WorldWideScience

Sample records for modeling tar production

  1. Cancer fear over coal tar products

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    Discusses a report by Dutch researchers which suggests that the regular use of coal tar shampoos may significantly increase the risk of cancer due to the high levels of polynuclear aromatic hydrocarbons (PAHs) in the products. The PAH exposure of volunteers using a coal tar anti-dandruff shampoo was studied by measuring the amount of hydroxypyrene, a PAH breakdown product in their urine. Volunteers who had used the shampoo excreted high levels of hydroxypyrene the day after exposure. Excretion by the control group using a non-coal tar anti-dandruff shampoo remained constant. 1 ref., 1 fig.

  2. Coal Tar and Coal-Tar Pitch

    Science.gov (United States)

    Learn about coal-tar products, which can raise your risk of skin cancer, lung cancer, and other types of cancer. Examples of coal-tar products include creosote, coal-tar pitch, and certain preparations used to treat skin conditions such as eczema, psoriasis, and dandruff.

  3. Numerical simulation of vortex pyrolysis reactors for condensable tar production from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.S.; Bellan, J. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

    1998-08-01

    A numerical study is performed in order to evaluate the performance and optimal operating conditions of vortex pyrolysis reactors used for condensable tar production from biomass. A detailed mathematical model of porous biomass particle pyrolysis is coupled with a compressible Reynolds stress transport model for the turbulent reactor swirling flow. An initial evaluation of particle dimensionality effects is made through comparisons of single- (1D) and multi-dimensional particle simulations and reveals that the 1D particle model results in conservative estimates for total pyrolysis conversion times and tar collection. The observed deviations are due predominantly to geometry effects while directional effects from thermal conductivity and permeability variations are relatively small. Rapid ablative particle heating rates are attributed to a mechanical fragmentation of the biomass particles that is modeled using a critical porosity for matrix breakup. Optimal thermal conditions for tar production are observed for 900 K. Effects of biomass identity, particle size distribution, and reactor geometry and scale are discussed.

  4. Hydrogen production from biomass tar by catalytic steam reforming

    International Nuclear Information System (INIS)

    Yoon, Sang Jun; Choi, Young-Chan; Lee, Jae-Goo

    2010-01-01

    The catalytic steam reforming of model biomass tar, toluene being a major component, was performed at various conditions of temperature, steam injection rate, catalyst size, and space time. Two kinds of nickel-based commercial catalyst, the Katalco 46-3Q and the Katalco 46-6Q, were evaluated and compared with dolomite catalyst. Production of hydrogen generally increased with reaction temperature, steam injection rate and space time and decreased with catalyst size. In particular, zirconia-promoted nickel-based catalyst, Katalco 46-6Q, showed a higher tar conversion efficiency and shows 100% conversion even relatively lower temperature conditions of 600 deg. C. Apparent activation energy was estimated to 94 and 57 kJ/mol for dolomite and nickel-based catalyst respectively.

  5. Phytotoxicity and Plant Productivity Analysis of Tar-Enriched Biochars

    Science.gov (United States)

    Keller, M. L.; Masiello, C. A.; Dugan, B.; Rudgers, J. A.; Capareda, S. C.

    2008-12-01

    Biochar is one of the three by-products obtained by the pyrolysis of organic material, the other two being syngas and bio-oil. The pyrolysis of biomass has generated a great amount of interest in recent years as all three by-products can be put toward beneficial uses. As part of a larger project designed to evaluate the hydrologic impact of biochar soil amendment, we generated a biochar through fast pyrolysis (less than 2 minutes) of sorghum stock at 600°C. In the initial biochar production run, the char bin was not purged with nitrogen. This inadvertent change in pyrolysis conditions produced a fast-pyrolysis biochar enriched with tars. We chose not to discard this batch, however, and instead used it to test the impact of tar-enriched biochars on plants. A suite of phytotoxicity tests were run to assess the effects of tar-rich biochar on plant germination and plant productivity. We designed the experiment to test for negative effects, using an organic carbon and nutrient-rich, greenhouse- optimized potting medium instead of soil. We used Black Seeded Simpson lettuce (Lactuca sativa) as the test organism. We found that even when tars are present within biochar, biochar amendment up to 10% by weight caused increased lettuce germination rates and increased biomass productivity. In this presentation, we will report the statistical significance of our germination and biomass data, as well as present preliminary data on how biochar amendment affects soil hydrologic properties.

  6. Modeling Tar Recirculation in Biomass Fluidized Bed Gasification

    NARCIS (Netherlands)

    Heineken, Wolfram; De la Cuesta de Cal, Daniel; Zobel, Nico

    2016-01-01

    A biomass gasification model is proposed and applied to investigate the benefits of tar recirculation within a gasification plant. In the model, tar is represented by the four species phenol, toluene, naphthalene, and benzene. The model is spatially one-dimensional, assuming plug flow for the

  7. Reaction Mechanism of Tar Evolution in Biomass Steam Gasification for Hydrogen Production

    International Nuclear Information System (INIS)

    Shingo Katayama; Masahiro Suzuki; Atsushi Tsutsumi

    2006-01-01

    Reaction mechanism of tar evolution in steam gasification of biomass was investigated with a continuous cross-flow moving bed type differential reactor, in which tar and gases can be fractionated according to reaction time. We estimated that time profile of tar and gas evolution in the gasification of cellulose, xylan, and lignin, and compared it with experimental product time profile of real biomass gasification. The experimental tar evolution rate is different from estimated tar evolution rate. The estimated tar evolution rate has a peak at 20 s. On the other hand, the experimental tar evolution rate at 20 s is little, and tar at initial stage includes more water-soluble and water-insoluble compounds. It can be concluded that in the real biomass steam gasification the evolution of tar from cellulose and lignin component was found to be precipitated by that from hemi-cellulose component. (authors)

  8. Avoiding tar formation in biocoke production from waste biomass

    International Nuclear Information System (INIS)

    Adrados, A.; De Marco, I.; Lopez-Urionabarrenechea, A.; Solar, J.; Caballero, B.

    2015-01-01

    This paper focuses in avoiding tar formation and in optimizing pyrolysis gas (maximizing H 2 and CO) in the production of biocoke from waste lignocellulosic biomass. In order to obtain metallurgical grade biochar (biocoke) slow heating rate and high temperature are required. Under such conditions useless pyrolysis liquids, mainly composed of water together with some heavy-sticky tars, are obtained. In order to make biocoke a cost-effective process it is necessary to optimize pyrolysis vapors avoiding tar formation and maximizing the amount and quality of both coke and gases. With this objective, in this work different heating rates (3–20 °C min −1 ) and catalysts (zeolite, Ni/CeO 2 –Al 2 O 3 ) have been tested in a two step pyrolysis process. Olive tree cuttings have been pyrolyzed in a 3.5 L batch reactor at 750 °C and the vapors generated have been thermally and catalytically treated at 900 °C in a second tubular reactor. About 25 wt.% biocoke useful as reducing agent in certain metallurgical processes, ≈57 wt.% gases with near 50 vol.% H 2 , and no tar production has been achieved when a heating rate of 3 °C min −1 and the homemade Ni/CeO 2 –Al 2 O 3 catalyst were used. - Highlights: • Metallurgical grade biochar was obtained by olive waste pyrolysis. • Low heating rates avoid tar formation and increase gas and biochar yields. • Ni/CeO 2 –Al 2 O 3 was better than HZSM5 zeolite for vapor upgrading in a second step. • Ni/CeO 2 –Al 2 O 3 and 3 °C min −1 gave the maximum H 2 , gas and biochar yields

  9. Treatment of lignite tars, etc

    Energy Technology Data Exchange (ETDEWEB)

    1936-08-07

    A process is described for treating tars such as lignite tar, shale tar, or peat tar, and similar tars, characterized by the fact that the tar is rectified to about 240/sup 0/C and the residue brought to a temperature above 50/sup 0/C after diluting with a product of the type of gasoline or ligroin at about 30/sup 0/C and treated with selective solvents preferably low-boiling phenols and eventually with water.

  10. Effects of electric current upon catalytic steam reforming of biomass gasification tar model compounds to syngas

    International Nuclear Information System (INIS)

    Tao, Jun; Lu, Qiang; Dong, Changqing; Du, Xiaoze; Dahlquist, Erik

    2015-01-01

    Highlights: • ECR technique was proposed to convert biomass gasification tar model compounds. • Electric current enhanced the reforming efficiency remarkably. • The highest toluene conversion reached 99.9%. • Ni–CeO 2 /γ-Al 2 O 3 exhibited good stability during the ECR performance. - Abstract: Electrochemical catalytic reforming (ECR) technique, known as electric current enhanced catalytic reforming technique, was proposed to convert the biomass gasification tar into syngas. In this study, Ni–CeO 2 /γ-Al 2 O 3 catalyst was prepared, and toluene was employed as the major feedstock for ECR experiments using a fixed-bed lab-scale setup where thermal electrons could be generated and provided to the catalyst. Several factors, including the electric current intensity, reaction temperature and steam/carbon (S/C) ratio, were investigated to reveal their effects on the conversion of toluene as well as the composition of the gas products. Moreover, toluene, two other tar model compounds (benzene and 1-methylnaphthalene) and real tar (tar-containing wastewater) were subjected to the long period catalytic stability tests. All the used catalysts were analyzed to determine their carbon contents. The results indicated that the presence of electric current enhanced the catalytic performance remarkably. The toluene conversion reached 99.9% under the electric current of 4 A, catalytic temperature of 800 °C and S/C ratio of 3. Stable conversion performances of benzene, 1-methylnaphthalene and tar-containing wastewater were also observed in the ECR process. H 2 and CO were the major gas products, while CO 2 and CH 4 were the minor ones. Due to the promising capability, the ECR technique deserves further investigation and application for efficient tar conversion

