stable molecular adsorption site was the hollow site and adsorptive capabilities of thiophene followed the order: Cr > Mo > Co ≈ Ni > Cu > Au ≈ Ag. By analyzing the nature of binding between thiophene and corresponding metals and the electronic structure of metals, the excessive activities of Cr and Mo were found to have a negative regeneration, the passive activities of Au and Ag were found to have an inactive adsorption for RADS adsorbent alone, while Ni and Co have appropriate characteristics as the active metals for RADS, followed by Cu.

  10. Carbonation of gypsum from wet flue gas desulfurization process: experiments and modeling.

    Science.gov (United States)

    Tan, Wenyi; Zhang, Zixin; Li, Hongyi; Li, Youxu; Shen, Zewen

    2017-03-01

    In this paper, waste gypsum from wet flue gas desulfurization (WFGD) mixed with NH3·H2O was applied for CO2 absorption in the solid-liquid-gas phase system. The effects of operation temperature, CO2 flow rates, and ammonia-to-gypsum ratio on carbonation process were discussed. Meanwhile, a model for CO2 absorption in the suspension of WFGD gypsum and ammonia was established. The results indicate that higher temperature favors the reaction, and WFGD gypsum conversion can be achieved above 90% even at lower ammonia-to-gypsum ratio, while CO2 conversion reaches 90% and ammonia utilization is up to 83.69%. The model fits well with the experimental results at various CO2 flow rates and predicts the concentration distribution of the main species, including CO2 absorbed, NH2COO(-), and HCO3(-).

  11. Use of flue gas desulfurization gypsum for leaching Cd and Pb in reclaimed tidal flat soil.

    Science.gov (United States)

    Yang, Ping; Li, Xian; Tong, Ze-Jun; Li, Qu-Sheng; He, Bao-Yan; Wang, Li-Li; Guo, Shi-Hong; Xu, Zhi-Min

    2016-04-01

    A soil column leaching experiment was conducted to eliminate heavy metals from reclaimed tidal flat soil. Flue gas desulfurization (FGD) gypsum was used for leaching. The highest removal rates of Cd and Pb in the upper soil layers (0-30 cm) were 52.7 and 30.5 %, respectively. Most of the exchangeable and carbonate-bound Cd and Pb were removed. The optimum FGD gypsum application rate was 7.05 kg·m(-2), and the optimum leaching water amount for the application was 217.74 L·m(-2). The application of FGD gypsum (two times) and the extension of the leaching interval time to 20 days increased the heavy metal removal rate in the upper soil layers. The heavy metals desorbed from the upper soil layers were re-adsorbed and fixed in the 30-70 cm soil layers.

  12. Mechanism of extractive/oxidative desulfurization using the ionic liquid inimidazole acetate: a computational study.

    Science.gov (United States)

    Wang, Hanlu; Xu, Mingsheng; Zhou, Rujin

    2017-02-01

    The dual role of the ionic liquid 1-butyl-3-methyl-imidazolium trifluoroacetic acid ([C4mim]TFA) as an extractant for thiophene (TH) and a catalyst for the oxidation of TH was explored at the molecular level by performing density functional theory (DFT) calculations. The calculated interaction energies demonstrated why [C4mim]TFA is a better extractant for thiophene sulfone (THO2) than for TH. Two pathways were proposed for the oxidation of TH to THO2 with [C4mim]TFA acting as a catalyst. In the dominant pathway, a peracid is formed which then oxidizes TH to the sulfoxide and sulfones. The presence of [C4mim]TFA was found to greatly reduce the barrier to the oxidative desulfurization (ODS) of TH using H2O2 as an oxidant. Graphical Abstract Possible reaction mechanisms of TH with the aid of [C4mim]TFAᅟ.

  13. Controllability analysis and decentralized control of a wet limestone flue gas desulfurization plant

    Energy Technology Data Exchange (ETDEWEB)

    Perales, A.L.V.; Ortiz, F.J.G.; Ollero, P.; Gil, F.M. [University of Seville, Seville (Spain)

    2008-12-15

    Presently, decentralized feedback control is the only control strategy used in wet limestone flue gas desulfurization (WLFGD) plants. Proper tuning of this control strategy is becoming an important issue in WLFGD plants because more stringent SO{sub 2} regulations have come into force recently. Controllability analysis is a highly valuable tool for proper design of control systems, but it has not been applied to WLFGD plants so far. In this paper a decentralized control strategy is designed and applied to a WLFGD pilot plant taking into account the conclusions of a controllability analysis. The results reveal that good SO{sub 2} control in WLFGD plants can be achieved mainly because the main disturbance of the process is well-aligned with the plant and interactions between control loops are beneficial to SO{sub 2} control.

  14. Model predictive control of a wet limestone flue gas desulfurization pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Perales, A.L.V.; Ollero, P.; Ortiz, F.J.G.; Gomez-Barea, A. [University of Seville, Seville (Spain). Dept. of Chemical & Environmental Engineering

    2009-06-15

    A model predictive control (MPC) strategy based on a dynamic matrix (DMC) is designed and applied to a wet limestone flue gas desulfurization (WLFGD) pilot plant to evaluate what enhancement in control performance can be achieved with respect to a conventional decentralized feedback control strategy. The results reveal that MPC can significantly improve both reference tracking and disturbance rejection. For disturbance rejection, the main control objective in WLFGD plants, selection of tuning parameters and sample time, is of paramount importance due to the fast effect of the main disturbance (inlet SO{sub 2} load to the absorber) on the most important controlled variable (outlet flue gas SO{sub 2} concentration). The proposed MPC strategy can be easily applied to full-scale WLFGD plants.

  15. Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Lew, S.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

    1991-10-01

    The overall objective of this project was to investigate the properties of and evaluate mixed oxides of zinc and titanium for hot fuel gas desulfurization. Uncombined ZnO was also investigated as a base case. Detailed investigation of the reduction and sulfidation reactions of Zn-Ti-O sorbents was performed. The intrinsic kinetics and the product layer diffusion rates in reduction and sulfidation were determined. Kinetic experiments with sorbents containing various Zn/Ti atomic ratios were performed. Chemical phase and structural transformations were followed by various methods. The results were compared to similar experiments performed with ZnO. The purpose of these experiments was to determine how the presence of titanium dioxide affects the reduction and sulfidation of ZnO. This information would be used to identify and select the sorbent composition that gives the best combination of low reduction rate and acceptable sulfidation performance at temperatures exceeding 600{degree}C. (VC)

  16. Hot particulate removal and desulfurization results from the METC integrated gasification and hot gas cleanup facility

    Energy Technology Data Exchange (ETDEWEB)

    Rockey, J.M.

    1995-06-01

    The Morgantown Energy Technology Center (METC) is conducting experimental testing using a 10-inch diameter fluid-bed gasifier (FBG) and modular hot gas cleanup rig (MGCR) to develop advanced methods for removing contaminants in hot coal gasifier gas streams for commercial development of integrated gasification combined-cycle (IGCC) power systems. The program focus is on hot gas particulate removal and desulfurization technologies that match the temperatures and pressures of the gasifier, cleanup system, and power generator. The purpose of this poster is to present the program objectives and results of the work conducted in cooperation with industrial users and vendors to meet the vision for IGCC of reducing the capital cost per kilowatt to $1050 and increasing the plant efficiency to 52% by the year 2010.

  17. Coal desulfurization

    Science.gov (United States)

    Corcoran, William H. (Inventor); Vasilakos, Nicholas P. (Inventor); Lawson, Daniel D. (Inventor)

    1982-01-01

    A method for enhancing solubilizing mass transport of reactive agents into and out of carbonaceous materials, such as coal. Solubility parameters of mass transfer and solvent media are matched to individual peaks in the solubility parameter spectrum of coals to enhance swelling and/or dissolution. Methanol containing reactive agent carriers are found particularly effective for removing organic sulfur from coals by chlorinolysis.

  18. Preparation of AAO-CeO2 nanotubes and their application in electrochemical oxidation desulfurization of diesel

    Science.gov (United States)

    Du, Xiaoqing; Yang, Yumeng; Yi, Chenxi; Chen, Yu; Cai, Chao; Zhang, Zhao

    2017-02-01

    The coaxial arrays of AAO-CeO2 NTs have been successfully galvanostatically deposited on an anode, characterized and adopted as a catalyst for removing organic sulfurs from diesel. The influence of the main electrochemical oxidation factors on the efficiency of desulfurization have also been investigated. The results show that the fabrication process of AAO-CeO2 NTs is accompanied by the formation of a new phase, namely Al3Ce, and the main oxidation products of the diesel are soluble inorganic sulphides, especially Ce2(SO4)3. When compared with dibenzothiophene and 4, 6-dimethyldibenzothiophene, benzothiophene is much more easily removed, with a removal efficiency that reaches 87.2%. Finally, a possible electrochemical oxidation desulfurization pathway for diesel is proposed.

  19. Silver nanocrystal-decorated polyoxometalate single-walled nanotubes as nanoreactors for desulfurization catalysis at room temperature.

    Science.gov (United States)

    Zhang, Hao; Xu, Xiaobin; Lin, Haifeng; Ud Din, Muhammad Aizaz; Wang, Haiqing; Wang, Xun

    2017-09-14

    Ultrathin nanocrystals generally provide a remarkable catalytic performance due to their high specific surface area and exposure of certain active sites. However, deactivation caused by growth and gathering limits the catalytic application of ultrathin nanocrystals. Here we report Ag nanocrystal-decorated polyoxometalate (Ag-POM) single-walled nanotubes assembled via a concise, surfactant-free soaking method as a new kind of well-defined core-sheath nanoreactor. The diameter of Ag nanocrystals inside polyoxometalate nanotubes can be controlled via simply adjusting the reactant concentration. Ag-POM provided outstanding oxidative desulfurization (ODS) catalytic performance for aromatic sulfocompounds at room temperature. It was suggested that Ag nanocrystals decorated on the inner surface played a key role in adjusting the electronic distribution and enhancing the catalytic activity. The as-prepared Ag-POM nanotubes are promising candidate catalysts with enhanced performance for practical catalytic applications in the gasoline desulfurization industry.

  20. Degradation and desulfurization of dibenzothiophene sulfone and other sulfur compounds by Agrobacterium MC501 and a mixed culture

    Energy Technology Data Exchange (ETDEWEB)

    Constanti, M.; Giralt, J.; Bordons, A. [Universidad de Rovira y Virgili, Tarragona (Spain). Dept. de Bioquimia y Biotecnologia

    1996-08-15

    Agrobacterium MC501 and the mixed culture composed of Agrobacterium MC501, Xanthomonas MC701, Corynebacterium sp. MC401, and Corynebacterium sp. MC402, all previously isolated from a coal mine area by an enrichment culture with dibenzothiophene (DBT), were used to study DBT sulfone desulfurization. Both cultures were able to use DBT sulfone as a sole source of sulfur for growth. This compound was metabolized to 2-hydroxybiphenyl (2PP) and sulfate. Agrobacterium MC501 and the mixed culture could also utilize a wide range of organic and inorganic sulfur compounds as sources of sulfur such as DBT, thianthrene, diphenylsulfide, thiophene-2-carboxylate, dibutilsulfide, methionine, cysteine, sulfate, and sulfite. Based on these results, the above-mentioned strains can be used to characterize and study coal desulfurization.

  1. Removal of viable bacteria and endotoxins by Electro Deionization (EDI).

    Science.gov (United States)

    Harada, Norimitsu; Otomo, Teruo; Watabe, Tomoichi; Ase, Tomonobu; Takemura, Takuto; Sato, Toshio

    2011-09-01

    Viable bacteria and endotoxins in water sometimes cause problems for human health. Endotoxins are major components of the outer cell wall of gram-negative bacteria (lipopolysaccharides). In medical procedures, especially haemodialysis (HD) and related therapies (haemodiafiltration (HDF), haemofiltration (HF)), endotoxins in the water for haemodialysis can permeate through the haemodialysis membrane and cause microinflammation or various haemodialysis-related illnesses. To decrease such a biological risk, RO and UF membranes are generally used. Also, hot water disinfection or the chemical disinfection is regularly executed to kill bacteria which produce endotoxins. However, simple treatment methods and equipment may be able to decrease the biological risk more efficiently. In our experiments, we confirmed that viable bacteria and endotoxins were removed by Electro Deionization (EDI) technology and also clarified the desorption mechanisms.

  2. Acupuntura un tratamiento viable para las adicciones en Colombia

    Directory of Open Access Journals (Sweden)

    Hernán López Seuscún

    2013-07-01

    Los tratamientos con auriculoterapia, como el protocolo NADA (National Acupuncture Detoxification Association, son los métodos más usados para las adicciones en el mundo, y aunque no se ha logrado evidenciar su efectividad, por su costo, facilidad y el poco riesgo de efectos adversos se hace viable en un país con pocos recursos económicos como Colombia.

  3. Academic Pediatric Dentistry is a Rewarding, Financially Viable Career Path.

    Science.gov (United States)

    Townsend, Janice A; Chi, Donald L

    2017-09-15

    Newly graduated pediatric dentists have unprecedented levels of debt. High levels of student debt may be perceived as an obstacle to pursue an academic career. However, opportunities exist through faculty compensation models and loan repayment programs that make an academic career financially viable. The purpose of this paper is to outline the benefits of a career in academic dentistry and provide examples of young pediatric dentistry faculty members who have been able to manage student debt while pursuing meaningful and rewarding careers.

  4. How Can We Prevent Violence Becoming a Viable Political Strategy?

    OpenAIRE

    Patricia Justino

    2009-01-01

    A basic issue that conflict analysis investigates is how non-peaceful ways of living and governing become viable political strategies. Macro-level studies provide some important insights but micro-level analysis is vital to understand the mechanisms that make violence possible. This briefing outlines some preliminary findings in this respect from MICROCON, a major research programme analysing violent conflict at the micro level. It also discusses their implications for policies aimed at preve...

  5. A novel metabolite (1,3-benzenediol, 5-hexyl) production by Exophiala spinifera strain FM through dibenzothiophene desulfurization.

    Science.gov (United States)

    Elmi, Fatemeh; Etemadifar, Zahra; Emtiazi, Giti

    2015-05-01

    Sulfur dioxide which is released from petroleum oil combustion causes pollution over the atmosphere and the soil. Biodesulfurization can be used as a complementary method of hydrodesulfurization, the common method of petroleum desulfurization in refineries. Many studies have been carried out to develop biological desulfurization of dibenzothiophene (DBT) with bacterial biocatalysts. However, fungi are capable to metabolize a wide range of aromatic hydrocarbons through cytochrome P450 and their extracellular enzymes. The aim of the present work was isolation and identification of fungi biocatalysts capable for DBT utilization as sulfur source and production of novel metabolites. DBT consumption and the related produced metabolites were analyzed by HPLC and GC-MS respectively. One of the isolated fungi that could utilize DBT as sole sulfur source was identified by both traditional and molecular experiments and registered in NCBI as Exophiala spinifera FM strain (accession no. KC952672). This strain could desulfurize 99 % of DBT (0.3 mM) as sulfur source by co-metabolism reaction with other carbon sources through the same pathway as 4S and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30 °C and 180 rpm shaking. However, the isolate was able to transform 2-HBP to 1,3-benzenediol, 5-hexyl. While biphenyl compounds are toxic to leaving cells, biotransformation of them can reduce their toxicity and the fungi will be more tolerant to the final product. These data are the first report about the desulfurization of DBT comparable to 4S-pathway and production of innovative metabolite by E. spinifera FM strain.

  6. Effect of Byproducts of Flue Gas Desulfurization on the Soluble Salts Composition and Chemical Properties of Sodic Soils

    OpenAIRE

    Jinman Wang; Zhongke Bai; Peiling Yang

    2013-01-01

    The byproducts of flue gas desulfurization (BFGD) are a useful external source of Ca(2+) for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using t...

  7. Multiphase Modeling of Bottom-Stirred Ladle for Prediction of Slag-Steel Interface and Estimation of Desulfurization Behavior

    Science.gov (United States)

    Singh, Umesh; Anapagaddi, Ravikiran; Mangal, Saurabh; Padmanabhan, Kuppuswamy Anantha; Singh, Amarendra Kumar

    2016-06-01

    Ladle furnace is a key unit in which various phenomena such as deoxidation, desulfurization, inclusion removal, and homogenization of alloy composition and temperature take place. Therefore, the processes present in the ladle play an important role in determining the quality of steel. Prediction of flow behavior of the phases present in the ladle furnace is needed to understand the phenomena that take place there and accordingly control the process parameters. In this study, first a mathematical model is developed to analyze the transient three-phase flow present. Argon gas bottom-stirred ladle with off-centered plugs has been used in this study. Volume of fluid method is used in a computational fluid dynamics (CFD) model to capture the behavior of slag, steel, and argon interfaces. The results are validated with data from literature. Eye opening and slag-steel interfacial area are calculated for different operating conditions and are compared with experimental and simulated results cited in literature. Desulfurization rate is then predicted using chemical kinetic equations, interfacial area, calculated from CFD model, and thermodynamic data, obtained from the Thermo-Calc software. Using the model, it is demonstrated that the double plug purging is more suitable than the single plug purging for the same level of total flow. The advantage is more distinct at higher flow rates as it leads higher interfacial area, needed for desulfurization and smaller eye openings (lower oxygen/nitrogen pickup).

  8. Enhancing mercury removal across air pollution control devices for coal-fired power plants by desulfurization wastewater evaporation.

    Science.gov (United States)

    Bin, Hu; Yang, Yi; Cai, Liang; Yang, Linjun; Roszak, Szczepan

    2017-10-09

    Desulfurization wastewater evaporation technology is used to enhance the removal of gaseous mercury (Hg) in conventional air pollution control devices (APCDs) for coal-fired power plants. Studies have affirmed that gaseous Hg is oxidized and removed by selective catalytic reduction (SCR), an electrostatic precipitator (ESP) and wet flue gas desulfurization (WFGD) in a coal-fired thermal experiment platform with WFGD wastewater evaporation. Effects of desulfurization wastewater evaporation position, evaporation temperature and chlorine ion concentration on Hg oxidation were studied as well. The Hg(0) oxidation efficiency was increased ranging from 30% to 60%, and the gaseous Hg removal efficiency was 62.16% in APCDs when wastewater evaporated before SCR. However, the Hg(0) oxidation efficiency was 18.99% and the gaseous Hg removal efficiency was 40.19% in APCDs when wastewater evaporated before ESP. The results show that WFGD wastewater evaporation before SCR is beneficial to improve the efficiency of Hg oxidized and removed in APCDs. Because Hg(2+) can be easily removed in ACPDs and WFGD wastewater in power plants is enriched with chlorine ions, this method realizes WFGD wastewater zero discharge and simultaneously enhances Hg removal in APCDs.

  9. Investigations in physical mechanism of the oxidative desulfurization process assisted simultaneously by phase transfer agent and ultrasound.

    Science.gov (United States)

    Bhasarkar, Jaykumar B; Chakma, Sankar; Moholkar, Vijayanand S

    2015-05-01

    This paper attempts to discern the physical mechanism of the oxidative desulfurization process simultaneously assisted by ultrasound and phase transfer agent (PTA). With different experimental protocols, an attempt is made to deduce individual beneficial effects of PTA and ultrasound on the oxidative desulfurization system, and also the synergy between the effects of PTA and ultrasound. Effect of PTA is more marked for mechanically stirred system due to mass transfer limitations, while intense emulsification due to ultrasound helps overcome the mass transfer limitations and reduces the extent of enhancement of oxidation by PTA. Despite application of PTA and ultrasound, the intrinsic factors and properties of the reactants such as polarity (and hence partition coefficient) and diffusivity have a crucial effect on the extent of oxidation. The intrinsic reactivity of the oxidant also plays a vital role, as seen from the extent of oxidation achieved with performic acid and peracetic acid. The interfacial transport of oxidant in the form of oxidant-PTA complex reduces the undesired consumption of oxidant by the reducing species formed during transient cavitation in organic medium, which helps effective utilization of oxidant towards desulfurization. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Evaluation of Synthetic Gypsum Recovered via Wet Flue-Gas Desulfurization from Electric Power Plants for Use in Foundries

    Directory of Open Access Journals (Sweden)

    R. Biernacki

    2012-09-01

    Full Text Available This article investigates possible use of waste gypsum (synthetic, recovered via flue-gas desulfurization from coal-fired electric powerplants, in foundries. Energy sector, which in Eastern Europe is mostly composed from coal-fired electric power plants, is one of the largestproducers of sulfur dioxide (SO2.In order to protect the environment and reduce the amount of pollution flue-gas desulfurization (FGD is used to remove SO2 fromexhaust flue gases of fossil-fuel power plants. As a result of this process gypsum waste is produced that can be used in practicalapplications.Strength and permeability tests have been made and also in-depth analysis of energy consumption of production process to investigateways of preparing the synthetic gypsum for casting moulds application. This paper also assesses the chemical composition, strength andpermeability of moulds made with synthetic gypsum, in comparison with moulds made with traditional GoldStar XL gypsum and withceramic molds. Moreover examination of structure of synthetic gypsum, the investigations on derivatograph and calculations of energyconsumption during production process of synthetic gypsum in wet flue-gas desulfurization were made.After analysis of gathered data it’s possible to conclude that synthetic gypsum can be used as a material for casting mould. There is nosignificant decrease in key properties, and on the other hand there is many additional benefits including low energy consumption,decreased cost, and decreased environmental impact.

  11. A rapid biosensor for viable B. anthracis spores.

    Science.gov (United States)

    Baeumner, Antje J; Leonard, Barbara; McElwee, John; Montagna, Richard A

    2004-09-01

    A simple membrane-strip-based biosensor assay has been combined with a nucleic acid sequence-based amplification (NASBA) reaction for rapid (4 h) detection of a small number (ten) of viable B. anthracis spores. The biosensor is based on identification of a unique mRNA sequence from one of the anthrax toxin genes, the protective antigen ( pag), encoded on the toxin plasmid, pXO1, and thus provides high specificity toward B. anthracis. Previously, the anthrax toxins activator ( atxA) mRNA had been used in our laboratory for the development of a biosensor for the detection of a single B. anthracis spore within 12 h. Changing the target sequence to the pag mRNA provided the ability to shorten the overall assay time significantly. The vaccine strain of B. anthracis (Sterne strain) was used in all experiments. A 500-microL sample containing as few as ten spores was mixed with 500 microL growth medium and incubated for 30 min for spore germination and mRNA production. Thus, only spores that are viable were detected. Subsequently, RNA was extracted from lysed cells, selectively amplified using NASBA, and rapidly identified by the biosensor. While the biosensor assay requires only 15 min assay time, the overall process takes 4 h for detection of ten viable B. anthracis spores, and is shortened significantly if more spores are present. The biosensor is based on an oligonucleotide sandwich-hybridization assay format. It uses a membrane flow-through system with an immobilized DNA probe that hybridizes with the target sequence. Signal amplification is provided when the target sequence hybridizes to a second DNA probe that has been coupled to liposomes encapsulating the dye sulforhodamine B. The amount of liposomes captured in the detection zone can be read visually or quantified with a hand-held reflectometer. The biosensor can detect as little as 1 fmol target mRNA (1 nmol L(-1)). Specificity analysis revealed no cross-reactivity with 11 organisms tested, among them closely

  12. Desulfurization of phosphorothioate oligonucleotides via the sulfur-by-oxygen replacement induced by the hydroxyl radical during negative electrospray ionization mass spectrometry.

    Science.gov (United States)

    Wu, Lianming; White, David E; Ye, Connie; Vogt, Frederick G; Terfloth, Gerald J; Matsuhashi, Hayao

    2012-07-01

    While the occurrence of desulfurization of phosphorothioate oligonucleotides in solution is well established, this study represents the first attempt to investigate the basis of the unexpected desulfurization via the net sulfur-by-oxygen (S-O) replacement during negative electrospray ionization (ESI). The current work, facilitated by quantitative mass deconvolution, demonstrates that considerable desulfurization can take place even under common negative ESI operating conditions. The extent of desulfurization is dependent on the molar phosphorothioate oligonucleotide-to-hydroxyl radical ratio, which is consistent with the corona discharge-induced origin of the hydroxyl radical leading to the S-O replacement. This hypothesis is supported by the fact that an increase of the high-performance liquid chromatography (HPLC) flow rate and the on-column concentration of a phosphorothioate oligonucleotide, as well as a decrease of the electrospray voltage reduce the degree of desulfurization. Comparative LC-tandem mass spectrometry (MS/MS) sequencing of a phosphorothioate oligonucleotide and its corresponding desulfurization product revealed evidence that the S-O replacement occurs at multiple phosphorothioate internucleotide linkage sites. In practice, the most convenient and effective strategy for minimizing this P = O artifact is to increase the LC flow rate and the on-column concentration of phosphorothioate oligonucleotides. Another approach to mitigate possible detrimental effects of the undesired desulfurization is to operate the ESI source at a very low electrospray voltage to diminish the corona discharge; however this will significantly compromise sensitivity when analyzing the low-level P = O impurities in phosphorothioate oligonucleotides. Copyright © 2012 John Wiley & Sons, Ltd.

  13. Modulation of the endocannabinoid system in viable and non-viable first trimester pregnancies by pregnancy-related hormones

    Directory of Open Access Journals (Sweden)

    Taylor Anthony H

    2011-11-01

    Full Text Available Abstract Background In early pregnancy, increased plasma levels of the endocannabinoid anandamide (AEA are associated with miscarriage through mechanisms that might affect the developing placenta or maternal decidua. Methods In this study, we compare AEA levels in failed and viable pregnancies with the levels of the trophoblastic hormones (beta-human chorionic gonadotrophin (beta-hCG, progesterone (P4 and (pregnancy-associated placental protein-A (PAPP-A essential for early pregnancy success and relate that to the expression of the cannabinoid receptors and enzymes that modulate AEA levels. Results The median plasma AEA level in non-viable pregnancies (1.48 nM; n = 20 was higher than in viable pregnancies (1.21 nM; n = 25; P = 0.013, as were progesterone and beta-hCG levels (41.0 vs 51.5 ng/mL; P = 0.052 for P4 and 28,650 vs 6,560 mIU/L; P = 0.144 for beta-hCG, respectively, but were not statistically significant. Serum PAPP-A levels in the viable group were approximately 6.8 times lower than those in the non-viable group (1.82 vs 12.25 mg/L; P = 0.071, but again these differences were statistically insignificant. In the spontaneous miscarriage group, significant correlations between P4 and beta-hCG, P4 and PAPP-A and AEA and PAPP-A levels were observed. Simultaneously, immunohistochemical distributions of the two main cannabinoid receptors and the AEA-modifying enzymes, fatty acid amide hydrolase (FAAH and N-acylphosphatidylethanolamine-phospholipase D (NAPE-PLD, changed within both the decidua and trophoblast. Conclusions The association of higher AEA levels with early pregnancy failure and with beta-hCG and PAPP-A, but not with progesterone concentrations suggest that plasma AEA levels and pregnancy failure are linked via a mechanism that may involve trophoblastic beta-hCG, and PAPP-A, but not, progesterone production. Although the trophoblast, decidua and embryo contain receptors for AEA, the main AEA target in early pregnancy failure

  14. Inkjet printing of viable human dental follicle stem cells

    Directory of Open Access Journals (Sweden)

    Mau Robert

    2015-09-01

    Full Text Available Inkjet printing technology has the potential to be used for seeding of viable cells for tissue engineering approaches. For this reason, a piezoelectrically actuated, drop-on-demand inkjet printing system was applied to deliver viable human dental follicle stem cells (hDFSC of sizes of about 15 μm up to 20 μm in diameter. The purpose of these investigations was to verify the stability of the printing process and to evaluate cell viability post printing. Using a Nanoplotter 2.1 (Gesim, Germany equipped with the piezoelectric printhead NanoTip HV (Gesim, Germany, a concentration of 6.6 ×106 cells ml−1 in DMEM with 10% fetal calf serum (FCS could be dispensed. The piezoelectric printhead has a nominal droplet volume of ~ 400 pl and was set to a voltage of 75 V and a pulse of 50 μs while dosing 50 000 droplets over a time of 100 seconds. The volume and trajectory of the droplet were checked by a stroboscope test right before and after the printing process. It was found that the droplet volume decreases significantly by 35% during printing process, while the trajectory of the droplets remains stable with only an insignificant number of degrees deviation from the vertical line. It is highly probable that some cell sedimentations or agglomerations affect the printing performance. The cell viability post printing was assessed by using the Trypan Blue dye exclusion test. The printing process was found to have no significant influence on cell survival. In conclusion, drop-on-demand inkjet printing can be a potent tool for the seeding of viable cells.

  15. Molar Pregnancy with a Co-Existing Viable Fetus

    Directory of Open Access Journals (Sweden)

    Ruya Deveer

    2014-03-01

    Full Text Available     The aim of this study was to report the clinical features, management, and outcome of a case of molar pregnancy with a coexisting viable fetus and to review the literature. In this article, we report a case of pregnancy with diffuse placental molar change and a normal fetus which presented with hyperemesis gravidarum and hyperthyroidism. Genetic amniocentesis showed normal fetal karyotype. A healthy full-term live male infant was delivered by cesarean section. In molar pregnancies with a normal karyotype fetus, with intensive maternal follow-up, continuation of pregnancy can be suggested.

  16. Bio desulfurization of a system containing synthetic fuel by rhodococcus erythropolis ATCC 4277; Remocao de compostos sulfurosos de sitema bifasico contendo combustivel sintetico por Rhodococcus erythropolis ATCC 4277

    Energy Technology Data Exchange (ETDEWEB)

    Maass, Danielle; Souza, Antonio Augusto Ulson de; Souza, Selene Maria de Arruda Guelli Ulson de [Universidade Federal de Santa Catarina (UFSC), SC (Brazil)

    2012-07-01

    For decades the burning of fossil fuels released a lot of pollutants in the atmosphere. Among the most harmful is sulfur dioxide (SO{sub 2}), which reacts with the moisture in the air and turns into sulfuric acid, being the main cause of acid rain. Acid rain is very harmful to animal and plant kingdoms; accelerates the corrosion's processes of buildings and monuments, and causes serious health problems for humans. As a result, many countries have reformed their legislation to require the sale of fuels with very low sulfur content. The existing processes of desulfurization are not capable of removing sulfur so low. Therefore, there has developed a new process called bio desulfurization. In this process, the degradation of sulfur occurs through the action of microorganisms that act as catalysts. The bacterium Rhodococcus erythropolis has emerged as one of the most promising for bio desulfurization because it removes the sulfur without breaking the benzene rings, thereby maintaining the potential energy of the same. Using dibenzothiophene as a model of sulfur compounds, the products of the bio desulfurization process are 2- hydroxybiphenyl and sulfate. In this study we sought to examine the desulfurizing capacity of national Rhodococcus erythropolis strain ATCC4277 in a batch reactor using concentrations of organic phase (n-dodecane) of 20 and 80% (v/v). Rhodococcus erythropolis ATCC4277 was capable of degrading DBT in 93.3 and 98.0% in the presence of 20 and 80% (v/v) of synthetic fuel, respectively. (author)

  17. Ultrasound-assisted oxidative desulfurization process of liquid fuel by phosphotungstic acid encapsulated in a interpenetrating amine-functionalized Zn(II)-based MOF as catalyst.

    Science.gov (United States)

    Afzalinia, Ahmad; Mirzaie, Abbas; Nikseresht, Ahmad; Musabeygi, Tahereh

    2017-01-01

    In this work, ultrasound-assisted oxidative desulfurization (UAOD) of liquid fuels performed with a novel heterogeneous highly dispersed Keggin-type phosphotungstic acid (H3PW12O40, PTA) catalyst that encapsulated into an amino-functionalized MOF (TMU-17-NH2). The prepared composite exhibits high catalytic activity and reusability in oxidative desulfurization of model fuel. Ultrasound-assisted oxidative desulfurization (UAOD) is a new way to performed oxidation reaction of sulfur-contain compounds rapidly, economically, environment-friendly and safely, under mild conditions. Ultrasound waves can be apply as an efficient tool to decrease the reaction time and improves oxidative desulfurization system performance. PTA@TMU-17-NH2 could be completely performed desulfurization of the model oil by 20mg of catalyst, O/S molar ratio of 1:1 in presence of MeCN as extraction solvent. The obtained results indicated that the conversions of DBT to DBTO2 achieve 98% after 15min in ambient temperature. In this work, we prepared TMU-17-NH2 and PTA/TMU-17-NH2 composite by ultrasound irradiation for first time and employed in UAOD process. Prepared catalyst exhibit an excellent reusability without PTA leaching and loss of activity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Flue gas desulfurization by-products additions to acid soil: alfalfa productivity and environmental quality

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.; Dick, W.A.; Nelson, S.

    2001-07-01

    Flue gas desulfurization (FGD) by-products are often alkaline and contain many plant nutrients. Land application of FGD by-products is encouraged but little information is available related to plant responses and environmental impacts concerning such use. Agricultural lime (ag-lime) and several new types of FGD by-products which contain either vermiculite or perlite were applied at 0, 0.5, 1.0, and 2.0 times the soil's lime requirement (LR) rate to an acidic soil (Wooster silt loam). The highest FGD by-products application rate was equivalent to 75.2 Mg ha{sup -1}. Growth of alfalfa (Medicago sativa L.) was significantly increased compared to the untreated control in the second year after treatment with yields for the 1 x LR rate of FGD approximately 7-8 times greater compared to the untreated control and 30% greater than for the commercial ag-lime. Concentrations of Mo in alfalfa were significantly increased by FGD by-products application, compared to the untreated control, while compared to the ag-lime treatment, concentrations of B increased and Ba decreased. No soil contamination problems were observed, even at the 2xLR rate, indicating these materials can be safely applied to agricultural soils.

  19. Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst

    Directory of Open Access Journals (Sweden)

    Risfidian Mohadi

    2016-03-01

    Full Text Available Catalyst (NH46[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH46[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH46[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH46[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH46[b-P2W18O62]/Ta after impregnation was higher than (NH46[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH46[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH46[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH46[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.

  20. Adsorptive Desulfurization of Model Gasoline by Using Different Zn Sources Exchanged NaY Zeolites

    Directory of Open Access Journals (Sweden)

    Jingwei Rui

    2017-02-01

    Full Text Available A series of Zn-modified NaY zeolites were prepared by the liquid-phase ion-exchange method with different Zn sources, including Zn(NO32, Zn(Ac2 and ZnSO4. The samples were tested as adsorbents for removing an organic sulfur compound from a model gasoline fuel containing 1000 ppmw sulfur. Zn(Ac2-Y exhibited the best performance for the desulfurization of gasoline at ambient conditions. Combined with the adsorbents’ characterization results, the higher adsorption capacity of Zn(Ac2-Y is associated with a higher ion-exchange degree. Further, the results demonstrated that the addition of 5 wt % toluene or 1-hexene to the diluted thiophene (TP solution in cyclohexane caused a large decrease in the removal of TP from the model gasoline fuel. This provides evidence about the competition through the π-complexation between TP and toluene for adsorption on the active sites. The acid-catalyzed alkylation by 1-hexene of TP and the generated complex mixture of bulky alkylthiophenes would adsorb on the surface active sites of the adsorbent and block the pores. The regenerated Zn(Ac2-Y adsorbent afforded 84.42% and 66.10% of the initial adsorption capacity after the first two regeneration cycles.

  1. Chemical desulfurization of petroleum fractions for ultra-low sulfur fuels

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Mohammad Farhat; Ahmed, Shakil [H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270 (Pakistan); Al-Malki, Abdullah [Research and Development Center, Saudi ARAMCO, Dhahran 31311 (Saudi Arabia)

    2009-04-15

    An improved desulfurization process for removing sulfur from hydro treated diesel oil based on the oxidation of thiophenic type sulfur-containing compounds with H{sub 2}O{sub 2} and acetic acid (AcOH) using H{sub 2}SO{sub 4} as catalyst has been studied. The experimental results show that the sulfone content in the oxidation product increased rapidly with an increase in acetic acid and sulfuric acid ratios from 1:0 to 2:1 mole ratios. The maximum DBT conversion (wt.%) was at 2:1 mole ratio of acetic acid/sulfuric acid. This oxidation process is found to be capable of removing up to 90% of the sulfur compounds in hydro treated real fuels and can provide an alternative way to meet the future sulfur environmental requirements. Fifty eight sulfur-containing compounds were identified in hydro treated diesel sample. The sulfur compounds that have been identified in the hydro treated diesel include mainly refractory sulfur compounds (thiophenes and multi ring aromatic sulfur compounds, such as dibenzothiophene (DBT)). Sulfur species in typically hydro treated diesel and ring number distribution in 254-385 C cut are also reported. (author)

  2. The optimization of saccharification of desulfurated red seaweed-derived polysaccharides and analysis of their composition.