  11. Modelling the low-tar BIG gasification concept[Biomass Integrated gasification

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Lars; Elmegaard, B.; Qvale, B.; Henriksen, Ulrrik [Technical univ. of Denmark (Denmark); Bentzen, J.D.; Hummelshoej, R. [COWI A/S (Denmark)

    2007-07-01

    A low-tar, high-efficient biomass gasification concept for medium- to large-scale power plants has been designed. The concept is named 'Low-Tar BIG' (BIG = Biomass Integrated Gasification). The concept is based on separate pyrolysis and gasification units. The volatile gases from the pyrolysis (containing tar) are partially oxidised in a separate chamber, and hereby the tar content is dramatically reduced. Thus, the investment, and running cost of a gas cleaning system can be reduced, and the reliability can be increased. Both pyrolysis and gasification chamber are bubbling fluid beds, fluidised with steam. For moist fuels, the gasifier can be integrated with a steam drying process, where the produced steam is used in the pyrolysis/gasification chamber. In this paper, mathematical models and results from initial tests of a laboratory Low-Tar BIG gasifier are presented. Two types of models are presented: 1. The gasifier-dryer applied in different power plant systems: Gas engine, Simple cycle gas turbine, Recuperated gas turbine and Integrated Gasification and Combined Cycle (IGCC). The paper determines the differences in efficiency of these systems and shows that the gasifier will be applicable for very different fuels with different moisture contents, depending on the system. 2. A thermodynamic Low-Tar BIG model. This model is based on mass and heat balance between four reactors: Pyrolysis, partial oxidation, gasification, gas-solid mixer. The paper describes the results from this study and compares the results to actual laboratory tests. The study shows, that the Low-Tar BIG process can use very wet fuels (up to 65-70% moist) and still produce heat and power with a remarkable high electric efficiency. Hereby the process offers the unique combination of large scale gasification and low-cost gas cleaning and use of low-cost fuels which very likely is the necessary combination that will lead to a breakthrough of gasification technology. (au)

  12. Economic and environmental effects of the FQD on crude oil production from tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; De Buck, A.; Afman, M. [CE Delft, Delft (Netherlands); Van den Berg, J.; Otten, G.J. [Carbon Matters, Den Haag (Netherlands)

    2013-05-15

    The production of unconventional crudes in Canada and Venezuela and exports of these crudes to the EU are investigated. In addition the potential economic and environmental impact of the proposed EU FQD measures (Fuel Quality Directive) on the production of crudes from tar sands and on new tar sand exploration projects are examined. CE Delft has analysed the impact by using a dedicated cost model. For existing projects, the model determines the effect on the basis of marginal production costs. For planned projects the model used the net present value (NPV) of proposed investments. The impacts were determined for a range of crude oil prices and FQD price effects. Combined, for existing and new projects together, the maximum effect would be at a price level at 60 USD/bbl, with savings of up to 19 Mt CO2/y at an FQD price differential of 3 euro/bbl. This overall effect would be substantial and come on top of the total emission reduction effect of the FQD of 60 Mt CO2/y, which will be achieved mostly by the blending of low-carbon fuels and reduced flaring and venting. As part of the reduction of transport greenhouse gas (GHG) emissions, the revised FQD obliges fuel suppliers to reduce these emissions by 6% by 2020 on a well-to-wheel basis. The EU is currently developing a methodology to differentiate fossil fuels on the basis of feedstock and GHG emissions. In the proposal, diesel produced from tar sands, has been given a default emission value of 108.5 gCO2 eq/MJ, while diesel from conventional crude was set at 89.1 gCO2 eq/MJ. The Commission's proposal is currently undergoing an impact assessment and is expected to be resubmitted to the Council later this year (2013)

  13. Secondary reactions of tar during thermochemical biomass conversion[Dissertation 14341

    Energy Technology Data Exchange (ETDEWEB)

    Morf, P.O.

    2001-07-01

    This dissertation submitted to the Swiss Federal Institute of Technology in Zurich presents and discusses the results obtained during the examination of the processes involved in the formation and conversion of tar in biomass gasification plant. Details are given on the laboratory reactor system used to provide separated tar production and conversion for the purposes of the experiments carried out. The results of analyses made of the tar and the gaseous products obtained after its conversion at various temperatures are presented. The development of kinetic models using the results of the experiments that were carried out is described. The results of the experiments and modelling are compared with the corresponding results obtained using a full-scale down-draft, fixed-bed gasifier. The author is of the opinion that the reaction conditions found in full-scale gasifiers can be well simulated using heterogeneous tar conversion experiments using the lab reactor system.

  14. Hydroconversion of coal tars: effect of the temperature of pyrolysis on the reactivity of tars

    Energy Technology Data Exchange (ETDEWEB)

    Lemberton, J.L.; Touzeyidio, M.; Guisnet, M.

    1988-12-01

    The hydroconversion of a low-temperature and of a high-temperature tar was carried out in the presence of a sulfided Ni and Mo on alumina catalyst - pure or mixed with an acid catalyst (HY zeolite). Significant amounts of light products can be obtained from low temperature tar, formed however through a non-catalytic process. On the contrary, there is a slight catalytic effect during the hydroprocessing of high temperature tar, but the yield in light products is very low. These results can be explained by an extensive poisoning of the NiMo on alumina catalyst by coke which is initiated by the O- and N-containing compounds of the tars. 10 refs., 1 fig., 3 tabs.

  15. Effect of water addition in a microwave assisted thermal cracking of biomass tar models

    International Nuclear Information System (INIS)

    Warsita, Aris; Al-attab, K.A.; Zainal, Z.A.

    2017-01-01

    Highlights: • Effective tar thermal treatment with water addition using microwave is proposed. • The reactor temperature of 1200 °C can be reached quickly at bed height 120 mm. • The optimum water to tar ratio W/T was 0.3 for tar models. • Temperature greatly effect tar removal at various W/T rates. - Abstract: Producer gas from biomass gasification is plagued by the presence of tar which causes pipe blockages. Thermal and catalytic treatments in a microwave reactor have been shown to be effective methods in removing tar from producer gas. A question arises as to the possibility of enhancing the removal mechanism by adding water into the reactor. Toluene and naphthalene were used as tar models in the present study with N_2 as the carrier gas followed by the use of simulated producer gas. Thermal treatment with various amount of water was added at temperatures in the range of 800–1200 °C. The tar removal efficiency obtained 95.83% at the optimum temperature of 1200 °C for naphthalene in for toluene 96.32% at 1050 °C at water to tar ratio (W/T) of 0.3. This study shows that the removal of tar by microwave irradiation with water addition is a significant and effective method in tar cracking.

  16. Indian coal tars. II

    Energy Technology Data Exchange (ETDEWEB)

    Basu, A N; Bhatnagar, J N; Roy, A K

    1954-01-01

    Laboratory experiments were carried out on these efforts: (1) rank and specific-gravity fractions on tar yield; (2) addition of water to the coal charge, or steam during carbonization, on yield of tar and tar acids; (3) the presence of a cracking agent (shale) with and without steam addition on the yield of tar and tar acids (the particular shale used without steam reduced the yield, and the restricted use of steam brought the yield to the former noncatalyzed level); and (4) catalytic effect of three different samples of shale, firebrick, quartz, coke, and silica-alumina on the cracking of tar acids (the most active were two of the shales, a freshly-prepared coke, and the Al/sub 2/O/sub 3/-SiO/sub 2/ catalysts that gave conversion up to 98%). The products were mainly carbon, aromatic hydrocarbons of the naphthalene series and gases (CO and H/sub 2/). The yield of the tar becomes less as coal of lower specific gravity is used or when higher temperatures are used for carbonization. The mineral matter associated with Indian coals acts as a decomposition catalyst for tar acids, as shown by experiments on the decomposition of PhOH at temperatures above 800/sup 0/.

  17. Coal tar pitch. Interrelations between properties and utilization of coal tar pitch

    Energy Technology Data Exchange (ETDEWEB)

    Collin, G; Koehler, H [Ruetgerswerke A.G., Duisburg (Germany, F.R.)

    1977-06-01

    Coal tar pitch is won as a highly aromatic, thermoplastic residue by destillating coal tar. In this paper the structure as well as the chemical and physical data of this pitch are introduced. In addition to this the actual as well as possible applications are indicated. For example, the pitch can be used for the production of binders, e.g. for electrodes and road construction as well as in combination with plastics for the production of insulating material and corrosion protection material.

  18. Production of oil from Intermountain West tar sands deposits

    Energy Technology Data Exchange (ETDEWEB)

    Glassett, J.M.; Glassett, J.A.

    1976-03-01

    Six tar sand deposits in the Intermountain West, each containing more than one billion barrels of oil in place, are identified. All of these deposits are in eastern Utah and contain a total of twenty-eight billion barrels of oil. The names of the six deposits arranged in descending order of desirability for large-scale surface-mining oil recovery operations are as follows: Sunnyside, Tar Sand Triangle, Asphalt Ridge, P.R. Spring, Circle Cliffs, and Hill Creek. An overview of each deposit is presented including geology, surface-mining variables, chemical processing variables, environmental aspects, and economics. A comparison of Utah tar sands and Athabasca, Alberta, Canada tar sands is also presented.

  19. Centrifuge treatment of coal tar

    Energy Technology Data Exchange (ETDEWEB)

    L.A. Kazak; V.Z. Kaidalov; L.F. Syrova; O.S. Miroshnichenko; A.S. Minakov [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

    2009-07-15

    New technology is required for the removal of water and heavy fractions from regular coal tar. Centrifuges offer the best option. Purification of coal tar by means of centrifuges at OAO NLMK permits the production of pitch coke or electrode pitch that complies with current standards.

  20. Fungal cultures of tar bush and creosote bush for production of two phenolic antioxidants (pyrocatechol and gallic acid).