    Science.gov (United States)

    Li, Xiaolin; Li, Yinping; Mou, Haijin; Gao, Yan; Hwang, Hueymin; Wang, Peng

    2014-01-01

    Currently processes of ethanol production from desulfurated red seaweed derived polysaccharides (De-RSDP) are well established. However, the optimization of the enzymatic saccharification process has not been reported. In this study, De-RSDP from Kappaphycus alvarezii was subjected to saccharification by different enzymes, including pectinase, cellobiase, cellulase, and hemicellulase. The best saccharification enzyme was determined as pectinase. In order to obtain more reducing sugar (RS), the single-factor experiment followed by central composite rotatable design (CCD) was used to optimize the parameters for enzymatic hydrolysis. The optimal saccharification parameters of De-RSDP were 4400 U/g pectinase dosage, 96 hr, and 55.5°C, respectively, and the yield of RS reached 81.3%. Subsequently, the saccharification liquids of De-RSDP were isolated and purified with gel permeation chromatography (GPC) to separate saccharides with different molecular weights. Simultaneously, the composition of saccharification liquids was analyzed by 1-phenyl-3-methyl-5-pyrazolone high-pressure liquid chromatography (PMP-HPLC) and mass spectroscopy (MS). The result showed that the content is mainly composed of galactose (65.2%) with the average molecular mass in the fourth peak 181.1 Da. The saccharification liquids of De-RSDP inoculated with Saccharomyces cerevisiae L-4 for ethanol fermentation produced 0.3 g ethanol/g De-RSDP, which corresponded to 71.8% of the theoretical yield (0.38 g ethanol/g).

  3. Preparation of ionic liquid-modified SBA-15 doped with molybdovanadophosphoric acid for oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Jiang Zhou; Jin, Xiao Yin; Shen, Xian Lin; Tan, Jun Jun; Nie, Long Hui; Xiang, Jian; Hu, Bing [Dept. of chool of Chemistry and Chemical Engineering, Hubei University of Technology, Wuhan (China)

    2015-07-15

    A series of catalysts, ionic liquid-modified SBA-15 (denoted ILSBA) doped with H{sub 5}PMo{sub 10}V{sub 2}O{sub 40} (HPMoV{sub 2}) have been synthesized and characterized by XRD, FT-IR, {sup 1}H NMR, TG-DTA, and TEM. The catalyst was used for the removal of dibenzothiophene (DBT) in model oil combined with hydrogen peroxide (the oxidant) and acetonitrile (the phase-transfer agent). It was observed that the sulfur content of DBT can be reduced from 500 to 2 ppm by adjusting the amount of catalyst, the reaction temperatures and the reaction time. Besides, the catalyst activity for different sulfur compounds showed a huge difference which may be mainly affected by the electron densities of sulfur atom. Moreover, the catalyst can be recycled seven times without a significant loss in activity, which could be ascribed to the strong electrostatic interaction between ILSBA and HPMoV{sub 2}. In addition, a postulated mechanism was proposed to reveal the oxidative desulfurization process.

  4. Adsorptive Desulfurization of Model Gasoline by Using Different Zn Sources Exchanged NaY Zeolites.

    Science.gov (United States)

    Rui, Jingwei; Liu, Fei; Wang, Rijie; Lu, Yanfei; Yang, Xiaoxia

    2017-02-17

    A series of Zn-modified NaY zeolites were prepared by the liquid-phase ion-exchange method with different Zn sources, including Zn(NO₃)₂, Zn(Ac)₂ and ZnSO₄. The samples were tested as adsorbents for removing an organic sulfur compound from a model gasoline fuel containing 1000 ppmw sulfur. Zn(Ac)₂-Y exhibited the best performance for the desulfurization of gasoline at ambient conditions. Combined with the adsorbents' characterization results, the higher adsorption capacity of Zn(Ac)₂-Y is associated with a higher ion-exchange degree. Further, the results demonstrated that the addition of 5 wt % toluene or 1-hexene to the diluted thiophene (TP) solution in cyclohexane caused a large decrease in the removal of TP from the model gasoline fuel. This provides evidence about the competition through the π-complexation between TP and toluene for adsorption on the active sites. The acid-catalyzed alkylation by 1-hexene of TP and the generated complex mixture of bulky alkylthiophenes would adsorb on the surface active sites of the adsorbent and block the pores. The regenerated Zn(Ac)₂-Y adsorbent afforded 84.42% and 66.10% of the initial adsorption capacity after the first two regeneration cycles.

  5. Preparation of manganese dioxide loaded activated carbon adsorbents and their desulfurization performance

    Science.gov (United States)

    Zhang, Jiaojing; Wang, Guojian; Wang, Wenyi; Song, Hua; Wang, Lu

    2016-12-01

    Manganese dioxide loaded activated carbon adsorbents (MnO2/AC) were prepared and characterized by N2 adsorption-desorption, BET method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometry (FT-IR) and scanning electron microscopy (SEM). Effects of preparation conditions and adsorption conditions on desulfurization performance of the adsorbents were studied in a fixed-bed adsorption apparatus. Experimental results show that the surface area and pore volume of MnO2/AC decreased compared with the unmodified activated carbon, but the adsorption capacity to H2S was improved greatly. A suitable H2S removal activity was obtained with manganese dioxide to activated carbon ratio of 1.1: 1 and the calcination temperature of 250°C. At the adsorption temperature of 40°C and gas flow rate of 20 mL/min, the H2S saturation capacity and H2S removal rate reached up to 713.25 mg/g and 89.9%, respectively.

  6. Sodic soil properties and sunflower growth as affected by byproducts of flue gas desulfurization.

    Directory of Open Access Journals (Sweden)

    Jinman Wang

    Full Text Available The main component of the byproducts of flue gas desulfurization (BFGD is CaSO(4, which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha(-1 and two leaching levels (750 and 1200 m(3 ha(-1. The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP, pH and total dissolved salts (TDS in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha(-1 and water was supplied at 1200 m(3·ha(-1. Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage.

  7. Adsorptive desulfurization with metal-organic frameworks: A density functional theory investigation

    Science.gov (United States)

    Chen, Zhiping; Ling, Lixia; Wang, Baojun; Fan, Huiling; Shangguan, Ju; Mi, Jie

    2016-11-01

    The contribution of each fragment of metal-organic frameworks (MOFs) to the adsorption of sulfur compounds were investigated using density functional theory (DFT). The involved sulfur compounds are dimethyl sulfide (CH3SCH3), ethyl mercaptan (CH3CH2SH) and hydrogen sulfide (H2S). MOFs with different organic ligands (NH2-BDC, BDC and NDC), metal centers structures (M, M-M and M3O) and metal ions (Zn, Cu and Fe) were used to study their effects on sulfur species adsorption. The results revealed that, MOFs with coordinatively unsaturated sites (CUS) have the strongest binding strength with sulfur compounds, MOFs with NH2-BDC substituent group ligand comes second, followed by that with saturated metal center, and the organic ligands without substituent group has the weakest adsorption strength. Moreover, it was also found that, among different metal ions (Fe, Zn and Cu), MOFs with unsaturated Fe has the strongest adsorption strength for sulfur compounds. These results are consistent with our previous experimental observations, and therefore provide insights on the better design of MOFs for desulfurization application.

  8. Synthesis of magnetic ordered mesoporous carbon (Fe-OMC) adsorbent and its evaluation for fuel desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Farzin Nejad, N., E-mail: Farzinnejadn@ripi.ir [Petroleum Refining Technology Development Division, Research Institute of Petroleum Industry, Tehran 14857-33111 (Iran, Islamic Republic of); Shams, E.; Amini, M.K. [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)

    2015-09-15

    In this work, magnetic ordered mesoporous carbon adsorbent was synthesized using soft templating method to adsorb sulfur from model oil (dibenzothiophene in n-hexane). Through this research, pluronic F-127, resorcinol-formaldehyde and hydrated iron nitrate were respectively used as soft template, carbon source and iron source. The adsorbent was characterized by X-ray diffraction, nitrogen adsorption–desorption isotherm and transmission electron microscopy. Nitrogen adsorption–desorption measurement revealed the high surface area (810 m{sup 2} g{sup −1}), maxima pore size of 3.3 nm and large pore volume (1.01 cm{sup 3} g{sup −1}) of the synthesized sample. The adsorbent showed a maximum adsorption capacity of 111 mg dibenzothiophene g{sup −1} of adsorbent. Sorption process was described by the pseudo-second-order rate equation and could be better fitted by the Freundlich model, showing the heterogeneous feature of the adsorption process. In addition, the adsorption capacity of regenerated adsorbent was 78.6% of the initial level, after five regeneration cycles. - Highlights: • Adsorptive desulfurization of model oil with magnetic ordered mesoporous carbon adsorbent, Fe-OMC, was studied. • Maximum adsorption capacity (q{sub max}) of Fe-OMC for DBT was found to be 111.1 mg g{sup −1}. • Freundlich isotherm best represents the equilibrium adsorption data. • Rate of DBT adsorption process onto Fe-OMC is controlled by at least two steps.

  9. Bio-desulfurization of biogas using acidic biotrickling filter with dissolved oxygen in step feed recirculation.

    Science.gov (United States)

    Chaiprapat, Sumate; Charnnok, Boonya; Kantachote, Duangporn; Sung, Shihwu

    2015-03-01

    Triple stage and single stage biotrickling filters (T-BTF and S-BTF) were operated with oxygenated liquid recirculation to enhance bio-desulfurization of biogas. Empty bed retention time (EBRT 100-180 s) and liquid recirculation velocity (q 2.4-7.1 m/h) were applied. H2S removal and sulfuric acid recovery increased with higher EBRT and q. But the highest q at 7.1 m/h induced large amount of liquid through the media, causing a reduction in bed porosity in S-BTF and H2S removal. Equivalent performance of S-BTF and T-BTF was obtained under the lowest loading of 165 gH2S/m(3)/h. In the subsequent continuous operation test, it was found that T-BTF could maintain higher H2S elimination capacity and removal efficiency at 175.6±41.6 gH2S/m(3)/h and 89.0±6.8% versus S-BTF at 159.9±42.8 gH2S/m(3)/h and 80.1±10.2%, respectively. Finally, the relationship between outlet concentration and bed height was modeled. Step feeding of oxygenated liquid recirculation in multiple stages clearly demonstrated an advantage for sulfide oxidation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Investigation on Mercury Reemission from Limestone-Gypsum Wet Flue Gas Desulfurization Slurry

    Science.gov (United States)

    Liu, Songtao; Liu, Yongchao

    2014-01-01

    Secondary atmospheric pollutions may result from wet flue gas desulfurization (WFGD) systems caused by the reduction of Hg2+ to Hg0 and lead to a damping of the cobenefit mercury removal efficiency by WFGD systems. The experiment on Hg0 reemission from limestone-gypsum WFGD slurry was carried out by changing the operating conditions such as the pH, temperature, Cl− concentrations, and oxygen concentrations. The partitioning behavior of mercury in the solid and liquid byproducts was also discussed. The experimental results indicated that the Hg0 reemission rate from WFGD slurry increased as the operational temperatures and pH values increased. The Hg0 reemission rates decreased as the O2 concentration of flue gas and Cl− concentration of WFGD slurry increased. The concentrations of O2 in flue gas have an evident effect on the mercury retention in the solid byproducts. The temperature and Cl− concentration have a slight effect on the mercury partitioning in the byproducts. No evident relation was found between mercury retention in the solid byproducts and the pH. The present findings could be valuable for industrial application of characterizing and optimizing mercury control in wet FGD systems. PMID:24737981

  11. Rate-limiting step analysis of the microbial desulfurization of dibenzothiophene in a model oil system

    Science.gov (United States)

    Abin-Fuentes, Andres; Leung, James C.; Mohamed, Magdy El-Said; Wang, Daniel IC; Prather, Kristala LJ

    2014-01-01

    A mechanistic analysis of the various mass transport and kinetic steps in the microbial desulfurization of dibenzothiophene (DBT) by Rhodococcus erythropolis IGTS8 in a model biphasic (oil-water), small-scale system was performed. The biocatalyst was distributed into three populations, free cells in the aqueous phase, cell aggregates and oil-adhered cells, and the fraction of cells in each population was measured. The power input per volume (P/V) and the impeller tip speed (vtip) were identified as key operating parameters in determining whether the system is mass transport controlled or kinetically controlled. Oil-water DBT mass transport was found to not be limiting under the conditions tested. Experimental results at both the 100 mL and 4L (bioreactor) scales suggest that agitation leading to P/V greater than 10,000 W/ m3 and/or vtip greater than 0.67 m/s is sufficient to overcome the major mass transport limitation in the system, which was the diffusion of DBT within the biocatalyst aggregates. PMID:24284557

  12. Bicarbonate-induced activation of H₂O₂ for metal-free oxidative desulfurization.

    Science.gov (United States)

    Bokare, Alok D; Choi, Wonyong

    2016-03-05

    Efficient oxidative desulfurization (ODS) of model oil containing dibenzothiophene (DBT) and aromatic thiophenic derivatives has been achieved at room temperature using hydrogen peroxide activation by inorganic bicarbonate (HCO3(-)). Using in-situ formation of peroxymonocarbonate as oxidant, the transformation of main model substrate DBT to corresponding DBT-sulfone was easily accomplished in biphasic reaction conditions. In the presence of water-acetonitrile polar phase, increasing the water content upto 50% decreased the extraction capacity more than 3 times, but ∼ 90% DBT oxidation was still achieved. The oxidizing capacity of bicarbonate catalyst was maintained during repeated ODS cycles, but DBT removal efficiency was critically dependent on the extraction capacity of the polar phase. Under heterogeneous reaction conditions, bicarbonate-modified ion-exchange resin achieved similar ODS activity compared to the homogeneous catalytic system. Additionally, the efficient formation of peroxymonocarbonate using gaseous CO2 precursor in alkaline conditions was also utilized for DBT oxidation. The present study proposes the NaHCO3/H2O2 catalytic system as an efficient and cheap metal-free alternative for the oxidative removal of aromatic sulfur compounds from fuel oil. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Highly Efficient Air Desulfurization on Self-Assembled Bundles of Copper Hydroxide Nanorods.

    Science.gov (United States)

    Giannakoudakis, Dimitrios A; Jiang, Mingyung; Bandosz, Teresa J

    2016-11-23

    Copper hydroxide and copper hydroxyl nitrate were successfully synthesized from copper nitrate. A slight alteration of a base addition pathway led to entirely different chemical and crystal structures. Structural, morphological, and surface chemical features were analyzed using various physical and chemical methods. The copper hydroxide texture consists of self-assembled bundles of nanorods with a diameter between 15 and 40 nm. They are stack together forming platelet-like particles. In the case of the copper hydroxyl nitrate, platelet-like particles with a smooth surface were detected. The fully hydroxylated sample showed a considerably higher surface area and mesoporous volume than those of copper hydroxyl nitrate. Both synthesized materials were used as air desulfurization media at moist or dry conditions. The results indicate a supreme chemical adsorption of H2S on copper hydroxide. Moisture in air has a positive effect on the adsorption performance. In humid conditions, almost 0.9 mol H2S/mol of Cu(OH)2 was adsorbed. CuS with almost a stoichiometric ratio was a product of surface reactions. The color change of the powder from sapphire blue to dark brown during the adsorption can be used as a fast indication of the adsorbent exhaustion level.

  14. Attapulgite-CeO2/MoS2 ternary nanocomposite for photocatalytic oxidative desulfurization

    Science.gov (United States)

    Li, Xiazhang; Zhang, Zuosong; Yao, Chao; Lu, Xiaowang; Zhao, Xiaobing; Ni, Chaoying

    2016-02-01

    Novel attapulgite(ATP)-CeO2/MoS2 ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV-vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO2/MoS2 composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO2 to MoS2 on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO2 particles and MoS2 nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO2/MoS2 is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

  15. Sodic Soil Properties and Sunflower Growth as Affected by Byproducts of Flue Gas Desulfurization

    Science.gov (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2012-01-01

    The main component of the byproducts of flue gas desulfurization (BFGD) is CaSO4, which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha−1) and two leaching levels (750 and 1200 m3 ha−1). The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP), pH and total dissolved salts (TDS) in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha−1 and water was supplied at 1200 m3·ha−1. Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage. PMID:23285042

  16. A polyoxometalate-encapsulating cationic metal-organic framework as a heterogeneous catalyst for desulfurization.

    Science.gov (United States)

    Hao, Xiu-Li; Ma, Yuan-Yuan; Zang, Hong-Ying; Wang, Yong-Hui; Li, Yang-Guang; Wang, En-Bo

    2015-02-23

    A new cationic triazole-based metal-organic framework encapsulating Keggin-type polyoxometalates, with the molecular formula [Co(BBPTZ)3][HPMo12O40]⋅24 H2O [compound 1; BBPTZ = 4,4'-bis(1,2,4-triazol-1-ylmethyl)biphenyl] is hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. The structure of compound 1 contains a non-interpenetrated 3D CdSO4 (cds)-type framework with two types of channels that are interconnected with each other; straight channels that are occupied by the Keggin-type POM anions, and wavelike channels that contain lattice water molecules. The catalytic activity of compound 1 in the oxidative desulfurization reaction indicates that it is not only an effective and size-selective heterogeneous catalyst, but it also exhibits distinct structural stability in the catalytic reaction system. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Heterogeneous oxidative desulfurization of diesel fuel catalyzed by mesoporous polyoxometallate-based polymeric hybrid.

    Science.gov (United States)

    Yang, Huawei; Jiang, Bin; Sun, Yongli; Zhang, Luhong; Huang, Zhaohe; Sun, Zhaoning; Yang, Na

    2017-07-05

    In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N,​N-​dimethyl-​dodecyl-​(4-​vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species. The catalyst with H2W12O4210- as counterion, which exhibited the best activity in the oxidation of benzothiophene (BT) and dibenzothiophene (DBT) to sulfones in model oil with hydrogen peroxide (H2O2, 30wt%) as oxidant, was characterized by different techniques and systematically studied for its sulfur removal performance. As for the oxidative desulfurization of a real diesel, it was observed that almost all of the original sulfur compounds could be completely converted, and the catalyst could be reused for at least eight cycles without noticeable changes in both catalytic activity and chemical structure. In the end, a catalytic mechanism was put forward with the assistant of Raman analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Sodic soil properties and sunflower growth as affected by byproducts of flue gas desulfurization.

    Science.gov (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2012-01-01

    The main component of the byproducts of flue gas desulfurization (BFGD) is CaSO(4), which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha(-1)) and two leaching levels (750 and 1200 m(3) ha(-1)). The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP), pH and total dissolved salts (TDS) in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha(-1) and water was supplied at 1200 m(3)·ha(-1). Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage.

  19. LIFAC flue gas desulfurization process an alternative SO{sub 2} control strategy

    Energy Technology Data Exchange (ETDEWEB)

    Patel, J.G. [Tampella Power Corp., Atlanta, GA (United States); Vilala, J. [Tampella Power Inc., Tampere (Finland)

    1995-12-01

    This paper discusses the results from two recently completed LIFAC flue gas desulfurization plants - 300 MW Shand lignite powered station owned by Saskatchewan Power Corporation and 60 MW Whitewater Valley high sulfur coal fired station owned by Richmond Powerand Light. LIFACis a dry FGD process in which limestone is injected into the upper regions of the boiler furnace and an activation reactor is used to humidify the unreacted limestone to achieve additional sulfur capture. The performance in both plants indicates that 70 to 80% sulfur is removed at a Ca/S ratio of 2. Cost performance data from these plants has shown that LI FAC both on construction cost and $/ton SO{sub 2} removed basis is very cost competitive compared to other SO{sub 2} control technologies. The Richmond plant has been realized under the auspices of the U.S. Department of Energy`s Clean Coal Technology program. The Shand plant is the first commercial installation in North America. The paper also discusses highlights of operating and maintenance experience, availability and handling of the solid waste product.

  20. Industrial application of gasoline aromatization and desulfurization technology in Hohhot refinery

    Directory of Open Access Journals (Sweden)

    Li Zixia

    2017-01-01

    Full Text Available Gasoline aromatization and desulfurization (GARDES technology is extensively used in refineries of Petrochina, aiming to produce high quality ultraclean fluid catalytic cracking (FCC gasoline. This article introduces the industrial application results on the hydrodesulfurization unit of the Hohhot refinery, which plays an important role in guiding next round gasoline upgrading. The characteristics and the principle of GARDES technology were elaborated by analyzing the distribution of sulfur and hydrocarbon compounds in the feed and product. The analysis results proved that the presence of broad ranged sulfur types in the feed can be removed at different stages. Olefin can be decreased by saturation and conversion into i-paraffins and aromatics. The sulfur content of the blend product can be limited under 10 mg/kg, showing GARDES technology has excellent sulfur removal ability. The olefin reduction can also satisfy the ever-increasing severe requirement about the olefin limitation, while the loss of research octane number (RON can be minimized to an acceptable level. Furthermore, according to the demand of gasoline upgrading, GARDES technology has great flexibility by adjusting operation condition without any further investment, which brings more economic benefits for refinery.

  1. Adsorptive desulfurization of model oil using untreated, acid activated and magnetite nanoparticle loaded bentonite as adsorbent

    Directory of Open Access Journals (Sweden)

    Muhammad Ishaq

    2017-02-01

    Full Text Available The present research work focuses on a novel ultraclean desulfurization process of model oil by the adsorption method using untreated, acid activated and magnetite nanoparticle loaded bentonite as adsorbent. The parameters investigated are effect of contact time, adsorbent dose, initial dibenzothiophene (DBT concentration and temperature. Experimental tests were conducted in batch process. Pseudo first and second order kinetic equations were used to examine the experimental data. It was found that pseudo second order kinetic equation described the data of the DBT adsorption onto all types of adsorbents very well. The isotherm data were analyzed using Langmuir and Freundlich isotherm models. The Langmuir isotherm model fits the data very well for the adsorption of DBT onto all three forms of adsorbents. The adsorption of DBT was also investigated at different adsorbent doses and was found that the percentage adsorption of DBT was increased with increasing the adsorbent dose, while the adsorption in mg/g was decreased with increasing the adsorbent dose. The prepared adsorbents were analyzed by scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDX and X-ray diffraction (XRD.

  2. Theoretical investigation of the interaction between aromatic sulfur compounds and [BMIM](+)[FeCl4](-) ionic liquid in desulfurization: A novel charge transfer mechanism.

    Science.gov (United States)

    Li, Hongping; Zhu, Wenshuai; Chang, Yonghui; Jiang, Wei; Zhang, Ming; Yin, Sheng; Xia, Jiexiang; Li, Huaming

    2015-06-01

    In this work, interaction nature between a group of aromatic sulfur compounds and [BMIM](+)[FeCl4](-) have been investigated by density functional theory (DFT). A coordination structure is found to be critical to the mechanism of extractive desulfurization. Interaction energy and extractive selectivity follow the order: thiophene (TH)desulfurization is attributed to the charge transfer effect. During extractive desulfurization, electrons on aromatic sulfur compounds transfer into the Lewis part of ionic liquid, namely, [FeCl4](-). Furthermore, it is better to consider the Lewis acidity of Fe-containing ionic liquid by the whole unit (such as [FeCl4](-) and aromatic sulfur compounds (X)) rather than only Fe or S atom. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Imidazole-Aided Native Chemical Ligation: Imidazole as a One-Pot Desulfurization-Amenable Non-Thiol-Type Alternative to 4-Mercaptophenylacetic Acid.

    Science.gov (United States)

    Sakamoto, Ken; Tsuda, Shugo; Mochizuki, Masayoshi; Nohara, Yukie; Nishio, Hideki; Yoshiya, Taku

    2016-12-12

    Various bioactive proteins have been synthesized by native chemical ligation (NCL) and its combination with subsequent desulfurization (e.g., conversion from Cys to Ala). In NCL, excess 4-mercaptophenylacetic acid (MPAA) is generally added to facilitate the reaction. However, co-elution of MPAA with the ligation product during preparative high-performance liquid chromatography sometimes reduces its usefulness. In addition, contamination of MPAA disturbs subsequent desulfurization. Here, we report for the first time that imidazole can be adopted as an alternative to MPAA in NCL using a peptide-alkylthioester. The efficiency of the imidazole-aided NCL (Im-NCL) is similar to that of traditional MPAA-aided NCL. As model cases, we successfully synthesized adiponectin(19-107) and [Ser(PO3 H2 )(65) ]-ubiquitin using Im-NCL with a one-pot desulfurization. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Social Networking and Smart Technology: Viable Environmental Communication Tools…?

    Science.gov (United States)

    Montain, J.; Byrne, J. M.

    2010-12-01

    To what extent do popular social networking channels represent a viable means for disseminating information regarding environmental change to the general public? Are new forms of communication such as YouTube™, Facebook™, MySpace™ and Twitter™ and smart devices such as iPhone™ and BlackBerry™ useful and effective in terms motivating people into social action and behavioural modification; or do they simply pay ‘lip service’ to these pressing environmental issues? This project will explore the background connections between social networking and environmental communication and education; and outline why such tools might be an appropriate way to connect to a broad audience in an efficient and unconventional manner. Further, research will survey the current prevalence of reliable environmental change information on social networking Internet-based media; and finally, suggestions for improved strategies and new directions will be provided.

  5. Dissolvable tattoo sensors: from science fiction to a viable technology

    Science.gov (United States)

    Cheng, Huanyu; Yi, Ning

    2017-01-01

    Early surrealistic painting and science fiction movies have envisioned dissolvable tattoo electronic devices. In this paper, we will review the recent advances that transform that vision into a viable technology, with extended capabilities even beyond the early vision. Specifically, we focus on the discussion of a stretchable design for tattoo sensors and degradable materials for dissolvable sensors, in the form of inorganic devices with a performance comparable to modern electronics. Integration of these two technologies as well as the future developments of bio-integrated devices is also discussed. Many of the appealing ideas behind developments of these devices are drawn from nature and especially biological systems. Thus, bio-inspiration is believed to continue playing a key role in future devices for bio-integration and beyond.

  6. A viable logarithmic f(R) model for inflation

    Energy Technology Data Exchange (ETDEWEB)

    Amin, M.; Khalil, S. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Salah, M. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Department of Mathematics, Faculty of Science, Cairo University,Giza (Egypt)

    2016-08-18

    Inflation in the framework of f(R) modified gravity is revisited. We study the conditions that f(R) should satisfy in order to lead to a viable inflationary model in the original form and in the Einstein frame. Based on these criteria we propose a new logarithmic model as a potential candidate for f(R) theories aiming to describe inflation consistent with observations from Planck satellite (2015). The model predicts scalar spectral index 0.9615

  7. Simultaneous pyometra and viable puppies’ gestation in a bitch

    Directory of Open Access Journals (Sweden)

    A. Risso

    2014-08-01

    Full Text Available Here we describe a case of pyometra coexisting with gestation in a 4.5 year-old miniature short-haired Dachshund. The dog exhibited depression, vaginal discharge, polydipsia and dehydration. Ultrasound examination revealed the presence of low to moderate anechoic fluid collection in the left uterine horn. Blood analysis revealed mild neutrophilia with a left shift. Based on these findings a presumptive diagnosis of pyometra was made and the bitch was treated using amoxicillin-clavulanate with dopaminergic agonist (cabergoline. A second ultrasound scan revealed the presence of two gestational vesicles in the right uterine horn that were successfully carried to term. Unusually, while pyometra persisted in the left uterine horn, two viable puppies were delivered by caesarean section from the right uterine horn.

  8. Profiling Total Viable Bacteria in a Hemodialysis Water Treatment System.

    Science.gov (United States)

    Chen, Lihua; Zhu, Xuan; Zhang, Menglu; Wang, Yuxin; Lv, Tianyu; Zhang, Shenghua; Yu, Xin

    2017-05-28

    Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of 2.14 × 10 7 copies/100 ml in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

  9. Development of a portable, modular unit for the optimization of ultrasound-assisted oxidative desulfurization of diesel

    Science.gov (United States)

    Wan, Meng-Wei

    Due to the stringent rules requiring ultra-low sulfur content in diesel fuels, it is necessary to develop alternative methods of desulfurization of fossil fuel derived oil, such as diesel. Current technology is not sufficient to solve this problem. Ultrasound applied to oxidative desulfurization which combined three complementary techniques: ultrasonication, phase transfer catalysis (PTC) and transition metal catalyzed oxidation, has accomplished high sulfur removal in a short contact time at ambient temperature and atmospheric pressure. This research has successfully demonstrated that the higher oxidation efficiency of BT to BTO and free of any by-products by using tetraoctylammonium fluoride as phase transfer agent. The oxidation rate of BT to BTO increased with increasing the carbon chain length of QAS cations. Under the same length of carbon chain, the oxidation rate of BT to BTO increased with decreasing the molecular size of QAS anions. Moreover, for diesel fuels containing various levels of sulfur content, UAOD process followed by solvent extraction has demonstrated that the sulfur reduction can reach above 95 % removal efficiency or final sulfur content below 15 ppm in mild condition. For large-scale commercial production, this research has successfully developed and operated a continuous desulfurization unit, which consists of a sonoractor, an RF amplifier, a function generator, a pretreatment tank, and a pipeline system. A single unit only needed 2' x 4' x 1' space for installation. The results indicated that the remarkable 92% removal efficiency for the sulfur in marine logistic diesel, even at a treatment rate as high as 25 lb/hour which is approximately 2 barrels per day. Therefore, this sonoreactor demonstrated the feasibility of large-scale operation even in a relatively small installation with low capital investment and maintenance cost. It also ensures the safety considerations by operating with diluted hydrogen peroxide under ambient temperature

  10. Foaming in wet flue gas desulfurization plants: Laboratory‐scale investigation of long‐term performance of antifoaming agents

    DEFF Research Database (Denmark)

    Qin, Siqiang; Hansen, Brian Brun; Kiil, Søren

    2013-01-01

    Spontaneous foaming can cause a range of operational problems in industrial processes such as wet flue gas desulfurization (FGD). This work investigates the performance of selected antifoaming agents (Nalco FM‐37, Foamtrol 2290, and rapeseed oil) on foams generated by egg white albumin (protein......), sodium dodecyl sulfate, and adipic acid at conditions of relevance for wet FGD plants. The addition of antifoaming agents breaks any existing foam and causes an induction period without foaming, after which the foam gradually will begin to reappear. Foaming by egg white albumin (2 g/L) at 0.014 m/s could...

  11. Combination of Thiol-Additive-Free Native Chemical Ligation/Desulfurization and Intentional Replacement of Alanine with Cysteine.

    Science.gov (United States)

    Tsuda, Shugo; Mochizuki, Masayoshi; Nishio, Hideki; Yoshiya, Taku

    2016-11-17

    We report a novel strategy for native chemical ligation (NCL). Alanines not located at a ligation site are temporarily replaced with cysteines, and this enables efficient thiol-additive-free NCL, with subsequent desulfurization to regenerate the target peptide. We synthesized stresscopin-related peptide and neuroendocrine regulatory peptide-2 (NERP-2) by this method. We confirmed that both conventional alkyl thioester and thioester-equivalent N-acyl-N'-methyl-benzimidazolinone (MeNbz) can be adopted as thioester components for thiol-additive-free NCL of multi-Cys-containing peptides. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Operation results of in-line type flue gas desulfurization system for Thai Union Paper Public Co. Ltd.

    Energy Technology Data Exchange (ETDEWEB)

    Tamaru, T.; Nakamura, N.; Inoue, H.; Fujino, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1999-10-01

    The in-line type flue gas desulfurization (FGD) system delivered to Thai Union Paper Public Co., Ltd, was inaugurated in July 1997 and demonstration operation was completed in March 1998. The project was supported by the Ministry International Trade and Industry of Japan as part of the Green Aid Plan. The FGD system has adopted the wet limestone-gypsum procees. The absorbent slurry is directly sprayed into the flue gas duct and does not require an absorber. This main feature minimizes the initial cost. The SO{sub 2} removal efficiency was more than 70% and the gypsum purity was of the same level as conventional FGD. (author)

  13. Anion-exchange resin-based desulfurization process. Quarterly technical progress report, October 1, 1991--December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Sheth, A.C.; Strevel, S.D.

    1991-12-31

    The University of Tennessee Space Institute (UTSI) has a Department of Energy grant to further develop the Institute`s anion-exchange resin-based flue gas, desulfurization concept. The developmental program proposed includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins` performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. The process schematic developed from the results will be used to estimate the related economics.

  14. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 12, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    In December 1989, the U.S. Department of Energy selected 13 projects for funding under the Federal Clean Coal Technology Program (Round III). One of the projects selected was the project sponsored by LIFAC North America, (LIFAC NA), titled {open_quotes}LIFAC Sorbent Injection Desulfurization Demonstration Project.{close_quotes} The LIFAC technology uses upper-furnace limestone injection with patented humidification of the flue gas to remove 75-85% of the sulfur dioxide (SO{sub 2}) in the flue gas. The host site for this $22 million, three-phase project is Richmond Power and Light`s Whitewater Valley Unit No. 2 in Richmond, Indiana. The three project phases are: (1) Design; (2A) Long Lead Procurement; (2B) Construction; and (3) Operations. The design phase began on August 8, 1990 and was scheduled to last six months. Phase 2A, long lead procurement, overlaps the design phase and was expected to require about four months to complete. The construction phase was then to continue for another seven months, while the operations phase was scheduled to last about twenty-six months. In November 1990, after a ten (10) month negotiation period, LIFAC NA and the U.S. DOE entered into a Cooperative Agreement for the design, construction, and demonstration of the LIFAC system. This report is the twelfth Technical Progress Report covering the period July 1, 1993 through the end of September 1993. Due to the power plant`s planned outage in March 1991, and the time needed for engineering, design and procurement of critical equipment, DOE and LIFAC NA agreed to execute the Design Phase of the project in August 1990, with DOE funding contingent upon final signing of the Cooperative Agreement.

  15. Genetic approach to microbial coal desulfurization: Final report, January 1--December 31, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D. P.

    1989-03-01

    Naturally occurring sulfur bacteria such as Thiobacillus and Sulfolobus have been shown to remove inorganic sulfur form coal. If genetically modified bacteria could be developed to attack the organic sulfur (which is not removed by natural sulfur bacteria) then it should be possible to devise a microbial process for coal desulfurization. Such a biological approach should be relatively cheap and safe and produce harmless waste products. We have developed a multiple mutant of Escherichia coli which can oxidize thiophene derivatives and are continuing to improve this strain. We have cloned DNA fragments from the chromosome of the triple mutant NAR30 thdA thdC thD. One plasmid pKA 15 carries what is presumably the thdA gene. Another plasmid, pKA 10, carries two genes designated thdF and thdG which, when present on a plasmid in multiple copies, confer the ability to oxidize thiophenes and furans. We think it probable that thdA is a regulator gene and that thdF and thdG are two of the structural genes which it regulates. Recently we have subcloned fragments of a large plasmid present in a natural isolate which degrades dibenzo-thiophene sulfone. No single fragment alone confers on an E. coli host the ability to degrade any aromatic substrate; however, certain mixtures of two or three fragments confer the ability to degrade benzoate. We have also mapped and partly characterized mutant affecting the enzyme thiosulfate: sulfur transferase (''rhodanese'') which removes (or inserts) sulfur from (or into) a variety of organic molecules. 26 refs., 6 figs., 6 tabs.

  16. Flue gas desulfurization products as sulfur sources for alfalfa and soybean

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.M.; Dick, W.A.; Nelson, S. [Ohio State University, Wooster, OH (US). School of Natural Resources

    2005-02-01

    Sulfur deficiencies in soil are expected to increase due to growth of high-yielding crop varieties, use of S-free fertilizers, and removal of S from industrial emissions. Flue gas desulfurization (FGD) products, created when coal is burned and SO{sub 2} is removed from the flue gases, may serve as efficient S sources. However, there are few reports on their use for the enhancement of crop growth. Agricultural gypsum and two types of FGD products, that contain either vermiculite or perlite, were applied at 0, 16, and 67 kg S ha{sup -1} to an agricultural soil (Wooster silt loam, Typic Fragiudalf). Dry weight of a new planting of alfalfa (Medicago sativa L.) was increased up to 40% by the treatments of FGD products or gypsum compared with the untreated control. Gypsum and FGD products were also applied at 0, 8,16, and 24 kg S ha{sup -1} to five established alfalfa stands in different Ohio regions. Mean alfalfa yield was significantly (P {le} 0.05) increased by approximately 5.0% in 2001 and 6.0% in 2002 with the S treatments of FGD products or gypsum compared with the untreated control. Alfalfa yields for FGD products and gypsum treatments were similar. A slight positive yield response was observed for soybean (Glycine max L.) when soils were treated with S-containing materials. Soil and plant analyses were made to assess potential adverse environmental impacts and none were observed. Thus, these FGD products can be safely applied to agricultural soils as S sources and can improve alfalfa yields in S-deficient soils.

  17. Limestone scrubbing for 2000 flue gas desulfurization system. Final report, October 1, 1993--April 1, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-16

    As emission limits for sulfur dioxide from utility coal-fired boilers become lower due to increased regulation and environmental concern around the globe, power generating companies require increasingly cost-effective pollution control technology in order to maintain or reduce the cost of electricity to the end user. Limestone based wet flue gas desulfurization, or WFGD, is the preferred sulfur dioxide removal technology for utilities in the US and worldwide. This is a result of its extensive reference list, lower risks, and lower evaluated overall costs. For more than two decades ABB has supplied WFGD systems and currently has greater than 29,000 MWe of scrubbing capacity in operation. Given the industry`s ever-present need for lower costs, ABB funds a continuous research and development program focused on technology advancements that will reduce both capital and operating costs for its customers. As a result of this effort the LS-2 Concept WFGD System was developed through revolutionary design changes in every significant subprocess of conventional WFGD technology. To demonstrate the cumulative effects of all the individual advancements of the LS-2 Concept and to prove the process`s viability and cost-efficiency under representative US power plant conditions, the Limestone Scrubbing for 2000 project was initiated. This report is the final submittal to the Ohio Coal Development Office to document the results of this demonstrate project. The four-phase project execution, from the initial design and procurement through erection and extensive testing, proceeded as scheduled and on budget. The project resulted in a successful reference program that illustrates, in detail, the improved efficiencies and costs of the LS-2 advancements.

  18. Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils

    Science.gov (United States)

    Chen, Qun; Wang, Shujuan; Li, Yan; Zhang, Ning; Zhao, Bo; Zhuo, Yuqun; Chen, Changhe

    2015-01-01

    Abstract Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline–alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation. PMID:26064038

  19. Desulfurizing Ability of the CaOsatd.-CaCl2-CaF2 Slags

    Science.gov (United States)

    Liu, Jiazhan; Kobayashi, Yoshinao

    2017-04-01

    Desulfurizing ability of the CaO-CaCl2-CaF2 slags saturated with CaO has been investigated from the viewpoint of the sulfide capacity and CaO solubility. The CaO-CaCl2-CaF2 slags containing small amounts of Cu2O and CaS were inserted in a CaO crucible with metallic copper. The CaO crucible was sealed in a nickel holder to prevent the evaporation of CaCl2, then heated up and kept at temperatures from 1573 K (1300 °C) to 1673 K (1400 °C) for 24 hours, which enabled the system inside the CaO crucible to reach the equilibrium. As expected, the sulfide capacity derived from the data obtained as well as CaO solubility of the slag increase with an increase in temperature at a constant ratio of CaCl2/CaF2. The solubility of CaO increases by the replacement of CaF2 with CaCl2, whereas the sulfide capacity slightly decreases and the activity coefficient of CaS ( γ CaS) increases. This suggests that CaF2 has stronger interaction with CaS than CaCl2. The sulfur distribution ratio between carbon-saturated iron melts and the CaO-CaCl2 slag has been calculated to be about 10 000 at 1573 K (1300 °C) using the sulfide capacity obtained, which value is still large enough even with the replacement of CaF2 by CaCl2.

  20. Advanced Flue Gas Desulfurization (AFGD) demonstration project: Volume 2, Project performance and economics. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-30

    The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These features all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.

  1. Preparation of flexible zinc oxide/carbon nanofiber webs for mid-temperature desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soojung; Bajaj, Bharat [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Byun, Chang Ki; Kwon, Soon-Jin [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Joh, Han-Ik [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Yi, Kwang Bok, E-mail: cosy32@cnu.ac.kr [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Sungho, E-mail: sunghol@kist.re.kr [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Department of Nano Material Engineering, University of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-11-30

    Graphical abstract: - Highlights: • Polyacrylonitrile (PAN) and zinc precursor were electrospun and heat-treated for preparing zinc oxide (ZnO) modified carbon nanofibers (CNF). • A facile synthesis of composite webs resulted in uniformly loaded ZnO on the surface of CNFs. • The composites showed significant hydrogen sulfide adsorption efficiency at 300 °C. • The flexible webs can be applied for mid-temperature desulfurization. - Abstract: Polyacrylonitrile (PAN) derived carbon nanofiber (CNF) webs loaded with zinc oxide (ZnO) were synthesized using electrospinning and heat treatment at 600 °C. Uniformly dispersed ZnO nanoparticles, clarified by X-ray diffraction and scanning electron microscopy, were observed on the surface of the nanofiber composites containing 13.6–29.5 wt% of ZnO. The further addition of ZnO up to 34.2 wt% caused agglomeration with a size of 50–80 nm. Higher ZnO contents led the concentrated ZnO nanoparticles on the surface of the nanofibers rather than uniform dispersion along the cross-section of the fiber. The flexible composite webs were crushed and tested for hydrogen sulfide (H{sub 2}S) adsorption at 300 °C. Breakthrough experiments with the ZnO/CNF composite containing 25.7 wt% of ZnO for H{sub 2}S adsorption showed three times higher ZnO utilization efficiency compared to pure ZnO nano powders, attributed to chemisorption of the larger surface area of well dispersed ZnO particles on nanofibers and physical adsorption of CNF.

  2. Sodic soils reclaimed with by-product from flue gas desulfurization: corn production and soil quality.

    Science.gov (United States)

    Chun, S; Nishiyama, M; Matsumoto, S

    2001-01-01

    Interest is growing in the use of by-product from flue gas desulfurization (FGD) to reclaim sodic soils by controlling the pH and excessive Na+. This study evaluated the effects on corn (Zea mays) production and pH and electrical conductivity (EC) of calcareous sodic soil during four times of cultivation when the by-product was applied once at the first cultivation (Study I) and the impacts on plant and soil quality at first cultivation when the by-product was applied to the soil at 23,000 kg ha-1 (Study II). In Study I, the germination rate and corn production increased by applying the by-product (0, 5,800, 11,600, and 23,100 kg ha-1), and the greatest total amounts of corn production during the four times of cultivation was when the by-product was applied at 23,100 kg ha-1. In Study II, the pH, exchangeable sodium percentage (ESP), clay dispersion and soluble Na+ in the soil decreased and soluble Mg2+ and soluble K+ in the soil increased. The soil pH was reduced from 9.0 to 7.7 by applying the by-product. However, the by-product decreased the concentrations of total N and P in corn leaves in this study. No significant difference in the concentrations of Mo, Zn, Pb, Ni, Cd, Mn, Cr, Cu, and Al in corn leaves and the soil was observed between the by-product addition and the control except for B in the soil and Fe in corn leaves. The concentration of B in the soil was reduced from 28.7 mg kg-1 to 25.4 mg kg-1 and the concentration of Fe in corn leaves increased from 17.5 mg kg-1 to 22.6 mg kg-1 by applying the by-product in our study.

  3. Influence of Flue Gas Desulfurization Gypsum Amendments on Heavy Metal Distribution in Reclaimed Sodic Soils.

    Science.gov (United States)

    Chen, Qun; Wang, Shujuan; Li, Yan; Zhang, Ning; Zhao, Bo; Zhuo, Yuqun; Chen, Changhe

    2015-06-01

    Although flue gas desulfurization (FGD) gypsum has become an effective soil amendment for sodic soil reclamation, it carries extra heavy metal contamination into the soil environment. The fate of heavy metals introduced by FGD gypsum in sodic or saline-alkali soils is still unclear. This work aims to investigate the effects of FGD gypsum addition on the heavy metal distributions in a sodic soil. Original soil samples were collected from typical sodic land in north China. Soil column leaching tests were conducted to investigate the influence of FGD gypsum addition on the soil properties, especially on distribution profiles of the heavy metals (Pb, Cd, Cr, As, and Hg) in the soil layers. Results showed that pH, electrical conductivity, and exchangeable sodium percentage in amended soils were significantly reduced from 10.2 to 8.46, 1.8 to 0.2 dS/m, and 18.14% to 1.28%, respectively. As and Hg concentrations in the soils were found to be positively correlated with FGD gypsum added. The amount of Hg in the leachate was positively correlated with FGD gypsum application ratio, whereas a negative correlation was observed between the Pb concentration in the leachate and the FGD gypsum ratio. Results revealed that heavy metal concentrations in soils complied well with Environmental Quality Standard for Soils in China (GB15618-1995). This work helps to understand the fate of FGD gypsum-introduced heavy metals in sodic soils and provides a baseline for further environmental risk assessment associated with applying FGD gypsum for sodic soil remediation.

  4. The elusive minimum viable population size for white sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL; Lepla, Ken B. [Idaho Power Company; Van Winkle, Webb [Van Windle Environmental Consulting; James, Mr Brad [Washington Department of Fish and Wildlife; McAdam, Dr Steve [University of British Columbia, Vancouver

    2010-01-01

    Biological conservation of sturgeon populations is a concern for many species. Those responsible for managing the white sturgeon (Acipenser transmontanus) and similar species are interested in identifying extinction thresholds to avoid. Two thresholds that exist in theory are the minimum viable population size (MVP) and minimum amount of suitable habitat. In this paper, we present both model and empirical estimates of these thresholds. We modified a population viability analysis (PVA) model for white sturgeon to include two new Allee mechanisms. Despite this, PVA-based MVP estimates were unrealistically low compared with empirical estimates unless opportunities for spawning were assumed to be less frequent. PVA results revealed a trade-off between MVP and habitat thresholds; smaller populations persisted in longer river segments and vice versa. Our empirical analyses suggested (1) a MVP range based on population trends from 1,194 to 27,700 individuals, and (2) a MVP estimate of 4,000 individuals based on recruitment. Long-term historical population surveys are needed for more populations to pinpoint an MVP based on trends, whereas the available data were sufficient to estimate MVP based on recruitment. Beyond the MVP, we developed a hierarchical model for population status based on empirical data. Metapopulation support was the most important predictor of population health, followed by the length of free-flowing habitat, with habitat thresholds at 26 and 150 km. Together, these results suggest that habitat and connectivity are important determinants of population status that likely influence the site-specific MVP thresholds.

  5. Towards a viable and just global nursing ethics.

    Science.gov (United States)

    Crigger, Nancy J

    2008-01-01

    Globalization, an outgrowth of technology, while informing us about people throughout the world, also raises our awareness of the extreme economic and social disparities that exist among nations. As part of a global discipline, nurses are vitally interested in reducing and eliminating disparities so that better health is achieved for all people. Recent literature in nursing encourages our discipline to engage more actively with social justice issues. Justice in health care is a major commitment of nursing; thus questions in the larger sphere of globalization, justice and ethics, are our discipline's questions also. Global justice, or fairness, is not an issue for some groups or institutions, but a deeper human rights issue that is a responsibility for everyone. What can we do to help reduce or eliminate the social and economic disparities that are so evident? What kind of ethical milieu is needed to address the threat that globalization imposes on justice and fairness? This article enriches the conceptualization of globalization by investigating recent work by Schweiker and Twiss. In addition, I discuss five qualities or characteristics that will facilitate the development of a viable and just global ethic. A global ethic guides all people in their response to human rights and poverty. Technology and business, two major forces in globalization that are generally considered beneficial, are critiqued as barriers to social justice and the common good.

  6. Keeping checkpoint/restart viable for exascale systems.

    Energy Technology Data Exchange (ETDEWEB)

    Riesen, Rolf E.; Bridges, Patrick G. (IBM Research, Ireland, Mulhuddart, Dublin); Stearley, Jon R.; Laros, James H., III; Oldfield, Ron A.; Arnold, Dorian (University of New Mexico, Albuquerque, NM); Pedretti, Kevin Thomas Tauke; Ferreira, Kurt Brian; Brightwell, Ronald Brian

    2011-09-01

    Next-generation exascale systems, those capable of performing a quintillion (10{sup 18}) operations per second, are expected to be delivered in the next 8-10 years. These systems, which will be 1,000 times faster than current systems, will be of unprecedented scale. As these systems continue to grow in size, faults will become increasingly common, even over the course of small calculations. Therefore, issues such as fault tolerance and reliability will limit application scalability. Current techniques to ensure progress across faults like checkpoint/restart, the dominant fault tolerance mechanism for the last 25 years, are increasingly problematic at the scales of future systems due to their excessive overheads. In this work, we evaluate a number of techniques to decrease the overhead of checkpoint/restart and keep this method viable for future exascale systems. More specifically, this work evaluates state-machine replication to dramatically increase the checkpoint interval (the time between successive checkpoint) and hash-based, probabilistic incremental checkpointing using graphics processing units to decrease the checkpoint commit time (the time to save one checkpoint). Using a combination of empirical analysis, modeling, and simulation, we study the costs and benefits of these approaches on a wide range of parameters. These results, which cover of number of high-performance computing capability workloads, different failure distributions, hardware mean time to failures, and I/O bandwidths, show the potential benefits of these techniques for meeting the reliability demands of future exascale platforms.

  7. Is Greenberg’s “Macro-Carib” viable?

    Directory of Open Access Journals (Sweden)

    Spike Gildea

    2007-08-01

    Full Text Available In his landmark work Language in the Americas, Greenberg (1987 proposed that Macro-Carib was one of the major low-level stocks of South America, which together with Macro-Panoan and Macro-Ge-Bororo were claimed to comprise the putative Ge-Pano-Carib Phylum. His Macro-Carib includes the isolates Andoke and Kukura, and the Witotoan, Peba-Yaguan, and Cariban families. Greenberg’s primary evidence came from person-marking paradigms in individual languages, plus scattered words from individual languages collected into 79 Macro-Carib ‘etymologies’ and another 64 Amerind ‘etymologies’. The goal of this paper is to re-evaluate Greenberg’s Macro-Carib claim in the light of the much more extensive and reliable language data that has become available largely since 1987. Based on full person-marking paradigms for Proto-Cariban, Yagua, Bora and Andoke, we conclude that Greenberg’s morphological claims are unfounded. For our lexical comparison, we created lexical lists for Proto-Cariban, Proto-Witotoan, Yagua and Andoke, for both Greenberg’s 143 putative etymologies and for the Swadesh 100 list. From both lists, a total of 23 potential cognates were found, but no consonantal correspondences were repeated even once. We conclude that our greatly expanded and improved database does not provide sufficient evidence to convince the skeptic that the Macro-Carib hypothesis is viable.

  8. Case-based anatomy teaching: a viable alternative?

    Science.gov (United States)

    Eseonu, Onyedikachi; Carachi, Robert; Brindley, Nicola

    2013-08-01

    Over the last two decades, there has been a decline in the amount of time available for anatomy teaching in the medical undergraduate curriculum, and new methods of anatomy teaching have been adopted for pragmatic reasons, with little evidence base to support their proposed educational benefits. This study seeks to establish the effect of a case-based teaching method on students' confidence in anatomy. Forty-three student volunteers in the clinical phase of the Glasgow medical course were given weekly anatomy teaching sessions based on clinical case presentations over 4 weeks. The students were given an anatomy test, and were asked to rate their confidence in their anatomy knowledge before and after the teaching sessions. There was a two-point increase in students' self-rated confidence, and a 10.9 per cent increase in average test score after the case-based anatomy teaching sessions. Both of these increases were statistically significant (p teaching was also highly rated by students, which may make it a viable option for the teaching of anatomy in the modern medical curriculum. © 2013 John Wiley & Sons Ltd.

  9. Protein design algorithms predict viable resistance to an experimental antifolate.

    Science.gov (United States)

    Reeve, Stephanie M; Gainza, Pablo; Frey, Kathleen M; Georgiev, Ivelin; Donald, Bruce R; Anderson, Amy C

    2015-01-20

    Methods to accurately predict potential drug target mutations in response to early-stage leads could drive the design of more resilient first generation drug candidates. In this study, a structure-based protein design algorithm (K* in the OSPREY suite) was used to prospectively identify single-nucleotide polymorphisms that confer resistance to an experimental inhibitor effective against dihydrofolate reductase (DHFR) from Staphylococcus aureus. Four of the top-ranked mutations in DHFR were found to be catalytically competent and resistant to the inhibitor. Selection of resistant bacteria in vitro reveals that two of the predicted mutations arise in the background of a compensatory mutation. Using enzyme kinetics, microbiology, and crystal structures of the complexes, we determined the fitness of the mutant enzymes and strains, the structural basis of resistance, and the compensatory relationship of the mutations. To our knowledge, this work illustrates the first application of protein design algorithms to prospectively predict viable resistance mutations that arise in bacteria under antibiotic pressure.

  10. Towards viable cosmological models of disformal theories of gravity

    Science.gov (United States)

    Sakstein, Jeremy

    2015-01-01

    The late-time cosmological dynamics of disformal gravity are investigated using dynamical systems methods. It is shown that in the general case there are no stable attractors that screen fifth forces locally and simultaneously describe a dark energy dominated universe. Viable scenarios have late-time properties that are independent of the disformal parameters and are identical to the equivalent conformal quintessence model. Our analysis reveals that configurations where the Jordan frame metric becomes singular are only reached in the infinite future, thus explaining the natural pathology resistance observed numerically by several previous works. The viability of models where this can happen is discussed in terms of both the cosmological dynamics and local phenomena. We identify a special parameter tuning such that there is a new fixed point that can match the presently observed dark energy density and equation of state. This model is unviable when the scalar couples to the visible sector but may provide a good candidate model for theories where only dark matter is disformally coupled.

  11. SMA actuators: a viable practical technology (Presentation Video)

    Science.gov (United States)

    Browne, Alan L.; Brown, Jeffrey; Hodgson, Darel E.

    2015-04-01

    Diverse products either based solely on or incorporating Shape Memory Alloys (SMA) have and are being made in a wide range of industries, and IP is being captured. Why then compared to SE (superelastic) Nitinol, and especially conventional technology, do so few ideas reach production? This presentation delves deeply into this topic in reaching the final assessment that SMA actuators are indeed now a viable practical technology. The presentation begins with an introduction to and description of the fundamental basis of SMA actuator technology. Examples of multiple commercially available geometric forms of SMA actuators are given and the functionalities that they provide are described. This is followed by examples of multiple commercial products incorporating such SMA actuators. Given that there are literally millions of commercial products incorporating conventional actuator technologies, indications are given as to why there are their less than 1000 that utilize SMA. Experience based challenges to the commercial use of SMA actuators are described. Besides having to compete with existing non-SMA technology which is quite mature additional challenges that are unique to SM actuators are indicated these including a wider than expected set of technical engineering problems and challenges and that a broader scope of dynamics is required.

  12. The control of H2S in biogas using iron ores as in situ desulfurizers during anaerobic digestion process.

    Science.gov (United States)

    Zhou, Qiying; Jiang, Xia; Li, Xi; Jiang, Wenju

    2016-09-01

    In this study, five kinds of iron ores, limonite, hematite, manganese ore, magnetite and lava rock, were used as the in situ desulfurizers in the anaerobic digestion reactors to investigate their effects on controlling H2S in biogas. The results show that the addition of the five iron ores could significantly control the content of H2S in biogas, with the best performance for limonite. As limonite dosages increase (10-60 g/L), the contents of H2S in biogas were evidently decreased in the digesters with different initial sulfate concentrations (0-1000 mg/L). After the anaerobic digestion, the removed sulfur was mostly deposited on the surface of limonite. A possible mechanism of H2S control in biogas by limonite was proposed preliminarily, including adsorption, FeS precipitation, and Fe (III) oxidation. The results demonstrated that limonite was a promising in situ desulfurizer for controlling H2S in biogas with low cost and high efficiency.

  13. Alloying effect of copper on the corrosion properties of low-alloy steel for flue gas desulfurization system

    Science.gov (United States)

    Kim, Seon-Hong; Park, Sun-Ah; Kim, Jung-Gu; Shin, Kee-Sam; He, Yinsheng

    2015-03-01

    The alloying effect of Cu for a flue gas desulfurization materials was investigated using the electrochemical methods in the modified green death solution and the surface analyses. The test results demonstrated that the densely formed rust layer with high metallic Cu content improves the corrosion resistance of Cu-containing steel in the flue gas desulfurization (FGD) environment. The rust layer on the surface of the 0.02 wt% Cu steel, which has an insufficient Cu content, was less protective than others. The 0.05 wt% Cu steel represented the highest corrosion resistance due to the formation of the densely formed rust layer with optimum Cu content. Because the free standing Cu2S precipitates had the insoluble characteristic in highly acidic solution, it produced the relatively porous Cu-enriched layer on the 0.08 wt% Cu steel surface. From these phenomena, the corrosion resistance of specimen decreased as the Cu content of specimen increased from 0.05 wt% to 0.08 wt%.

  14. Efficient H2O2/CH3COOH oxidative desulfurization/denitrification of liquid fuels in sonochemical flow-reactors.

    Science.gov (United States)

    Calcio Gaudino, Emanuela; Carnaroglio, Diego; Boffa, Luisa; Cravotto, Giancarlo; Moreira, Elizabeth M; Nunes, Matheus A G; Dressler, Valderi L; Flores, Erico M M

    2014-01-01

    The oxidative desulfurization/denitrification of liquid fuels has been widely investigated as an alternative or complement to common catalytic hydrorefining. In this process, all oxidation reactions occur in the heterogeneous phase (the oil and the polar phase containing the oxidant) and therefore the optimization of mass and heat transfer is of crucial importance to enhancing the oxidation rate. This goal can be achieved by performing the reaction in suitable ultrasound (US) reactors. In fact, flow and loop US reactors stand out above classic batch US reactors thanks to their greater efficiency and flexibility as well as lower energy consumption. This paper describes an efficient sonochemical oxidation with H2O2/CH3COOH at flow rates ranging from 60 to 800 ml/min of both a model compound, dibenzotiophene (DBT), and of a mild hydro-treated diesel feedstock. Four different commercially available US loop reactors (single and multi-probe) were tested, two of which were developed in the authors' laboratory. Full DBT oxidation and efficient diesel feedstock desulfurization/denitrification were observed after the separation of the polar oxidized S/N-containing compounds (S≤5 ppmw, N≤1 ppmw). Our studies confirm that high-throughput US applications benefit greatly from flow-reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Removal of hazardous gaseous pollutants from industrial flue gases by a novel multi-stage fluidized bed desulfurizer

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, C.R. [State Pollution Control Board, Bhubaneswar, Orissa (India); Adapala, Sivaji [Department of Chemical Engineering, Indian Institute of Technology (IIT) Kharagpur, P.O. Kharagpur Technology, Kharagpur 721302, West Bengal (India); Meikap, B.C., E-mail: bcmeikap@che.iitkgp.ernet.in [Department of Chemical Engineering, Indian Institute of Technology (IIT) Kharagpur, P.O. Kharagpur Technology, Kharagpur 721302, West Bengal (India)

    2009-06-15

    Sulfur dioxide and other sulfur compounds are generated as primary pollutants from the major industries such as sulfuric acid plants, cupper smelters, catalytic cracking units, etc. and cause acid rain. To remove the SO{sub 2} from waste flue gas a three-stage counter-current multi-stage fluidized bed adsorber was developed as desulfurization equipment and operated in continuous bubbling fluidization regime for the two-phase system. This paper represents the desulfurization of gas mixtures by chemical sorption of sulfur dioxide on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of the multi-stage fluidized bed reactor are of high mass transfer and high gas-solid residence time that can enhance the removal of acid gas at low temperature by dry method. Experiments were carried out in the bubbling fluidization regime supported by visual observation. The effects of the operating parameters such as sorbent (lime) flow rate, superficial gas velocity, and the weir height on SO{sub 2} removal efficiency in the multistage fluidized bed are reported. The results have indicated that the removal efficiency of the sulfur dioxide was found to be 65% at high solid flow rate (2.0 kg/h) corresponding to lower gas velocity (0.265 m/s), wier height of 70 mm and SO{sub 2} concentration of 500 ppm at room temperature.

  16. Improvement of desulfurizing activity of haloalkaliphilic Thialkalivibrio versutus SOB306 with the expression of Vitreoscilla hemoglobin gene.

    Science.gov (United States)

    Mu, Tingzhen; Yang, Maohua; Zhao, Jixiang; Sharshar, Moustafa Mohammed; Tian, Jiangnan; Xing, Jianmin

    2017-03-01

    To construct efficient transformation and expression system and further improve desulfurizing activity of cells through expression of Vitreoscilla hemoglobin (VHb) in haloalkaliphilic Thialkalivibrio versutus SOB306. We transferred plasmids pKT230 and pBBR-smr into T. versutus SOB306 via a conjugation method. We identified four promoters from among several predicted promoters by scoring for streptomycin resistance, and finally selected tac and p3 based on the efficiency of expression of red fluorescent protein (RFP). Expression of RFP when regulated by tac was more than three times that of p3 in SOB306. Further, we expressed VHb under the control of tac promoter in SOB306. Expression of VHb was verified using CO-difference spectra. The results showed that VHb expression can boost sulfur metabolism, as evidenced by an increase of about 11.7 ± 1.8% in the average rate of thiosulfate removal in the presence of VHb. A conjugation transfer and an expression system for Thialkalivibrio, has been developed for the first time and used for expression of VHb to improve desulfurizing activity.

  17. The effect of hydrogen peroxide solution on SO2 removal in the semidry flue gas desulfurization process.

    Science.gov (United States)

    Zhou, Yuegui; Zhu, Xian; Peng, Jun; Liu, Yaobin; Zhang, Dingwang; Zhang, Mingchuan

    2009-10-15

    The present study attempts to use hydrogen peroxide solution to humidify Ca(OH)(2) particles to enhance the absorption of SO(2) to achieve higher removal efficiency and to solve the valuable reuse of the reaction product in the semidry flue gas desulfurization (FGD) process. Experiments were carried out to examine the effect of various operating parameters including hydrogen peroxide solution concentration, Ca/S molar ratio and approach to adiabatic saturation temperature on SO(2) removal efficiency in a laboratory scale spray reactor. The product samples were analyzed to obtain semi-quantitative measures of mineralogical composition by X-ray diffraction (XRD) with reference intensity ratio (RIR) method and the morphology of the samples was examined by scanning electron microscope (SEM). Compared with spraying water to humidify Ca(OH)(2), SO(2) removal efficiency was improved significantly by spraying hydrogen peroxide solution of 1-3 wt.% to humidify Ca(OH)(2) because hydrogen peroxide solution enhanced the dissolution and absorption rate of SO(2). Moreover, XRD and SEM analyses show that the desulfurization products contain less amount of unreacted Ca(OH)(2) and more amount of stable calcium sulfate with increasing hydrogen peroxide solution concentration. Thus, the process mechanism of the enhanced absorption of SO(2) by spraying hydrogen peroxide solution to humidify Ca(OH)(2) was elucidated on the basis of the experimental results.

  18. A review on prospects and challenges of biological H2S removal from biogas with focus on biotrickling filtration and microaerobic desulfurization

    DEFF Research Database (Denmark)

    Khoshnevisan, Benyamin; Tsapekos, Panagiotis; Alfaro, Natalia

    2017-01-01

    is required to avoid damages to combustion equipment and prevent the formation of sulfur dioxide (SO2) which is an acid rain precursor. It has been well documented that physical, thermal, and chemical desulfurization approaches suffer from high operation costs as well as waste production needing...

  19. Inhibiting Mercury Re-emission and Enhancing Magnesia Recovery by Cobalt-Loaded Carbon Nanotubes in a Novel Magnesia Desulfurization Process.

    Science.gov (United States)

    Wang, Lidong; Qi, Tieyue; Hu, Mengxuan; Zhang, Shihan; Xu, Peiyao; Qi, Dan; Wu, Siyu; Xiao, Huining

    2017-10-03

    Mercury re-emission, because of the reduction of Hg(2+) to form Hg(0) by sulfite, has become a great concern in the desulfurization process. Lowering the concentrations of Hg(2+) and sulfite in the desulfurization slurry can retard the Hg(0) formation and, thus, mitigate mercury re-emission. To that end, cobalt-based carbon nanotubes (Co-CNTs) were developed for the simultaneous Hg(2+) removal and sulfite oxidation in this work. Furthermore, the thermodynamics and kinetics of the Hg(2+) adsorption and effect of Hg(2+) adsorption on catalytic activity of Co-CNTs were investigated. Experimental results revealed that the Co-CNTs not only accelerated sulfite oxidation to enable the recovery of desulfurization by-products but also acted as an effective adsorbent of Hg(2+) removal. The Hg(2+) adsorption rate mainly depended on the structure of the adsorption material regardless of the cobalt loading and morphological distribution. The catalytic activity of the Co-CNTs for sulfite oxidation was not significantly affected due to the Hg(2+) adsorption. Additionally, the isothermal adsorption behavior was well-fitted to the Langmuir model with an adsorption capacity of 166.7 mg/g. The mercury mass balance analysis revealed that the Hg(0) re-emission was decreased by 156% by adding 2.0 g/L of Co-CNTs. These results can be used as a reference for the simultaneous removal of multiple pollutants in the wet-desulfurization process.

  20. Acupuntura un tratamiento viable para las adicciones en Colombia

    Directory of Open Access Journals (Sweden)

    Hernán López-Suescún

    2013-09-01

    Full Text Available Resumen La acupuntura es una antigua técnica terapéutica desarrollada en China, que ha evidenciado ser efectiva en síntomas como las náuseas, vómito y dolor dentario. A pesar del sustento fisiológico que posibilitaría un uso efectivo en otras patologías, incluyendo el campo de las adicciones, los estudios son contradictorios, posiblemente por la diferencias de visión entre la medicina oriental y la occidental. El consumo de psicoactivos es un problema de salud pública en Colombia y en el mundo que genera grandes costos tangibles e intangibles, los cuales, en países desarrollados, puede llegar hasta el 1,6 % del PIB. En contraste, el beneficio económico del tratamiento de las adicciones, según las Naciones Unidas Contra la Droga y el Delito (UNODC, está entre 1:3 a 1:13; por lo tanto, cualquier esfuerzo que se realice en favor de los consumidores es una ganancia. Con base en estos datos, los organismos internacionales han generado políticas que ayudan a aminorar estos efectos. Colombia, como integrante de estos organismos, ha realizado varios compromisos para llevar a cabo dichas metas. Los tratamientos con auriculoterapia, como el protocolo NADA (National Acupuncture Detoxification Association, son los métodos más usados para las adicciones en el mundo, y aunque no se ha logrado evidenciar su efectividad, por su costo, facilidad y el poco riesgo de efectos adversos se hace viable en un país con pocos recursos económicos como Colombia.

  1. Technoeconomic Optimization of Waste Heat Driven Forward Osmosis for Flue Gas Desulfurization Wastewater Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Gingerich, Daniel B [Carnegie Mellon Univ., Pittsburgh, PA (United States); Bartholomew, Timothy V [Carnegie Mellon Univ., Pittsburgh, PA (United States); Mauter, Meagan S [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-06-26

    With the Environmental Protection Agency’s recent Effluent Limitation Guidelines for Steam Electric Generators, power plants are having to install and operate new wastewater technologies. Many plants are evaluating desalination technologies as possible compliance options. However, the desalination technologies under review that can reduce wastewater volume or treat to a zero-liquid discharges standard have a significant energy penalty to the plant. Waste heat, available from the exhaust gas or cooling water from coal-fired power plants, offers an opportunity to drive wastewater treatment using thermal desalination technologies. One such technology is forward osmosis (FO). Forward osmosis utilizes an osmotic pressure gradient to passively pull water from a saline or wastewater stream across a semi-permeable membrane and into a more concentrated draw solution. This diluted draw solution is then fed into a distillation column, where the addition of low temperature waste heat can drive the separation to produce a reconcentrated draw solution and treated water for internal plant reuse. The use of low-temperature waste heat decouples water treatment from electricity production and eliminates the link between reducing water pollution and increasing air emissions from auxiliary electricity generation. In order to evaluate the feasibility of waste heat driven FO, we first build a model of an FO system for flue gas desulfurization (FGD) wastewater treatment at coal-fired power plants. This model includes the FO membrane module, the distillation column for draw solution recovery, and waste heat recovery from the exhaust gas. We then add a costing model to account for capital and operating costs of the forward osmosis system. We use this techno-economic model to optimize waste heat driven FO for the treatment of FGD wastewater. We apply this model to three case studies: the National Energy Technology Laboratory (NETL) 550 MW model coal fired power plant without carbon

  2. Coscheduling in Clusters: Is It a Viable Alternative?

    Energy Technology Data Exchange (ETDEWEB)

    Choi, G S; Kim, J H; Ersoz, D; Yoo, A B; Das, C R

    2003-11-10

    than spin-based techniques like PB on a Linux platform. Third, the proposed HYBRID scheduling provides the best performance-energy behavior and can be implemented on any cluster with little effort. All these results suggest that blocking-based coscheduling techniques are viable candidates to be used instead of batching scheme for significant performance-energy benefits.

  3. Studies involving high temperature desulfurization/regeneration reactions of metal oxides for fuel cell development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jalan, V.

    1983-10-01

    Research conducted at Giner, Inc. during 1981 to 1983 under the present contract has been a continuation of the investigation of a high temperature regenerable desulfurization process capable of reducing the sulfur content in coal gases from 200 ppM to 1 ppM. The overall objective has been the integration of a coal gasifier with a molten carbonate fuel cell, which requires that the sulfur content be below 1 ppM. Commercially available low temperature processes incur an excessive energy penalty. Results obtained with packed-bed and fluidized bed reactors have demonstrated that a CuO/ZnO mixed oxide sorbent is regenerable and capable of lowering the sulfur content (as H/sub 2/S and COS) from 200 ppM in simulated hot coal-derived gases to below 1 ppM level at 600 to 650/sup 0/C. Four potential sorbents (copper, tungsten oxide, vanadium oxide and zinc oxide) were initially selected for experimental use in hot regenerable desulfurization in the temperature range 500 to 650/sup 0/C. Based on engineering considerations, such as desulfurization capacity in per weight or volume of sorbents, a coprecipitated CuO/ZnO was selected for further study. A structural reorganization mechanism, unique to mixed oxides, was identified: the creation of relatively fine crystallites of the sulfided components (Cu/sub 2/S and ZnS) to counteract the loss of surface area due to sintering during regeneration. Studies with 9 to 26% water vapor in simulated coal gases show that sulfur levels below 1 ppM can be achieved in the temperature range of 500/sup 0/ to 650/sup 0/C. The ability of CuO/ZnO to remove COS, CS/sub 2/ and CH/sub 3/SH at these conditions has been demonstrated in this study. Also a previously proposed pore-plugging model was further developed with good success for data treatment of both packed bed and fluidized-bed reactors. 96 references, 42 figures, 21 tables.

  4. Effect of myocardial revascularisation on left ventricular systolic function in patients with and without viable myocardium: should non-viable segments be revascularised?

    Science.gov (United States)

    Stipac, Alja Vlahovic; Stankovic, Ivan; Vidakovic, Radosav; Putnikovic, Biljana; Ilic, Ivan; Milicic, Biljana; Neskovic, Aleksandar N

    2013-12-01

    To assess the effect of surgical revascularisation on left ventricular (LV) systolic function in patients with viable and non-viable dysfunctional LV segments determined by low dose dobutamine stress echocardiography (DSE). Prospective observational cohort study. Single tertiary care centre. Consecutive patients referred to surgical revascularisation (n=115). DSE and surgical revascularisation. Functional recovery defined as increase in ejection fraction ≥ 5% 1 year after revascularisation in patients with and without viable myocardium (viability defined as improvement of contractility in ≥ 4 LV segments on DSE). The mean age, ejection fraction and wall motion score index (WMSi) of patients were 59 ± 9 years, 44 ± 9% and 1.82 ± 0.31, respectively. There was no difference between DSE positive and DSE negative patients for any of those parameters at baseline study (p>0.05 for all). After 12 months, the ejection fraction increased 11 ± 1% in patients with viable myocardium vs 7 ± 1% in patients without viable myocardium (p=0.002). Moreover, in patients with viable myocardium, the greatest increase of ejection fraction occurred 1 month after surgery (9 ± 1%), whereas in those patients with negative DSE the ejection fraction increased more gradually (2±1% after 1 month, p=0.002 between groups for 1 month vs preoperative value), but still improved after 12 months follow-up (pmyocardial revascularisation. Functional recovery continuously occurs throughout the first year after surgical treatment.

  5. A technique for determining viable military logistics support alternatives

    Science.gov (United States)

    Hester, Jesse Stuart

    A look at today's US military will see them operating much beyond the scope of protecting and defending the United States. These operations now consist of, but are not limited to humanitarian aid, disaster relief, peace keeping, and conflict resolution. This broad spectrum of operational environments has necessitated a transformation of the individual military services to a hybrid force that is attempting to leverage the inherent and emerging capabilities and strengths of all those under the umbrella of the Department of Defense (DOD), this concept has been coined Joint Operations. Supporting Joint Operations requires a new approach to determining a viable military logistics support system. The logistics architecture for these operations has to accommodate scale, time, varied mission objectives, and imperfect information. Compounding the problem is the human in the loop (HITL) decision maker (DM) who is a necessary component for quickly assessing and planning logistics support activities. Past outcomes are not necessarily good indicators of future results, but they can provide a reasonable starting point for planning and prediction of specific needs for future requirements. Adequately forecasting the necessary logistical support structure and commodities needed for any resource intensive environment has progressed well beyond stable demand assumptions to one in which dynamic and nonlinear environments can be captured with some degree of fidelity and accuracy. While these advances are important, a holistic approach that allows exploration of the operational environment or design space does not exist to guide the military logistician in a methodical way to support military forecasting activities. To bridge this capability gap, a method called Adaptive Technique for Logistics Architecture Solutions (ATLAS) has been developed. This method provides a process that facilitates the use of techniques and tools that filter and provide relevant information to the DM. By doing

  6. Desulfurization of fuel oils using an advanced oxidation method; Desulfuracion de combustibles usando un metodo de oxidacion avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    In the present work, the oxidative desulfurization of fuel oils assisted by ultrasound was analyzed. It was studied the effect of hydrogen peroxide concentration, the fuel oil to aqueous solution volumetric ratio, and type of catalyst. The Fenton-like catalysts studied were ferric chloride and copper sulfate. [Spanish] En esta investigacion se analiza la desulfuracion oxidativa de combustoleo asistida con ultrasonido. Tambien se estudia el efecto de la concentracion de peroxido de hidrogeno (H{sub 2}O{sub 2}), la relacion volumetrica combustoleo/solucion acuosa y el tipo de catalizador. Los catalizadores tipo Fenton que se estudiaron fueron el cloruro ferrico (FeCl{sub 3}) y el sulfato de cobre (CuSO{sub 4}).