    Science.gov (United States)

    Ventura, J; Gutiérrez-Sanchez, G; Rodríguez-Herrera, R; Aguilar, C N

    2009-01-01

    'Tar bush' and 'creosote bush' were substrates of fungal cultivation for tannase production and gallic acid and pyrocatechol accumulation. Aspergillus niger GH1 grew similarly on both plant materials under solid state culture conditions, reaching maximal levels after 4 d. Fungal strain degraded all tannin content of creosote bush after 4 d of fermentation and >75 % of tar bush after 5 d. Higher level of tannase activity was detected in tar bush fermentation. Biotransformation of tannins to gallic acid was high (93 % in creosote bush and 89 % in tar bush). Pyrocatechol was released poorly. Kinetic parameters of tannin conversion were calculated.

  1. DECOMPOSITION OF TARS IN MICROWAVE PLASMA – PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    Mateusz Wnukowski

    2014-07-01

    Full Text Available The paper refers to the main problem connected with biomass gasification - a presence of tar in a product gas. This paper presents preliminary results of tar decomposition in a microwave plasma reactor. It gives a basic insight into the construction and work of the plasma reactor. During the experiment, researches were carried out on toluene as a tar surrogate. As a carrier gas for toluene and as a plasma agent, nitrogen was used. Flow rates of the gases and the microwave generator’s power were constant during the whole experiment. Results of the experiment showed that the decomposition process of toluene was effective because the decomposition efficiency attained above 95%. The main products of tar decomposition were light hydrocarbons and soot. The article also gives plans for further research in a matter of tar removal from the product gas.

  2. The role of char and tar in determining the gas-phase partitioning of nitrogen during biomass gasification

    International Nuclear Information System (INIS)

    Broer, Karl M.; Brown, Robert C.

    2015-01-01

    Highlights: • Switchgrass was gasified at an equivalence ratio of zero and 650–850 °C. • Short residence times were employed to minimize secondary reactions. • Char- and tar-bound nitrogen, NH_3, HCN, and N_2 were all significant products. • Increasing temperature leads to increased release of gaseous nitrogen compounds. • Kinetic models of gasification should include nitrogen release from char and tar. - Abstract: Gasification is an attractive option for converting biomass into fuels and chemicals. Most biomass contains significant amounts of fuel-bound nitrogen (FBN), which partially converts into ammonia (NH_3) and hydrogen cyanide (HCN) during gasification. These nitrogen compounds are problematic as they can lead to NO_X emissions or catalyst poisoning in downstream applications of syngas. FBN can convert to other products as well, including diatomic nitrogen (N_2), char-bound nitrogen (char-N), and tar-bound nitrogen (tar-N). Efforts to predict concentrations of NH_3 and HCN have been hindered by a lack of accurate, comprehensive measurements of nitrogen partitioning among gasification products. The present study gasified switchgrass under allothermal, short residence time conditions and measured NH_3, HCN, char-N, and tar-N as a function of temperature in the range of 650–850 °C with diatomic nitrogen determined by difference. It was found that a major portion of FBN was retained in the char and tar products. As temperature was increased, char and tar were consumed, releasing nitrogen as gaseous NH_3 and HCN. This increase in undesirable nitrogen compounds is contrary to the predictions of most gasification models, which overlook the presence of significant nitrogen in char and tar even if they include tar cracking and char gasification reactions. The results of this study demonstrate that gas-phase reactions alone are not sufficient to predict the fate of nitrogen during gasification. In order for modeling efforts to obtain more accurate

  3. Tar removal from biosyngas in the biomass gasification process. (Liquid + liquid) equilibrium {water + solvent (paraxylene and methyl hexadecanoate) + model molecules of tar (benzene, toluene, phenol)}

    International Nuclear Information System (INIS)

    Bassil, Georgio; Mokbel, Ilham; Abou Naccoul, Ramy; Stephan, Juliette; Jose, Jacques; Goutaudier, Christelle

    2012-01-01

    Highlights: ► (Liquid + liquid) equilibria at atmospheric pressure. ► Solubility of benzene (or toluene or phenol) in paraxylene at (303 to 343) K. ► Solubility of benzene (or toluene or phenol) in methyl palmitate or methyl hexadecanoate at (303 to 343) K. ► Correlation of LLE using NRTL model. - Abstract: Tar is generated in the process by the condensation of the gas resulting from biomass gasification. The objective of this work is a contribution to the database on thermodynamic quantity which will be useful at the operation of tar removal from aqueous medium. With this aim, (liquid + liquid) equilibrium of {water + solvent (paraxylene and methyl hexadecanoate) + model molecules of tar (benzene, toluene, phenol)} was studied at temperatures (303.2, 323.2, and 343.2) K. The data obtained were correlated with the non-random two-liquid (NRTL) model.

  4. Final Safety Assessment of Coal Tar as Used in Cosmetics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Coal Tar is a semisolid by-product obtained in the destructive distillation of bituminous coal, which functions in cosmetic products as a cosmetic biocide and denaturant-antidandruff agent is also listed as a function, but this is considered an over-the-counter (OTC) drug use. In 2002, Coal Tar was reported to the Food and Drug Administration (FDA) to be used in four formulations, all of which appear to be OTC drug products. Coal Tar is monographed by the FDA as Category I (safe and effective) OTC drug ingredient for use in the treatment of dandruff, seborrhoea, and psoriasis. Coal Tar is absorbed through the skin of animals and humans and is systemically distributed. Although the Cosmetic Ingredient Review (CIR) Expert Panel believes that Coal Tar use as an antidandruff ingredient in OTC drug preparations is adequately addressed by the FDA regulations, the Panel also believes that the appropriate concentration of use of Coal Tar in cosmetic formulations should be that level that does not have a biological effect in the user. Additional data needed to make a safety assessment include product types in which Coal Tar is used (other than as an OTC drug ingredient), use concentrations, and the maximum concentration that does not induce a biological effect in users.

  5. Physical and performance properties of coal tar urethanes - pipe

    International Nuclear Information System (INIS)

    Hickney, J.; Hendry, M.

    1984-01-01

    The purpose of this paper is to review certain physical properties of coal tar extended urethane coatings designed specifically for use in the pipe coatings market. The blend of coal tar and urethane resins provides a novel finished product with properties cumulatively inherent in its constituents. Typically, coal tar and coal tar pitch offer exceptional water resistance and cathodic alkali resistance when blended with other resins. An example is the standard coal tar epoxies used for many years in the marine markets for shipbottoms

  6. Modelling of thermal removal of tars in a high temperature stage fed by a plasma torch

    International Nuclear Information System (INIS)

    Fourcault, A.; Marias, F.; Michon, U.

    2010-01-01

    The thermal degradation of tars in a chamber fed by a non-transferred plasma torch is theoretically examined in this study. The input of this reactor is a product gas coming from a gasification unit with a temperature of about 800 o C. According to literature, naphthalene and toluene are chosen as model compounds to represent the behaviour of their classes. According to this choice and to the data available in the literature, a reaction pathway for the thermal degradation of tars and its associated kinetics are proposed in this study. This mechanism is introduced in a CSTR model in order to check the influence of the operating parameters of the reactor on the degradation efficiency. These computations clearly show that a complete conversion of toluene (>99.9%) and an important conversion of naphthalene (96.7%) can be reached in the reactor, with concentration levels compatible with the further use of gas engines for electricity production. This theoretical study requires to be validated by comparison with experimental results.

  7. Modelling of thermal removal of tars in a high temperature stage fed by a plasma torch

    Energy Technology Data Exchange (ETDEWEB)

    Fourcault, A. [Laboratoire Thermique Energetique et Procedes, LaTEP-ENSGTI, rue Jules Ferry, BP 7511, 64075 Pau Cedex (France); Europlasma, 21 rue Daugere, 33520 Bruges (France); Marias, F. [Laboratoire Thermique Energetique et Procedes, LaTEP-ENSGTI, rue Jules Ferry, BP 7511, 64075 Pau Cedex (France); Michon, U. [Europlasma, 21 rue Daugere, 33520 Bruges (France)

    2010-09-15

    The thermal degradation of tars in a chamber fed by a non-transferred plasma torch is theoretically examined in this study. The input of this reactor is a product gas coming from a gasification unit with a temperature of about 800 C. According to literature, naphthalene and toluene are chosen as model compounds to represent the behaviour of their classes. According to this choice and to the data available in the literature, a reaction pathway for the thermal degradation of tars and its associated kinetics are proposed in this study. This mechanism is introduced in a CSTR model in order to check the influence of the operating parameters of the reactor on the degradation efficiency. These computations clearly show that a complete conversion of toluene (>99.9%) and an important conversion of naphthalene (96.7%) can be reached in the reactor, with concentration levels compatible with the further use of gas engines for electricity production. This theoretical study requires to be validated by comparison with experimental results. (author)

  8. Coal tar phototherapy for psoriasis reevaluated: erythemogenic versus suberythemogenic ultraviolet with a tar extract in oil and crude coal tar

    International Nuclear Information System (INIS)

    Lowe, N.J.; Wortzman, M.S.; Breeding, J.; Koudsi, H.; Taylor, L.