  7. Summary and assessment of METC zinc ferrite hot coal gas desulfurization test program, final report: Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Underkoffler, V.S.

    1986-12-01

    The Morgantown Energy Technology Center (METC) has conducted a test program to develop a zinc ferrite-based high temperature desulfurization process which could be applied to fuel gas entering downstream components such as molten carbonate fuel cells or gas turbines. As a result of prior METC work with iron oxide and zinc oxide sorbents, zinc ferrite evolved as a candidate with the potential for high capacity, low equilibrium levels of H/sub 2/S, and structural stability after multiple regenerations. The program consisted of laboratory-scale testing with a two-inch diameter reactor and simulated fixed-bed gasifier gas; bench-scale testing with a six-inch diameter reactor and actual gas from the METC 42-inch fixed bed gasifier; as well as laboratory-scale testing of zinc ferrite with simulated fluidized bed gasifier gas. Data from sidestream testing are presented. 18 refs.

  8. Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

    Directory of Open Access Journals (Sweden)

    Henok H. Kinfe

    2015-04-01

    Full Text Available 1-C and 2-C-branched carbohydrates are present as substructures in a number of biologically important compounds. Although the synthesis of such carbohydrate derivatives is extensively studied, the synthesis of 1,2-cis-2-C-branched C-, S-, and N-glycosides is less explored. In this article a synthetic strategy for the synthesis of 1,2-cis-2-C-branched-aryl-C-glucosides is reported via a hydrogenolytic desulfurization of suitably orientated carbohydrate based hemithioacetals. 1,2-cis-2-Hydroxymethyl and 2-carbaldehyde of aryl-C-glucosides have been synthesized using the current strategy in very good yields. The 2-carbaldehyde-aryl-C-glucosides have been identified as suitable substrates for the stereospecific preparation of 2,3-unsaturated-aryl-C-glycosides (Ferrier products.

  9. Management of dry flue gas desulfurization by-products in underground mines. Annual report, October 1994--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Dutta, D.; Esling, S. [and others

    1995-10-01

    On September 30, 1993, the U.S. Department of Energy-Morgantown Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate several technologies for the placement of coal combustion residues (CCBs) in abandoned coal mines, and will assess the environmental impact of such underground CCB placement. This report describes progress in the following areas: environmental characterization, mix development and geotechnical characterization, material handling and system economics, underground placement, and field demonstration.

  10. Effects of pore sizes and oxygen-containing functional groups on desulfurization activity of Fe/NAC prepared by ultrasonic-assisted impregnation

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Song [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Guo, Jia-Xiu, E-mail: guojiaxiu@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Liu, Xiao-Li [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Wang, Xue-Jiao [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); Yin, Hua-Qiang [College of Architecture and Environment, Sichuan University, Chengdu 610065, Sichuan (China); National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China); Sichuan Provincial Environmental Protection Environmental Catalysis and Materials Engineering Technology Center, Chengdu 610065, Sichuan (China); Luo, De-Ming [National Engineering Technology Research Center for Flue Gas Desulfurization, Chengdu 610065, Sichuan (China)

    2016-01-01

    Graphical abstract: - Highlights: • Fe/NAC-60 exhibits the best desulfurization activity. • Different oscillation time can change surface area and pore volume of catalysts. • Ultrasonic oscillation increases Fe dispersion on carrier and effective pores. • Pore sizes play a crucial role during the SO{sub 2} removal. - Abstract: A series of Fe-loaded activated carbons treated by HNO{sub 3} (Fe/NAC) were prepared by incipient impregnation method with or without ultrasonic assistance and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy disperse spectroscope (SEM-EDS), transmission electron microscopy (TEM) and N{sub 2} adsorption/desorption. The desulfurization activities were evaluated at a fixed bed reactor under a mixed gas simulated from flue gas. The results showed that desulfurization activity from excellent to poor is as follows: Fe/NAC-60 > Fe/NAC-80 > Fe/NAC-30 > Fe/NAC-15 > Fe/NAC-0 > Fe/NAC-100 > NAC. Fe/NAC-60 exhibits the best desulfurization activity and has breakthrough sulfur capacity of 319 mg/g and breakthrough time of 540 min. The introduction of ultrasonic oscillation does not change the form of Fe oxides on activated carbon but can change the dispersion and relative contents of Fe{sub 3}O{sub 4}. The types of oxygen-containing functional groups have no obvious change for all samples but the texture properties show some differences when they are oscillated for different times. The fresh Fe/NAC-60 has a surface area of 1045 m{sup 2}/g and total pore volume of 0.961 cm{sup 3}/g with micropore volume of 0.437 cm{sup 3}/g and is larger than Fe/NAC-0 (823 m{sup 2}/g, 0.733 and 0.342 cm{sup 3}/g). After desulfurization, surface area and pore volume of all samples decrease significantly, and those of the exhausted Fe/NAC-60 decrease to 233 m{sup 2}/g and 0.481 cm{sup 3}/g, indicating that some byproducts deposit on surface to cover pores. Pore size distribution

  11. Grazing of particle-associated bacteria-an elimination of the non-viable fraction.

    Science.gov (United States)

    Gonsalves, Maria-Judith; Fernandes, Sheryl Oliveira; Priya, Madasamy Lakshmi; LokaBharathi, Ponnapakkam Adikesavan

    Quantification of bacteria being grazed by microzooplankton is gaining importance since they serve as energy subsidies for higher trophic levels which consequently influence fish production. Hence, grazing pressure on viable and non-viable fraction of free and particle-associated bacteria in a tropical estuary controlled mainly by protist grazers was estimated using the seawater dilution technique. In vitro incubations over a period of 42h showed that at the end of 24h, growth coefficient (k) of particle-associated bacteria was 9 times higher at 0.546 than that of free forms. Further, 'k' value of viable cells on particles was double that of free forms at 0.016 and 0.007, respectively. While bacteria associated with particles were grazed (coefficient of removal (g)=0.564), the free forms were relatively less grazed indicating that particle-associated bacteria were exposed to grazers in these waters. Among the viable and non-viable forms, 'g' of non-viable fraction (particle-associated bacteria=0.615, Free=0.0086) was much greater than the viable fraction (particle-associated bacteria=0.056, Free=0.068). Thus, grazing on viable cells was relatively low in both the free and attached states. These observations suggest that non-viable forms of particle-associated bacteria were more prone to grazing and were weeded out leaving the viable cells to replenish the bacterial standing stock. Particle colonization could thus be a temporary refuge for the "persistent variants" where the viable fraction multiply and release their progeny. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  12. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization.

    Science.gov (United States)

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-11-01

    An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO2 from by-products was summarized. Results showed that the SO2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900-1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO2 as well as MgO, a temperature range of 900-927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries.

  13. Attapulgite-CeO{sub 2}/MoS{sub 2} ternary nanocomposite for photocatalytic oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiazhang, E-mail: lixiazhang509@163.com [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory for Environment Functional Materials, Suzhou University of Science and Technology, Suzhou 215009 (China); W.M.Keck Center for Advanced Microscopy and Microanalysis, University of Delaware, Newark, DE 19716 (United States); Zhang, Zuosong [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Yao, Chao [Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164 (China); Lu, Xiaowang [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Zhao, Xiaobing [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory for Environment Functional Materials, Suzhou University of Science and Technology, Suzhou 215009 (China); Ni, Chaoying [W.M.Keck Center for Advanced Microscopy and Microanalysis, University of Delaware, Newark, DE 19716 (United States)

    2016-02-28

    Graphical abstract: - Highlights: • Novel attapulgite(ATP)-CeO{sub 2}/MoS{sub 2} ternary nanocomposites were fabricated. • ATP possessed outstanding adsorption property and enhanced the stability of the network structure. • CeO{sub 2}/MoS{sub 2} couples facilitated the separation of photo-induced electrons and holes. • Mass ratio of CeO{sub 2}/MoS{sub 2} influenced the photocatalytic oxidation desulfurization. - Abstract: Novel attapulgite(ATP)-CeO{sub 2}/MoS{sub 2} ternary nanocomposites were synthesized by microwave assisted assembly method. The structures of the nanocomposites were characterized by XRD, FT-IR, UV–vis, XPS and in situ TEM. The photocatalytic activities of ATP-CeO{sub 2}/MoS{sub 2} composites were investigated by degradating dibenzothiophene (DBT) in gasoline under visible light irradiation. The effect of the mass ratio of CeO{sub 2} to MoS{sub 2} on photocatalytic activity was investigated. The results indicate that the three-dimensional network structure is firmly constructed by ATP skeleton, CeO{sub 2} particles and MoS{sub 2} nanosheet which effectively increase the surface area of the composites and promote the separation of electrons and holes by resulting electronic transmission channels of multi-channel in space. The degradation rate of DBT can reach 95% under 3 h irradiation when the mass ratio of CeO{sub 2}/MoS{sub 2} is 4/10. A plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite is put forward.

  14. Recovery of SO2 and MgO from By-Products of MgO Wet Flue Gas Desulfurization

    Science.gov (United States)

    Yan, Liyun; Lu, Xiaofeng; Wang, Quanhai; Guo, Qiang

    2014-01-01

    Abstract An industrial demonstration unit using natural gas as a heat source was built to calcine the by-products of MgO wet flue gas desulfurization from power plants; influencing factors on the SO2 content in calciner gas were comprehensively analyzed; and an advantageous recycling condition of MgO and SO2 from by-products was summarized. Results showed that the SO2 content in the calciner gas was increased by more than 10 times under a lower excess air coefficient, a higher feed rate, a lower crystal water in by-products, and a higher feed port position. For the tests conducted under the excess air coefficient above and below one, the effect of the furnace temperature on the SO2 content in the calciner gas was reversed. Results of activity analysis indicate that particles of MgO generated under the calcination temperature of 900–1,000°C had a high activity. In contrast, due to the slight sintering, MgO generated under the calcination temperature of 1,100°C had a low activity. To recycle SO2 as well as MgO, a temperature range of 900–927°C for TE103 is proposed. These studies will prompt the desulfurization market diversification, reduce the sulfur's dependence on imports for making sulfuric acid, be meaningful to balance the usage of the natural resource in China, and be regarded as a reference for the development of this technology for other similar developing countries. PMID:25371652

  15. Preparation of WO3/g-C3N4 composites and their application in oxidative desulfurization

    Science.gov (United States)

    Zhao, Rongxiang; Li, Xiuping; Su, Jianxun; Gao, Xiaohan

    2017-01-01

    WO3/graphitic carbon nitride (g-C3N4) composites were successfully synthesized through direct calcining of a mixture of WO3 and g-C3N4 at 400 °C for 2 h. The WO3 was prepared by calcination of phosphotungstic acid at 550 °C for 4 h, and the g-C3N4 was obtained by calcination of melamine at 520 °C for 4 h. The WO3/g-C3N4 composites were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunner-Emmett-Teller analysis (BET). The WO3/g-C3N4 composites exhibited stronger XRD peaks of WO3 and g-C3N4 than the WO3 and pure g-C3N4. In addition, two WO3 peaks at 25.7° and 26.6° emerged for the 36% -WO3/g-C3N4 composite. This finding indicated that WO3 was highly dispersed on the surface of the g-C3N4 nanosheets and interacted with the nanosheets, which resulted in the appearance of (012) and (022) planes of WO3. The WO3/g-C3N4 composite also exhibited a larger specific surface area and higher degree of crystallization than WO3 or pure g-C3N4, which resulted in high catalytic activity of the catalyst. Desulfurization experiments demonstrated that the desulfurization rate of dibenzothiophene (DBT) in model oil reached 91.2% under optimal conditions. Moreover, the activity of the catalyst was not significantly decreased after five recycles.

  16. The Effect of Oxygen Supply on the Dual Growth Kinetics of Acidithiobacillus thiooxidans under Acidic Conditions for Biogas Desulfurization

    Science.gov (United States)

    Namgung, Hyeong-Kyu; Song, JiHyeon

    2015-01-01

    In this study, to simulate a biogas desulfurization process, a modified Monod-Gompertz kinetic model incorporating a dissolved oxygen (DO) effect was proposed for a sulfur-oxidizing bacterial (SOB) strain, Acidithiobacillus thiooxidans, under extremely acidic conditions of pH 2. The kinetic model was calibrated and validated using experimental data obtained from a bubble-column bioreactor. The SOB strain was effective for H2S degradation, but the H2S removal efficiency dropped rapidly at DO concentrations less than 2.0 mg/L. A low H2S loading was effectively treated with oxygen supplied in a range of 2%–6%, but a H2S guideline of 10 ppm could not be met, even with an oxygen supply greater than 6%, when the H2S loading was high at a short gas retention time of 1 min and a H2S inlet concentration of 5000 ppm. The oxygen supply should be increased in the aerobic desulfurization to meet the H2S guideline; however, the excess oxygen above the optimum was not effective because of the decline in oxygen efficiency. The model estimation indicated that the maximum H2S removal rate was approximately 400 ppm/%-O2 at the influent oxygen concentration of 4.9% under the given condition. The kinetic model with a low DO threshold for the interacting substrates was a useful tool to simulate the effect of the oxygen supply on the H2S removal and to determine the optimal oxygen concentration. PMID:25633028

  17. Investigation of the potential for mercury release from flue gas desulfurization solids applied as an agricultural amendment.

    Science.gov (United States)

    Briggs, Christian W; Fine, Rebekka; Markee, Melissa; Gustin, Mae Sexauer

    2014-01-01

    The potential for beneficial use of flue gas desulfurization-derived gypsum (FGDG), a coal combustion byproduct, as an agricultural soil amendment is currently being debated. This study investigated the hypothesis that Hg released to air from FGDG will be reduced when amended to planted and bare soils. The potential for enhanced methylmercury (MeHg) production and Hg uptake by plants in soils amended with FGDG was also investigated. Flue gas desulfurization-derived gypsum from three sources was homogenized into three soils at 4.5, 45, and 170 t ha and applied at 4.9 t ha as a thin layer to simulate tilled and no-till applications, respectively. Twenty-four-hour Hg flux was measured from unamended and FGDG-amended soils on a seasonal time step over 1 yr and after disturbing, watering, and planting. Methylmercury in soil, irrigation drainage, and total Hg in plant tissues were quantified. Results should be interpreted within the confines of the experimental setting and materials used for this study. Total Hg concentrations in soils, homogenized with FGDG, were below that considered representative of soil with background values (<100 ng g). Emissions from amended soils were higher initially relative to unamended soils but became similar over time. Significantly less Hg (2%) was lost to the air from FGDG-amended soils (90 g FGDG added for lowest application) than that released from the FGDG alone (30-70%) (50 g FGDG) over 1 yr. Total Hg and MeHg in irrigation drainage and total Hg concentrations measured in plants were similar for amended and unamended soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Cybernetically sound organizational structures II: Relating de Sitter's design theory to Beer's viable system model

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Vriens, D.J.

    2011-01-01

    - Purpose – The purpose of this paper is to show how the viable system model (VSM) and de Sitter's design theory can complement each other in the context of the diagnosis and design of viable organizations. - Design/methodology/approach – Key concepts from Beer's model and de Sitter's design

  19. Hymenolepis nana: immunity against oncosphere challenge in mice previously given viable or non-viable oncospheres of H. nana, H. diminuta, H. microstoma and Taenia taeniaeformis.

    Science.gov (United States)

    Ito, A; Onitake, K; Sasaki, J; Takami, T

    1991-04-01

    When mice, previously given oral inoculation with viable oncospheres of the heterologous cestode species (Hymenolepis diminuta, H. microstoma, Taenia taeniaeformis) and the homologous one (H. nana), were challenged with oncospheres of H. nana 4 days after the primary inoculation, they showed strong and complete resistance to H. nana challenge, respectively. However, the resistance was not evoked in mice given either infective eggs of Toxocara canis or non-viable oncospheres of all cestode species examined. Congenitally athymic nude mice given viable oncospheres did not show any resistance to H. nana either. Eosinophil infiltration around cysticercoids of H. nana in the intestinal villi appeared to be more prominent in mice previously given viable oncospheres of H. diminuta than in mice given non-viable oncospheres or PBS only. Some of the eosinophils in the villus harboring cysticercoid(s) of H. nana invaded the epithelia in the former, whereas all eosinophils remained in the lamina propria in the latter. There was almost no eosinophil infiltration in nude mice. Microscopic observations revealed that oncospheres of H. diminuta, which require beetles as the intermediate host like H. microstoma, could invade the mouse intestinal tissue. Therefore, it is strongly suggested that the strong cross resistance to H. nana in mice, induced by oncospheres of all heterologous cestode species, is thymus-dependent and due to oncospheral invasion into the intestinal tissue of mice.

  20. Comparative study on the regeneration of flue-gas desulfurizing agents by using conventional electrodialysis (ED) and bipolar membrane electrodialysis (BMED)

    Energy Technology Data Exchange (ETDEWEB)

    Chuanhui Huang; Tongwen Xu [University of Science and Technology of China, Hefei (China). Laboratory of Functional Membranes, School of Chemistry and Material Science

    2006-09-01

    Piperazine (Pz) is an ideal desulfurizing agent but the heat-stable salts formed in desulfurization have caused secondary pollution and waste of resources. In the previous paper, a method was reported to regenerate piperazine by using bipolar membrane electrodialysis (BMED). To find the variety of that regeneration process, experiments were performed on the regeneration of piperazine by using ED. In comparison, ED has higher piperazine yield and current efficiency, and much lower voltage drop and energy consumption. However, its process cost is higher than that of BMED due to an extra expenditure for the base and its tank and pumps. The process cost is estimated to be 0.96 $/kg Pz for BMED and 1.14 $/kg Pz for ED. Notably, BMED has more environmental benefits and will be more economically attractive as the control on secondary pollution is strengthened and the bipolar membrane cost decreases. 9 refs., 4 figs., 1 tab.

  1. Modification of C/TiO2@MCM-41 with nickel nanoparticles for photocatalytic desulfurization enhancement of a diesel fuel model under visible light.

    Science.gov (United States)

    Zarrabi, M; Entezari, M H

    2015-11-01

    Ni metal nanoparticles were attached on the C/TiO2@MCM-41 (CTM-41) via facile and fast method based on dispersing of C/TiO2@MCM-41 in aqueous solution containing nickel ions by ultrasonic bath. Then, for the first time, the Ni ions were converted to Ni nanoparticles under UV light (photo-assisted deposition, PAD method), without using reducing agents and hydrogen gas. This process was carried out under the relatively mild conditions. The results showed that Ni (II) was reduced to Ni metallic nanoparticle in the size of about 2.7 nm on the surface of CTM-41 (Ni/CTM-41) with specific surface area of 754.37 m(2) g(-1). The photocatalytic ultra-deep desulfurization of a fuel-like n-octane containing dibenzothiophene (DBT) was conducted over the Ni/CTM-41 nanophotocatalyst. Using this method, the total sulfur content efficiently decreased under mild conditions in one phase and without using an oxidant. The synthesized Ni/CTM-41 (3% Ni) exhibited the maximum photocatalytic desulfurization of DBT for all different ratios of Si/Ti. In contrast, the synthesized CTM-41 (without Ni) exhibited the maximum photocatalytic desulfurization of DBT only for minimum ratio of Si/Ti. The Ni/CTM-41 was characterized by several techniques including N2 adsorption-desorption isotherms, XRD, TEM, and atomic absorption spectroscopy techniques. The results confirmed that Ni was highly dispersed on the support phase. The GC-MS analysis confirmed the photocatalytic removal of DBT. Based on the experimental results, it is proposed that the hydroxyl radical and hole have key role in the photocatalytic desulfurization process. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Reutilization of low-grade magnesium oxides for flue gas desulfurization during calcination of natural magnesite: A closed-loop process

    OpenAIRE

    del Valle Zermeño, Ricardo; Formosa Mitjans, Joan; Aparicio, J.A,; Chimenos Ribera, Josep Maria

    2014-01-01

    The European Commission is encouraging the Cement, Lime and Magnesium Oxide Manufacturing Industries to reutilize collected particulate matter or wastes in the emission control of SO2 with a 100% removal efficiency. Following this directive, three different by-products from the calcination of natural magnesite were selected in order to evaluate their desulfurization capacity. The saturation time, defined as the time for the total neutralization of SO2 was used to determine consumption values ...

  3. Ultra-deep adsorptive desulfurization of a model diesel fuel on regenerable Ni-Cu/γ-Al₂O₃ at low temperatures in absence of hydrogen.

    Science.gov (United States)

    Mansouri, Ali; Khodadadi, Abbas Ali; Mortazavi, Yadollah

    2014-04-30

    A model diesel fuel containing 250 ppmw sulfur (as dibenzothiophene) in n-hexadecane was desulfurized at low temperatures in absence of hydrogen, down to about zero ppmwS on a novel adsorbent of well dispersed 3-12 nm Nix-Cu10-x (x=Ni wt%) nanoparticles formed by impregnation on γ-Al2O3 and reduced in H2 at 275 or 450°C. The sorbents were characterized by XRD, TEM-EDX, FESEM-EDS, H2-TPR, TPO, BJH and BET surface area measurement techniques. Effects of various parameters comprising Cu content, reduction and desulfurization temperatures, inhibition by naphthalene, and regeneration of spent sorbents were investigated. As copper is added to nickel: (a) the sorbent reduction temperature shifts to dramatically lower values, (b) sulfur adsorption capacity of the sorbents at lower reduction and desulfurization temperatures is significantly improved, and when 14 wt% Ni5Cu5 sorbent is added to the fuel, the sulfur content reduces from 250 ppmwS to about zero in less than 1 min, (c) loss of adsorption capacity after the regeneration of the spent sorbent reduced at 275°C is significantly diminished, and (d) the selectivity of the sorbents to dibenzothiophene in the presence of naphthalene is improved. A higher reduction temperature tends to agglomerate nickel nanoparticles and reduce the sulfur adsorption capacity. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Carbonate Minerals with Magnesium in Triassic Terebratula Limestone in the Term of Limestone with Magnesium Application as a Sorbent in Desulfurization of Flue Gases

    Science.gov (United States)

    Stanienda-Pilecki, Katarzyna

    2017-09-01

    This article presents the results of studies of Triassic (Muschelkalk) carbonate rock samples of the Terebratula Beds taken from the area of the Polish part of the Germanic Basin. It is the area of Opole Silesia. The rocks were studied in the term of possibility of limestone with magnesium application in desulfurization of flue gases executed in power plants. Characteristic features of especially carbonate phases including magnesium-low-Mg calcite, high-Mg calcite, dolomite and huntite were presented in the article. They were studied to show that the presence of carbonate phases with magnesium, especially high-Mg calcite makes the desulfurization process more effective. Selected rock samples were examined using a microscope with polarized, transmitted light, X-ray diffraction, microprobe measurements and FTIR spectroscopy. The results of studies show a domination of low magnesium calcite in the limestones of the Terebratula Beds. In some samples dolomite and lower amounts of high-Mg calcite occurred. Moreover, huntite was identified. The studies were very important, because carbonate phases like high-Mg calcite and huntite which occurred in rocks of the Triassic Terebratula Beds were not investigated in details by other scientists but they presence in limestone sorbent could influence the effectiveness of desulfurization process.

  5. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    Science.gov (United States)

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A novel resource utilization of the calcium-based semi-dry flue gas desulfurization ash: As a reductant to remove chromium and vanadium from vanadium industrial wastewater.

    Science.gov (United States)

    Fang, Dean; Liao, Xiang; Zhang, Xuefei; Teng, Aijun; Xue, Xiangxin

    2018-01-15

    A novel resource utilization of the calcium-based semi-dry flue gas desulfurization ash is investigated. In the present study, the semi-dry desulfurization ash is used as a reductant for chromium and vanadium removal by chemical reduction precipitation, the byproduct gypsum and chromium-contained sludge are obtained. Besides, the effects of main operational parameters (reaction pH, desulfurization ash dosage and reaction time) on the heavy metal removal are investigated, and the main reaction mechanism for this treatment technology is also proposed. Under the optimal conditions, the residual concentrations of Cr(VI), total Cr and V are 0.163mg/L, 0.395mg/L and 0.155mg/L, respectively. Additionally, byproduct gypsum and chromium-contained sludge are characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and thermogravimetry differential scanning calorimetry (TG-DSC), respectively. Finally, the resource utilization methods of the byproduct gypsum and chromium-contained sludge from this technology are also submitted. The byproduct gypsum can be utilized to produce hemihydrate calcium sulfate whisker, and the roasted heavy metal precipitation can be used as a primary chromium raw material (Cr2O3 content is about 83%). Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Non-viable antagonist cells are associated with reduced biocontrol performance by viable cells of the yeast Papiliotrema flavescens against Fusarium head blight of wheat.

    Science.gov (United States)

    Microbially-based plant disease control products have achieved commercial market success, but the efficacy of such biocontrol products is sometimes deemed inconsistent. Improper processing of harvested microbial biomass or long-term storage can reduce the proportion of viable cells and necessitate t...

  8. Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2012-01-01

    Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

  9. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

    NARCIS (Netherlands)

    F. Sozzi (Fabiola); D. Poldermans (Don); J.J. Bax (Jeroen); A. Elhendy (Abdou); E.C. Vourvouri (Eleni); R. Valkema (Roelf); J. de Sutter; A.F.L. Schinkel (Arend); A. Borghetti; J.R.T.C. Roelandt (Jos)

    2001-01-01

    textabstractOBJECTIVE: To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. PATIENTS: 30 patients with chronic left

  10. Marine environmental pollution stress detection through direct viable counts of bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Kenkre, V.D.; Verlecar, X.N.

    Direct viable counts (DVC) of bacteria were quantified from polluted and relatively less/non-polluted coastal locations during different seasons to assess whether they can be routinely monitored for an understanding of environmental stress(es...

  11. Immunization of rodents against Hymenolepis infections using non-viable homologous oncospheres.

    Science.gov (United States)

    Fan, Ping-Chin; Chung, Wen-Cheng; Ito, Akira

    2004-12-01

    Immunity to Taiwan Taenia infection in pigs can be stimulated using homologous or heterologous non-viable Taenia oncospheres. This study was designed to determine whether homologous non-viable oncospheres could stimulate immunity to Hymenolepis infection in rodents. Hatched oncospheres were prepared from eggs of Hymenolepis diminuta, Hymenolepis nana, and Hymenolepis microstoma and kept at -70 degrees C for more than 1 month. A mixture of 500 non-viable oncospheres of each tapeworm and complete Freund's adjuvant was injected subcutaneously in four groups of Sprague-Dawley rats or ICR mice one to four times at an interval of 1 week; controls were not immunized. After immunization, each rodent was orally inoculated with three fresh active cysticercoids of H. diminuta or H. microstoma or 500 fresh eggs of H. nana. The animals were then necropsied for adult tapeworms. No rats or mice immunized with non-viable oncospheres of H. diminuta or H. nana were infected by the challenge inoculation. However, 28 of 34 mice immunized with non-viable H. microstoma oncospheres were infected after inoculation with cysticercoids. This study demonstrated complete protection against infection by homologous parasites in rats or mice immunized with non-viable oncospheres of H. diminuta and H. nana, respectively. Repeated immunization may not be required if resistance is stimulated in rodent hosts.

  12. [Viable myocardium detecting by CARTO voltage mapping in swine model of acute myocardial infarction].

    Science.gov (United States)

    Lin, Tao; Ma, Yi-Tong; Yang, Yi-Ning; Mu, Hu-Yati; He, Peng-Yi; Yang, Yu-Chun; Chou, Ping; Liu, Fen; Zhang, Yan-Yi

    2010-08-01

    To evaluate the accuracy and practicability of detecting viable myocardium by CARTO voltage mapping in swine model of acute myocardial infarction (MI). MI was induced in 13 anesthetized swines via occluding the distal of left anterior descending coronary arteries by angioplasty balloon for 60-90 minutes. The viable myocardium detection by CARTO voltage mapping was made after reconstruction of the left ventricle using CARTO and the results were compared with TTC staining. The standard of CARTO voltage to detect viable myocardium was 0.5 - 1.5 mV while viable myocardium showed pink color by TTC staining. Eleven out of 13 swines survived the operation and 2 swines died of ventricular fibrillation at 45 and 65 minutes post ischemia. Left ventricle was divided into 16 segments and 176 segments from 11 swines were analyzed. Viable myocardium detected by CARTO voltage mapping was identical as identified by TTC staining (Kappa = 0.816, P < 0.001). Taken the TTC result as standard, the sensitivity, specificity and accuracy rate of CARTO voltage mapping are 71.8%, 96.5% and 90.9% respectively. CARTO voltage mapping could be used as a reliable tool to detect viable myocardium in this model.

  13. Economic assessment of advanced flue gas desulfurization processes. Final report. Volume 2. Appendices G, H, and I

    Energy Technology Data Exchange (ETDEWEB)

    Bierman, G. R.; May, E. H.; Mirabelli, R. E.; Pow, C. N.; Scardino, C.; Wan, E. I.

    1981-09-01

    This report presents the results of a project sponsored by the Morgantown Energy Technology Center (METC). The purpose of the study was to perform an economic and market assessment of advanced flue gas desulfurization (FGD) processes for application to coal-fired electric utility plants. The time period considered in the study is 1981 through 1990, and costs are reported in 1980 dollars. The task was divided into the following four subtasks: (1) determine the factors affecting FGD cost evaluations; (2) select FGD processes to be cost-analyzed; (3) define the future electric utility FGD system market; and (4) perform cost analyses for the selected FGD processes. The study was initiated in September 1979, and separate reports were prepared for the first two subtasks. The results of the latter two subtasks appear only in this final report, since the end-date of those subtasks coincided with the end-date of the overall task. The Subtask 1 report, Criteria and Methods for Performing FGD Cost Evaluation, was completed in October 1980. A slightly modified and condensed version of that report appears as Appendix B to this report. The Subtask 2 report, FGD Candidate Process Selection, was completed in January 1981, and the principal outputs of that subtask appear in Appendices C and D to this report.

  14. Desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by selective oil agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Ayhan, F.D. [Dicle University, Diyarbakir (Turkey). Dept. of Mining Engineering

    2009-11-15

    The aim of this study was to investigate desulfurization and de-ashing of a mixture of subbituminous coal and gangue minerals by the agglomeration method. For this purpose, experimental studies were conducted on a mixture containing subbituminous coal, pyrite, quartz and calcite. The effects of some parameters that markedly influence the effectiveness of selective oil agglomeration, such as solid concentration, pH, bridging liquid type and concentration, and depressant type and amount, were investigated. Agglomeration results showed that the usage of various depressants (Na{sub 2}SiO{sub 3}, FeCl3, corn starch, wheat starch) in the agglomeration medium has a positive effect on the reduction of ash and total sulfur content of agglomerates. It was found that an agglomerate product containing 3.03% total sulfur and 25.01% ash with a total sulfur reduction of 56.71% was obtained from a feed that contained 7% total sulfur and 43.58% ash when FeCl{sub 3} was used in the agglomeration medium.

  15. Flue-gas desulfurization gypsum effects on urea-degrading bacteria and ammonia volatilization from broiler litter.

    Science.gov (United States)

    Burt, Christopher D; Cabrera, Miguel L; Rothrock, Michael J; Kissel, D E

    2017-08-01

    A major concern of the broiler industry is the volatilization of ammonia (NH3) from the mixture of bedding material and broiler excretion that covers the floor of broiler houses. Gypsum has been proposed as a litter amendment to reduce NH3 volatilization, but reports of NH3 abatement vary among studies and the mechanism responsible for decreasing NH3 volatilization is not well understood. The goal of this study was to evaluate the effect of adding 20 or 40% flue-gas desulfurization gypsum (FGDG) to broiler litter on pH, electrical conductivity (EC), water potential, urea-degrading bacteria abundance, NH3 and carbon dioxide (CO2) evolution, and nitrogen (N) mineralization in several 21-d experiments. The addition of FGDG to broiler litter increased EC by 24 to 33% (P broiler litter decreased NH3 volatilization by 18 to 28% (P broiler litter with 20% FGDG can decrease NH3 volatilization and increase the fertlizer value of broiler litter. © 2017 Poultry Science Association Inc.

  16. Extractive oxidative desulfurization of model oil/crude oil using KSF montmorillonite-supported 12-tungstophosphoric acid

    Directory of Open Access Journals (Sweden)

    Ezzat Rafiee

    2016-10-01

    Full Text Available Abstract 12-Tungstophosphoric acid (PW supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization (ODS of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide (H2O2 as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-to-sulfur compounds (S-compounds molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene (DBT and mixed thiophenic model oil under atmospheric pressure at 75 °C in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.

  17. Hot-gas desulfurization. II. Use of gasifier ash in a fluidized-bed process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schrodt, J.T.

    1981-02-01

    Three gasifier coal ashes were used as reactant/sorbents in batch fluidized-beds to remove hydrogen sulfide from hot, made-up fuel gases. It is predominantly the iron oxide in the ash that reacts with and removes the hydrogen sulfide; the sulfur reappears in ferrous sulfide. Sulfided ashes were regenerated by hot, fluidizing streams of oxygen in air; the sulfur is recovered as sulfur dioxide, exclusively. Ash sorption efficiency and sulfur capacity increase and stabilize after several cycles of use. These two parameters vary directly with the iron oxide content of the ash and process temperature, but are independent of particle size in the range 0.01 - 0.02 cm. A western Kentucky No. 9 ash containing 22 weight percent iron as iron oxide sorbed 4.3 weight percent sulfur at 1200/sup 0/F with an ash sorption efficiency of 0.83 at ten percent breakthrough. A global, fluidized-bed, reaction rate model was fitted to the data and it was concluded that chemical kinetics is the controlling mechanism with a predicted activation energy of 19,600 Btu/lb mol. Iron oxide reduction and the water-gas-shift reaction were two side reactions that occurred during desulfurization. The regeneration reaction occurred very rapidly in the fluid-bed regime, and it is suspected that mass transfer is the controlling phenomenon.

  18. Effect of pH on elemental sulfur conversion and microbial communities by autotrophic simultaneous desulfurization and denitrification.

    Science.gov (United States)

    Xu, Jinlan; Fan, Yimin; Li, Zhixu

    2016-12-01

    pH has an important influence on the elemental sulfur accumulated in an autotrophic simultaneous desulfurization and denitrification process. The influent nitrate to sulfide (N/S) mole ratio was set to 0.5, 0.67, 1.0, 1.33 and 2.0 with a 200 mg/L sulfide concentration. The effect of pH on elemental sulfur conversion and microbial communities was studied. Sulfide removal was achieved to the extent of 98% under near-neutral and weak base conditions after 24 h of reaction. The conversion rate of elemental sulfur was 29.41% under the near-neutral condition. The weak base condition led to greater formation of sulfate, and the nitrate used by the microorganisms was transformed mainly to N2 with a removal rate of 96%. Increasing the retention time from 24 to 48 h caused the removal rate of nitrate increased from 63.58% to 90% under the near-neutral condition. Sulfurovum sp. was the functioning bacterial species, and bands 1 and 2 represent different species of Sulfurovum sp. in the system according to the PCR-DGGE analysis of the microbial community structure. The functional bacteria represented by band 1 produced mainly sulfate, but the functional bacteria represented by band 2 produced mainly elemental sulfur.

  19. The efficient removal of thallium from sintering flue gas desulfurization wastewater in ferrous metallurgy using emulsion liquid membrane.

    Science.gov (United States)

    Yang, Li; Xiao, Jiangping; Shen, Yi; Liu, Xian; Li, Wensong; Wang, Weiyan; Yang, Yunquan

    2017-11-01

    The removal of thallium ions in flue gas desulfurization wastewater from ferrous metallurgic industry was studied by emulsion liquid membrane (ELM) method using 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (P507) as carrier, aviation kerosene (AK) as organic solvent, polyisobutylene succinimide (T154) as surfactant, polyisobutylene (PIB) as additive, and sulfuric acid as internal reagent. Some important influence parameters such as concentrations of carrier, surfactant and stripping agent, agitation speed, extraction time, volume ratios of feed solution to emulsion phase and internal phase to membrane phase, and their effects on the removal efficiency of Tl in the ELM process were investigated and optimized. Under the optimum operating conditions of 2% of carrier, 5% of surfactant, 0.5 M of stripping agent, 350 rpm of agitation speed, 12.5:1 of volume ratio of feed solution to emulsion phase, and 3:1 volume ratio of membrane to internal phase, the maximum extraction efficiency of thallium reached 99.76% within 15-min reaction time. The ICP-MS analysis indicated that the thallium concentration in treated wastewater was below 5 μg/L and could meet the emission standard demand for industrial wastewater enacted by the local government of Hunan province of China. Meanwhile, the extraction of impurity ions calcium and magnesium in the ELM system was investigated. The result showed that an acidic environment would be in favor of the removal of Tl from calcium and magnesium contained in wastewater. Graphical abstract ᅟ.

  20. Continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process: An efficient diesel treatment by injection of the aqueous phase.

    Science.gov (United States)

    Rahimi, Masoud; Shahhosseini, Shahrokh; Movahedirad, Salman

    2017-11-01

    A new continuous-flow ultrasound assisted oxidative desulfurization (UAOD) process was developed in order to decrease energy and aqueous phase consumption. In this process the aqueous phase is injected below the horn tip leading to enhanced mixing of the phases. Diesel fuel as the oil phase with sulfur content of 1550ppmw and an appropriate mixture of hydrogen peroxide and formic acid as the aqueous phase were used. At the first step, the optimized condition for the sulfur removal has been obtained in the batch mode operation. Hence, the effect of more important oxidation parameters; oxidant-to-sulfur molar ratio, acid-to-sulfur molar ratio and sonication time were investigated. Then the optimized conditions were obtained using Response Surface Methodology (RSM) technique. Afterwards, some experiments corresponding to the best batch condition and also with objective of minimizing the residence time and aqueous phase to fuel volume ratio have been conducted in a newly designed double-compartment reactor with injection of the aqueous phase to evaluate the process in a continuous flow operation. In addition, the effect of nozzle diameter has been examined. Significant improvement on the sulfur removal was observed specially in lower sonication time in the case of dispersion method in comparison with the conventional contact between two phases. Ultimately, the flow pattern induced by ultrasonic device, and also injection of the aqueous phase were analyzed quantitatively and qualitatively by capturing the sequential images. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Fabrication of magnetically responsive HKUST-1/Fe3O4 composites by dry gel conversion for deep desulfurization and denitrogenation.

    Science.gov (United States)

    Tan, Peng; Xie, Xiao-Yan; Liu, Xiao-Qin; Pan, Ting; Gu, Chen; Chen, Peng-Fei; Zhou, Jia-Yu; Pan, Yichang; Sun, Lin-Bing

    2017-01-05

    Selective adsorption by use of metal-organic frameworks (MOFs) is an effective method for purification of hydrocarbon fuels. In consideration that the adsorption processes proceed in liquid phases, separation and recycling of adsorbents should be greatly facilitated if MOFs were endowed with magnetism. In the present study, we reported for the first time a dry gel conversion (DGC) strategy to fabricate magnetically responsive MOFs as adsorbents for deep desulfurization and denitrogenation. The solvent is separated from the solid materials in the DGC strategy, and vapor is generated at elevated temperatures to induce the growth of MOFs around magnetic Fe3O4 nanoparticles. This strategy can greatly simplify the complicated procedures of the well-known layer-by-layer method and avoid the blockage of pores confronted by introducing magnetic Fe3O4 nanoparticles to the pores of MOFs. Our results show that the adsorbents are capable of efficiently removing aromatic sulfur and nitrogen compounds from model fuels, for example removing 0.62mmolg(-1)S and 0.89mmolg(-1)N of thiophene and indole, respectively. In addition, the adsorbents are facile to separate from liquid phases by use of an external field. After 6 cycles, the adsorbents still show a good adsorption capacity that is comparable to the fresh one. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Pyrosequencing reveals microbial community dynamics in integrated simultaneous desulfurization and denitrification process at different influent nitrate concentrations.

    Science.gov (United States)

    Chen, Chuan; Xu, Xi-Jun; Xie, Peng; Yuan, Ye; Zhou, Xu; Wang, Ai-Jie; Lee, Duu-Jong; Ren, Nan-Qi

    2017-03-01

    Integrated simultaneous desulfurization and denitrification (ISDD) process has proven to be feasible for the coremoval of sulfate, nitrate, and chemical oxygen demand (COD). In this study, we aimed to reveal the microbial community dynamics in the ISDD process with different influent nitrate (NO3-) concentrations. For all tested scenarios, full denitrification was accomplished while sulfate removal efficiency decreased along with increased influent NO3- concentrations. The proportion of S0 to influent SO42- maintained a low level (5.6-17.0%) regardless of the increased influent NO3- concentrations. Microbial community analysis results showed that higher influent NO3- concentrations affected the microbial community structure greatly. Phyla Proteobacteria, Spirochaetae, Firmicutes, Synergistetes, and Chloroflexi dominated in all the community compositions, of which Proteobacteria exhibited a clear difference among eight microbial samples. Members of δ-Proteobacteria, with 16S rRNA gene sequences related to Desulfobulbus, were clearly decreased at influent NO3- = 3000 and 3500 mg/L, suggesting an inhibitory effect of NO3- on sulfate reduction. In contrast, as influent NO3- concentration increased, microbial community was notably enriched in γ-Proteobacteria and ε-Proteobacteria, which revealed the enrichment of 16S rRNA gene sequences related to Pseudomonas (γ-Proteobacteria), and Arcobacteria and Sulfurospirillum (ε-Proteobacteria). Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Remediation of saline-sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China.

    Science.gov (United States)

    Mao, Yumei; Li, Xiaping; Dick, Warren A; Chen, Liming

    2016-07-01

    Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization (FGD)-gypsum applied at rates of 0, 15, 30, 45 and 60Mg/ha to remediate tidal flat soils of the Yangtze River estuary. Exchangeable sodium percentage (ESP), exchangeable sodium (ExNa), pH, soluble salt concentration, and composition of soluble salts were measured in 10cm increments from the surface to 30cm depth after 6 and 18months. The results indicated that the effect of FGD-gypsum is greatest in the 0-10cm mixing soil layer and 60Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil pH to neutral (7.0). The improvement effect was reached after 6months, and remained after 18months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na(+), HCO3(-)+CO3(2-) and Cl(-) to neutral salt ions mainly containing Ca(2+) and SO4(2-). Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising. Copyright © 2016. Published by Elsevier B.V.

  4. Molecular dynamics simulations on desulfurization of n-octane/thiophene mixture using silica filled polydimethylsiloxane nanocomposite membranes

    Science.gov (United States)

    Shariatinia, Zahra; Mazloom Jalali, Azin; Afshar Taromi, Faramarz

    2016-03-01

    Molecular dynamics (MD) simulations were performed at 298.15 K and 1 atm in order to study microstructure and transport behaviors of polydimethylsiloxane (PDMS) membranes containing 0%-8% SiO2 nanoparticles used for the separation of thiophene from n-octane. It was found that the fractional free volume (FFV) of 0% SiO2 was the highest (47.24%) among five nanocomposite membranes and addition of 2%-8% silica nanoparticles led to dramatic decrease in the FFV of the cells. The x-ray diffraction (XRD) patterns of all membranes showed that they had a semi-crystalline structure containing a broad peak around 15°-18°. The radial distribution function (RDF) analysis proved that the smallest C(CH2-octane)-O(SiO2), C(PDMS)-O(SiO2) and H(thiophene)-O(SiO2) distances were present in 4% SiO2 membrane reflecting the silica-octane, silica-polymer and silica-thiophene interactions were the strongest in this membrane. The mean squared displacement (MSD) and diffusion coefficients of n-octane were both small in the 6% silica membrane but they were high for thiophene suggesting this membrane was the most suitable for the desulfurization process and separation of thiophene from n-octane.

  5. Management of dry flue gas desulfurization by-products in underground mines. Topical report, April 1, 1996--April 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Brackebusch, F.; Carpenter, J. [and others

    1998-12-31

    This report represents the Final Technical Progress Report for Phase II of the overall program for a cooperative research agreement between the U.S. Department of Energy - MORGANTOWN Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SIUC). Under the agreement, SIUC will develop and demonstrate technologies for the handling, transport, and placement in abandoned underground coal mines of dry flue gas desulfurization by-products, such as fly ash, scrubber sludge, fluidized bed combustion by-products, and will assess the environmental impact of such underground placement. The overall program is divided into three (3) phases. Phase II of the program is primarily concerned with developing and testing the hardware for the actual underground placement demonstrations. Two technologies have been identified and hardware procured for full-scale demonstrations: (1) hydraulic placement, where coal combustion by-products (CCBs) will be placed underground as a past-like mixture containing about 70 to 75 percent solids; and (2) pneumatic placement, where CCBs will be placed underground as a relatively dry material using compressed air. 42 refs., 36 figs., 36 tabs.

  6. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, April 1--June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    On September 30, 1993, the US Department of Energy - Morgantown Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate two technologies for the placement of coal combustion residues in abandoned underground coal mines, and will assess the environmental impact of these technologies for the management of coal combustion by-products. The two technologies for the underground placement that will be developed and demonstrated are: (1) pneumatic placement, using virtually dry materials, and (2) hydraulic placement, using a {open_quotes}paste{close_quotes} mixture of materials with about 70% solids. Phase II of the overall program began April 1, 1996. The principal objective of Phase II is to develop and fabricate the equipment for placing the coal combustion by-products underground, and to conduct a demonstration of the technologies on the surface. Therefore, this quarter has been largely devoted to developing specifications for equipment components, visiting fabrication plants throughout Southern Illinois to determine their capability for building the equipment components in compliance with the specifications, and delivering the components in a timely manner.

  7. Integrated operation of a pressurized fixed-bed gasifier, hot gas desulfurization system, and turbine simulator

    Energy Technology Data Exchange (ETDEWEB)

    Bevan, S.; Ayala, R.E.; Feitelberg, A.; Furman, A.

    1995-11-01

    The overall objective of the General Electric Hot Gas Cleanup (HGCU) Program is to develop a commercially viable technology to remove sulfur, particulates, and halogens from a high-temperature fuel gas stream using a moving bed, regenerable mixed metal oxide sorbent based process. The HGCU Program is based on the design and demonstration of the HGCU system in a test facility made up of a pilot-scale fixed bed gasifier, a HGCU system, and a turbine simulator in Schenectady, NY, at the General Electric Research and Development Center. The objectives of the turbine simulator testing are (1) to demonstrate the suitability of fuel gas processed by the HGCU system for use in state-of-the-art gas turbines firing at 2,350 F rotor inlet temperature and (2) to quantify the combustion characteristics and emissions on low-Btu fuel gas. The turbine simulator program also includes the development and operation of experimental combustors based on the rich-quench-lean concept (RQL) to minimize the conversion of ammonia and other fuel-bound nitrogen species to NO{sub x} during combustion. The HGCU system and turbine simulator have been designed to process approximately 8,000 lb/hr of low heating value fuel gas produced by the GE fixed bed gasifier. The HGCU system has utilized several mixed metal oxide sorbents, including zinc ferrite, zinc titanate, and Z-Sorb, with the objective of demonstrating good sulfur removal and mechanical attrition resistance as well as economic cost characteristics. Demonstration of halogen removal and the characterization of alkali and trace metal concentrations in the fuel gas are subordinate objectives of the overall program. This report describes the results of several long-duration pilot tests.

  8. Immunization of Rodents Against Hymenolepis Infections using Non-Viable Homologous Oncospheres

    Directory of Open Access Journals (Sweden)

    Ping-Chin Fan

    2004-12-01

    Full Text Available Immunity to Taiwan Taenia infection in pigs can be stimulated using homologous or heterologous nonviable Taenia oncospheres. This study was designed to determine whether homologous non-viable oncospheres could stimulate immunity to Hymenolepis infection in rodents. Hatched oncospheres were prepared from eggs of Hymenolepis diminuta, Hymenolepis nana, and Hymenolepis microstoma and kept at −70°C for more than 1 month. A mixture of 500 non-viable oncospheres of each tapeworm and complete Freund's adjuvant was injected subcutaneously in four groups of Sprague-Dawley rats or ICR mice one to four times at an interval of 1 week; controls were not immunized. After immunization, each rodent was orally inoculated with three fresh active cysticercoids of H. diminuta or H. microstoma or 500 fresh eggs of H. nana. The animals were then necropsied for adult tapeworms. No rats or mice immunized with non-viable oncospheres of H. diminuta or H. nana were infected by the challenge inoculation. However, 28 of 34 mice immunized with non-viable H. microstoma oncospheres were infected after inoculation with cysticercoids. This study demonstrated complete protection against infection by homologous parasites in rats or mice immunized with non-viable oncospheres of H. diminuta and H. nana, respectively. Repeated immunization may not be required if resistance is stimulated in rodent hosts.

  9. PMA-Linked Fluorescence for Rapid Detection of Viable Bacterial Endospores

    Science.gov (United States)

    LaDuc, Myron T.; Venkateswaran, Kasthuri; Mohapatra, Bidyut

    2012-01-01

    The most common approach for assessing the abundance of viable bacterial endospores is the culture-based plating method. However, culture-based approaches are heavily biased and oftentimes incompatible with upstream sample processing strategies, which make viable cells/spores uncultivable. This shortcoming highlights the need for rapid molecular diagnostic tools to assess more accurately the abundance of viable spacecraft-associated microbiota, perhaps most importantly bacterial endospores. Propidium monoazide (PMA) has received a great deal of attention due to its ability to differentiate live, viable bacterial cells from dead ones. PMA gains access to the DNA of dead cells through compromised membranes. Once inside the cell, it intercalates and eventually covalently bonds with the double-helix structures upon photoactivation with visible light. The covalently bound DNA is significantly altered, and unavailable to downstream molecular-based manipulations and analyses. Microbiological samples can be treated with appropriate concentrations of PMA and exposed to visible light prior to undergoing total genomic DNA extraction, resulting in an extract comprised solely of DNA arising from viable cells. This ability to extract DNA selectively from living cells is extremely powerful, and bears great relevance to many microbiological arenas.

  10. Airborne viable fungi in school environments in different climatic regions - A review

    Science.gov (United States)

    Salonen, Heidi; Duchaine, Caroline; Mazaheri, Mandana; Clifford, Sam; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

    2015-03-01

    Elevated levels of fungi in indoor environments have been linked with mould/moisture damage in building structures. However, there is a lack of information about "normal" concentrations and flora as well as guidelines of viable fungi in the school environment in different climatic conditions. We have reviewed existing guidelines for indoor fungi and the current knowledge of the concentrations and flora of viable fungi in different climatic areas, the impact of the local factors on concentrations and flora of viable fungi in school environments. Meta-regression was performed to estimate the average behaviour for each analysis of interest, showing wide variation in the mean concentrations in outdoor and indoor school environments (range: 101-103 cfu/m3). These concentrations were significantly higher for both outdoors and indoors in the moderate than in the continental climatic area, showing that the climatic condition was a determinant for the concentrations of airborne viable fungi. The most common fungal species both in the moderate and continental area were Cladosporium spp. and Penicillium spp. The suggested few quantitative guidelines for indoor air viable fungi for school buildings are much lower than for residential areas. This review provides a synthesis, which can be used to guide the interpretation of the fungi measurements results and help to find indications of mould/moisture in school building structures.

  11. Synthesis of mesoporous TS-1 using a hybrid SiO{sub 2}–TiO{sub 2} xerogel for catalytic oxidative desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung-Tae [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Jeong, Kwang-Eun; Jeong, Soon-Yong [Research Center for Green Catalysis, Division of Green Chemistry and Engineering Research, Korea Research Institute of Chemical Technology, P.O. Box 107, 141 Gajeong-ro, Yuseong, Daejeon 305-600 (Korea, Republic of); Ahn, Wha-Seung, E-mail: whasahn@inha.ac.kr [Department of Chemical Engineering, Inha University, Incheon 402-751 (Korea, Republic of)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Meso-TS-1 catalyst was synthesized using a SiO{sub 2}–TiO{sub 2} xerogel with an organosilane precursor. ► Hierarchical pore structure was confirmed by characterization of the materials. ► Catalytic activity was tested using oxidative desulfurization of the model sulfur compounds. ► Meso-TS-1 demonstrated significantly improved catalytic activity than TS-1. -- Abstract: Mesoporous TS-1 (M-TS-1) was synthesized using a hybrid SiO{sub 2}–TiO{sub 2} xerogel combined with an organosilane precursor. Prepared samples were characterized by XRD, UV–vis spectroscopy, SEM, and N{sub 2} adsorption–desorption measurement. M-TS-1, prepared in 2 days, showed high crystallinity and the best textural properties among the samples. The N{sub 2} adsorption–desorption isotherms of M-TS-1 exhibited a hysteresis loop at pressure higher than P/P{sub 0} = 0.4, clearly indicating the existence of mesopores. M-TS-1 has significantly larger mesopore volume (0.48 cm{sup 3}/g) than that of conventional TS-1 (0.07 cm{sup 3}/g), and showed a narrow peak centered at ca. 6.3 nm. In the oxidative desulfurization reaction, M-TS-1 was more active than conventional TS-1 at the same Ti-loading; M-TS-1 produced a dibenzothiophene (DBT) conversion of 96%, whereas conventional TS-1 produced a final DBT conversion of 5.6% after a reaction time of 180 min. Oxidative desulfurization over TS-1 was influenced both by electron density and steric hindrance in the sulfur compounds tested.

  12. Reactions of VX, HD, and their simulants with NaY and AgY zeolites. Desulfurization of VX on AgY

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.W.; Bartram, P.W.

    1999-11-09

    The room-temperature reactions of the chemical warfare agents VX (O-ethyl S-2-(diisopropylamino)-ethyl methylphosphonothioate), HD (2,2{prime}-dichloroethyl sulfide, or mustard), and their common simulants, O,S-diethyl phenylphosphonothioate (DEPPT) and 2-chloroethyl phenyl sulfide (CEPS), with NaY and silver-exchanged (AgY) zeolites have been studied using solid-state magic angle spinning NMR. VX hydrolyzes via exclusive cleavage of the P{single{underscore}bond}S bond on both NaY and AgY to yield ethyl methylphosphonate (EMPA). The reaction is significantly faster on AgY than on NaY, suggesting catalysis by silver. On AgY, an intermediate silver salt of EMPA is apparently formed which is slowly converted to ethyl 2-(diisopropylamino)ethyl methylphosphonate (QB, the desulfurized analogue of VX) in about a 78% yield. DEPPT similarly hydrolyzes via P{single{underscore}bond}S cleavage on AgY to yield an apparent silver salt of ethyl phenylphosphonate, which does not undergo further reaction to the desulfurized analogue. No reaction is observed for DEPPT on NaY. HD on AgY forms both vinyl sulfide and the cyclic ether 1,4-thioxane. HD reacts faster on NaY to exclusively form the CH-TG sulfonium ion (HOCH{sub 2}CH{sub 2}SCH{sub 2}CH{sub 2}S{sup +}[CH{sub 2}CH{sub 2}OH]{sub 2}). CEPS also reacts faster on NaY, forming 2-hydroxyethyl phenyl sulfide. On AgY, CEPS does not give the vinyl product, but does yield the ether product PhSCH{sub 2}CH{sub 2}OCH{sub 2}CH{sub 2}SPh. A mechanism is proposed for the silver-catalyzed hydrolysis of VX, the desulfurization of the cleaved thiol, and the formation of QB.

  13. Combining ethidium monoazide treatment with real-time PCR selectively quantifies viable Batrachochytrium dendrobatidis cells.

    Science.gov (United States)

    Blooi, Mark; Martel, An; Vercammen, Francis; Pasmans, Frank

    2013-02-01

    Detection of the lethal amphibian fungus Batrachochytrium dendrobatidis relies on PCR-based techniques. Although highly accurate and sensitive, these methods fail to distinguish between viable and dead cells. In this study a novel approach combining the DNA intercalating dye ethidium monoazide (EMA) and real-time PCR is presented that allows quantification of viable B. dendrobatidis cells without the need for culturing. The developed method is able to suppress real-time PCR signals of heat-killed B. dendrobatidis zoospores by 99.9 % and is able to discriminate viable from heat-killed B. dendrobatidis zoospores in mixed samples. Furthermore, the novel approach was applied to assess the antifungal activity of the veterinary antiseptic F10(®) Antiseptic Solution. This disinfectant killed B. dendrobatidis zoospores effectively within 1 min at concentrations as low as 1:6400. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  14. A multicenter study of viable PCR using propidium monoazide to detect Legionella in water samples.

    Science.gov (United States)

    Scaturro, Maria; Fontana, Stefano; Dell'eva, Italo; Helfer, Fabrizia; Marchio, Michele; Stefanetti, Maria Vittoria; Cavallaro, Mario; Miglietta, Marilena; Montagna, Maria Teresa; De Giglio, Osvalda; Cuna, Teresa; Chetti, Leonarda; Sabattini, Maria Antonietta Bucci; Carlotti, Michela; Viggiani, Mariagabriella; Stenico, Alberta; Romanin, Elisa; Bonanni, Emma; Ottaviano, Claudio; Franzin, Laura; Avanzini, Claudio; Demarie, Valerio; Corbella, Marta; Cambieri, Patrizia; Marone, Piero; Rota, Maria Cristina; Bella, Antonino; Ricci, Maria Luisa

    2016-07-01

    Legionella quantification in environmental samples is overestimated by qPCR. Combination with a viable dye, such as Propidium monoazide (PMA), could make qPCR (named then vPCR) very reliable. In this multicentre study 717 artificial water samples, spiked with fixed concentrations of Legionella and interfering bacterial flora, were analysed by qPCR, vPCR and culture and data were compared by statistical analysis. A heat-treatment at 55 °C for 10 minutes was also performed to obtain viable and not-viable bacteria. When data of vPCR were compared with those of culture and qPCR, statistical analysis showed significant differences (P 0.05). Overall this study provided a good experimental reproducibility of vPCR but also highlighted limits of PMA in the discriminating capability of dead and live bacteria, making vPCR not completely reliable. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Issues of organizational cybernetics and viability beyond Beer's viable systems model

    Science.gov (United States)

    Nechansky, Helmut

    2013-11-01

    The paper starts summarizing the claims of Beer's viable systems model to identify five issues any viable organizations has to deal with in an unequivocal hierarchical structure of five interrelated systems. Then the evidence is introduced for additional issues and related viable structures of organizations, which deviate from Beer's model. These issues are: (1) the establishment and (2) evolution of an organization; (3) systems for independent top-down control (like "Six Sigma"); (4) systems for independent bottom-up correction of performance problems (like "Kaizen"), both working outside a hierarchical structure; (5) pull production systems ("Just in Time") and (6) systems for checks and balances of top-level power (like boards and shareholder meetings). Based on that an evolutionary approach to organizational cybernetics is outlined, addressing the establishment of organizations and possible courses of developments, including recent developments in quality and production engineering, as well as problems of setting and changing goal values determining organizational policies.

  16. El modelo de sistema viable: un instrumento para la organización efectiva

    Directory of Open Access Journals (Sweden)

    Norlando Sánchez Rueda

    2015-05-01

    Full Text Available RESUMEN En este ensayo se presenta una interpretación teórica del denominado Modelo de Sistema Viable (MSV, de Stafford Beer y su Potencial Aplicación en Tareas de Diagnóstico  y diseño empresarial, al igual que para Mejorar las capacidades Organizacionales de Auto- Regulación  y Auto- Organización. Se explica como el Modelo del Sistema Viable permite conocer e interpretar  los mecanismos de estabilidad y adaptabilidad de las organizaciones, pilares para el crecimiento de una verdadera organización Efectiva.

  17. Biogeochemical oxidation of calcium sulfite hemihydrate to gypsum in flue gas desulfurization byproduct using sulfur-oxidizing bacteria.

    Science.gov (United States)

    Graves, Duane; Smith, Jacques J; Chen, Linxi; Kreinberg, Allison; Wallace, Brianna; White, Robby

    2017-10-01

    Flue gas desulfurization (FGD) is a well-established air treatment technology for coal and oil combustion gases that commonly uses lime or pulverized limestone aqueous slurries to precipitate sulfur dioxide (SO2) as crystalline calcium salts. Under forced oxidation (excess oxygen) conditions, FGD byproduct contains almost entirely (>92%) gypsum (CaSO4·2H2O), a useful and marketable commodity. In contrast, FGD byproduct formed in oxygen deficient oxidation systems contains a high percentage of hannebachite (CaSO3·0.5H2O) to yield a material with no commercial value, poor dewatering characteristics, and that is typically disposed in landfills. Hannebachite in FGD byproduct can be chemically converted to gypsum; however, the conditions that support rapid formation of gypsum require large quantities of acids or oxidizers. This work describes a novel, patent pending application of microbial physiology where a natural consortium of sulfur-oxidizing bacteria (SOB) was used to convert hannebachite-enriched FGD byproduct into a commercially valuable, gypsum-enriched product (US Patent Assignment 503373611). To optimize the conversion of hannebachite into gypsum, physiological studies on the SOB were performed to define their growth characteristics. The SOB were found to be aerobic, mesophilic, neutrophilic, and dependent on a ready supply of ammonia. They were capable of converting hannebachite to gypsum at a rate of approximately five percent per day when the culture was applied to a 20 percent FGD byproduct slurry and SOB growth medium. 16S rDNA sequencing revealed that the SOB consortium contained a variety of different bacterial genera including both SOB and sulfate-reducing bacteria. Halothiobacillus, Thiovirga and Thiomonas were the dominant sulfur-oxidizing genera. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Effect of Byproducts of Flue Gas Desulfurization on the Soluble Salts Composition and Chemical Properties of Sodic Soils

    Science.gov (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2013-01-01

    The byproducts of flue gas desulfurization (BFGD) are a useful external source of Ca2+ for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two different sodic soils (sodic soil I and sodic soil II) and two BFGD rates. After the application of BFGD and leaching, the soil soluble salts were transformed from sodic salts containing Na2CO3 and NaHCO3 to neutral salts containing NaCl and Na2SO4. The sodium adsorption ratio (SAR), pH and electrical conductivity (EC) decreased at all soil depths, and more significantly in the top soil depth. At a depth of 0–40 cm in both sodic soil I and sodic soil II, the SAR, EC and pH were less than 13, 4 dS m−1 and 8.5, respectively. The changes in the chemical properties of the sodic soils reflected the changes in the ion composition of soluble salts. Leaching played a key role in the reclamation process and the reclamation effect was positively associated with the amount of leaching. The soil salts did not accumulate in the top soil layer, but there was a slight increase in the middle and bottom soil depths. The results demonstrate that the reclamation of sodic soils using BFGD is promising. PMID:23936481

  19. Calcium Sulfate Hemihydrate Whiskers Obtained from Flue Gas Desulfurization Gypsum and Used for the Adsorption Removal of Lead

    Directory of Open Access Journals (Sweden)

    Xiaoshu Wang

    2017-09-01

    Full Text Available Abstract: As a recycled material, flue gas desulfurization gypsum has been used to prepare calcium sulfate hemihydrate whisker (CSHW through hydrothermal synthesis for several decades. However, the subsequent utilization of this resultant material has not yet received considerable attention. In the present research, CSHW was successfully synthesized at a certain region, and was used for the adsorption of lead ions from aqueous solutions, thereby broadening the research field for the practical application of CSHW. Its adsorption capacity was significantly influenced by various parameters, particularly, the pH level and initial lead concentration. The pH value highly affected the hydrolysis degree of lead ions and dominated the adsorption of lead. The equilibrium isotherms under two different temperatures were simulated using Langmuir, Freundlich, and Temkin models. Both Langmuir and Temkin models showed a good fit to the data. Combined with the well-fitted pseudo-second-order model, the adsorption mechanism was thought to be a chemisorption process that was enforced by the ion exchange reaction. In addition, the specific crystal structure of CSHW revealed that ion exchange reaction occurred on the (010 and (100 facets due to their preferential growth and negatively charged property. The residual solid phase after adsorption was collected and detected using X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy. Results revealed that PbSO4 was formed on the surface of CSHW. The alkaline condition introduced the tribasic lead sulfate, and thus reduced the stability of the adsorption system.

  20. Effect of byproducts of flue gas desulfurization on the soluble salts composition and chemical properties of sodic soils.

    Science.gov (United States)

    Wang, Jinman; Bai, Zhongke; Yang, Peiling

    2013-01-01

    The byproducts of flue gas desulfurization (BFGD) are a useful external source of Ca(2+) for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two different sodic soils (sodic soil I and sodic soil II) and two BFGD rates. After the application of BFGD and leaching, the soil soluble salts were transformed from sodic salts containing Na2CO3 and NaHCO3 to neutral salts containing NaCl and Na2SO4. The sodium adsorption ratio (SAR), pH and electrical conductivity (EC) decreased at all soil depths, and more significantly in the top soil depth. At a depth of 0-40 cm in both sodic soil I and sodic soil II, the SAR, EC and pH were less than 13, 4 dS m(-1) and 8.5, respectively. The changes in the chemical properties of the sodic soils reflected the changes in the ion composition of soluble salts. Leaching played a key role in the reclamation process and the reclamation effect was positively associated with the amount of leaching. The soil salts did not accumulate in the top soil layer, but there was a slight increase in the middle and bottom soil depths. The results demonstrate that the reclamation of sodic soils using BFGD is promising.

  1. Effect of byproducts of flue gas desulfurization on the soluble salts composition and chemical properties of sodic soils.

    Directory of Open Access Journals (Sweden)

    Jinman Wang

    Full Text Available The byproducts of flue gas desulfurization (BFGD are a useful external source of Ca(2+ for the reclamation of sodic soils because they are comparatively cheap, generally available and have high gypsum content. The ion solution composition of sodic soils also plays an important role in the reclamation process. The effect of BFGD on the soluble salts composition and chemical properties of sodic soils were studied in a soil column experiment. The experiment consisted of four treatments using two different sodic soils (sodic soil I and sodic soil II and two BFGD rates. After the application of BFGD and leaching, the soil soluble salts were transformed from sodic salts containing Na2CO3 and NaHCO3 to neutral salts containing NaCl and Na2SO4. The sodium adsorption ratio (SAR, pH and electrical conductivity (EC decreased at all soil depths, and more significantly in the top soil depth. At a depth of 0-40 cm in both sodic soil I and sodic soil II, the SAR, EC and pH were less than 13, 4 dS m(-1 and 8.5, respectively. The changes in the chemical properties of the sodic soils reflected the changes in the ion composition of soluble salts. Leaching played a key role in the reclamation process and the reclamation effect was positively associated with the amount of leaching. The soil salts did not accumulate in the top soil layer, but there was a slight increase in the middle and bottom soil depths. The results demonstrate that the reclamation of sodic soils using BFGD is promising.

  2. Management of dry flue gas desulfurization by-products in underground mines. Quarterly technical progress report, April 1995--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Dutta, D.; Esling, S. [and others

    1995-07-01

    On September 30, 1993, the U.S. Department of Energy-Morgantown Energy Technology Center and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate several technologies for the placement of coal combustion residues in abandoned coal mines, and will assess the environmental impact of such underground residues placement. Previous quarterly Technical Progress Reports have set forth the specific objectives of the program, and a discussion of these is not repeated here. Rather, this report discusses the technical progress made during the period April 1 - June 30, 1995. A final topical report on the SEEC, Inc. demonstration of its technology for the transporting of coal combustion residues was completed during the quarter, although final printing of the report was accomplished early in July, 1995. The SEEC technology involves the use of Collapsible Intermodal Containers (CIC`s) developed by SEEC, and the transportation of such containers - filled with fly ash or other coal combustion residues - on rail coal cars or other transportation means. Copies of the final topical report, entitled {open_quotes}The Development and Testing of Collapsible Intermodal Containers for the Handling and Transport of Coal Combustion Residues{close_quotes} were furnished to the Morgantown Energy Technology Center. The Rapid Aging Test colums were placed in operation during the quarter. This test is to determine the long-term reaction of both the pneumatic and hydraulic mixtures to brine as a leaching material, and simulates the conditions that will be encountered in the actual underground placement of the coal combustion residues mixtures. The tests will continue for about one year.

  3. FY 1999 report on the feasibility study on the project for assisting introduction of an environmentally-friendly coal utilization system (Green Helmet Project). Desulfurization agent added CWM for Beijing Yanshan; 1999 nendo kankyo chowagata sekitan riyo system donyu shien jigyo (green helmet jigyo) chosa hokokusho. Datsuryugata CWM setsubi (Beijing Yanshan)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The Green Helmet Project is aimed at demonstration of the clean coal technologies to be disseminated in China, and controlling generation of pollutants caused by coal utilization by constructing the dissemination infrastructures. It is also aimed at promotion of stable energy supply for Japan. Described herein are the FY 1999 results of the desulfurization agent added CWM project at Beijing Yanshan Petrochemical Co., Ltd., where CWM is incorporated with finely crushed limestone as the desulfurization agent and the mixture is supplied to a boiler as the desulfurization agent added CWM. This removes/abates sulfur oxides without needing a desulfurization treatment after combustion. The Japanese engineers dispatched offer comprehensive technical guidance for design/fabrication/installation of the machines and equipment, test runs, performance tests and demonstration runs, which are completed in March 2000. The system starts the commercial operation in April. The follow-up project is implemented to confirm the results of the project, and further improve CWM burner reliability/performance and desulfurization rate. It is found that decreasing burner flame temperature is essential for increasing desulfurization rate. The combustion variables, e.g., air/fuel ratio, steam/CWM ratio and cooling by sprayed steam, are tested to increase desulfurization rate to around 50%. (NEDO)

  4. Use of propidium monoazide for selective profiling of viable microbial cells during Gouda cheese ripening

    NARCIS (Netherlands)

    Erkus, O.; Jager, V.C. de; Geene, R.T.; Alen-Boerrigter, I.J. van; Hazelwood, L.; Hijum, S.A.F.T. van; Kleerebezem, M; Smid, E.J.

    2016-01-01

    DNA based microbial community profiling of food samples is confounded by the presence of DNA derived from membrane compromised (dead or injured) cells. Selective amplification of DNA from viable (intact) fraction of the community by propidium monoazide (PMA) treatment could circumvent this problem.

  5. Induction of viable 2n pollen in sterile Oriental × Trumpet Lilium hybrids

    NARCIS (Netherlands)

    Luo, J.R.; Arens, P.; Niu, L.X.; Tuyl, van J.M.

    2016-01-01

    In order to induce viable 2n pollen from highly sterile diploid Oriental × Trumpet (OT) (Lilium), N2O was used to treat flower buds of four sterile diploid OT cultivars (‘Nymph’, ‘Gluhwein’, ‘Yelloween’, and ‘Shocking’) at different stages of meiosis. There was no pollen germination in

  6. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be tested...

  7. Oligonucleotide microarrays for the detection and identification of viable beer spoilage bacteria.

    Science.gov (United States)

    Weber, D G; Sahm, K; Polen, T; Wendisch, V F; Antranikian, G

    2008-10-01

    The design and evaluation of an oligonucleotide microarray in order to detect and identify viable bacterial species that play a significant role in beer spoilage. These belong to the species of the genera Lactobacillus, Megasphaera, Pediococcus and Pectinatus. Oligonucleotide probes specific to beer spoilage bacteria were designed. In order to detect viable bacteria, the probes were designed to target the intergenic spacer regions (ISR) between 16S and 23S rRNA. Prior to hybridization the ISR were amplified by combining reverse transcriptase and polymerase chain reactions using a designed consenus primer. The developed oligonucleotide microarrays allows the detection of viable beer spoilage bacteria. This method allows the detection and discrimination of single bacterial species in a sample containing complex microbial community. Furthermore, microarrays using oligonucleotide probes targeting the ISR allow the distinction between viable bacteria with the potential to grow and non growing bacteria. The results demonstrate the feasibility of oligonucleotide microarrays as a contamination control in food industry for the detection and identification of spoilage micro-organisms within a mixed population.

  8. Separable Bilayer Microfiltration Device for Viable Label-free Enrichment of Circulating Tumour Cells

    Science.gov (United States)

    Zhou, Ming-Da; Hao, Sijie; Williams, Anthony J.; Harouaka, Ramdane A.; Schrand, Brett; Rawal, Siddarth; Ao, Zheng; Brennaman, Randall; Gilboa, Eli; Lu, Bo; Wang, Shuwen; Zhu, Jiyue; Datar, Ram; Cote, Richard; Tai, Yu-Chong; Zheng, Si-Yang

    2014-12-01

    The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished. Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture. Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably. Using multiple cancer cell lines spiked in healthy donor blood, the SB microfilter demonstrated high capture efficiency (78-83%), high retention of cell viability (71-74%), high tumour cell enrichment against leukocytes (1.7-2 × 103), and widespread ability to establish cultures post-capture (100% of cell lines tested). In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis. Our preliminary studies reflect the efficacy of the SB microfilter device to efficiently and reliably enrich viable CTCs in animal model studies, constituting an exciting technology for new insights in cancer research.