    1983-01-01

    Recent studies have questioned the therapeutic value of coal tar versus ultraviolet (UV) radiation and their relative necessity in phototherapy for psoriasis. In this investigation, different aspects of tar phototherapy have been studied in single-blind bilateral paired comparison studies. The effects of 1% crude coal tar were compared with those of petrolatum in conjunction with erythemogenic and suberythemogenic doses of ultraviolet light (UVB) using a FS72 sunlamp tubed cabinet. Crude coal tar was clinically superior to petrolatum with suberythemogenic ultraviolet. With the erythemogenic UVB, petrolatum was equal in efficacy to crude coal tar. Suberythemogenic UVB was also used adjunctively to compare the effects of a 5% concentration of a tar extract in an oil base to 5% crude coal tar in petrolatum or the oil base without tar. The tar extract in oil plus suberythemogenic UVB produced significantly more rapid improvement than the oil base plus UVB. The direct bilateral comparison of equal concentrations of tar extract in oil base versus crude coal tar in petrolatum in a suberythemogenic UV photo regimen revealed no statistical differences between treatments. In a study comparing tar extract in oil and the oil base without ultraviolet radiation, the tar extract in oil side responded more rapidly

  9. BTX production by in-situ contact reforming of low-temperature tar from coal with zeolite-derived catalysts; Zeolite kei shokubai wo mochiita sekitan teion tar no sesshoku kaishitsu ni yoru BTX no seisei

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, T.; Fuda, K.; Murakami, K.; Kyo, M.; Hosoya, S.; Kobayashi, S. [Akita University, Akita (Japan). Mining College

    1996-10-28

    On BTX production process from low-temperature tar obtained by pyrolysis of coal, the effect of exchanged metallic species and reaction temperature were studied using metallic ion-exchanged Y-zeolite as catalyst. In experiment, three kinds of coals with different produced tar structures such as Taiheiyo and PSOC-830 sub-bituminous coals and Loy Yang brown coal were used. Y-zeolite ion-exchanged with metal chloride aqueous solution was used as catalyst. Zn{sup 2+}, Ni{sup 2+} and In{sup 3+} were used as metal ions to be exchanged. The experiment was conducted by heating a pyrolysis section up to 600{degree}C for one hour after preheating a contact reforming section up to a certain proper temperature. As a result, the Ni system catalyst was effective for BTX production from aromatic-abundant tar, while the Zn system one from lower aromatic tar. In general, relatively high yields of toluene and xylene were obtained at lower temperature, while those of benzene at higher temperature. 4 figs., 1 tab.

  10. The catalytic cracking mechanism of lignite pyrolysis char on tar

    International Nuclear Information System (INIS)

    Lei, Z.; Huibin, H.; Xiangling, S.; Zhenhua, M.; Lei, Z.

    2017-01-01

    The influence of different pyrolysis conditions for tar catalytic cracking will be analyzed according to the lignite pyrolysis char as catalyst on pyrolytic tar in this paper. The pyrolysis char what is the by-product of the cracking of coal has an abundant of pore structure and it has good catalytic activity. On this basis, making the modified catalyst when the pyrolysis char is activation and loads Fe by impregnation method. The cracking mechanism of lignite pyrolytic tar is explored by applying gas chromatograph to analyze splitting products of tar. The experimental results showed that: (1) The effect of tar cracking as the pyrolysis temperature, the heating rate, the volatilization of pyrolysis char and particle size increasing is better and better. The effect of the catalytic and cracking of lignite pyrolysis char in tar is best when the heating rate, the pyrolysis temperature, the volatiles of pyrolysis char, particle size is in specific conditions.(2) The activation of pyrolysis char can improve the catalytic effect of pyrolysis char on the tar cracking. But it reduces the effect of the tar cracking when the pyrolysis char is activation loading Fe. (author)

  11. A DEVICE AND METHOD FOR MEASURING TAR IN A TAR-ENVIRONMENT

    DEFF Research Database (Denmark)

    2017-01-01

    The present disclosure describes a device and corresponding method for measuring tar in a tar environment, e.g., a tar producing environment such as a stove or a combustion engine, based on UV absorption spectroscopy. A first measurement along an optical path in the tar environment is performed...

  12. Main component analysis of nuclear magnetic resonance /sup 1/H and /sup 13/C quantitative spectra of hydrogenation products of tars from Kansk-Achinsk Achinsk and Cheremkhovsk coals

    Energy Technology Data Exchange (ETDEWEB)

    Kushnarev, D.F.; Polonov, V.M.; Donskikh, V.I.; Rokhina, E.F.; Kalabin, G.A.

    1986-03-01

    Possibility is discussed of examining nuclear magnetic resonance /sup 1/H and /sup 13/C quantitative spectra of coal tar hydrogenation products using main component factorial analysis and applying special mathematical methods of processing experimental data. Nuclear magnetic resonance spectra of hydrogenation products of low temperature Cheremkhovsk coal carbonization tar and rapid pyrolysis Kansk-Achinsk coal tar were obtained on a WP-200SY (Bruker) spectrometer at 50.3 and 200.1 MHz, respectively. Data processing was carried out on an ODRA-1304 computer. Comparative correlation of parameters are given of tars and hydrogenation products which consist of hydrogenation of aromatic cycles and destruction of alkyl substituents, and factorial loads on structural parameters of tar hydrogenation products. 11 references.

  13. Evaluation of lignite tar

    Energy Technology Data Exchange (ETDEWEB)

    Gossedin, A

    1946-01-01

    Tar from the low-temperature (450/sup 0/) carbonization of lignite from Bouches-du-Rhone was hydrogenated in the presence of a catalyst based on MoS/sub 2/ with a 3:1 H:N mixture. Processing (at 470/sup 0/ and 400 atmospheres) for maximum production of gasoline yielded 86 wt % of a product of boiling 55 to 186/sup 0/ and motor octane number 75. An alternative is to hydrogenate with a view to producing solvents and lubricants. For this purpose the tar was separated by distillation (at 20 millimeters, cutting at 220/sup 0/) into two fractions of equal volume. On hydrogenation (at 300/sup 0/ and 400 atmospheres) the light part yields a gasoline H/sub 2/O-soluble cut, a highly aromatic solvent fraction, a heavier cut (280/sup 0/ to 320/sup 0/) suitable as a plasticizer, and a phenol fraction. The heavier part of the tar is hydrogenated (at 380/sup 0/ and 400 atmospheres) to give spindle oil and lubricating oil of medium eta (11.2 centistokes at 98.2/sup 0/), moderate eta index (64), good pour point (-7/sup 0/), and good oxidizing characteristics. The overall yield of products from the two portions is 86.9% (gasoline and solvent 32, light phenols 9.7, spindle oil 14.2, medium lubricating oil 25.7, wax, 5.3%).

  14. Modelling the low-tar BIG process; Modellering af low-tar BIG processen

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Lars Henrik

    2002-09-15

    This report describes the possibilities of integrating a biomass gasifier in a combined heat and power plant. The purpose of the study is, among others, to see if the gasification technology can challenge existing heat and power production methods. A research programme dealing with the construction of a low far gasifier (LT-BIG), which easily can be scaled to large gasification plants, is in progress. This report also contains a model formulation and implementation for this suggested low tar gasifier. All the models are created by the use of the energy simulation tool DNA. For some cases it has been necessary to develop new components or to alter existing components in DNA. Three different systems are considered; Gas Engine, Simple Cycle Gas Turbine and Combined Cycle. When biomass with and lower heating value of 19 MJ/kg and a moisture content of 50% is employed the subsequent results and designs are achieved: 1) The Engine plant utilizes the hot flue-gas to dry the biomass, but has difficulties taking advantage of the potential energy from the cooling of the syngas. An engine with a net electric efficiency of 40% at full load is computed to convert 38,5% of the energy content in the biomass to electricity. 2) The Simple Cycle Gas Turbine plant has good potential for integration with a gasifier. It dries the biomass by means of the flue-gas and recuperates the energy from the hot syngas to preheat the pressurised gas before it enters the combustion chamber. With an isentropic efficiency of 89% and a pressure ratio of 20, an electric efficiency of 38% is computed. 3) The Combined Cycle plant almost reach a computed efficiency of 45%. It utilises the cooling of the hot syngas to produce extra steam for the cycle, which results in a very steady efficiency, even when the moisture content of the fuel is changed. A grand parametric and sensitivity study of the LT-BIG model is carried out. The study includes estimates of the air demand for the gasifier and the partial

  15. Release of polyaromatic hydrocarbons from coal tar contaminated soils

    International Nuclear Information System (INIS)

    Priddy, N.D.; Lee, L.S.

    1996-01-01

    A variety of process wastes generated from manufactured gas production (MGP) have contaminated soils and groundwater at production and disposal sites. Coal tar, consisting of a complex mixture of hydrocarbons present as a nonaqueous phase liquid, makes up a large portion of MGP wastes. Of the compounds in coal tar, polyaromatic hydrocarbons (PAHs) are the major constituents of environmental concern due to their potential mutagenic and carcinogenic hazards. Characterization of the release of PAHs from the waste-soil matrix is essential to quantifying long-term environmental impacts in soils and groundwater. Currently, conservative estimates for the release of PAHs to the groundwater are made assuming equilibrium conditions and using relationships derived from artificially contaminated soils. Preliminary work suggests that aged coal tar contaminated soils have much lower rates of desorption and a greater affinity for retaining organic contaminants. To obtain better estimates of desorption rates, the release of PAHs from a coal tar soil was investigated using a flow-interruption, miscible displacement technique. Methanol/water solutions were employed to enhance PAH concentrations above limits of detection. For each methanol/water solution employed, a series of flow interrupts of varying times was invoked. Release rates from each methanol/water solution were estimated from the increase in concentration with duration of flow interruption. Aqueous-phase release rates were then estimated by extrapolation using a log-linear cosolvency model

  16. Process of transforming tars, etc

    Energy Technology Data Exchange (ETDEWEB)

    1929-04-11

    A process is described for treating tars obtained by carbonization, at high or low temperature, of coals, lignites, shales, and other carbonaceous materials or fractions of these tars, for obtaining products of greater value, consisting of polymerizing or saturating the unstable hydrocarbons in the presence of catalyzers by the progressing action particularly of halogenated metals, such as titanium tetrachloride, iron chloride, etc. and applying a known process of recovery, the disclosed process leading to an important reduction of final losses.

  17. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  18. ANALYSIS OF MEASURED AND MODELED SOLAR RADIATION AT THE TARS SOLAR HEATING PLANT IN DENMARK

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    , such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, Wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate...... collector field have been measured in Tars solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tars solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total......A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tars, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters...