  9. Viable Techniques, Leontief’s Closed Model, and Sraffa’s Subsistence Economies

    Directory of Open Access Journals (Sweden)

    Alberto Benítez

    2014-11-01

    Full Text Available This paper studies the production techniques employed in economies that reproduce themselves. Special attention is paid to the distinction usually made between those that do not produce a surplus and those that do, which are referred to as first and second class economies, respectively. Based on this, we present a new definition of viable economies and show that every viable economy of the second class can be represented as a viable economy of the first class under two different forms, Leontief‘s closed model and Sraffa’s subsistence economies. This allows us to present some remarks concerning the economic interpretation of the two models. On the one hand, we argue that the participation of each good in the production of every good can be considered as a normal characteristic of the first model and, on the other hand, we provide a justification for the same condition to be considered a characteristic of the second model. Furthermore, we discuss three definitions of viable techniques advanced by other authors and show that they differ from ours because they admit economies that do not reproduce themselves completely.

  10. Modelling the number of viable vegetative cells of Bacillus cereus passing through the stomach

    NARCIS (Netherlands)

    Wijnands, L.M.; Pielaat, A.; Dufrenne, J.B.; Zwietering, M.H.; Leusden, van F.M.

    2009-01-01

    Aims: Model the number of viable vegetative cells of B. cereus surviving the gastric passage after experiments in simulated gastric conditions. Materials and Methods: The inactivation of stationary and exponential phase vegetative cells of twelve different strains of Bacillus cereus, both mesophilic

  11. Determination of viable Salmonellae from potable and source water through PMA assisted qPCR.

    Science.gov (United States)

    Singh, Gulshan; Vajpayee, Poornima; Bhatti, Saurabh; Ronnie, Nirmala; Shah, Nimish; McClure, Peter; Shanker, Rishi

    2013-07-01

    Resource constrained countries identified as endemic zones for pathogenicity of Salmonella bear an economic burden due to recurring expenditure on medical treatment. qPCR used for Salmonella detection could not discriminate between viable and nonviable cells. Propidium monoazide (PMA) that selectively penetrates nonviable cells to cross-link their DNA, was coupled with ttr gene specific qPCR for quantifying viable salmonellae in source/potable waters collected from a north Indian city. Source water (raw water for urban potable water supply) and urban potable water exhibited viable salmonellae in the range of 2.1×10(4)-2.6×10(6) and 2-7160CFU/100mL, respectively. Potable water at water works exhibited DNA from dead cells but no viable cells were detected. PMA assisted qPCR could specifically detect low numbers of live salmonellae in Source and potable waters. This strategy can be used in surveillance of urban potable water distribution networks to map contamination points for better microbial risk management. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Science.gov (United States)

    2010-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section. A...

  13. Food web (bio-)manipulation of South African reservoirs – viable ...

    African Journals Online (AJOL)

    2006-10-04

    Oct 4, 2006 ... Food web (bio-)manipulation of South African reservoirs – viable eutrophication ... Microcystis in local eutrophic waters is perceived as a primary major constraint in implementing 'classical' food-web manip- ulation. Intrinsic ... cially in 'shallow' lakes) to dismal failure (often in deep lakes) and a range of ...

  14. Uniform dispersion of cobalt nanoparticles over nonporous TiO2 with low activation energy for magnesium sulfate recovery in a novel magnesia-based desulfurization process.

    Science.gov (United States)

    Wang, Lidong; Qi, Tieyue; Wang, Juan; Zhang, Shihan; Xiao, Huining; Ma, Yongliang

    2018-01-15

    The forced oxidation of magnesium sulfite (MgSO3) aims to not only reclaim the by-product in the magnesia desulfurization, but also lower the risk of secondary pollution. The non-porous titanium dioxide nanoparticle was used as a support to prepare the cobalt catalyst (Co-TiO2) in order to expedite the oxidation rate. This fabricated Co-TiO2 was characterized by inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive spectroscopy (EDS) to figure out its catalytic mechanism. The results revealed that the cobalt nanoparticles were uniformly dispersed on the surface of the TiO2 in forms of Co3O4 and Co2O3. The kinetics of the MgSO3 oxidation catalyzed by the prepared Co-TiO2 was investigated in a bubbling tank reactor, indicating that the oxidation rate was dependent on the catalyst concentration, oxygen partial pressure, pH value, and the reaction temperature. Compared with the reported porous catalyst (Co-CNTs), the activation energy with the Co-TiO2 (17.29kJmol(-1)) decreased by 50.9%, resulting in a good catalytic performance in sulfite oxidation. The findings will help advance the industrial application of the novel magnesia desulfurization process. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Deep Oxidative Desulfurization of Dibenzothiophene in Simulated Oil and Real Diesel Using Heteropolyanion-Substituted Hydrotalcite-Like Compounds as Catalysts

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2013-11-01

    Full Text Available Three heteropolyanion substituted hydrotalcite-like compounds (HPA-HTLcs including Mg9Al3(OH24[PW12O40](MgAl-PW12, Mg9Al3(OH24[PMo12O40] (MgAl-PMo12 and Mg12Al4(OH32[SiW12O40] (MgAl-SiW12, were synthesized, characterized and used as catalysts for the oxidative desulfurization of simulated oil (dibenzothiophene, DBT, in n-octane. MgAl-PMo12 was identified as an effective catalyst for the oxidative removal of DBT under very mild conditions of atmospheric pressure and 60 °C in a biphasic system using hydrogen peroxide as oxidant and acetonitrile as extractant. The conversion of DBT was nearly 100%. As a result, because of the influence of the electron density and the space steric hindrance, the oxidation reactivity of the different sulfur compounds in simulated oil followed the order DBT > 4,6-dimethyldibenzothiophene (4,6-DMDBT > benzothiophene (BT > thiophene (TH. When the reaction is finished, the catalysts can be recovered from the acetonitrile phase by filtration. The recovered MgAl-PMo12 retains nearly the same catalytic activity as the fresh material. Moreover, MgAl-PMo12 was found to exhibit an ideal catalytic activity in the oxidative desulfurization of real diesel resulting in a total remaining sulfur content of 9.12 ppm(w.

  16. Effects of flue gas desulfurization and mined gypsums on soil properties and on hay and corn growth in eastern ohio.

    Science.gov (United States)

    Kost, David; Chen, Liming; Guo, Xialou; Tian, Yongqiang; Ladwig, Ken; Dick, Warren A

    2014-01-01

    Gypsum (CaSO·2HO) is a quality source of Ca and S and has various beneficial uses that can improve agricultural production. This study was conducted to compare rates of flue gas desulfurization (FGD) gypsum and commercially available agricultural (i.e., mined) gypsum as soil amendments on soils typical of eastern Ohio or western Pennsylvania. Two field experiments were conducted, one involving a mixed grass hay field and the other corn ( L.). Gypsum was applied once at rates of 0.2, 2.0, and 20 Mg ha and a seventh treatment was a zero rate control. Corn grain yields response to gypsum was mixed with significant differences between low and high gypsum rates in 2010 but not between gypsum and no gypsum treatments. In the hay study, the low and intermediate gypsum rates generally did not result in any significant changes compared with the control treatment. At the high rate of 20 Mg ha, the following results were observed for the hay study: (i) both gypsums generally increased Ca, S, and soluble salts (electrical conductivity) in the topsoil and subsoil, when compared with the control; (ii) the FGD gypsum decreased Mg in soil when compared with all other treatments, and mined gypsum decreased Mg when compared with the control; and (iii) there were few effects on soil concentrations of trace elements, including Hg. Also at the high application rate, hay yield for the first cutting (May) in 2009 and 2010 was significantly less for mined and FGD gypsum compared with the control, but increased yields in subsequent cutting resulted in no significant treatment differences in total annual hay yield for 2008, 2009, or 2010 or cumulative yield for 2008 to 2010. Overall, for the hay study, the absence of significant soil chemical effects for the intermediate gypsum rate and the decrease in soil Mg concentrations for the high gypsum rate indicate that an application rate of approximately 2.0 Mg ha would be optimal for this soil. Copyright © by the American Society of Agronomy

  17. Isolation of viable Neospora caninum from brains of wild gray wolves (Canis lupus).

    Science.gov (United States)

    Dubey, J P; Jenkins, M C; Ferreira, L R; Choudhary, S; Verma, S K; Kwok, O C H; Fetterer, R; Butler, E; Carstensen, M

    2014-03-17

    Neospora caninum is a common cause of abortion in cattle worldwide. Canids, including the dog and the dingo (Canis familiaris), the coyote (Canis latrans), and the gray wolf (Canis lupus) are its definitive hosts that can excrete environmentally resistant oocysts in the environment, but also can act as intermediate hosts, harboring tissue stages of the parasite. In an attempt to isolate viable N. caninum from tissues of naturally infected wolves, brain and heart tissue from 109 wolves from Minnesota were bioassayed in mice. Viable N. caninum (NcWolfMn1, NcWolfMn2) was isolated from the brains of two wolves by bioassays in interferon gamma gene knockout mice. DNA obtained from culture-derived N. caninum tachyzoites of the two isolates were analyzed by N. caninum-specific Nc5 polymerase chain reaction and confirmed diagnosis. This is the first report of isolation of N. caninum from tissues of any wild canid host. Published by Elsevier B.V.

  18. Viable Intrauterine Pregnancy and Coexisting Molar Pregnancy in a Bicornuate Uterus: A Rare Presentation

    Directory of Open Access Journals (Sweden)

    Kavitha Krishnamoorthy

    2016-01-01

    Full Text Available A complete hydatidiform mole with a viable coexisting fetus (CMCF is a rare occurrence. Similarly, Mullerian anomalies such as a bicornuate uterus are uncommon variants of normal anatomy. We report a case of a 40-year-old female with a known bicornuate uterus presenting at 13 weeks gestation with vaginal bleeding. Ultrasound findings showed a healthy viable pregnancy in the right horn with complete molar pregnancy in the left horn. After extensive counseling, the patient desired conservative management, however, was unable to continue due to profuse vaginal bleeding. The patient underwent suction dilation and curettage under general anesthesia and evacuation of the uterine horns. Postoperatively, the patient was followed until serum beta-human chorionic gonadotropin (β-hCG level dropped to <5 mU. This is the first case of a CMCF reported in a bicornuate uterus, diagnosed with the use of ultrasound imaging.

  19. Non-viable Borrelia burgdorferi induce inflammatory mediators and apoptosis in human oligodendrocytes.

    Science.gov (United States)

    Parthasarathy, Geetha; Fevrier, Helene B; Philipp, Mario T

    2013-11-27

    In previous studies, exposure to live Borrelia burgdorferi was shown to induce inflammation and apoptosis of human oligodendrocytes. In this study we assessed the ability of non-viable bacteria (heat killed or sonicated) to induce inflammatory mediators and cell death. Both heat-killed and sonicated bacteria induced release of CCL2, IL-6, and CXCL8 from oligodendrocytes in a dose dependent manner. In addition, non-viable B. burgdorferi also induced cell death as evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and another cell viability assay. These results suggest that spirochetal residues left after bacterial demise, due to treatment or otherwise, may continue to be pathogenic to the central nervous system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. PMA-PhyloChip DNA Microarray to Elucidate Viable Microbial Community Structure

    Science.gov (United States)

    Venkateswaran, Kasthuri J.; Stam, Christina N.; Andersen, Gary L.; DeSantis, Todd

    2011-01-01

    Since the Viking missions in the mid-1970s, traditional culture-based methods have been used for microbial enumeration by various NASA programs. Viable microbes are of particular concern for spacecraft cleanliness, for forward contamination of extraterrestrial bodies (proliferation of microbes), and for crew health/safety (viable pathogenic microbes). However, a "true" estimation of viable microbial population and differentiation from their dead cells using the most sensitive molecular methods is a challenge, because of the stability of DNA from dead cells. The goal of this research is to evaluate a rapid and sensitive microbial detection concept that will selectively estimate viable microbes. Nucleic acid amplification approaches such as the polymerase chain reaction (PCR) have shown promise for reducing time to detection for a wide range of applications. The proposed method is based on the use of a fluorescent DNA intercalating agent, propidium monoazide (PMA), which can only penetrate the membrane of dead cells. The PMA-quenched reaction mixtures can be screened, where only the DNA from live cells will be available for subsequent PCR reaction and microarray detection, and be identified as part of the viable microbial community. An additional advantage of the proposed rapid method is that it will detect viable microbes and differentiate from dead cells in only a few hours, as opposed to less comprehensive culture-based assays, which take days to complete. This novel combination approach is called the PMA-Microarray method. DNA intercalating agents such as PMA have previously been used to selectively distinguish between viable and dead bacterial cells. Once in the cell, the dye intercalates with the DNA and, upon photolysis under visible light, produces stable DNA adducts. DNA cross-linked in this way is unavailable for PCR. Environmental samples suspected of containing a mixture of live and dead microbial cells/spores will be treated with PMA, and then incubated

  1. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    Directory of Open Access Journals (Sweden)

    Truernit Elisabeth

    2008-06-01

    Full Text Available Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP fluorescence was possible. Conclusion The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy.

  2. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

    OpenAIRE

    Sozzi, Fabiola; Poldermans, Don; Bax, Jeroen; Elhendy, Abdou; Vourvouri, Eleni; Valkema, Roelf; Sutter, J.; Schinkel, Arend; Borghetti, A; Roelandt, Jos

    2001-01-01

    OBJECTIVE—To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference.
PATIENTS—30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men).
METHODS—Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simul...

  3. Molecular approaches for viable bacterial population and transcriptional analyses in a rodent model of dental caries.

    Science.gov (United States)

    Klein, M I; Scott-Anne, K M; Gregoire, S; Rosalen, P L; Koo, H

    2012-10-01

    Culturing methods are the primary approach for microbiological analysis of plaque biofilms in rodent models of dental caries. In this study, we developed strategies for the isolation of DNA and RNA from plaque biofilms formed in vivo to analyse the viable bacterial population and gene expression. Plaque biofilm samples from rats were treated with propidium monoazide to isolate DNA from viable cells, and the purified DNA was used to quantify total bacteria and the Streptococcus mutans population via quantitative polymerase chain reaction (qPCR) and specific primers; the same samples were also analysed by counting colony-forming units (CFU). In parallel, RNA was isolated from plaque-biofilm samples (from the same animals) and used for transcriptional analyses via reverse transcription-qPCR. The viable populations of both S. mutans and total bacteria assessed by qPCR were positively correlated with the CFU data (P  0.8). However, the qPCR data showed higher bacterial cell counts, particularly for total bacteria (vs. CFU). Moreover, S. mutans proportion in the plaque biofilm determined by qPCR analysis showed strong correlation with incidence of smooth-surface caries (P = 0.0022, r = 0.71). The purified RNAs presented high RNA integrity numbers (> 7), which allowed measurement of the expression of genes that are critical for S. mutans virulence (e.g. gtfB and gtfC). Our data show that the viable microbial population and the gene expression can be analysed simultaneously, providing a global assessment of the infectious aspect of dental caries. Our approach could enhance the value of the current rodent model in further understanding the pathophysiology of this disease and facilitating the exploration of novel anti-caries therapies. © 2012 John Wiley & Sons A/S.

  4. Characterization of the Viable but Nonculturable (VBNC State in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Mohammad Salma

    Full Text Available The Viable But Non Culturable (VBNC state has been thoroughly studied in bacteria. In contrast, it has received much less attention in other microorganisms. However, it has been suggested that various yeast species occurring in wine may enter in VBNC following sulfite stress.In order to provide conclusive evidences for the existence of a VBNC state in yeast, the ability of Saccharomyces cerevisiae to enter into a VBNC state by applying sulfite stress was investigated. Viable populations were monitored by flow cytometry while culturable populations were followed by plating on culture medium. Twenty-four hours after the application of the stress, the comparison between the culturable population and the viable population demonstrated the presence of viable cells that were non culturable. In addition, removal of the stress by increasing the pH of the medium at different time intervals into the VBNC state allowed the VBNC S. cerevisiae cells to "resuscitate". The similarity between the cell cycle profiles of VBNC cells and cells exiting the VBNC state together with the generation rate of cells exiting VBNC state demonstrated the absence of cellular multiplication during the exit from the VBNC state. This provides evidence of a true VBNC state. To get further insight into the molecular mechanism pertaining to the VBNC state, we studied the involvement of the SSU1 gene, encoding a sulfite pump in S. cerevisiae. The physiological behavior of wild-type S. cerevisiae was compared to those of a recombinant strain overexpressing SSU1 and null Δssu1 mutant. Our results demonstrated that the SSU1 gene is only implicated in the first stages of sulfite resistance but not per se in the VBNC phenotype. Our study clearly demonstrated the existence of an SO2-induced VBNC state in S. cerevisiae and that the stress removal allows the "resuscitation" of VBNC cells during the VBNC state.

  5. Mitochondrial respiration in human viable platelets-Methodology and influence of gender, age and storage

    DEFF Research Database (Denmark)

    Sjövall, Fredrik; Ehinger, Johannes K H; Marelsson, Sigurður E

    2013-01-01

    Studying whole cell preparations with intact mitochondria and respiratory complexes has a clear benefit compared to isolated or disrupted mitochondria due to the dynamic interplay between mitochondria and other cellular compartments. Platelet mitochondria have a potential to serve as a source...... of human viable mitochondria when studying mitochondrial physiology and pathogenic mechanisms, as well as for the diagnostics of mitochondrial diseases. The objective of the present study was to perform a detailed evaluation of platelet mitochondrial respiration using high-resolution respirometry. Further...

  6. An advanced PCR method for the specific detection of viable total coliform bacteria in pasteurized milk.

    Science.gov (United States)

    Soejima, Takashi; Minami, Jun-ichi; Yaeshima, Tomoko; Iwatsuki, Keiji

    2012-07-01

    Pasteurized milk is a complex food that contains various inhibitors of polymerase chain reaction (PCR) and may contain a large number of dead bacteria, depending on the milking conditions and environment. Ethidium monoazide bromide (EMA)-PCR is occasionally used to distinguish between viable and dead bacteria in foods other than pasteurized milk. EMA is a DNA-intercalating dye that selectively permeates the compromised cell membranes of dead bacteria and cleaves DNA. Usually, EMA-PCR techniques reduce the detection of dead bacteria by up to 3.5 logs compared with techniques that do not use EMA. However, this difference may still be insufficient to suppress the amplification of DNA from dead Gram-negative bacteria (e.g., total coliform bacteria) if they are present in pasteurized milk in large numbers. Thus, false positives may result. We developed a new method that uses real-time PCR targeting of a long DNA template (16S-23S rRNA gene, principally 2,451 bp) following EMA treatment to completely suppress the amplification of DNA of up to 7 logs (10(7) cells) of dead total coliforms. Furthermore, we found that a low dose of proteinase K (25 U/ml) removed PCR inhibitors and simultaneously increased the signal from viable coliform bacteria. In conclusion, our simple protocol specifically detects viable total coliforms in pasteurized milk at an initial count of ≥1 colony forming unit (CFU)/2.22 ml within 7.5 h of total testing time. This detection limit for viable cells complies with the requirements for the analysis of total coliforms in pasteurized milk set by the Japanese Sanitation Act (which specifies <1 CFU/2.22 ml).

  7. Concurrent detection of other respiratory viruses in children shedding viable human respiratory syncytial virus.

    Science.gov (United States)

    Gagliardi, T B; Paula, F E; Iwamoto, M A; Proença-Modena, J L; Santos, A E; Camara, A A; Cervi, M C; Cintra, O A L; Arruda, E

    2013-10-01

    Human respiratory syncytial virus (HRSV) is an important cause of respiratory disease. The majority of studies addressing the importance of virus co-infections to the HRSV-disease have been based on the detection of HRSV by RT-PCR, which may not distinguish current replication from prolonged shedding of remnant RNA from previous HRSV infections. To assess whether co-detections of other common respiratory viruses are associated with increased severity of HRSV illnesses from patients who were shedding viable-HRSV, nasopharyngeal aspirates from children younger than 5 years who sought medical care for respiratory infections in Ribeirão Preto (Brazil) were tested for HRSV by immunofluorescence, RT-PCR and virus isolation in cell culture. All samples with viable-HRSV were tested further by PCR for other respiratory viruses. HRSV-disease severity was assessed by a clinical score scale. A total of 266 samples from 247 children were collected and 111 (42%) were HRSV-positive. HRSV was isolated from 70 (63%), and 52 (74%) of them were positive for at least one additional virus. HRSV-positive diseases were more severe than HRSV-negative ones, but there was no difference in disease severity between patients with viable-HRSV and those HRSV-positives by RT-PCR. Co-detection of other viruses did not correlate with increased disease severity. HRSV isolation in cell culture does not seem to be superior to RT-PCR to distinguish infections associated with HRSV replication in studies of clinical impact of HRSV. A high rate of co-detection of other respiratory viruses was found in samples with viable-HRSV, but this was not associated with more severe HRSV infection. Copyright © 2013 Wiley Periodicals, Inc.

  8. Cosmic constraint on massive neutrinos in viable f( R) gravity with producing Λ CDM background expansion

    Science.gov (United States)

    Lu, Jianbo; Liu, Molin; Wu, Yabo; Wang, Yan; Yang, Weiqiang

    2016-12-01

    Tensions between several cosmic observations were found recently, such as the inconsistent values of H0 (or σ 8) were indicated by the different cosmic observations. Introducing the massive neutrinos in Λ CDM could potentially solve the tensions. Viable f( R) gravity producing Λ CDM background expansion with massive neutrinos is investigated in this paper. We fit the current observational data: Planck-2015 CMB, RSD, BAO, and SNIa to constrain the mass of neutrinos in viable f( R) theory. The constraint results at 95% confidence level are: Σ m_ν case, m_{ν , sterile}^effcase. For the effects due to the mass of the neutrinos, the constraint results on model parameter at 95% confidence level become f_{R0}× 10^{-6}> -1.89 and f_{R0}× 10^{-6}> -2.02 for two cases, respectively. It is also shown that the fitting values of several parameters much depend on the neutrino properties, such as the cold dark matter density, the cosmological quantities at matter-radiation equality, the neutrino density and the fraction of baryonic mass in helium. Finally, the constraint result shows that the tension between direct and CMB measurements of H_0 gets slightly weaker in the viable f( R) model than that in the base Λ CDM model.

  9. Fate of viable but non-culturable Listeria monocytogenes in pig manure microcosms

    Directory of Open Access Journals (Sweden)

    Jeremy eDesneux

    2016-03-01

    Full Text Available The fate of two strains of L. monocytogenes and their ability to become viable but non-culturable (VBNC was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures stored for two months at 8°C and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA. The chemical composition and the microbial community structure of the manures were also analysed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5-94.8% than in treated manures (67.8-79.2%. The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behaviour of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents.

  10. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography.

    Science.gov (United States)

    Sozzi, F B; Poldermans, D; Bax, J J; Elhendy, A; Vourvouri, E C; Valkema, R; De Sutter, J; Schinkel, A F; Borghetti, A; Roelandt, J R

    2001-12-01

    To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. 30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men). Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with (99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch. Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, kappa = 0.77, p = 0.001 v fundamental imaging). Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability.

  11. Mice carrying a complete deletion of the talin2 coding sequence are viable and fertile

    Energy Technology Data Exchange (ETDEWEB)

    Debrand, Emmanuel; Conti, Francesco J.; Bate, Neil; Spence, Lorraine; Mazzeo, Daniela; Pritchard, Catrin A.; Monkley, Susan J. [Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN (United Kingdom); Critchley, David R., E-mail: drc@le.ac.uk [Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN (United Kingdom)

    2012-09-21

    Highlights: Black-Right-Pointing-Pointer Mice lacking talin2 are viable and fertile with only a mildly dystrophic phenotype. Black-Right-Pointing-Pointer Talin2 null fibroblasts show no major defects in proliferation, adhesion or migration. Black-Right-Pointing-Pointer Maintaining a colony of talin2 null mice is difficult indicating an underlying defect. -- Abstract: Mice homozygous for several Tln2 gene targeted alleles are viable and fertile. Here we show that although the expression of talin2 protein is drastically reduced in muscle from these mice, other tissues continue to express talin2 albeit at reduced levels. We therefore generated a Tln2 allele lacking the entire coding sequence (Tln2{sup cd}). Tln2{sup cd/cd} mice were viable and fertile, and the genotypes of Tln2{sup cd/+} intercrosses were at the expected Mendelian ratio. Tln2{sup cd/cd} mice showed no major difference in body mass or the weight of the major organs compared to wild-type, although they displayed a mildly dystrophic phenotype. Moreover, Tln2{sup cd/cd} mouse embryo fibroblasts showed no obvious defects in cell adhesion, migration or proliferation. However, the number of Tln2{sup cd/cd} pups surviving to adulthood was variable suggesting that such mice have an underlying defect.

  12. Glioma Surgical Aspirate: A Viable Source of Tumor Tissue for Experimental Research

    Directory of Open Access Journals (Sweden)

    Perry F. Bartlett

    2013-04-01

    Full Text Available Brain cancer research has been hampered by a paucity of viable clinical tissue of sufficient quality and quantity for experimental research. This has driven researchers to rely heavily on long term cultured cells which no longer represent the cancers from which they were derived. Resection of brain tumors, particularly at the interface between normal and tumorigenic tissue, can be carried out using an ultrasonic surgical aspirator (CUSA that deposits liquid (blood and irrigation fluid and resected tissue into a sterile bottle for disposal. To determine the utility of CUSA-derived glioma tissue for experimental research, we collected 48 CUSA specimen bottles from glioma patients and analyzed both the solid tissue fragments and dissociated tumor cells suspended in the liquid waste fraction. We investigated if these fractions would be useful for analyzing tumor heterogeneity, using IHC and multi-parameter flow cytometry; we also assessed culture generation and orthotopic xenograft potential. Both cell sources proved to be an abundant, highly viable source of live tumor cells for cytometric analysis, animal studies and in-vitro studies. Our findings demonstrate that CUSA tissue represents an abundant viable source to conduct experimental research and to carry out diagnostic analyses by flow cytometry or other molecular diagnostic procedures.

  13. Desiccation induces viable but Non-Culturable cells in Sinorhizobium meliloti 1021.

    Science.gov (United States)

    Vriezen, Jan Ac; de Bruijn, Frans J; Nüsslein, Klaus R

    2012-01-20

    Sinorhizobium meliloti is a microorganism commercially used in the production of e.g. Medicago sativa seed inocula. Many inocula are powder-based and production includes a drying step. Although S. meliloti survives drying well, the quality of the inocula is reduced during this process. In this study we determined survival during desiccation of the commercial strains 102F84 and 102F85 as well as the model strain USDA1021.The survival of S. meliloti 1021 was estimated during nine weeks at 22% relative humidity. We found that after an initial rapid decline of colony forming units, the decline slowed to a steady 10-fold reduction in colony forming units every 22 days. In spite of the reduction in colony forming units, the fraction of the population identified as viable (42-54%) based on the Baclight live/dead stain did not change significantly over time. This change in the ability of viable cells to form colonies shows (i) an underestimation of the survival of rhizobial cells using plating methods, and that (ii) in a part of the population desiccation induces a Viable But Non Culturable (VBNC)-like state, which has not been reported before. Resuscitation attempts did not lead to a higher recovery of colony forming units indicating the VBNC state is stable under the conditions tested. This observation has important consequences for the use of rhizobia. Finding methods to resuscitate this fraction may increase the quality of powder-based seed inocula.

  14. TiO2-Containing Carbon Derived from a Metal-Organic Framework Composite: A Highly Active Catalyst for Oxidative Desulfurization.

    Science.gov (United States)

    Bhadra, Biswa Nath; Song, Ji Yoon; Khan, Nazmul Abedin; Jhung, Sung Hwa

    2017-09-13

    A new metal-organic framework (MOF) composite consisting of Ti- and Zn-based MOFs (ZIF-8(x)@H2N-MIL-125; in brief, ZIF(x)@MOF) was designed and synthesized. The pristine MOF [H2N-MIL-125 (MOF)]- and an MOF-composite [ZIF(30)@MOF]-derived mesoporous carbons consisting of TiO2 nanoparticles were prepared by pyrolysis (named MDC-P and MDC-C, respectively). MDC-C showed a higher surface area, larger pore sizes, and larger mesopore volumes than MDC-P. In addition, the TiO2 nanoparticles on MDC-C have more uniform shapes and sizes and are smaller than those of MDC-P. The obtained MDC-C and MDC-P [together with MOF, ZIF(30)@MOF, pure/nanocrystalline TiO2, and activated carbon] were applied in the oxidative desulfurization reaction of dibenzothiophene in a model fuel. The MDC-C, even with a lower TiO2 content than that of MDC-P, showed an outstanding catalytic performance, especially with a very low catalyst dose (i.e., a very high quantity of dibenzothiophene was converted per unit weight of the catalyst), fast kinetics (∼3 times faster than that for MDC-P), and a low activation energy (lower than that for any reported catalyst) for the oxidation of dibenzothiophene. The large mesopores of MDC-C and the well-dispersed/small TiO2 might be the dominant factors for the superior catalytic conversions. The oxidative desulfurization of other sulfur-containing organic compounds with various electron densities was also studied with MDC-C to understand the mechanism of catalysis. Moreover, the MDC-C catalyst can be reused many times in the oxidative desulfurization reaction after a simple washing with acetone. Finally, composing MOFs and subsequent pyrolysis is suggested as an effective way to prepare a catalyst with well-dispersed active sites, large pores, and high mesoporosity.

  15. Reverse transcriptase real-time PCR for detection and quantification of viable Campylobacter jejuni directly from poultry faecal samples

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Wolff, Anders; Madsen, Mogens

    2012-01-01

    and quantification of viable Campylobacter jejuni directly from chicken faecal samples. The results of this method anda DNA-based quantitative real-time PCR (qPCR) method were compared with those of a bacterial culture method. Using bacterial culture andRT-qPCR methods, viable C. jejuni cells could be detected...

  16. Marble waste characterization as a desulfurizing slag component for steel; Caracterizacao do residuo de marmore como componente de escorias dessulfurantes para aco

    Energy Technology Data Exchange (ETDEWEB)

    Coleti, J.L.; Grillo, F.F.; Tenorio, J.A.S. [Universidade de Sao Paulo (USP), SP (Brazil); De Oliveira, J.R. [Instituto Federal do Espirito Santo (IFES), ES (Brazil)

    2014-07-01

    The current steel market requires from steel plants better quality of its products. As a result, steel plants need to search for improvements and costs reduction in its process. Hence, the residue of marble containing significant quantities of calcium and magnesium carbonates, raw materials of steel refining slag, was characterized in order to replace the conventional lime used. Therefore, it will be possible to reduce the cost and volume of waste produced by the ornamental rock industry. The following methods were applied to test the waste potential: SEM with EDS, x-ray diffraction, x-ray fluorescence (EDX), Thermogravimetry (TG) and analysis of surface area and particle size by the BET method using dispersion leisure. The results indicated the feasibility of waste as raw material in the composition of desulfurizing slags. (author)

  17. Comparison of Corrosion Behavior of Low-Alloy Steel Containing Copper and Antimony with 409L Stainless Steel for a Flue Gas Desulfurization System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun-Ah; Shin, Su-Bin; Kim, Jung-Gu [Sungkyunkwan University, Suwon (Korea, Republic of)

    2016-07-15

    The corrosion behavior of low alloy steel containing Cu, Sb and 409L stainless steel was investigated for application in the low-temperature section of a flue gas desulfurization (FGD) system. The electrochemical properties were evaluated by potentiodynamic polarization testing and electrochemical impedance spectroscopy (EIS) in 16.9 vol% H{sub 2}SO{sub 4} + 0.35 vol% HCl at 60 ℃. The inclusions in these steels ere identified by electron probe microanalyzer (EPMA). The corrosion products of the steels were analyzed using scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The corrosion rate of the low alloy steel containing Cu, Sb was about 100 times lower than that of 409L stainless steel. For stainless steel without passivation, active corrosion behavior was shown. In contrast, in the low alloy steel, the Cu, Sb compounds accumulated on the surface improved the corrosion resistance by suppressing the anodic dissolution reaction.

  18. Characterization of Thioether-Linked Protein Adducts of DNA Using a Raney-Ni Mediated Desulfurization Method and Liquid Chromatography-Electrospray-Tandem Mass Spectrometry

    Science.gov (United States)

    Chowdhury, Goutam; Guengerich, F. Peter

    2015-01-01

    This unit contains a complete procedure for the detection and structural characterization of DNA protein crosslinks (DPCs). The procedure also describes an approach for the quantitation of the various structurally distinct DPCs. Although various methods have been described in the literature for labile DPCs, characterization of non-labile adducts remain a challenge. Here we present a novel approach for characterization of both labile and non-labile adducts by the use of a combination of chemical, enzymatic, and mass spectrometric approaches. A Raney Ni-catalyzed reductive desulfurization method was used for removal of the bulky peptide adducts, enzymatic digestion was used to digest the protein to smaller peptides and DNA to nucleosides, and finally LC-ESI-tandem mass spectrometry (MS) was utilized for detection and characterization of nucleoside adducts. PMID:25754888

  19. Phenyl Groups Result in the Highest Benzene Storage and Most Efficient Desulfurization in a Series of Isostructural Metal-Organic Frameworks.

    Science.gov (United States)

    He, Wen-Wen; Yang, Guang-Sheng; Tang, Yu-Jia; Li, Shun-Li; Zhang, Shu-Ran; Su, Zhong-Min; Lan, Ya-Qian

    2015-06-26

    A series of isoreticular metal-organic frameworks (MOFs; NENU-511-NENU-514), which all have high surface areas and strong adsorption capacities, have been successfully constructed by using mixed ligands. NENU-513 has the highest benzene capacity of 1687 mg g(-1) at 298 K, which ranks as the top MOF material among those reported up to now. This NENU series has been used for adsorptive desulfurization because of its permanent porosity. The results indicate that this series has a higher adsorptive efficiency in the removal of organosulfur compounds than other MOF materials, especially NENU-511, which has the highest adsorptive efficiency in the ambient atmosphere. This study proves that the design and synthesis of targeted MOFs with higher surface areas and with functional groups present is an efficient method to enhance benzene-storage capacity and the adsorption of organosulfur compounds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of pH on nitrate and selenate reduction in flue gas desulfurization brine using the H2-based membrane biofilm reactor (MBfR).

    Science.gov (United States)

    Van Ginkel, Steven W; Yang, Ziming; Kim, Bi-o; Sholin, Mark; Rittmann, Bruce E

    2011-01-01

    Increased tightening of air regulations is leading more electric utilities to install flue gas desulfurization (FGD) systems. These systems produce brine containing high concentrations of nitrate, nitrite, and selenate which must be removed before discharge. The H2-based membrane biofilm reactor (MBfR) was shown to consistently remove nitrate, nitrite, and selenate at high efficiencies. The maximum selenate removal flux reached 362 mgSe m(-2)d(-1) and was higher than that observed in earlier research, which shows continual improvement of the biofilm for selenate reduction. A low pH of 6.8 inhibited precipitation when treating actual FGD brine, yet did not inhibit removal. SO4(2-) was not removed and therefore did not compete with nitrate, nitrite, and selenate reduction for the available H2.

  1. The Influence of Micro-Oxygen Addition on Desulfurization Performance and Microbial Communities during Waste-Activated Sludge Digestion in a Rusty Scrap Iron-Loaded Anaerobic Digester

    Directory of Open Access Journals (Sweden)

    Renjun Ruan

    2017-02-01

    Full Text Available In this study, micro-oxygen was integrated into a rusty scrap iron (RSI-loaded anaerobic digester. Under an optimal RSI dosage of 20 g/L, increasing O2 levels were added stepwise in seven stages in a semi-continuous experiment. Results showed the average methane yield was 306 mL/g COD (chemical oxygen demand, and the hydrogen sulphide (H2S concentration was 1933 ppmv with RSI addition. O2 addition induced the microbial oxidation of sulphide by stimulating sulfur-oxidizing bacteria and chemical corrosion of iron, which promoted the generation of FeS and Fe2S3. In the 6th phase of the semi-continuous test, deep desulfurization was achieved without negatively impacting system performance. Average methane yield was 301.1 mL/g COD, and H2S concentration was 75 ppmv. Sulfur mass balance was described, with 84.0%, 11.90% and 0.21% of sulfur present in solid, liquid and gaseous phases, respectively. The Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE analysis revealed that RSI addition could enrich the diversity of hydrogenotrophic methanogens and iron-reducing bacteria to benefit methanogenesis and organic mineralization, and impoverish the methanotroph (Methylocella silvestris to reduce the consumption of methane. Micro-oxygen supplementation could enhance the diversity of iron-oxidizing bacteria arising from the improvement of Fe(II release rate and enrich the sulphur-oxidising bacteria to achieved desulfurization. These results demonstrated that RSI addition in combination with micro-oxygenation represents a promising method for simultaneously controlling biogas H2S concentration and improving digestion performance.