  19. PFB air gasification of biomass. Investigation of product formation and problematic issues related to ammonia, tar and alkali

    Energy Technology Data Exchange (ETDEWEB)

    Padban, Nader

    2000-09-01

    Fluidised bed thermal gasification of biomass is an effective route that results in 100 % conversion of the fuel. In contrast to chemical, enzymatic or anaerobic methods of biomass treatment, the thermal conversion leaves no contaminated residue after the process. The product gas evolved within thermal conversion can be used in several applications such as: fuel for gas turbines, combustion engines and fuel cells, and raw material for production of chemicals and synthetic liquid fuels. This thesis treats a part of the experimental data from two different gasifiers: a 90 kW{sub th} pressurised fluidised bubbling bed gasifier at Lund University and a 18 MW{sub th} circulating fluidised bed gasifier integrated with gas turbine (IGCC) in Vaernamo. A series of parallel and consecutive chemical reactions is involved in thermal gasification, giving origin to formation of a variety of products. These products can be classified within three major groups: gases, tars and oils, and char. The proportion of these categories of species in the final product is a matter of the gasifier design and the process parameters. The thesis addresses the technical and theoretical aspects of the biomass thermochemical conversion and presents a new approach in describing the gasification reactions. There is an evidence of fuel effect on the characteristics of the final products: a mixture of plastic waste (polyethylene) and biomass results in higher concentration of linear hydrocarbons in the gas than gasification of pure biomass. Mixing the biomass with textile waste (containing aromatic structure) results in a high degree of formation of aromatic compounds and light tars. Three topic questions within biomass gasification, namely: tar, NO{sub x} and alkali are discussed in the thesis. The experimental results show that gasification at high ER or high temperature decreases the total amount of the tars and simultaneously reduces the contents of the oxygenated and alkyl-substituted poly

  20. Lab-scale pyrolysis of the Automotive Shredder Residue light fraction and characterization of tar and solid products.

    Science.gov (United States)

    Anzano, Manuela; Collina, Elena; Piccinelli, Elsa; Lasagni, Marina

    2017-06-01

    The general aim of this study is the recovery of Automotive Shredder Residue (ASR). The ASR light fraction, or car fluff, that was collected at an Italian shredding plant was pyrolysed at various temperatures (500-800°C) in a lab-scale reactor. The condensable gases (tar) and solid residue yields increased with decreasing temperature, and these products were characterized to suggest a potential use to reclaim them. The higher heating value (HHV) of tar was 34-37MJ/kg, which is comparable with those of fossil fuels. Furthermore, the ash content was low (0.06-4.98%). Thus, tar can be used as an alternative fuel. With this prospect, the concentrations of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in tar were determined. The toxicity of tar changes with temperature (1-5ng I-TEQ/g), and the PCDFs significantly contribute to tar toxicity, which was 75-100% with a maximum of 99.6% at 700°C. Regarding the characterization of the solid residue, the low HHV (2.4-3.3MJ/kg) does not make it suitable for energy recovery. Regarding material recovery, we considered its use as a filler in construction materials or a secondary source for metals. It shows a high metal concentration (280,000-395,000mg/kg), which is similar at different pyrolysis temperatures. At 500°C, polycyclic aromatic hydrocarbons (PAHs) were not detected in the solid residue, whereas the maximum total PAH concentration (19.41ng/g, 700°C) was lower than that in fly ash from MSWI. In conclusion, 500°C is a suitable pyrolysis temperature to obtain valuable tar and solid residue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Production of gas and volatile materials by distillation of tars, etc

    Energy Technology Data Exchange (ETDEWEB)

    Arson, M

    1860-04-25

    The principle of this production is in the treating of heavy oils with heat, their transformation occurring nearly completely by the action of this agent. The apparatus used consists of a retort of such a form that it has openings at the two ends immediately opposed to each other. One serves to introduce the oil and the other to remove the tar and gas produced. At the exit of the apparatus the gas passes into coolers like those used for coal gas.

  2. Coal tar in dermatology

    Energy Technology Data Exchange (ETDEWEB)

    Roelofzen, J.H.J.; Aben, K.K.H.; Van Der Valk, P.G.M.; Van Houtum, J.L.M.; Van De Kerkhof, P.C.M.; Kiemeney, L.A.L.M. [Radboud University Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Dermatology

    2007-07-01

    Coal tar is one of the oldest treatments for psoriasis and eczema. It has anti-inflammatory, antibacterial, antipruritic and antimitotic effects. The short-term side effects are folliculitis, irritation and contact allergy. Coal tar contains carcinogens. The carcinogenicity of coal tar has been shown in animal studies and studies in occupational settings. There is no clear evidence of an increased risk of skin tumors or internal tumors. Until now, most studies have been fairly small and they did not investigate the risk of coal tar alone, but the risk of coal tar combined with other therapies. New, well-designed, epidemiological studies are necessary to assess the risk of skin tumors and other malignancies after dermatological use of coal tar.

  3. Distillation of tar and tar fractions in the presence of surface-active coke

    Energy Technology Data Exchange (ETDEWEB)

    Jaeppelt, A; Klaus, J

    1943-01-01

    The tar obtained by low-temperature carbonization of Upper Silesian gas coke and fractions from this tar were distilled in the presence of different grades of coke dust with varying surface activity; the coke had been activated by steam in the course of its production by low-temperature carbonization. The surface activity of the coke dusts was measured by determining the heat of wetting with C/sub 6/H/sub 6/. Tar and coke dust, both anhydrous, were mixed in a kneading machine in such proportions that the capillaries of the dust were saturated and enough ''externally'' bound tar was present to permit briquetting. The briquets were distilled without cracking and with steam as heating medium. The yield and quality of the distillate depended on the magnitude of the internal surface of the coke dust used; a mixture of a very active coke from brown coal and tar yielded a distillate with Conradson carbon residue of 1.34 percent, asphalt content 6.1 percent and eta/sub 20/ 5.4/sup 0/ E. as compared with C residue of 10.95 percent, asphalt content 33.5 percent and eta/sub 20/ 123.6/sup 0/ E. of the distillate obtained in the absence of surface-active coke. Even higher-boiling fractions can be improved by this treatment, although it is preferable to use oils with an initial boiling point below 300/sup 0/. The ratio of oil to adsorbent is not critical, but better results were obtained with higher percentages of added coke dust. The process in its present form is not suited for the conversion of crude creosote to useful phenols.

  4. Mineral oils, tars. [British patent

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, A M; Handmarch, E

    1933-08-11

    Hydrocarbon materials such as mineral oils and tars from coal, shale, lignite, or peat are freed from phenols and like oxy-bodies by heating under pressure in a closed vessel to a temperature and for a time sufficient to effect reduction of the oxy-bodies, and then removing the water formed by the reaction. 350/sup 0/ to 400/sup 0/C. for 30 to 60 minutes is suitable. Any wax-like constituents are converted to liquids of lower viscosity and settling point. The product may be fractionated to give light oils and a residue of aviation Diesel fuel. In an example, oil from the low-temperature distillation of coal and having a tar acid content of 30 per cent is treated in a tubular converter at 380/sup 0/C. and 400 lb. per sq. in for 40 min., and the benzine toluol, and xylol distilled; the residue has a tar acid content of only 7.6 per cent.

  5. Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance.

    Directory of Open Access Journals (Sweden)

    Solmaz Sobhanifar

    2016-12-01

    Full Text Available In recent years, there has been a growing interest in teichoic acids as targets for antibiotic drug design against major clinical pathogens such as Staphylococcus aureus, reflecting the disquieting increase in antibiotic resistance and the historical success of bacterial cell wall components as drug targets. It is now becoming clear that β-O-GlcNAcylation of S. aureus wall teichoic acids plays a major role in both pathogenicity and antibiotic resistance. Here we present the first structure of S. aureus TarS, the enzyme responsible for polyribitol phosphate β-O-GlcNAcylation. Using a divide and conquer strategy, we obtained crystal structures of various TarS constructs, mapping high resolution overlapping N-terminal and C-terminal structures onto a lower resolution full-length structure that resulted in a high resolution view of the entire enzyme. Using the N-terminal structure that encapsulates the catalytic domain, we furthermore captured several snapshots of TarS, including the native structure, the UDP-GlcNAc donor complex, and the UDP product complex. These structures along with structure-guided mutants allowed us to elucidate various catalytic features and identify key active site residues and catalytic loop rearrangements that provide a valuable platform for anti-MRSA drug design. We furthermore observed for the first time the presence of a trimerization domain composed of stacked carbohydrate binding modules, commonly observed in starch active enzymes, but adapted here for a poly sugar-phosphate glycosyltransferase.

  6. Tar bases in low-temperature coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Sugiura, S; Ueno, H; Yokoyama, H

    1951-01-01

    Tar bases were extracted from three fractions, that boil below 260/sup 0/ at 260/sup 0/ to 280/sup 0/, and 280/sup 0/ to 330/sup 0/, respectively, of the low-temperature tar obtained by the carbonization of Ube coal in a Koppers' vertical retort at approximately 750/sup 0/. These were divided, respectively, into three groups, acetate-forming amine, HCl salt-forming bases (I), and CHCl/sub 3/-soluble bases (II), and further fractionally distilled. From the physical and chemical properties of the fractions thus obtained, it was concluded that low-temperature coal tar contained no low boiling pyridine homologues and that, besides higher homologues of pyridine, nonaromatic, more saturated, and less basic compounds of larger atomic weight and smaller refractive index, such as derivatives of pyrrole and indole, also existed as in crude petroleum.

  7. Contact sensitivity to newsprint: a rare manifestation of coal tar allergy

    Energy Technology Data Exchange (ETDEWEB)

    Illchyshyn, A; Cartwright, P H; Smith, A G

    1987-07-01

    Contact dermatitis due to coal tar is infrequently reported in spite of the fact that it consists of a mixture of 10,000 constituents, and is still often used to treat both eczema and psoriasis. Discusses patient with coal tar sensitivity in whom the source of exacerbation of her dermatitis is shown to be newsprint, a common product containing coal tar-derived material. 6 refs.

  8. Low-temperature tar and oil: properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Heinze, R

    1942-01-01

    In Germany the value of low-temperature tar is largely dependent on its fuel fractions; these vary with the coal and the method of carbonization (external heating or recirculated gases). Brown-coal tars can be processed by distillation, cracking under pressure, hydrogenation under pressure (largest volume of tar is processed by this method) and by solvent extraction, with EtOH, SO/sub 2/, or phenol. Each of these processes is discussed in detail. In the pressure-hydrogenation process, 1.25 kilogram of brown-coal tar yields approximately 1 kilogram of gasoline with an octane number of 60 to 70. Low-temperature tars from bituminous coals can be hydrogenated readily but are not well adapted to solvent extraction. Attempts should be made to produce tar approximating the desired characteristics for fuel directly from the carbonizing apparatus. For laboratory carbonization tests, an approximation to results secured by externally heated retorts is secured by using an insert consisting of a series of perforated trays in the 200-gram Fischer aluminum retort; this reduces the capacity to 100 gram. Fractional condensation is used to separate heavy oil, middle oil, and liquor; low-boiling products are condensed at -20/sup 0/ by solid CO/sub 2/.

  9. Analytical aspects of the remediation of soil by wet oxidation - Characterisation of tar contaminants and their degradation products

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Nielsen, T.; Plöger, A.

    1999-01-01

    Wet oxidation of tar compounds gives rise to a wide range of products. Due to the incorporation of oxygen, these products become increasingly more water soluble and the analytical strategy has to take into account the different physical/chemicalproperties of the compounds. An interplay between ga...

  10. Characterization of Tar Deposits, Extraction and Sorption Properties

    Directory of Open Access Journals (Sweden)

    Pryszcz Adrian

    2016-06-01

    Full Text Available The main goal of this paper was to characterize and find a useful solution for the decomposition of tar deposits. For the experimental part, tar deposits, formed by polymerization and condensation reactions, were chosen from a storage tank for tars. At first the initial analyses of tar deposits (elemental, thermogravimetric, and calorimetric analyses were performed. After the characterization, the tar deposits were extracted in the Soxhlet extractor by acetone, toluene, and quinolone and activated with potassium hydroxide. As the final step of this work, the sorption characterization on the 3Flex Surface Characterization Analyzer (Micromeritics was performed. The specific surface area of the samples was evaluated using two methods - a single point measurement at p/p0=0.2 and BET method. Micropore and external surface areas were calculated based on a t-plot analysis (carbon black model.

  11. Comprehensive database of Manufactured Gas Plant tars. Part C. Heterocyclic and hydroxylated polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatized post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatized samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 865 heterocyclic compounds and 359 hydroxylated polycyclic aromatic hydrocarbons (PAHs) were detected in 16 tar samples produced by five different processes. The contents of both heterocyclic and hydroxylated PAHs varied greatly with the production process used, with the heterocyclic compounds giving information about the feedstock used. Of the 359 hydroxylated PAHs detected the majority would not have been be detected without the use of derivatization. Coal tars produced using different production processes and feedstocks yielded tars with significantly different heterocyclic and hydroxylated contents. The concentrations of the individual heterocyclic compounds varied greatly even within the different production processes and provided information about the feedstock used to produce the tars. The hydroxylated PAH content of the samples provided important analytical information that would otherwise not have been obtained without the use of derivatization and GCxGC/TOFMS. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Process of treating tars

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, C; Hempel, H; Weissenburger, H

    1955-05-05

    A process is described for treating tars or tar oils, especially carbonization tars, characterized in that the tars or tar oils are mixed with benzene or light oils which contain no aromatic material or only slight amounts, or with gas oil in such amounts that the asphalt precipitates, and after separation of the precipitated material the mixture is treated with caustic solution for separation of the phenols, and after separation of the phenolate liquor the mixture is subjected to heating for removal of the dilution medium, then the remaining oil can be used as heating oil or it is submitted to distillation for the purpose of recovering a fuel suitable for diesel motors, while the phenolate liquor is worked up into phenols.

  13. UTILIZATION OF AQUEOUS-TAR CONDENSATES FORMED DURING GASIFICATION

    Directory of Open Access Journals (Sweden)

    Anna Kwiecińska

    2016-11-01

    Full Text Available Gasification of solid fuels is an alternative process for energy production using conventional and renewable fuels. Apart from desired compounds, i.e. carbon oxide, hydrogen and methane, the produced gas contains complex organic (tars and inorganic (carbonizate, ammonia contaminants. Those substances, together with water vapor, condensate during cooling of the process gas, what results in the formation of aqueous-tar condensate, which requires proper methods of utilization. The management of this stream is crucial for commercialization and application of the gasification technology. In the paper the treatment of aqueous-tar condensates formed during biomass gasification process is discussed. The removal of tars from the stream was based on their spontaneous separation. The aqueous stream was subjected to ultrafiltration operated at different pressures. Such a treatment configuration enabled to obtain highly concentrated retentate, which could be recycled to the gasifier, and filtrate, which could be subjected to further treatment.

  14. Analysis of low-temperature tar fractions

    Energy Technology Data Exchange (ETDEWEB)

    Kikkawa, S; Yamada, F

    1952-01-01

    A preliminary comparative study was made on the applicability of the methods commonly used for the type analysis of petroleum products to the low-temperature tar fractions. The usability of chromatography was also studied.

  15. Topical tar: Back to the future

    Energy Technology Data Exchange (ETDEWEB)

    Paghdal, K.V.; Schwartz, R.A. [University of Medicine & Dentistry of New Jersey, Newark, NJ (United States)

    2009-08-15

    The use of medicinal tar for dermatologic disorders dates back to the ancient times. Although coal tar is utilized more frequently in modern dermatology, wood tars have also been widely employed. Tar is used mainly in the treatment of chronic stable plaque psoriasis, scalp psoriasis, atopic dermatitis, and seborrheic dermatitis, either alone or in combination therapy with other medications, phototherapy, or both. Many modifications have been made to tar preparations to increase their acceptability, as some dislike its odor, messy application, and staining of clothing. One should consider a tried and true treatment with tar that has led to clearing of lesions and prolonged remission times. Occupational studies have demonstrated the carcinogenicity of tar; however, epidemiologic studies do not confirm similar outcomes when used topically. This article will review the pharmacology, formulations, efficacy, and adverse effects of crude coal tar and other tars in the treatment of selected dermatologic conditions.

  16. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18... (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes... coal tar hair dye containing any ingredient listed in paragraph (b) of this section shall bear, in...

  17. Removing tar information from cigarette packages may reduce South Korean smokers' misconceptions about low-tar cigarettes

    Directory of Open Access Journals (Sweden)

    Hye-Jin Paek

    2018-03-01

    Full Text Available Background Many smokers still have misconceptions about “light” or “low tar” cigarettes. In South Korea, low-tar (< 3 mg cigarette sales have increased sharply from 1.8% in 2002 to 49.2% in 2015. Although government regulations forbid cigarette packages from displaying messages such as “mild,” “low-tar,” and “light,” numbers indicating tar amounts are still permitted. This study examines whether removing tar information from packaging altogether reduces people's misconceptions about low tar cigarettes. Methods An online experiment was conducted among 531 smokers who were randomly assigned to one of two conditions. In the “tar” condition, 271 participants were shown in random order three cigarette packages for three major brands (Esse, The One, Marlboro with different tar amounts. In the “no-tar” condition, 260 participants were shown the same packages without tar information. Next, participants evaluated which type of cigarette was mildest, least harmful, easier for nonsmokers to start smoking, and easier for smokers to quit. After descriptive statistics were checked, twelve sets of chi-square tests were performed. Results Average age of the participants was 26.22 (14 - 62 years; 53.5% were male. All 12 chi-square tests were statistically significant. Participants in the tar condition judged the lowest-tar cigarette to be mildest, least harmful, easier to start, and easier to quit. In the no-tar condition, for the Korean brands Esse and The One, most respondents evaluated all cigarette types to be the same only for harm, ease of starting, and ease of quitting; for Marlboro, judgments were the same as those in the tar condition except that “easier to quit” was judged to be the same across the three types. Conclusions Banning tar information from cigarette packages may help reduce smokers' misconceptions about low-tar cigarettes. People have inconsistent judgments about differently packaged cigarettes when tar

  18. Distilling tar; distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Brash, P; Young, W

    1866-09-17

    The tarry residue, which separates on treating crude shale oil with sulfuric acid, is redistilled, in the manner described in Specification No. 1278, A.D. 1866, together with shale. Previous to the distillation, the acid is neutralized with lime, or may be separated by blowing steam into the tar and adding salt. The purified tar thus obtained is absorbed by ashes, or is mixed with lime or other alkaline matter, or the shale may be mixed with lime and distilled with the tar, which is allowed to flow over and through the shale during the process. The tar obtained in the purification of natural paraffin may be similarly utilized.