  2. Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix F. Flue gas desulfurization in the United States, 1977. [108 references

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    This report details the current status of flue gas desulfurization (FGD) in conventional coal-fired power plants in the U.S. Sepecifications and features are listed for all commercial FGD installations now in operation or being constructed in this country. The FGD operational experience in each plant is summarized and evaluations are made of process, equipment, and operational performance. FGD in other countries, mainly Japan and West Germany, is reviewed for applicability in the U.S. Federal and state air quality control standards are described and their prime influence on FGD development and plant installation is noted. The rising importance of coal is discussed and some limitations on low-sulfur coal are included. Other potential approaches to desulfurization, such as fluidized-bed combustion, are discussed as far as relevant to FGD. Limestone and lime slurry processes greatly predominate among existing and planned FGD installations in the U.S. However, soluble SO/sub 2/ sorbants are noted as entering use for both throwaway and recoverable SO/sub 2/ products. It is recognized that recovery processes offer attractive long-term prospects in terms of resources and of apparent cost of operation. However, they remain very limited, both in number of processes and in level of development. The report shows that sustained commercial FGD operation in the U.S. is very young, and that process and equipment experience only now is starting its second cycle. Additional progress can be expected as knowledge is derived from sound development programs and from operating experience at recent installations.

  3. Surface coal mine land reclamation using a dry flue gas desulfurization product: Short-term and long-term water responses.

    Science.gov (United States)

    Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A

    2015-09-01

    Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.

  4. Mercury isotope signatures of seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.

    Science.gov (United States)

    Lin, Haiying; Peng, Jingji; Yuan, Dongxing; Lu, Bingyan; Lin, Kunning; Huang, Shuyuan

    2016-07-01

    Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ(202)Hg of particulate mercury (PHg) gradually decreased from -0.30‰ to -1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A novel approach to realize SANI process in freshwater sewage treatment--Use of wet flue gas desulfurization waste streams as sulfur source.

    Science.gov (United States)

    Jiang, Feng; Zhang, Liang; Peng, Guo-Liang; Liang, Si-Yun; Qian, Jin; Wei, Li; Chen, Guang-Hao

    2013-10-01

    SANI (Sulfate reduction, Autotrophic denitrification and Nitrification Integrated) process has been approved to be a sludge-minimized sewage treatment process in warm and coastal cities with seawater supply. In order to apply this sulfur-based process in inland cold areas, wet flue gas desulfurization (FGD) can be simplified and integrated with SANI process, to provide sulfite as electron carrier for sulfur cycle in sewage treatment. In this study, a lab-scale system of the proposed novel process was developed and run for over 200 days while temperature varied between 30 and 5 °C, fed with synthetic FGD wastewaters and sewage. The sulfite-reducing upflow anaerobic sludge bed (SrUASB) reactor, as the major bioreactor of the system, removed 86.9% of organics while the whole system removed 94% of organics even when water temperature decreased to around 10 °C. The bactericidal effect of sulfite was not observed in the SrUASB reactor, while thiosulfate was found accumulated under psychrophilic conditions. The sludge yield of the SrUASB reactor was determined to be 0.095 kg VSS/kg COD, higher than of sulfate reduction process but still much lower than of conventional activated sludge processes. The dominant microbes in the SrUASB reactor were determined as Lactococcus spp. rather than sulfate-reducing bacteria, but sulfite reduction still contributed 85.5% to the organic carbon mineralization in this reactor. Ammonia and nitrate were effectively removed in the aerobic and anoxic filters, respectively. This study confirms the proposed process was promising to achieve sludge-minimized sewage treatment integrating with flue gas desulfurization in inland and cold areas. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella.

    Science.gov (United States)

    Ku, Seockmo; Ximenes, Eduardo; Kreke, Thomas; Foster, Kirk; Deering, Amanda J; Ladisch, Michael R

    2016-11-01

    We report detection of egg white within 7 h by concentrating the bacteria using microfiltration through 0.2-μm cutoff polyethersulfone hollow fiber membranes. A combination of enzyme treatment, controlled cross-flow on both sides of the hollow fibers, and media selection were key to controlling membrane fouling so that rapid concentration and the subsequent detection of low numbers of microbial cells were achieved. We leveraged the protective effect of egg white proteins and peptone so that the proteolytic enzymes did not attack the living cells while hydrolyzing the egg white proteins responsible for fouling. The molecular weight of egg white proteins was reduced from about 70 kDa to 15 kDa during hydrolysis. This enabled a 50-fold concentration of the cells when a volume of 525 mL of peptone and egg white, containing 13 CFU of Salmonella, was decreased to a 10 mL volume in 50 min. A 10-min microcentrifugation step further concentrated the viable Salmonella cells by 10×. The final cell recovery exceeded 100%, indicating that microbial growth occurred during the 3-h processing time. The experiments leading to rapid concentration, recovery, and detection provided further insights on the nature of membrane fouling enabling fouling effects to be mitigated. Unlike most membrane processes where protein recovery is the goal, recovery of viable microorganisms for pathogen detection is the key measure of success, with modification of cell-free proteins being both acceptable and required to achieve rapid microfiltration of viable microorganisms. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1464-1471, 2016. © 2016 American Institute of Chemical Engineers.

  7. A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection

    Science.gov (United States)

    Yu, F. P.; Pyle, B. H.; McFeters, G. A.

    1993-01-01

    This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.

  8. Viable group A streptococci in macrophages during acute soft tissue infection.

    Directory of Open Access Journals (Sweden)

    Pontus Thulin

    2006-03-01

    Full Text Available Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells.We characterized in vivo interactions between group A streptococci (GAS and cells involved in innate immune responses, using human biopsies (n = 70 collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria.This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis of streptococcal soft tissue infections

  9. Viable Group A Streptococci in Macrophages during Acute Soft Tissue Infection.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available BACKGROUND: Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells. METHODS AND FINDINGS: We characterized in vivo interactions between group A streptococci (GAS and cells involved in innate immune responses, using human biopsies (n = 70 collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria. CONCLUSIONS: This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis

  10. Detection of viable Salmonella in lettuce by propidium monoazide real-time PCR.

    Science.gov (United States)

    Liang, Ningjian; Dong, Jin; Luo, Laixin; Li, Yong

    2011-05-01

    Contamination of lettuce by Salmonella has caused serious public health problems. Polymerase chain reaction (PCR) allows rapid detection of pathogenic bacteria in food, but it is inaccurate as it might amplify DNA from dead target cells as well. This study aimed to investigate the stability of DNA of dead Salmonella cells in lettuce and to develop an approach to detecting viable Salmonella in lettuce. Salmonella-free lettuce was inoculated with heat-killed Salmonella Typhimurium cells and stored at 4 °C. Bacterial DNA extracted from the sample was amplified by real-time PCR targeting the invA gene. Our results indicate that DNA from the dead cells remained stable in lettuce for at least 8 d. To overcome this limitation, propidium monoazide (PMA), a dye that can selectively penetrate dead bacterial cells and cross-link their DNA upon light exposure, was combined with real-time PCR. Lettuce samples inoculated with different levels of dead or viable S. Typhimurium cells were treated or untreated with PMA before DNA extraction. Real-time PCR suggests that PMA treatment effectively prevented PCR amplification from as high as 10(8) CFU/g dead S. Typhimurium cells in lettuce. The PMA real-time PCR assay could detect viable Salmonella at as low as 10(2) CFU/mL in pure culture and 10(3) CFU/g in lettuce. With 12-h enrichment, S. Typhimurium of 10(1) CFU/g in lettuce was detectable. In conclusion, the PMA real-time PCR assay provides an alternative to real-time PCR assay for accurate detection of Salmonella in food. © 2011 Institute of Food Technologists®

  11. Sorption and precipitation of Mn2+ by viable and autoclaved Shewanella putrefaciens: Effect of contact time

    KAUST Repository

    Chubar, Natalia

    2013-01-01

    The sorption of Mn(II) by viable and inactivated cells of Shewanella putrefaciens, a non-pathogenic, facultative anaerobic, gram-negative bacterium characterised as a Mn(IV) and Fe(III) reducer, was studied under aerobic conditions, as a function of pH, bacterial density and metal loading. During a short contact time (3-24h), the adsorptive behaviour of live and dead bacteria toward Mn(II) was sufficiently similar, an observation that was reflected in the studies on adsorption kinetics at various metal loadings, effects of pH, bacteria density, isotherms and drifting of pH during adsorption. Continuing the experiment for an additional 2-30days demonstrated that the Mn(II) sorption by suspensions of viable and autoclaved cells differed significantly from one another. The sorption to dead cells was characterised by a rapid equilibration and was described by an isotherm. In contrast, the sorption (uptake) to live bacteria exhibited a complex time-dependent uptake. This uptake began as adsorption and ion exchange processes followed by bioprecipitation, and it was accompanied by the formation of polymeric sugars (EPS) and the release of dissolved organic substances. FTIR, EXAFS/XANES and XPS demonstrated that manganese(II) phosphate was the main precipitate formed in 125ml batches, which is the first evidence of the ability of microbes to synthesise manganese phosphates. XPS and XANES spectra did not detect Mn(II) oxidation. Although the release of protein-like compounds by the viable bacteria increased in the presence of Mn2+ (and, by contrast, the release of carbohydrates did not change), electrochemical analyses did not indicate any aqueous complexation of Mn(II) by the organic ligands. © 2012 Elsevier Ltd.

  12. An Extension of the Hawkins and Simon Condition Characterizing Viable Techniques

    Directory of Open Access Journals (Sweden)

    Alberto Benítez Sánchez

    2015-01-01

    Full Text Available This paper discusses an extended version of the Hawkins and Simon condition which constitutes a synthetic formulation of the mathematical properties that viable economies must satisfy in single production models. The new version is implicit in the economic interpretations offered by them of the Hawkins and Simon condition, once a correction is introduced in one of those interpretations. Moreover, the paper details the meaning of the extended version following the interpretation of the original version proposed by Dorfman, Samuelson, and Solow. It also introduces a characteristic property of indecomposable matrices that has not previously been published.

  13. THE CIVILIZATIONAL PROJECT AND lTS DISCONTENTS: TOWARD A VIABLE GLOBAL MARKET SOCIETY?

    Directory of Open Access Journals (Sweden)

    Volker Bornschier

    2015-08-01

    Full Text Available I agree with the point of an anonymous reviewer arguing that a pro-found discussion on the prerequisites of a viable global market society has too many facets to be contained within the bounds of a single journal article. Yet, in order to enter the debate now we should not wait until book length treatments become available-often only after years. This is, therfore, an essay attempting to overview various conflicts and contradictions within the global social system. It sythesizes arguments developed in more detail else-where.

  14. Fake Journals: Their Features and Some Viable Ways to Distinguishing Them

    DEFF Research Database (Denmark)

    Hemmat Esfe, Mohammad; Wongwises, Somchai; Asadi, Amin

    2015-01-01

    In this paper, we aim to discuss the fake journals and their advertisement and publication techniques. These types of journals mostly start and continue their activities by using the name of some indexed journals and establishing fake websites. The fake journals and publishers, while asking...... the authors for a significant amount of money for publishing their papers, have no peer-review process, publish the papers without any revision on the fake sites, and put the scientific reputation and prestige of the researchers in jeopardy. In the rest of the paper, we present some viable techniques in order...

  15. Information Warfare: using the viable system model as a framework to attack organisations

    Directory of Open Access Journals (Sweden)

    Bill Hutchinson

    2002-05-01

    Full Text Available Information is the glue in any organization. It is needed for policy, decision-making, control, and co-ordination. If an organisation's information systems are disrupted or destroyed, then damage to the whole inevitably follows. This paper uses a proven systemic, analytic framework the Viable System Model (VSM - in a functionalist mode, to analyse the vulnerabilities of an organisation's information resources to this form of aggression. It examines the tactics available, and where they can be used to effectively attack an organisation.

  16. Current progress and challenges in engineering viable artificial leaf for solar water splitting

    Directory of Open Access Journals (Sweden)

    Phuc D. Nguyen

    2017-12-01

    Full Text Available Large scale production of H2, a clean fuel, can be realized with just water and solar light energy by employing a viable energy conversion device called artificial leaf. In this tutorial review, we discuss on advances achieved recently and technical challenges remained toward the creation of such a leaf. Development of key components like catalysts for water electrolysis process and light harvester for harvesting solar energy as well as strategies being developed for assembling these components to create a complete artificial leaf will be highlighted.

  17. Emergency total thyroidectomy for bleeding anaplastic thyroid carcinoma: A viable option for palliation

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2011-01-01

    Full Text Available Anaplastic thyroid carcinoma (ATC is a rare and highly aggressive thyroid neoplasm. Bleeding from tumor is an uncommon, but potentially life-threatening complication requiring sophisticated intervention facilities which are not usually available at odd hours in emergency. We report the case of a 45-year-old woman who presented with exsanguinating hemorrhage from ATC and was treated by emergency total thyroidectomy. The patient is well three months postoperatively. Emergency total thyroidectomy is a viable option for palliation in ATC presenting with bleeding.

  18. Texture analysis of cardiac cine magnetic resonance imaging to detect non-viable segments in patients with chronic myocardial infarction.

    Science.gov (United States)

    Larroza, Andrés; López-Lereu, María P; Monmeneu, José V; Gavara, Jose; Chorro, Francisco J; Bodí, Vicente; Moratal, David

    2018-02-01

    To investigate the ability of texture analysis to differentiate between infarcted non-viable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). This retrospective study included 50 patients suffering chronic myocardial infarction. The data was randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Non-viable segments were identified as those showing LGE ≥ 50%, and viable segments those showing 0 cine images. A support vector machine (SVM) classifier was trained with different combination of texture features to obtain a model that provided optimal classification performance. The best classification on testing set was achieved with local binary patterns features using a 2D + t approach, in which the features are computed by including information of the time dimension available in cine sequences. The best overall area under the receiver operating characteristic curve (AUC) were: 0.849, sensitivity of 92% to detect non-viable segments, 72% to detect viable segments, and 85% to detect remote segments. Non-viable segments can be detected on cine MRI using texture analysis and this may be used as hypothesis for future research aiming to detect the infarcted myocardium by means of a gadolinium-free approach. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Steven E. Bonde; David Nunn

    2003-04-01

    Research activities in the second quarter have largely been a continuation of efforts previously described in the first quarterly report as well as a degree of redirection of effort as a result of discussions during the first quarterly meeting held in San Diego. Chemical synthesis efforts have been refined and are currently being used to support generation of substrates for evaluation and evolution of enzymes for their oxidation. Analysis of the sulfur species in Petro Star diesel, CED extract and refinement of the speciation data is nearly complete. Molecular biology efforts continue with the cloning, expression and characterization of the DszA and DszC proteins as well as the flavin reductases to support regeneration of the essential FMN cofactors. In addition, we have initiated an evolution effort for the extension and improvement of DszA enzyme activity using Diversa's Gene Site Saturation Mutagenesis (GSSM{trademark}) technology. To support the evolution effort as well as of characterization of enzyme activities on a variety of substrates, a high-throughput mass spectroscopy-based assay has been developed. Two selection/screen strategies for the discovery and evolution of biocatalyst enzyme have been developed and are being evaluated for performance using gene libraries constructed from known biodesulfurization strains and environmental libraries.

  20. Reductive desulfurization of dibenzyldisulfide.

    Science.gov (United States)

    Miller, K W

    1992-07-01

    Dibenzyldisulfide was reductively degraded by a methanogenic mixed culture derived from a sewage digestor. Toluene was produced with benzyl mercaptan as an intermediate in sulfur-limited medium. Toluene production was strictly associated with biological activity; however, the reducing agent for the culture medium, Ti(III), was partially responsible for production of benzyl mercaptan. Sulfide was not detected. Additions of sodium sulfide did not inhibit toluene production. Additions of 2-bromoethane sulfonic acid prevented methanogenesis but did not adversely affect toluene yields.

  1. Coal desulfurization process

    Science.gov (United States)

    Hsu, G. C.; Gavalas, G. R.; Ganguli, P. S.; Kalfayan, S. H.

    1978-01-01

    A method for chlorinolysis of coal is an organic solvent at a moderate temperautre and atmospheric pressure has been proven to be effective in removing sulfur, particularly the organic sulfur, from coal. Chlorine gas is bubbled through a slurry of moist coal in chlorinated solvent. The chlorinated coal is separated, hydrolyzed and the dechlorinated. Preliminary results of treating a high sulfutr (4.77%S) bituminous coal show that up to 70% organic sulfur, 90% hyritic sulfur and 76% total sulfur can be removed. The treated coal is dechlorinated by heating at 500 C. The presence of moisture helps to remove organic sulfur.

  2. Flue gas desulfurization

    Science.gov (United States)

    Im, Kwan H.; Ahluwalia, Rajesh K.

    1985-01-01

    A process and apparatus for removing sulfur oxide from combustion gas to form Na.sub.2 SO.sub.4 and for reducing the harmful effects of Na.sub.2 SO.sub.4 on auxiliary heat exchangers in which a sodium compound is injected into the hot combustion gas forming liquid Na.sub.2 SO.sub.4 in a gas-gas reaction and the resultant gas containing Na.sub.2 SO.sub.4 is cooled to below about 1150.degree. K. to form particles of Na.sub.2 SO.sub.4 prior to contact with at least one heat exchanger with the cooling being provided by the recycling of combustion gas from a cooled zone downstream from the introduction of the cooling gas.

  3. Desulfurization sorbent regeneration

    Science.gov (United States)

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  4. Transportation fuels: Desulfurizing diesel

    Science.gov (United States)

    Lamonier, Carole

    2017-02-01

    Transportation fuels such as diesel contain organosulfur molecules that, when combusted, form sulfur oxides that are toxic and poison vehicles' catalytic convertors. Now, a method is demonstrated that can reduce the sulfur concentration of diesel fuel to very low levels at low temperatures and pressures.

  5. Biofilms in Full-Scale Drinking Water Ozone Contactors Contribute Viable Bacteria to Ozonated Water.

    Science.gov (United States)

    Kotlarz, Nadine; Rockey, Nicole; Olson, Terese M; Haig, Sarah-Jane; Sanford, Larry; LiPuma, John J; Raskin, Lutgarde

    2018-02-13

    Concentrations of viable microbial cells were monitored using culture-based and culture-independent methods across multichamber ozone contactors in a full-scale drinking water treatment plant. Membrane-intact and culturable cell concentrations in ozone contactor effluents ranged from 1200 to 3750 cells/mL and from 200 to 3850 colony forming units/mL, respectively. Viable cell concentrations decreased significantly in the first ozone contact chamber, but rose, even as ozone exposure increased, in subsequent chambers. Our results implicate microbial detachment from biofilms on contactor surfaces, and from biomass present within lime softening sediments in a hydraulic dead zone, as a possible reason for increasing cell concentrations in water samples from sequential ozone chambers. Biofilm community structures on baffle walls upstream and downstream from the dead zone were significantly different from each other (p = 0.017). The biofilms downstream of the dead zone contained a significantly (p = 0.036) higher relative abundance of bacteria of the genera Mycobacterium and Legionella than the upstream biofilms. These results have important implications as the effluent from ozone contactors is often treated further in biologically active filters and bacteria in ozonated water continuously seed filter microbial communities.

  6. Identification of Viable Helicobacter pylori in Drinking Water Supplies by Cultural and Molecular Techniques.

    Science.gov (United States)

    Santiago, Paula; Moreno, Yolanda; Ferrús, M Antonía

    2015-08-01

    Helicobacter pylori is one of the most common causes of chronic bacterial infection in humans, directly related to peptic ulcer and gastric cancer. It has been suggested that H. pylori can be acquired through different transmission routes, including water. In this study, culture and qPCR were used to detect and identify the presence of H. pylori in drinking water. Furthermore, the combined techniques PMA-qPCR and DVC-FISH were applied for detection of viable cells of H. pylori. Among 24 drinking water samples, 16 samples were positive for the presence of H. pylori, but viable cells were only detected in six samples. Characteristic colonies, covered by a mass of bacterial unspecific growth, were observed on selective agar plates from an only sample, after enrichment. The mixed culture was submitted to DVC-FISH and qPCR analysis, followed by sequencing of the amplicons. Molecular techniques confirmed the growth of H. pylori on the agar plate. Our results demonstrate for the first time that H. pylori can survive and be potentially infective in drinking water, showing that water distribution systems could be a potential route for H. pylori transmission. © 2015 John Wiley & Sons Ltd.

  7. Viable Reserve Networks Arise From Individual Landholder Responses To Conservation Incentives

    Directory of Open Access Journals (Sweden)

    Kenneth M. Chomitz

    2006-12-01

    Full Text Available Conservation in densely settled biodiversity hotspots often requires setting up reserve networks that maintain sufficient contiguous habitat to support viable species populations. Because it is difficult to secure landholder compliance with a tightly constrained reserve network design, attention has shifted to voluntary incentive mechanisms, such as purchase of conservation easements by reverse auction or through a fixed-price offer. These mechanisms carry potential advantages of transparency, simplicity, and low cost. However, uncoordinated individual response to these incentives has been assumed incompatible with the conservation goal of viability, which depends on contiguous habitat and biodiversity representation. We model such incentives for southern Bahia in the Brazilian Atlantic Forest, one of the biologically richest and most threatened global biodiversity hotspots. Here, forest cover is spatially autocorrelated and associated with depressed land values, a situation that may be characteristic of long-settled areas with forests fragmented by agriculture. We find that in this situation, a voluntary incentive system can yield a reserve network characterized by large, viable patches of contiguous forest, and representation of subregions with distinct vegetation types and biotic assemblages, without explicit planning for those outcomes.

  8. Generation of viable progeny from dead brooders of endangered catfish Clarias magur (Hamilton, 1822

    Directory of Open Access Journals (Sweden)

    Sullip Kumar Majhi

    2017-10-01

    Full Text Available The obligatory air-breathing catfish Clarias magur is a prime candidate for aquaculture owing to its unique taste, high growth rate, and hardy nature. However, recently the IUCN has listed the species under the endangered category because the population has critically declined in the wild. The sexually mature C. magur brooders are often collected from their natural habitats for seed production in captivity. In many cases, the brooder dies due to handling injuries or confinement stress. In this study, we demonstrated that viable progeny could be generated from freshly dead sexually mature C. magur. Three hours after death, the gonads were excised, macroscopically examined and gamete viability was evaluated. Artificial fertilization was performed by mixing the sperm suspension with the eggs. Water was added after 1 min of mixing to activate the fertilization process. We observed 85%-93% fertilization success from gametes derived from dead donors as opposed to 90%-95% from those derived from live control donors. The embryos showed normal development and resulted in the generation of 88%-92% viable progeny, which was similar to the progeny derived from control donors (92%-93%. The results obtained in this study will have profound implications in enhancing the seed production of endangered C. magur and could potentially be applied to other key commercially or endangered fish species. Keywords: Biological sciences, Developmental biology, Zoology

  9. Real-time quantification of viable bacteria in liquid medium using infrared thermography

    Science.gov (United States)

    Salaimeh, Ahmad A.; Campion, Jeffrey J.; Gharaibeh, Belal Y.; Evans, Martin E.; Saito, Kozo

    2011-11-01

    Quantifying viable bacteria in liquids is important in environmental, food processing, manufacturing, and medical applications. Since vegetative bacteria generate heat as a result of biochemical reactions associated with cellular functions, thermal sensing techniques, including infrared thermography (IRT), have been used to detect viable cells in biologic samples. We developed a novel method that extends the dynamic range and improves the sensitivity of bacterial quantification by IRT. The approach uses IRT video, thermodynamics laws, and heat transfer mechanisms to directly measure, in real-time, the amount of energy lost as heat from the surface of a liquid sample containing bacteria when the specimen cools to a lower temperature over 2 min. We show that the Energy Content ( EC) of liquid media containing as few as 120 colony-forming units (CFU) of Escherichia coli per ml was significantly higher than that of sterile media ( P method that provides real-time bacterial enumeration over a wide dynamic range without the need for sample concentration, modification, or destruction. The approach could be adapted to quantify other living cells in a liquid milieu and has the potential for automation and high throughput.

  10. Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L. in a Biorefinery Concept

    Directory of Open Access Journals (Sweden)

    Eva Johansson

    2015-04-01

    Full Text Available Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L. is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  11. Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

    Science.gov (United States)

    Ordax, Mónica; Marco-Noales, Ester; López, María M.; Biosca, Elena G.

    2006-01-01

    Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper. PMID:16672494

  12. In vitro and in vivo bioluminescent quantification of viable stem cells in engineered constructs.

    Science.gov (United States)

    Logeart-Avramoglou, Delphine; Oudina, Karim; Bourguignon, Marianne; Delpierre, Laetitia; Nicola, Marie-Anne; Bensidhoum, Morad; Arnaud, Eric; Petite, Herve

    2010-06-01

    Bioluminescent quantification of viable cells inside three-dimensional porous scaffolds was performed in vitro and in vivo. The assay quantified the bioluminescence of murine stem (C3H10T1/2) cells tagged with the luciferase gene reporter and distributed inside scaffolds of either soft, translucent, AN69 polymeric hydrogel or hard, opaque, coral ceramic materials. Quantitative evaluation of bioluminescence emitted from tagged cells adhering to these scaffolds was performed in situ using either cell lysates and a luminometer or intact cells and a bioluminescence imaging system. Despite attenuation of the signal when compared to cells alone, the bioluminescence correlated with the number of cells (up to 1.5 x 10(5)) present on each material scaffold tested, both in vitro and noninvasively in vivo (subcutaneous implants in the mouse model). The noninvasive bioluminescence measurement technique proved to be comparable to the cell-destructive bioluminescence measurement technique. Monitoring the kinetics of luciferase expression via bioluminescence enabled real-time assessment of cell survival and proliferation on the scaffolds tested over prolonged (up to 59 days) periods of time. This novel, sensitive, easy, fast-to-implement, quantitative bioluminescence assay has great, though untapped, potential for screening and determining noninvasively the presence of viable cells on biomaterial constructs in the tissue engineering and tissue regeneration fields.

  13. Mobilization of Viable Tumor Cells Into the Circulation During Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Olga A. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); Anderson, Robin L. [The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); Metastasis Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Russell, Prudence A. [Department of Anatomical Pathology, St. Vincent Hospital, Fitzroy, VIC (Australia); Ashley Cox, R. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Ivashkevich, Alesia [Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Laboratory of DNA Repair and Genomics, Centre for Innate Immunity and Infectious Disease, Monash Institute for Medical Research, Monash University, Clayton, VIC (Australia); Swierczak, Agnieszka; Doherty, Judy P. [Metastasis Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Jacobs, Daphne H.M. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Smith, Jai [Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Siva, Shankar; Daly, Patricia E. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Ball, David L. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); and others

    2014-02-01

    Purpose: To determine whether radiation therapy (RT) could mobilize viable tumor cells into the circulation of non-small cell lung cancer (NSCLC) patients. Methods and Materials: We enumerated circulating tumor cells (CTCs) by fluorescence microscopy of blood samples immunostained with conventional CTC markers. We measured their DNA damage levels using γ-H2AX, a biomarker for radiation-induced DNA double-strand breaks, either by fluorescence-activated cell sorting or by immunofluorescence microscopy. Results: Twenty-seven RT-treated NSCLC patients had blood samples analyzed by 1 or more methods. We identified increased CTC numbers after commencement of RT in 7 of 9 patients treated with palliative RT, and in 4 of 8 patients treated with curative-intent RT. Circulating tumor cells were also identified, singly and in clumps in large numbers, during RT by cytopathologic examination (in all 5 cases studied). Elevated γ-H2AX signal in post-RT blood samples signified the presence of CTCs derived from irradiated tumors. Blood taken after the commencement of RT contained tumor cells that proliferated extensively in vitro (in all 6 cases studied). Circulating tumor cells formed γ-H2AX foci in response to ex vivo irradiation, providing further evidence of their viability. Conclusions: Our findings provide a rationale for the development of strategies to reduce the concentration of viable CTCs by modulating RT fractionation or by coadministering systemic therapies.

  14. Determination of viable wine yeast using DNA binding dyes and quantitative PCR.

    Science.gov (United States)

    Andorrà, Imma; Esteve-Zarzoso, Braulio; Guillamón, José M; Mas, Albert

    2010-12-15

    The detection and quantification of wine yeast can be misleading due to under or overestimation of these microorganisms. Underestimation may be caused by variable growing rates of different microorganisms in culture media or the presence of viable but non-cultivable microorganisms. Overestimation may be caused by the lack of discrimination between live and dead microorganisms if quantitative PCR is used to quantify with DNA as the template. However, culture-independent methods that use dyes have been described to remove the DNA from dead cells and then quantify the live microorganisms. Two dyes have been studied in this paper: ethidium monoazide bromide (EMA) and propidium monoazide bromide (PMA). The technique was applied to grape must fermentation and ageing wines. Both dyes presented similar results on yeast monitoring. Membrane cell recovery was necessary when yeasts were originated from ethanol-containing media. When applied to grape must fermentation, differences of up to 1 log unit were seen between the QPCR estimation with or without the dye during the stationary phase. In ageing wines, good agreement was found between plating techniques and QPCR. Most of the viable cells were also culturable and no differences were observed with the methods, except for Zygosaccharomyces bailii and Dekkera bruxellensis where much higher counts were occasionally detected by QPCR. The presence of excess dead cells did not interfere with the quantification of live cells with either of the dyes. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Economically viable components from Jerusalem artichoke (Helianthus tuberosus L.) in a biorefinery concept.

    Science.gov (United States)

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R; Gunnarsson, Ingólfur Bragi; Hovmalm, Helena Persson

    2015-04-22

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  16. Ultra-deep oxidative desulfurization of diesel fuel with H{sub 2}O{sub 2} catalyzed under mild conditions by polymolybdates supported on Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, Jose Luis; Murrieta, Florentino; Navarrete, Juan; Jimenez-Cruz, Federico [Instituto Mexicano del Petroleo, Programa de Procesos y Reactores, Eje Central Lazaro Cardenas 152, 07730 Mexico D.F. (Mexico); Fuentes, Gustavo A.; Hernandez-Teran, Maria Eugenia [Area de Ingenieria Quimica, Universidad A. Metropolitana-Iztapalapa, 09340 Mexico D.F. (Mexico)

    2006-05-17

    The evaluation of the catalytic oxidative desulfurization (OD) activity of alumina-supported polymolybdates (Mo/Al{sub 2}O{sub 3}) was carried out using organosulfur model compounds and diesel fuel. Hydrogen peroxide was the oxidizing reagent. Ultra-deep desulfurization, 97.8% removal of sulfur in diesel fuel, was achieved by reaction under mild conditions followed by solvent extraction. The catalyst was prepared by equilibrium adsorption and characterized by infrared, Raman, X-ray photoelectron, {sup 31}P and {sup 27}Al MAS NMR spectroscopies. Our results indicate that the phosphomolybdate used during synthesis of the catalysts decomposes and forms hydrated hepta- and octamolybdates as well as phosphate ions on the surface of alumina. (author)

  17. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, December 11, 1992--March 11, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sublette, K.L.

    1993-12-31

    This report describes the potential of sulfate reducing bacteria to fix sulfur derived from flue gas desulfurization. The first section reviews the problem, the second section reviews progress of this study to use desulfovibrio desulfuricans for this purpose. The final section related progress during the current reporting period. This latter section describes studies to immobilize the bacteria in co-culture with floc-forming anaerobes, use of sewage sludges in the culture media, and sulfate production from sulfur dioxide.

  18. Microbial reduction of SO{sub 2} and NO{sub x} as a means of by-product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, March 11, 1993--June 11, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sublette, K.L.

    1993-11-01

    There are two basic approaches to addressing the problem of SO{sub 2} and NO{sub x} emissions: (1) desulfurize (and denitrogenate) the feedstock prior to or during combustion; or (2) scrub the resultant SO{sub 2} and oxides of nitrogen from the boiler flue gases. The flue gas processing alternative has been addressed in this project via microbial reduction of SO{sub 2} and NO{sub x} by sulfate-reducing bacteria

  19. Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics

    NARCIS (Netherlands)

    Sweller, John; Clark, Richard; Kirschner, Paul A.

    2010-01-01

    Sweller, J., Clark, R., & Kirschner, P. A. (2010). Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics. Notices of the American Mathematical Society, 57, 1303-1304.

  20. The Belem Framework for Action: Harnessing the Power and Potential of Adult Learning and Education for a Viable Future

    Science.gov (United States)

    Adult Learning, 2012

    2012-01-01

    This article presents the Belem Framework for Action. This framework focuses on harnessing the power and potential of adult learning and education for a viable future. This framework begins with a preamble on adult education and towards lifelong learning.

  1. Changes in the relative population size of selected ruminal bacteria following an induced episode of acidosis in beef heifers receiving viable and non-viable active dried yeast.

    Science.gov (United States)

    Mohammed, R; Vyas, D; Yang, W Z; Beauchemin, K A

    2017-06-01

    To characterize the changes in the relative population size (RPS) of select ruminal bacteria and rumen fermentation variables in beef heifers supplemented with a strain of Saccharomyces cerevisiae as viable active dried (ADY) or killed dried (KDY) yeast following an induced episode of ruminal acidosis. Six ruminally cannulated beef heifers fed a diet consisting of 50% forage and 50% grain (dry matter basis) were used in a replicated 3 × 3 Latin square design with three 28-day periods. Treatments were: (i) control (CTRL; no yeast); (ii) ADY (4 g day-1 providing 1010  CFU per g; AB Vista, UK); and (iii) KDY (4 g day-1 autoclaved ADY). The acidosis challenge was induced on day 22 and rumen samples were collected on day 15 (baseline; BASE), day 22 (challenge day; CHAL), and on day 29 (168th hour post acid challenge or recovery, REC) of each period. Over the study, duration of pH acidosis) was less for ADY and KDY than CTRL, with ADY less than KDY. No treatment effects were observed on relative abundance of ruminal bacteria, but the day effect was significant. The RPS of lactate producers and utilizers was greater while RPS of fibrolytic bacteria was lower during CHAL than BASE and REC. Yeast supplementation, irrespective of its viability, showed beneficial effects on ruminal pH variables in animals more susceptible to acidosis. Rumen microbial population was altered with the induction of severe acidosis. Most of the changes reverted back to baseline values during the recovery phase. Yeast supplementation reduced subacute rumen acidosis in the most susceptible cattle, but failed to attenuate severe acidosis induced by a grain challenge. The study provided valuable insight into the mechanism by which acidosis affects cattle performance. Individual animal variation in ruminal fermentation partly explained the variability in response to yeast supplementation in the study. © 2017 Her Majesty the Queen in Right of Canada. Journal of Applied Microbiology © 2017 The

  2. Factors affecting the numbers of expected viable lactic acid bacteria in inoculant applicator tanks.

    Science.gov (United States)

    Windle, M C; Kung, L

    2016-11-01

    The application of correct numbers of viable microorganisms to forages at the time of ensiling is one of the most important factors affecting the probability of a beneficial effect from an inoculant. The objective of this study was to determine relationships between numbers of expected lactic acid bacteria (LAB) from silage inoculants in application tanks and various factors that might affect their viability. The pH and temperature of inoculant-water mixes were measured in applicator tanks (n=53) on farms in Wisconsin, Minnesota, South Dakota, and California during the corn harvest season of 2012. Samples were collected on-farm and plated on de Man, Rogosa, and Sharpe agar to enumerate LAB and establish the number of viable LAB (cfu/mL). Expected numbers of LAB were calculated from the minimum label guarantees for viable bacteria and mixing rates with water. In addition, the pH of the inoculant-water mixes at sampling, the ambient temperature at sampling, and the length of time that the samples had been in the tank were measured and obtained. The log difference between the measured and expected numbers of LAB was calculated and expressed as ΔM - E in log scale. Ambient temperature at sampling had no relationship with time in the tank or ΔM - E. Most (83%) of the inoculants had been mixed with water in the applicator tanks for <10h. For these samples, a negative linear correlation (R2=0.36) existed between time that the inoculant-water mixes were in the applicators tanks and ΔM - E. The pH of the inoculant-water mixes was also negatively correlated (R2=0.28) with time in the applicator tank, but pH was not related to ΔM - E. The temperatures of the inoculant-water mixtures were negatively correlated with ΔM - E (R2=0.39). Seven of 8 samples whose ΔM - E were at least -0.95 or more lower than expected (equivalent of about 1 or more log concentration less than expected) had water temperatures above 35°C. These data support our previous laboratory findings and

  3. CONCEIVING AND GENERATING A VIABLE COMPLEXITY MODEL FOR PERSONAL AND/OR ENTREPRENEURIAL CHANGE AND DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    George Niculescu

    2012-03-01

    Full Text Available This article proposes on the one hand to do research and study – with a genuine approach, inspiredand deep-rooted in the method of the sociological school in Bucharest and creatively renewed and integrating thenewest acquisitions of complexity science – the representative intricate entity “man as an economic actor (resourceand potential within the industrial organization and corporation in mono-industrial area (region in the period inwhich the phenomenon of transition from an industrial society to knowledge society takes place; and on the otherhand our project proposes to conceive a viable model of change and career of the human resources in the ElectricPlant of Rovinari as well as to conceive and accomplish a pilot-model of a platform in order to support the efficientimplement through a research-action approach of the model of personal and/or entrepreneurship change and careerof the human resources in the Electric Plant of Rovinari.