  19. Experimental comparison of biomass chars with other catalysts for tar reduction

    NARCIS (Netherlands)

    Abu El-Rub, Ziad; Bramer, Eduard A.; Brem, Gerrit

    2008-01-01

    In this paper the potential of using biomass char as a catalyst for tar reduction is discussed. Biomass char is compared with other known catalysts used for tar conversion. Model tar compounds, phenol and naphthalene, were used to test char and other catalysts. Tests were carried out in a fixed bed

  20. Pyrolysis of aseptic packages (tetrapak) in a laboratory screw type reactor and secondary thermal/catalytic tar decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Haydary, J., E-mail: juma.haydary@stuba.sk [Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava (Slovakia); Susa, D.; Dudáš, J. [Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava (Slovakia)

    2013-05-15

    Highlights: ► Pyrolysis of aseptic packages was carried out in a laboratory flow reactor. ► Distribution of tetrapak into the product yields was obtained. ► Composition of the pyrolysis products was estimated. ► Secondary thermal and catalytic decomposition of tars was studied. ► Two types of catalysts (dolomite and red clay marked AFRC) were used. - Abstract: Pyrolysis of aseptic packages (tetrapak cartons) in a laboratory apparatus using a flow screw type reactor and a secondary catalytic reactor for tar cracking was studied. The pyrolysis experiments were realized at temperatures ranging from 650 °C to 850 °C aimed at maximizing of the amount of the gas product and reducing its tar content. Distribution of tetrapak into the product yields at different conditions was obtained. The presence of H{sub 2}, CO, CH{sub 4}, CO{sub 2} and light hydrocarbons, HCx, in the gas product was observed. The Aluminum foil was easily separated from the solid product. The rest part of char was characterized by proximate and elemental analysis and calorimetric measurements. The total organic carbon in the tar product was estimated by elemental analysis of tars. Two types of catalysts (dolomite and red clay marked AFRC) were used for catalytic thermal tar decomposition. Three series of experiments (without catalyst in a secondary cracking reactor, with dolomite and with AFRC) at temperatures of 650, 700, 750, 800 and 850 °C were carried out. Both types of catalysts have significantly affected the content of tars and other components in pyrolytic gases. The effect of catalyst on the tetrapack distribution into the product yield on the composition of gas and on the total organic carbon in the tar product is presented in this work.

  1. Solid state 13 C NMR quantitative study of wood tar pitches

    International Nuclear Information System (INIS)

    Prauchner, Marcos Juliano; Pasa, Vanya Marcia Duarte; Menezes, Sonia Maria Cabral de

    1999-01-01

    In this work, solid-state 13 C NMR is used with other techniques to characterize Eucalyptus tar pitches and to follow their polymerization reactions. The pitches are the residues of distillation (about 50% m;m) of the tar generated in Eucalyptus slow pyrolysis for charcoal production in metal industry

  2. Low-temperature tar from bituminous coal and its further treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, C J

    1950-01-01

    High-temperature carbonization of bituminous coal yields only 3 to 4 percent tar, as compared with 8 to 10 percent or even more for low-temperature carbonization. The yield of phenols is 20 to 30 times as great from the low-temperature tar. Five conditions that must be met by a satisfactory low-temperature carbonization process are listed. The only method that satisfies all of these conditions is the Brennstoff-Technik (BT) process, in which iron retorts with movable walls are used. One disadvantage of most of the other processes is the high-pitch content of the tar. These tars are processed further to a neutral oil and a phenol-containing oil which are good diesel fuels with high-cetane numbers; the neutral oil can be fractionated to give oils of high-, medium-, and low-cetane number. Attempts to fractionate the tar oil by solvents have not proved commercially useful. However, the tar can be diluted with low-temperature light oil and phenols extracted with NaOH solution without distillation. Some difficulty is found, owing to the simultaneous extraction of viscous resins and other products that are readily removed from the phenols by distillation.

  3. Fresh tar (from biomass gasification) destruction with downstream catalysts: comparison of their intrinsic activity with a realistic kinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

    1996-12-31

    A model for fresh tar destruction over catalysts placed downstream a biomass gasifier is presented. It includes the stoichio-metry and the calculation of the kinetic constants for the tar destruction. Catalysts studied include commercial Ni steam reforming catalysts and calcinated dolomites. Kinetic constants for tar destruction are calculated for several particle sizes, times- on-stream and temperatures of the catalyst and equivalence ratios in the gasifier. Such intrinsic kinetic constants allow a rigorous or scientific comparison of solids and conditions to be used in an advanced gasification process. (orig.) 4 refs.

  4. Fresh tar (from biomass gasification) destruction with downstream catalysts: comparison of their intrinsic activity with a realistic kinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J; Narvaez, I; Orio, A [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

    1997-12-31

    A model for fresh tar destruction over catalysts placed downstream a biomass gasifier is presented. It includes the stoichio-metry and the calculation of the kinetic constants for the tar destruction. Catalysts studied include commercial Ni steam reforming catalysts and calcinated dolomites. Kinetic constants for tar destruction are calculated for several particle sizes, times- on-stream and temperatures of the catalyst and equivalence ratios in the gasifier. Such intrinsic kinetic constants allow a rigorous or scientific comparison of solids and conditions to be used in an advanced gasification process. (orig.) 4 refs.

  5. Technology unlocks tar sands energy

    Energy Technology Data Exchange (ETDEWEB)

    Law, C

    1967-09-25

    Tar sand processing technology has been developed primarily in the categories of extraction techniques and in-situ processing. In October, a $235 million venture into tar sand processing will be inspected by visitors from many points on the globe. A synthetic crude of premium quality will be flowing through a 16-in. pipeline from the Tar Island plant site of Great Canadian Oil Sands to Edmonton. This processing plant uses an extractive mining technique. The tar sand pay zone in this area averages approximately 150 ft in thickness with a 50-ft overburden. It has been estimated that the tar sands cannot be exploited when the formation thickness is less than 100 ft and overburden exceeds the same amount. This indicates that extraction techniques can only be used to recover approximately 15% of the tar sand deposits. An in-situ recovery technique developed by Shell of Canada is discussed in detail. In essence it is selective hydraulic fracturing, followed by the injection of emulsifying chemicals and steam.

  6. Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Wicakso, Doni Rahmat [Chemical Engineering Department, Faculty of Engineering, Lambung Mangkurat University, Jalan A. Yani KM. 36 Banjarbaru, 70714, South Kalimantan (Indonesia); Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Sutijan; Rochmadi [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Budiman, Arief, E-mail: abudiman@ugm.ac.id [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Center for Energy Studies, Gadjah Mada University, Sekip K1A, Yogyakarta, 55281 (Indonesia)

    2016-06-03

    Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 – 600 °C and catalyst weight between 0 – 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore pores to from gases, light hydrocarbon (bio-oil) and carbon, thus decreasing content tar in bio-oil and increasing the total gas product. In conclusion, the more low grade iron ore used as catalyst, the tar content in the liquid decrease, the H{sup 2} productivity increased and calorimetric value of bio-oil increased.

  7. Coliquefaction of coal, tar sand bitumen and plastic (interaction among coal, bitumen and plastic); Sekitan/tar sand bitumen/plastic no kyoekika ni okeru kyozon busshitsu no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H.; Okuyama, Y.; Matsubara, K. [NKK Corp., Tokyo (Japan); Kamo, T.; Sato, Y. [National Institute for Resources and Environment, Tsukuba (Japan)

    1996-10-28

    For the improvement of economy, coliquefaction of coal, tar sand bitumen and plastic was performed under low hydrogen pressure, to investigate the influence of interaction among these on the liquefaction characteristics. For comparison, coliquefaction was also performed under the hydrogen pressure same as the NEDOL process. In addition, for clarifying its reaction mechanism, coliquefaction of dibenzyl and plastic was performed as a model experiment, to illustrate the distribution of products and composition of oil, and to discuss the interaction between dibenzyl and various plastics, and between various plastics. Under direct coal liquefaction conditions, coprocessing of Tanito Harum coal, Athabasca tar sand and plastic was carried out under low hydrogen pressure with an autoclave. The observed value of oil yield was higher than the calculated value based on the values from separate liquefaction of coal and plastic, which suggested the interaction between coal and the mixed plastic. The results of coliquefaction of coal, tar sand bitumen and plastic could be explained from the obtained oil yield and its composition by the coliquefaction of dibenzyl and plastic. 2 refs., 3 tabs.

  8. Upgrading of hydropyrolysis coal tar by hydroprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Haglund, R.; Otterstedt, J.E.; Sterte, J. (Chalmers Univ. of Tech., Goeteborg (Sweden). 1. Dept. of Engineering Chemistry)

    1991-05-01

    Upgrading of a hydropyrolysis coal tar by hydroprocessing was investigated using different process conditions. The response of the hydropyrolysis tar to hydroprocessing was compared to those of a conventional coal tar and two heavy oil fractions. At comparable conditions, the removal of heteroatoms from the hydropyrolysis tar was more effective than from the conventional tar and, in particular, than from the oil fractions. Using conditions typical for hydroprocessing of heavy oil fractions, the contents of N, O as well as S in the hydropyrolysis tar were reduced by more than 90%. Hydroprocessing also resulted in a considerable increase in the gasoline fraction of the tar. (orig.).

  9. Tar analysis from biomass gasification by means of online fluorescence spectroscopy

    Science.gov (United States)

    Baumhakl, Christoph; Karellas, Sotirios

    2011-07-01

    Optical methods in gas analysis are very valuable mainly due to their non-intrusive character. That gives the possibility to use them for in-situ or online measurements with only optical intervention in the measurement volume. In processes like the gasification of biomass, it is of high importance to monitor the gas quality in order to use the product gas in proper machines for energy production following the restrictions in the gas composition but also improving its quality, which leads to high efficient systems. One of the main problems in the biomass gasification process is the formation of tars. These higher hydrocarbons can lead to problems in the operation of the energy system. Up to date, the state of the art method used widely for the determination of tars is a standardized offline measurement system, the so-called "Tar Protocol". The aim of this work is to describe an innovative, online, optical method for determining the tar content of the product gas by means of fluorescence spectroscopy. This method uses optical sources and detectors that can be found in the market at low cost and therefore it is very attractive, especially for industrial applications where cost efficiency followed by medium to high precision are of high importance.

  10. The Legend of Hot Tar or Pitch as a Defensive Weapon

    DEFF Research Database (Denmark)

    Atzbach, Rainer

    2015-01-01

    research. In reality, this way of fighting can only be seen as a legend, i.e. a story with only a relative truth at its core. This paper will examine the origin of this historical tradition and its archaeological and architectural sources. The chemical and physical properties of tar pitch and its...... production and use during the Middle Ages will be discussed with special focus on the application of tar pitch as an ingredient in medieval and post-medieval thermal weapons (especially Greek Fire, the firebomb and the fire arrow). The punishment of tarring and feathering will also be considered...