  4. A fusion-driven subcritical system concept based on viable technologies

    Science.gov (United States)

    Wu, Y.; Jiang, J.; Wang, M.; Jin, M.; FDS Team

    2011-10-01

    A fusion-driven hybrid subcritical system (FDS) concept has been designed and proposed as spent fuel burner based on viable technologies. The plasma fusion driver can be designed based on relatively easily achieved plasma parameters extrapolated from the successful operation of existing fusion experimental devices such as the EAST tokamak in China and other tokamaks in the world, and the subcritical fission blanket can be designed based on the well-developed technologies of fission power plants. The simulation calculations and performance analyses of plasma physics, neutronics, thermal-hydraulics, thermomechanics and safety have shown that the proposed concept can meet the requirements of tritium self-sufficiency and sufficient energy gain as well as effective burning of nuclear waste from fission power plants and efficient breeding of nuclear fuel to feed fission power plants.

  5. Drug delivery interfaces in the 21st century: from science fiction ideas to viable technologies.

    Science.gov (United States)

    Chertok, Beata; Webber, Matthew J; Succi, Marc D; Langer, Robert

    2013-10-07

    Early science fiction envisioned the future of drug delivery as targeted micrometer-scale submarines and "cyborg" body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery: the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the predefined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics.

  6. The viable but non-culturable state in pathogenic Escherichia coli: A general review

    Directory of Open Access Journals (Sweden)

    Jennifer A. Pienaar

    2016-05-01

    Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state. Method: A literature review was conducted to ascertain the possibleimpact of E. coli entering into the VBNC state. Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation. Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at anytime, be resuscitated and become virulent again.

  7. An online listserv for nurse practitioners: a viable venue for continuous nursing professional development?

    Science.gov (United States)

    Hew, Khe Foon; Hara, Noriko

    2008-05-01

    This study reports the results of a qualitative study involving a large and longstanding online nurse listserv in the United States. A sample of 27 critical care and advanced-practice nurse practitioners was interviewed using semi-structured individual interviews. This study found evidence that participation in an online listserv offers a viable avenue for the continuous professional development of nurses by providing nurses the opportunity to make more informed decisions about their professional practice and keeping abreast with up-to-date changes in their specialty areas when they shared knowledge with one another. Follow-up interviews with 10 nurses who frequently shared their knowledge revealed six motivators that helped promote knowledge sharing: (a) reciprocity, (b) collectivism, (c) personal gain, (d) respectful environment, (e) altruism, and (f) technology. Implications for sustaining knowledge sharing in an online listserv are discussed. The finding will inform educators and administrators who support continuing education and professional development of healthcare professionals.

  8. Environmental assessment and viable interdependence: the Great Whale River case in northern Quebec (First Nations)

    Energy Technology Data Exchange (ETDEWEB)

    Mulvihill, P. R.

    1997-12-31

    This study is based on the belief that environmental assessment (EA) can be supportive of viable interdependence between regions and cultures. The central focus is on the scoping stage of the EA conducted for the proposed Great Whale hydroelectric project in northern Quebec. The evaluative framework consists of 16 criteria divided into three interrelated categories, i.e. substantive, general process-oriented and specific process-oriented. The specific process-oriented criteria constitute the primary analytical focus and are the subject of five separate sub-analysis, which reveal various strengths and weaknesses in the performance of the case study. It was concluded that environmental assessment in an intercultural setting is largely within the control of EA panels and the key shortcoming of the process, namely the lack of dialogue between the proponents and the intervenors, could be addressed by making public hearings more dynamic and interactive.

  9. Is Telemental Health Services a Viable Alternative to Traditional Psychotherapy for Deaf Individuals?

    Science.gov (United States)

    Crowe, Teresa V

    2017-02-01

    Access to mental health treatment is a vital part of a comprehensive health care plan. Deaf individuals often have difficulty accessing mental health services. Four-hundred twenty-two participants completed an anonymous questionnaire about their perspectives of telemental health services for deaf individuals. Results showed that several variables, such as if the participant was unable to receive another type of psychotherapy and whether the therapist was ASL-fluent, were significantly related to whether the respondent would use TMH. The participants reported that TMH services are a viable option for treating a variety of mental health issues. Telemental health services can act as a bridge between consumers of mental health care and their providers allowing accessible and equitable healthcare opportunities.

  10. Drug Delivery Interfaces in the 21st Century: From Science Fiction Ideas to Viable Technologies

    Science.gov (United States)

    Chertok, Beata; Webber, Matthew J.; Succi, Marc D.; Langer, Robert S.

    2013-01-01

    Early science fiction envisioned the future of drug delivery as targeted micron-scale submarines and ‘Cyborg’ body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery – the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the pre-defined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics. PMID:23915375

  11. Minimum Viable Product and the Importance of Experimentation in Technology Startups

    Directory of Open Access Journals (Sweden)

    Dobrila Rancic Moogk

    2012-03-01

    Full Text Available Entrepreneurs are often faced with limited resources in their quest to commercialize new technology. This article presents the model of a lean startup, which can be applied to an organization regardless of its size or environment. It also emphasizes the conditions of extreme uncertainty under which the commercialization of new technology is carried out. The lean startup philosophy advocates efficient use of resources by introducing a minimum viable product to the market as soon as possible in order to test its value and the entrepreneur’s growth projections. This testing is done by running experiments that examine the metrics relevant to three distinct types of the growth. These experiments bring about accelerated learning to help reduce the uncertainty that accompanies commercialization projects, thereby bringing the resulting new technology to market faster.

  12. FREE OPEN SOURCE AND SOFTWARE IN THE TEACHING OF CAT TOOLS: OMEGAT, A VIABLE ALTERNATIVE

    Directory of Open Access Journals (Sweden)

    Adauto Lúcio Caetano Villela

    2016-12-01

    Full Text Available The teaching of Computer Aided Translation (CAT tools is essential to all courses aimed at preparing students for the effective exercise of this profession, in particular those students who will translate technical texts, especially in the field of localization. As an alternative to the paid commercial software which dominate the translation industry (such as SDL Trados Studio, Wordfast Pro and MemoQ, there are free proprietary softwares (such as Wordfast Anywhere and Google Translator Toolkit, and free open source ones (such as OmegaT and Anaphraseus. Starting from a description of CAT types and main functions, the purpose of this article is to point out, through an evaluative-comparative analysis based on a research and on a comparison between OmegaT, free proprietary softwares and others open source softwares, why and for which situations OmegaT is a viable alternative for the teaching of CAT tools in higher education.

  13. Mathematical modelling of the viable epidermis: impact of cell shape and vertical arrangement

    KAUST Repository

    Wittum, Rebecca

    2017-12-07

    In-silico methods are valuable tools for understanding the barrier function of the skin. The key benefit is that mathematical modelling allows the interplay between cell shape and function to be elucidated. This study focuses on the viable (living) epidermis. For this region, previous works suggested a diffusion model and an approximation of the cells by hexagonal prisms. The work at hand extends this in three ways. First, the extracellular space is treated with full spatial resolution. This induces a decrease of permeability by about 10%. Second, cells of tetrakaidecahedral shape are considered, in addition to the original hexagonal prisms. For both cell types, the resulting membrane permeabilities are compared. Third, for the first time, the influence of cell stacking in the vertical direction is considered. This is particularly important for the stratum granulosum, where tight junctions are present.

  14. Development of a Commercially Viable, Modular Autonomous Robotic Systems for Converting any Vehicle to Autonomous Control

    Science.gov (United States)

    Parish, David W.; Grabbe, Robert D.; Marzwell, Neville I.

    1994-01-01

    A Modular Autonomous Robotic System (MARS), consisting of a modular autonomous vehicle control system that can be retrofit on to any vehicle to convert it to autonomous control and support a modular payload for multiple applications is being developed. The MARS design is scalable, reconfigurable, and cost effective due to the use of modern open system architecture design methodologies, including serial control bus technology to simplify system wiring and enhance scalability. The design is augmented with modular, object oriented (C++) software implementing a hierarchy of five levels of control including teleoperated, continuous guidepath following, periodic guidepath following, absolute position autonomous navigation, and relative position autonomous navigation. The present effort is focused on producing a system that is commercially viable for routine autonomous patrolling of known, semistructured environments, like environmental monitoring of chemical and petroleum refineries, exterior physical security and surveillance, perimeter patrolling, and intrafacility transport applications.

  15. Heterogeneity, politics of ethnicity, and multiculturalism What is a viable framework for Indonesia?

    Directory of Open Access Journals (Sweden)

    Thung Ju Lan

    2011-10-01

    Full Text Available Indonesia is a plural society that consists of several hundred ethnic and sub-ethnic groups. One of its generic characteristics is heterogeneity. In the last ten years after the implementation of regional autonomy, we have witnessed the emergence of strong ethnic and religiously flavoured local identity politics in various places in Indonesia that created open and vicious conflicts. This periodical violence exploded especially during the election of district and provincial heads. The intimate relation multiculturalism, with the actual political praxis of everyday life as an alternative to the existing paradigm of the “homogenization” of nationhood, has not been discussed. I believe it is time to discuss the strategic junctures between heterogeneity, politics of ethnicity (and religion and multiculturalism as well as their possible realization at the local and national levels in order to find a viable framework for a future Indonesia.

  16. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications.

    Science.gov (United States)

    Polakovič, Milan; Švitel, Juraj; Bučko, Marek; Filip, Jaroslav; Neděla, Vilém; Ansorge-Schumacher, Marion B; Gemeiner, Peter

    2017-05-01

    Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques. This review summarizes the current progress in the development of immobilized whole-cell biocatalysts, the immobilization methods as well as in the bioreaction engineering aspects and economical aspects of their biocatalytic applications.

  17. Viable bacteria associated with red blood cells and plasma in freshly drawn blood donations.

    Directory of Open Access Journals (Sweden)

    Christian Damgaard

    Full Text Available Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC-fraction.Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA.Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29th to December 10th 2013.60 donors (≥50 years old, self-reported medically healthy.Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35% of 60 RBC-fractions and in 32 (53% of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10-6, respectively. Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5% or anaerobic (27.8% species, which are not likely to be detected during current routine screening.Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended.

  18. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Directory of Open Access Journals (Sweden)

    G Arjen de Groot

    Full Text Available Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  19. The viable but non-culturable state in pathogenic Escherichia coli: A general review

    Directory of Open Access Journals (Sweden)

    Jennifer A. Pienaar

    2016-02-01

    Full Text Available Background: The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC state, where they are ‘alive’ or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state.Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state.Method: A literature review was conducted to ascertain the possibleimpact of E. coli entering into the VBNC state.Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation.Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at anytime, be resuscitated and become virulent again.

  20. Allogeneic human dermal fibroblasts are viable in peripheral blood mononuclear co-culture

    Directory of Open Access Journals (Sweden)

    Restu Syamsul Hadi

    2014-08-01

    Full Text Available Background Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. Methods In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. Results Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1-fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity Conclusions Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.

  1. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  2. Allogeneic human dermal fibroblasts are viable in peripheral blood mononuclear co-culture

    Directory of Open Access Journals (Sweden)

    Restu Syamsul Hadi

    2015-12-01

    Full Text Available BACKGROUND Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. METHODS In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. RESULTS Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1- fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity CONCLUSIONS Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.

  3. Tecnología de desulfuración de fundiciones grises con el fin de obtener hierro con grafito esferoidal // A desulfuration technology for gray iron in order to obtain spheroidal graphite iron

    Directory of Open Access Journals (Sweden)

    A. Batista Cabrera

    1999-01-01

    Full Text Available En el siguiente trabajo se describe una tecnología de desulfuracíon del hierro fundido gris, tomando como base el ya conocidométodo de Volianik (1. En este caso se modificaron algunos parámetros del citado método, adecuándolos a las condicionesexistentes en la Empresa de Fundición de Hierro y Acero de Holguín.( E.F. H. A.Como agente desulfurante se empleó carburo de calcio empleado por Volianik. Como agente activador del desulfurante seutilizó aire comprimido seco. El desulfurante con la granulometría apropiada fue introducido en la cazuela con hierro fundido a1460 oC, por medio de un dispositivo diseñado y construido para este fin.Una gráfica con la dependencia entre el tiempo de soplado y el rendimiento fue obtenida. Como resultado se logró estableceruna tecnología de desulfuración que permite disminuir el contenido de azufre en el hierro fundido desde 0,067 hasta 0,0148%para un rendimiento de 78%.Palabras claves: Hierro gris, desul furación, hierro nodular._____________________________________________________________________AbstractA desulfuration technology for gray cast iron is shown based on the well-known Volianik’s desulfuration method. In this casesome of its parameters were modified, for fitting them to the existent conditions in the Empresa de Hierro Fundido y Acero deHolguín (E.F. H. A..As desulfuration agent calcium carbide was used instead of lime, as it is usually employed by Volianik.Dry compressed air was used as activating agent for the calcium carbide. This one, with the proper grain size it was introducedin a ladle containing 160 RG of melted gray iron at 1460 oC, by means of a mixing device designed and constructed by theauthors.A graphic dependence between air compressed blowing time and desulfuration efficiency was obtained.As a result, a desulfuration technology which permits decrease melted gray iron sulfur contain, from 0,067 till 0,0148 %, wasobtained for a yield of 78 %.Key words: Gray iron, desul

  4. Pre-Combustion Carbon Dioxide Capture by a New Dual Phase Ceramic-Carbonate Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jerry Y. S. [Arizona State Univ., Tempe, AZ (United States)

    2015-01-31

    This report documents synthesis, characterization and carbon dioxide permeation and separation properties of a new group of ceramic-carbonate dual-phase membranes and results of a laboratory study on their application for water gas shift reaction with carbon dioxide separation. A series of ceramic-carbonate dual phase membranes with various oxygen ionic or mixed ionic and electronic conducting metal oxide materials in disk, tube, symmetric, and asymmetric geometric configurations was developed. These membranes, with the thickness of 10 μm to 1.5 mm, show CO2 permeance in the range of 0.5-5×10-7 mol·m-2·s-1·Pa-1 in 500-900°C and measured CO2/N2 selectivity of up to 3000. CO2 permeation mechanism and factors that affect CO2 permeation through the dual-phase membranes have been identified. A reliable CO2 permeation model was developed. A robust method was established for the optimization of the microstructures of ceramic-carbonate membranes. The ceramic-carbonate membranes exhibit high stability for high temperature CO2 separations and water gas shift reaction. Water gas shift reaction in the dual-phase membrane reactors was studied by both modeling and experiments. It is found that high temperature syngas water gas shift reaction in tubular ceramic-carbonate dual phase membrane reactor is feasible even without catalyst. The membrane reactor exhibits good CO2 permeation flux, high thermal and chemical stability and high thermal shock resistance. Reaction and separation conditions in the membrane reactor to produce hydrogen of 93% purity and CO2 stream of >95% purity, with 90% CO2 capture have been identified. Integration of the ceramic-carbonate dual-phase membrane reactor with IGCC process for carbon dioxide capture was analyzed. A methodology was developed to identify optimum operation conditions for a membrane tube of given dimensions that would treat coal syngas with targeted performance. The calculation results show that the dual-phase membrane reactor could improve IGCC process efficiency but the cost of the membrane reactor with membranes having current CO2 permeance is high. Further research should be directed towards improving the performance of the membranes and developing cost-effective, scalable methods for fabrication of dual-phase membranes and membrane reactors.

  5. High-Throughput Sequencing of Viable Microbial Communities in Raw Pork Subjected to a Fast Cooling Process.

    Science.gov (United States)

    Yang, Chao; Che, You; Qi, Yan; Liang, Peixin; Song, Cunjiang

    2017-01-01

    This study aimed to investigate the effect of the fast cooling process on the microbiological community in chilled fresh pork during storage. We established a culture-independent method to study viable microbes in raw pork. Tray-packaged fresh pork and chilled fresh pork were completely spoiled after 18 and 49 d in aseptic bags at 4 °C, respectively. 16S/18S ribosomal RNAs were reverse transcribed to cDNA to characterize the activity of viable bacteria/fungi in the 2 types of pork. Both cDNA and total DNA were analyzed by high-throughput sequencing, which revealed that viable Bacteroides sp. were the most active genus in rotten pork, although viable Myroides sp. and Pseudomonas sp. were also active. Moreover, viable fungi were only detected in chilled fresh pork. The sequencing results revealed that the fast cooling process could suppress the growth of microbes present initially in the raw meat to extend its shelf life. Our results also suggested that fungi associated with pork spoilage could not grow well in aseptic tray-packaged conditions. © 2016 Institute of Food Technologists®.

  6. A Rapid Method for Quantifying Viable Mycobacterium avium subsp. paratuberculosis in Cellular Infection Assays

    Science.gov (United States)

    Pooley, Hannah B.; de Silva, Kumudika; Purdie, Auriol C.; Begg, Douglas J.; Whittington, Richard J.

    2016-01-01

    ABSTRACT Determining the viability of bacteria is a key outcome of in vitro cellular infection assays. Currently, this is done by culture, which is problematic for fastidious slow-growing bacteria such as Mycobacterium avium subsp. paratuberculosis, where it can take up to 4 months to confirm growth. This study aimed to identify an assay that can rapidly quantify the number of viable M. avium subsp. paratuberculosis cells in a cellular sample. Three commercially available bacterial viability assays along with a modified liquid culture method coupled with high-throughput quantitative PCR growth detection were assessed. Criteria for assessment included the ability of each assay to differentiate live and dead M. avium subsp. paratuberculosis organisms and their accuracy at low bacterial concentrations. Using the culture-based method, M. avium subsp. paratuberculosis growth was reliably detected and quantified within 2 weeks. There was a strong linear association between the 2-week growth rate and the initial inoculum concentration. The number of viable M. avium subsp. paratuberculosis cells in an unknown sample was quantified based on the growth rate, by using growth standards. In contrast, none of the commercially available viability assays were suitable for use with samples from in vitro cellular infection assays. IMPORTANCE Rapid quantification of the viability of Mycobacterium avium subsp. paratuberculosis in samples from in vitro cellular infection assays is important, as it allows these assays to be carried out on a large scale. In vitro cellular infection assays can function as a preliminary screening tool, for vaccine development or antimicrobial screening, and also to extend findings derived from experimental animal trials. Currently, by using culture, it takes up to 4 months to obtain quantifiable results regarding M. avium subsp. paratuberculosis viability after an in vitro infection assay; however, with the quantitative PCR and liquid culture method

  7. Detection of Only Viable Bacterial Spores Using a Live/Dead Indicator in Mixed Populations

    Science.gov (United States)

    Behar, Alberto E.; Stam, Christina N.; Smiley, Ronald

    2013-01-01

    This method uses a photoaffinity label that recognizes DNA and can be used to distinguish populations of bacterial cells from bacterial spores without the use of heat shocking during conventional culture, and live from dead bacterial spores using molecular-based methods. Biological validation of commercial sterility using traditional and alternative technologies remains challenging. Recovery of viable spores is cumbersome, as the process requires substantial incubation time, and the extended time to results limits the ability to quickly evaluate the efficacy of existing technologies. Nucleic acid amplification approaches such as PCR (polymerase chain reaction) have shown promise for improving time to detection for a wide range of applications. Recent real-time PCR methods are particularly promising, as these methods can be made at least semi-quantitative by correspondence to a standard curve. Nonetheless, PCR-based methods are rarely used for process validation, largely because the DNA from dead bacterial cells is highly stable and hence, DNA-based amplification methods fail to discriminate between live and inactivated microorganisms. Currently, no published method has been shown to effectively distinguish between live and dead bacterial spores. This technology uses a DNA binding photoaffinity label that can be used to distinguish between live and dead bacterial spores with detection limits ranging from 109 to 102 spores/mL. An environmental sample suspected of containing a mixture of live and dead vegetative cells and bacterial endospores is treated with a photoaffinity label. This step will eliminate any vegetative cells (live or dead) and dead endospores present in the sample. To further determine the bacterial spore viability, DNA is extracted from the spores and total population is quantified by real-time PCR. The current NASA standard assay takes 72 hours for results. Part of this procedure requires a heat shock step at 80 degC for 15 minutes before the

  8. Stack gas desulfurization using adsorbent materials based on copper oxide; Desulfuracion de gases de combustion usando materiales adsorbentes basados en oxido de cobre

    Energy Technology Data Exchange (ETDEWEB)

    Flores Velazquez, Roberto; Rodas Grapain, Arturo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    One of main fossil fuels used to date in Mexico for power generation is the fuel oil, with a total participation of 32%. The Mexican fuel oil is constituted in average by 84% in weight of carbon, 11% hydrogen, 0.4% nitrogen, 0.2% oxygen, 4% sulfur and the remaining is assumed to be metals such as vanadium, nickel, calcium, magnesium among others. The purpose of the present paper is to show a new route of preparation of materials impregnated through the application of ultrasonic energy and to evaluate its performance in the stack gas desulfurization. [Spanish] Uno de los principales combustibles fosiles empleados actualmente en Mexico para la generacion de energia electrica es el combustoleo, con una participacion total del 32%. El combustoleo mexicano esta constituido en promedio por 84% en peso de carbono, 11% de hidrogeno, 0.4% de nitrogeno, 0.2% de oxigeno, 4% de azufre y el resto se asume a metales como vanadio, niquel, calcio, magnesio entre otros. El proposito del presente trabajo es mostrar una nueva ruta de preparacion de materiales impregnados a traves de la aplicacion de energia ultrasonica y evaluar su desempeno en la desulfuracion de gases de combustion.

  9. Novel Oxidative Desulfurization of a Model Fuel with H2O2 Catalyzed by AlPMo12O40 under Phase Transfer Catalyst-Free Conditions

    Directory of Open Access Journals (Sweden)

    Márcio José da Silva

    2013-01-01

    Full Text Available A novel process was developed for oxidative desulfurization (ODS in the absence of a phase transfer catalyst (PTC using only Keggin heteropolyacids and their aluminum salts as catalysts. Reactions were performed in biphasic mixtures of isooctane/acetonitrile, with dibenzothiophene (DBT as a model sulfur compound and hydrogen peroxide as the oxidant. Remarkably, only the AlPMo12O40-catalyzed reactions resulted in complete oxidation of DBT into DBT sulfone, which was totally extracted by acetonitrile, reducing the sulfur content of isooctane from the 1000 ppm to  H3PMo12O40 > AlPW12O40 > H3PW12O40. The absence of a PTC, acidic organic peroxides, and the use of hydrogen peroxide, an environmentally benign oxidant, make up the positive aspects of AlPMo12O40-catalyzed ODS reactions. In these reactions, high rates of DBT removal (ca. 100% were achieved within a short time (ca. 2 hours and under mild reaction conditions.

  10. Impact of operating state changes on the behaviour of mercury in wet fuel gas desulfurization plants; Auswirkung von Betriebszustandsaenderungen auf das Verhalten von Quecksilber in nassen Rauchgasentschwefelungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Heidel, Barna; Farr, Silvio; Brechtel Kevin [Institut fuer Feuerungs- und Kraftwerkstechnik (IFK), Universitaet Stuttgart (Germany); Scheffknecht, Guenter [EnBW Kraftwerke AG, Stuttgart (Germany); Thorwarth, Harald

    2011-07-01

    During the combustion of coal, mercury is released in its elemental form and is oxidized by existing flue gas purification plants. Changing operating conditions may result in a re-emission of elemental mercury. With regard to future demands, knowledge of the operation stability is necessary in order to prevent re-emissions from wet flue gas desulphurisation plants. With this in mind, the authors of the contribution under consideration investigate the behaviour of sulfur dioxide and mercury at laboratory scale and pilot plant scale. At first, the effects of load changes, the starting and stopping of flue gas desulfurization systems and the fuel switch on the deposition of sulfur dioxide and mercury are presented. Furthermore, the changes in the suspension solution with regard to the composition, the pH value and the redox potential will be described. In addition, operating conditions resulting in the re-emission of elemental mercury are discussed in detail. Finally, measures such as the change in the L/G value, the adjustment of the addition of air oxidation as well as the possibility of an early process adaptation and their influences on the re-emission of elemental mercury are considered.

  11. A novel method to remove chromium, vanadium and ammonium from vanadium industrial wastewater using a byproduct of magnesium-based wet flue gas desulfurization.

    Science.gov (United States)

    Fang, Dean; Zhang, Xuefei; Dong, Mengge; Xue, Xiangxin

    2017-08-15

    A novel treatment for chromium, vanadium and ammonium from vanadium industrial wastewater using a byproduct of magnesium-based wet flue gas desulfurization is investigated. In the present study, the byproduct is used as a reductant for chromium and vanadium removal by chemical precipitation, and the residual magnesium ion can also be used to remove ammonium in the present of phosphate by struvite crystallization. Besides, the effects of main operational parameters (reaction pH, byproduct dosage and reaction time) on the heavy metal removal and ammonium removal (reaction pH, Mg(2+):NH4(+):PO4(3-) molar ratio and reaction time) are investigated, and the reaction mechanism for this treatment technology is also proposed. Under the optimal conditions, the residual concentrations of chromium(IV), total chromium and vanadium are 0.046mg/L, 0.468mg/L and 0.06mg/L, respectively. The removal efficiency of ammonium is 95.72% and the residual concentrations of ammonium and phosphorus are 137.12mg/L and 5.49mg/L, respectively. Additionally, the precipitations are characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and thermogravimetry differential scanning calorimetry (TG-DSC), respectively. Finally, a resource utilization method of the precipitation sludge from this technology is also presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The performance and microbial communities of biodegradation-electron transfer with sulfur metabolism integrated process for flue gas desulfurization wastewater treatment.

    Science.gov (United States)

    Wei, Chao; He, Wenjie; Wei, Li; Ma, Jun; Li, Chunying

    2017-07-22

    The biodegradation-electron transfer with sulfur metabolism integrated (BESI(®)) process was used for the treatment of real flue gas desulfurization wastewater. The BESI(®) process consists of an anaerobic activated sludge reactor, an anoxic activated sludge reactor, and an aerobic bio-film reactor. The performance of the integrated process was evaluated by the removal efficiencies of organics and nitrogen pollutants. The sulfate in the wastewater was used as an abundant sulfur source to drive the integrated process. The removal efficiencies of chemical oxygen demand, total organic carbon, ammonia nitrogen, and total nitrogen of the integrated process were 87.99, 87.04, 30.77, and 45.17%, respectively. High-throughput 454-pyrosequencing was applied for the analysis of microbial communities in the integrated process. From the anaerobic activated sludge (Sample 1), anoxic activated sludge (Sample 2), and aerobic bio-film (Sample 3), totals of 1701, 1181, and 857 operational taxonomic units were obtained, respectively. The sulfur cycle was associated with the removal of organics and nitrogen pollutants. The sulfate-reducing bacteria participated in the organics removal in the anaerobic reactor, and the sulfide oxidation was related with the denitrification in the anoxic reactor. A complete nitrogen degradation chain was built in the integrated process. Through the degradation chain, the nitrogenous organic pollutants, ammonia nitrogen, and nitrate could be removed. The participant functional bacteria were also detected by pyrosequencing.

  13. Influence of flue gas desulfurization (FGD) installations on emission characteristics of PM2.5 from coal-fired power plants equipped with selective catalytic reduction (SCR).

    Science.gov (United States)

    Li, Zhen; Jiang, Jingkun; Ma, Zizhen; Fajardo, Oscar A; Deng, Jianguo; Duan, Lei

    2017-11-01

    Flue gas desulfurization (FGD) and selective catalytic reduction (SCR) technologies have been widely used to control the emissions of sulphur dioxide (SO2) and nitrogen oxides (NOX) from coal-fired power plants (CFPPs). Field measurements of emission characteristics of four conventional CFPPs indicated a significant increase in particulate ionic species, increasing PM2.5 emission with FGD and SCR installations. The mean concentrations of PM2.5 from all CFPPs tested were 3.79 ± 1.37 mg/m(3) and 5.02 ± 1.73 mg/m(3) at the FGD inlet and outlet, respectively, and the corresponding contributions of ionic species were 19.1 ± 7.7% and 38.2 ± 7.8%, respectively. The FGD was found to enhance the conversion of NH3 slip from the SCR to NH4(+) in the PM2.5, together with the conversion of SO2 to SO4(2-), and increased the primary NH4(+) and SO4(2-) aerosol emissions by approximately 18.9 and 4.2 times, respectively. This adverse effect should be considered when updating the emission inventory of CFPPs and should draw the attention of policy-makers for future air pollution control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Facile method to disperse nonporous metal organic frameworks: composite formation with a porous metal organic framework and application in adsorptive desulfurization.

    Science.gov (United States)

    Hasan, Zubair; Jhung, Sung Hwa

    2015-05-20

    It is generally not easy to utilize nonporous metal organic frameworks (MOFs) with a large crystal size (especially for catalysis or adsorption) because their surface area is low and the majority of the active sites exist inside the MOFs. Composing with porous materials may be one way to disperse the nonporous materials. In this study, a nonporous/nonsoluble MOF (in which the particle size was much larger than the cavity size of the porous MOFs) containing Cu(I) ((Cu2(pyz)2(SO4)(H2O)2)n, denoted as CP) was composed with typical porous MOFs such as MIL100(Fe) (iron-benzenetricarboxylate) and CuBTC (cupper-benzenetricarboxylate). The Cu(I) species of the nonporous MOF was effectively utilized for the adsorptive desulfurization (ADS) of model fuel. Even though the porosities of the composed MOFs decreased as the content of CP increased, the adsorption capacity increased as the content of CP increased (up to a certain content). Considering the negligible capacity of CP for ADS, the enhanced adsorption capacity may be a result of the well-dispersed Cu(I), which is known to be beneficial for ADS via π-complexation. The dispersed CP was also observed by transmission electron microscopy mapping. Therefore, composing a nonporous MOF with porous MOF is a new and facile way to disperse/utilize the active sites of a nonporous MOF.

  15. Significance of Viable but Nonculturable Escherichia coli: Induction, Detection, and Control.

    Science.gov (United States)

    Ding, Tian; Suo, Yuanjie; Xiang, Qisen; Zhao, Xihong; Chen, Shiguo; Ye, Xingqian; Liu, Donghong

    2017-03-28

    Diseases caused by foodborne or waterborne pathogens are emerging. Many pathogens can enter into the viable but nonculturable (VBNC) state, which is a survival strategy when exposed to harsh environmental stresses. Pathogens in the VBNC state have the ability to evade conventional microbiological detection methods, posing a significant and potential health risk. Therefore, controlling VBNC bacteria in food processing and the environment is of great importance. As the typical one of the gram-negatives, Escherichia coli (E. coli) is a widespread foodborne and waterborne pathogenic bacterium and is able to enter into a VBNC state in extreme conditions (similar to the other gram-negative bacteria), including inducing factors and resuscitation stimulus. VBNC E. coli has the ability to recover both culturability and pathogenicity, which may bring potential health risk. This review describes the concrete factors (nonthermal treatment, chemical agents, and environmental factors) that induce E. coli into the VBNC state, the condition or stimulus required for resuscitation of VBNC E. coli, and the methods for detecting VBNC E. coli. Furthermore, the mechanism of genes and proteins involved in the VBNC E. coli is also discussed in this review.

  16. Graphene oxide and carboxylated graphene oxide: Viable two-dimensional nanolabels for lateral flow immunoassays.

    Science.gov (United States)

    Yu, Li; Li, Peiwu; Ding, Xiaoxia; Zhang, Qi

    2017-04-01

    Graphene oxide (GO) and carboxylated GO were used as labels for lateral flow immunoassays, instead of the conventionally used colloidal gold and colored latex labels. A sensor is demonstrated that enables fast screening for aflatoxin B 1 (AFB 1 ) as a model analyte using the antibody-GO complex as the recognition element. The visual limit of detection and cut-off value for AFB 1 are 0.3 and 1ng/mL, respectively. It is shown that GO and carboxylated GO are viable black labels for use in lateral flow assays, one typical advantage being the saving cost (compared to the use of colloidal gold). Qualitative results are achieved within 15min, and the analytical results were in good agreement with the reference LC MS/MS method. The method was successfully applied to the on-site determination of AFB 1 in agricultural products. In our perception, it opens new possibilities for the screening of other toxins by lateral flow immunoassays using GO and carboxylated GO as labels. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Meatal Mobilization and Glanuloplasty: A Viable Option for Coronal and Glanular Hypospadias Repair.

    Science.gov (United States)

    Moradi, Mahmoudreza; Kazemzadeh, Babak; Hood, Brandy; Rezaee, Haress; Kaseb, Kaveh

    2016-08-01

    To present the meatal mobilization with glanuloplasty inclusive (MMGPI) modification of meatal advancement and glanuloplasty inclusive. A total of 120 patients with anterior hypospadias underwent MMGPI between September 2008 and October 2014 at Kermanshah University of Medical Sciences. Satisfactory outcomes were defined as continuous straight urinary flow and catheterization of new meatus without difficulty. Cosmetic outcomes were considered acceptable if patients maintained a slit-like meatus at the glanular tip. Patients were examined at 1 week, 1, 3, 6, 12, and 24 months. The 120 patients with anterior hypospadias underwent MMGPI. There were no hematoma, meatal necrosis, or other early complications. In patients with glanular hypospadias, there were no meatal regressions or stenosis, all voiding patterns were normal, and all patients maintained a slit-like meatus at the glanular tip. Two patients with coronal hypospadias had meatal stenosis and 2 patients had meatal regression. Five patients with sub-coronal hypospadias had 2-mm meatal regression with downward sloping urinary stream, and 2 patients had meatal stenosis. In all, meatus remained distal to the preoperative meatus with no necrosis. Small sample size was the major limitation of this study. MMGPI represents a viable option for glanular and coronal hypospadias repair. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Eradication of high viable loads of Listeria monocytogenes contaminating food-contact surfaces

    Directory of Open Access Journals (Sweden)

    Silvia ede Candia

    2015-07-01

    Full Text Available This study demonstrates the efficacy of cold gaseous ozone treatments at low concentrations in the eradication of high Listeria monocytogenes viable cell loads from glass, polypropylene, stainless steel and expanded polystyrene food-contact surfaces. Using a step by step approach, involving the selection of the most resistant strain-surface combinations, 11 Listeria spp. strains resulted inactivated by a continuous ozone flow at 1.07 mg m-3 after 24 or 48 h of cold incubation, depending on both strain and surface evaluated. Increasing the inoculum level to 9 log CFU coupon-1, the best inactivation rate was obtained after 48h of treatment at 3.21 mg m-3 ozone concentration when cells were deposited onto stainless steel and expanded polystyrene coupons, resulted the most resistant food-contact surfaces in the previous assays.The addition of naturally microbiologically contaminated meat extract to a high load of L. monocytogenes LMG 23775 cells, the most resistant strain out of the 11 assayed Listeria spp. strains, led to its complete inactivation after four days of treatment.To the best of our knowledge, this is the first report describing the survival of L. monocytogenes and the effect of ozone treatment under cold storage conditions on expanded polystyrene, a commonly-used material in food packaging. These results could be useful for reducing pathogen cross-contamination phenomena during cold food storage.

  19. A clinically viable capsule endoscopy video analysis platform for automatic bleeding detection

    Science.gov (United States)

    Yi, Steven; Jiao, Heng; Xie, Jean; Mui, Peter; Leighton, Jonathan A.; Pasha, Shabana; Rentz, Lauri; Abedi, Mahmood

    2013-02-01

    In this paper, we present a novel and clinically valuable software platform for automatic bleeding detection on gastrointestinal (GI) tract from Capsule Endoscopy (CE) videos. Typical CE videos for GI tract run about 8 hours and are manually reviewed by physicians to locate diseases such as bleedings and polyps. As a result, the process is time consuming and is prone to disease miss-finding. While researchers have made efforts to automate this process, however, no clinically acceptable software is available on the marketplace today. Working with our collaborators, we have developed a clinically viable software platform called GISentinel for fully automated GI tract bleeding detection and classification. Major functional modules of the SW include: the innovative graph based NCut segmentation algorithm, the unique feature selection and validation method (e.g. illumination invariant features, color independent features, and symmetrical texture features), and the cascade SVM classification for handling various GI tract scenes (e.g. normal tissue, food particles, bubbles, fluid, and specular reflection). Initial evaluation results on the SW have shown zero bleeding instance miss-finding rate and 4.03% false alarm rate. This work is part of our innovative 2D/3D based GI tract disease detection software platform. While the overall SW framework is designed for intelligent finding and classification of major GI tract diseases such as bleeding, ulcer, and polyp from the CE videos, this paper will focus on the automatic bleeding detection functional module.

  20. Determining size and dispersion of minimum viable populations for land management planning and species conservation

    Science.gov (United States)

    Lehmkuhl, John F.

    1984-03-01

    The concept of minimum populations of wildlife and plants has only recently been discussed in the literature. Population genetics has emerged as a basic underlying criterion for determining minimum population size. This paper presents a genetic framework and procedure for determining minimum viable population size and dispersion strategies in the context of multiple-use land management planning. A procedure is presented for determining minimum population size based on maintenance of genetic heterozygosity and reduction of inbreeding. A minimum effective population size ( N e ) of 50 breeding animals is taken from the literature as the minimum shortterm size to keep inbreeding below 1% per generation. Steps in the procedure adjust N e to account for variance in progeny number, unequal sex ratios, overlapping generations, population fluctuations, and period of habitat/population constraint. The result is an approximate census number that falls within a range of effective population size of 50 500 individuals. This population range defines the time range of short- to long-term population fitness and evolutionary potential. The length of the term is a relative function of the species generation time. Two population dispersion strategies are proposed: core population and dispersed population.