  11. Preparation of pure phenols from tars

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J

    1933-02-07

    A process is disclosed for the preparation of pure phenols from brown coal tar, shale tar, or primary tar, characterized in that the raw oil obtained from the tar is carefully fractionated, in a suitable way without or with a slight pressure decrease, or before the fractionation the raw oil is heated to free the prepared phenolate solution from impurities after successful oxidation by passing in steam at a temperature between 100 and 120/sup 0/C.

  12. Analysis of tars produced in biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.; Wang, Y.; Kinoshita, C.M. [Univ. of Hawaii, Honolulu, HI (United States)

    1993-12-31

    Parametric tests on tar formation, varying temperature, equivalence ratio, and residence time, are performed on a bench-scale, indirectly-heated fluidized bed gasifier. Prepared tar samples are analyzed in a gas chromatograph (GC) with a flame ionization detector, using a capillary column. Standards containing dominant tar species have been prepared for GC calibration. The identified peaks include single-ring hydrocarbons, such as benzene, to five-ring hydrocarbons, such as perylene; depending on the gasification conditions, the identified species represent about 70 to 90% (mass basis) of the tar constituents. Under all conditions tested, benzene and naphthalene were the most dominant species. Temperature and equivalence ratio have significant effect on tar yield and tar composition. Tar yield decreases with increasing temperature or equivalence ratio. The test results suggest that lower temperature favors the formation of more aromatic tar species with diversified substituent groups, while higher temperature favors the formation of fewer aromatic tar species without substituent groups. Higher temperature or equivalence ratio favors the formation of polyaromatic compounds. Oxygen-containing compounds exist in significant quantities only at temperature below 800{degrees}C and decrease with increasing temperature, equivalence ratio, or residence time.

  13. Determination of phenol in tar

    Energy Technology Data Exchange (ETDEWEB)

    Dierichs, A; Heinichen, G

    1955-01-01

    During low-temperature carbonization of lignite, the phenols and other oxygenated compounds appear both in the aqueous-process liquor and in the tar. Measurements of these oxygenated components resulting from low-temperature carbonization may serve as a parameter for the classification of lignites. However, such measurements are complicated by the instability of the tar and the complex nature of some of the acidic substances. Difficulties with the previous methods of analysis are reviewed. The present method outlines separation of aqueous-process liquor from lignite tar in a Fischer retort, followed by determination of phenols and fatty acids in the tar phase. The jacketed tar receiver is washed with 300 milliliter xylol and treated with aqueous caustic washes. Neutral oils are separated from the aqueous alkali solution. It is then extracted with ether and finally acidified with HCl. Solids are filtered off, and phenols and fatty acids are separated by Na/sub 2/CO/sub 3/ solution.

  14. Thermodynamic analysis of tar reforming through auto-thermal reforming process

    Energy Technology Data Exchange (ETDEWEB)

    Nurhadi, N., E-mail: nurhadi@tekmira.esdm.go.id; Diniyati, Dahlia; Efendi, M. Ade Andriansyah [R& D Centre for Mineral and Coal Technology, Jln. Jend.Sudirman no. 623, Bandung. Telp. 022-6030483 (Malaysia); Istadi, I. [Department of Chemical Engineering, Diponegoro University, Jln. Jl. Prof. Soedarto, SH, Semarang (Malaysia)

    2015-12-29

    Fixed bed gasification is a simple and suitable technology for small scale power generation. One of the disadvantages of this technology is producing tar. So far, tar is not utilized yet and being waste that should be treated into a more useful product. This paper presents a thermodynamic analysis of tar conversion into gas producer through non-catalytic auto-thermal reforming technology. Tar was converted into components, C, H, O, N and S, and then reacted with oxidant such as mixture of air or pure oxygen. Thus, this reaction occurred auto-thermally and reached chemical equilibrium. The sensitivity analysis resulted that the most promising process performance occurred at flow rate of air was reached 43% of stoichiometry while temperature of process is 1100°C, the addition of pure oxygen is 40% and preheating of oxidant flow is 250°C. The yield of the most promising process performance between 11.15-11.17 kmol/h and cold gas efficiency was between 73.8-73.9%.The results of this study indicated that thermodynamically the conversion of tar into producer gas through non-catalytic auto-thermal reformingis more promising.

  15. Heavy crude and tar sands - the long-term oil reserve

    Energy Technology Data Exchange (ETDEWEB)

    Barnea, J

    1984-10-01

    It appears that heavy crude and tar sands occur in many sedimentary areas, and estimates of known world-wide quantities exceed those known for conventional light crude resources. Although there are not precise figures available, production could be as high as three million barrels per day, with Venezuela, the US, and Canada the largest producers. There are different scales to measure the costs of production because of differences in the quality of various types of heavy crude and tar sands. Economic development of these resources should banish fears of oil scarcity in the foreseeable future. A center for information exchange through international meetings and publications is under development.

  16. Technological changes illustrated by the coal tar and tar dye industry; Die Wandlung der Technik am Beispiel der Steinkohlenteer- und Teerfarben-Chemie

    Energy Technology Data Exchange (ETDEWEB)

    Collin, G. [Deutsche Gesellschaft fuer Chemisches Apparatewesen, Chemische Technik und Biotechnologie e.V. (DECHEMA), Frankfurt am Main (Germany)

    2001-05-01

    Coal tar was detected in the 17th century in laboratory experiments based on empirical knowledge. In the 18th century industrial revolution, coal tar was an undesired by-product of iron production and coking plants. It was first used in the 19th century for impregnating railway sleepers. Later developments in atomic theory, new chemical symbols and organic element analysis provided the basis for discovering and chemical characterisation of coal tar constituents. Laboratory experiments with these tar constituents resulted in the first synthetic dyes, the postulation of tetravalent carbon and the resulting structural theory in organic chemistry for systematic synthesis of many tar dyes to substitute natural dyes in the textile industry. The technical application of these syntheses was part 2 of the industrial revolution and the foundation of the chemical industry in Germany, which developed rapidly in the 2nd half of the 19th century. Tar dye chemistry has made a significant contribution to Germany's economic growth and the change from an agricultural to an industrialized country. [German] Die Entdeckung des Steinkohlenteers im 17. Jahrhundert basiert auf durch Erfahrungswissen gepraegten Laboratoriumsexperimenten. Im Verlauf der 'Industriellen Revolution' des 18. Jahrhunderts ist der Steinkohlenteer zunaechst ein laestiges Abfallprodukt der Eisengewinnung im Kokshochofen und der Leuchtgasherstellung durch Kohlenverkokung. Erste technische Applikation finden Steinkohlenteeroele im 19. Jahrhundert durch den Eisenbahnbau zur Langzeit-Konservierung der dafuer benoetigten Holzschwellen. Die wissenschaftlichen Erfkenntnisse zur Atomtheorie, eine neue chemische Zeichensprache und die organische Elementaranalyse werden Voraussetzungen zur Entdeckung und chemischen Charakterisierung der Hauptinhaltsstoffe des Steinkohlenteers. Laboratoriumsexperimente mit den entdeckten Teerinhaltsstoffen fuehren zur Erfindung der ersten synthetischen Farbstoffe, die

  17. Dehydration of hydrated low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T

    1949-01-01

    Yoshida examined the mechanism of the dehydration of hydrated low-temperature tar with a microscope. The tar containing free carbon and coal dust is so stable that the removal of the above substances and water by a physical method is very difficult. Addition of light oil produced by fractionation of low-temperature tar facilitates the operations. Yoshida tried using the separate acid, neutral, and basic components of the light oil; the acid oil proved to be most effective. For many reasons it is convenient to use light oil as it is. In this method the quantity of light oil required is 2 to 3 times that of tar. But in supplementing the centrifugal method, the quantity of light oil needed might be only half the amount of tar.

  18. Receiving demulsifying agent from the acid tar

    Energy Technology Data Exchange (ETDEWEB)

    Nikitina, A.A.; Belyaeva, A.S.; Kunakova, R.V. [FGBIHE ' Ufa State Academy of Economics and Services' , Ufa (Russian Federation); Movsumzade, E.M. [FGBIHE ' Ufa State Petroleum Technological Univ.' , Ufa (Russian Federation); Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry

    2012-07-01

    The processing of wastes of petrochemical production makes it possible to reduce the price of produced commodity of petroleum products substantially. Bitumen, fuel oils, tars and other mixture of heavy organic compounds are widely used in road construction, in paint and cable industries, manufacture of roofing materials, are used as boiler and furnace fuel, fuel for marine diesel engines, raw material for the production of modifying additives, fillers, surfaceactive substances, etc. (orig.)

  19. Separating cresote from tars, mineral oils, etc

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, E

    1921-01-07

    Phenolic bodies are extracted from tars such as lignite, shale, peat, coal, producer and low temperature tars, and from tar distillates and residues and from mineral oils and distillates by washing with a mixture of acetone and water. Acetone extracts of the tars etc., may be mixed with water or aqueous acetone to cause the separation of the oils, while the creosote remains in solution.

  20. Carbon materials for syngas conditioning and tar removal

    International Nuclear Information System (INIS)

    Romero Millán, Lina María; Sierra Vargas, Fabio Emiro

    2017-01-01

    Within the framework of worldwide energy context, the development of technologies and processes for energy production form renewable and non-conventional sources is a priority. According to this, gasification is an interesting process that converts different kinds of organic materials in fuel gases. The main issue related with this process is the fact that the producer gas contains also contaminants and tars that are undesirable for the gas usage in internal combustion motors or turbines. The present work aims to analyze the actual state of the existing methods to remove tars form gasification fuel gases, emphasizing the use of different kinds of carbon materials. (author)

  1. Chemical and physical characteristics of tar samples from selected Manufactured Gas Plant (MGP) sites

    International Nuclear Information System (INIS)

    Ripp, J.; Taylor, B.; Mauro, D.; Young, M.

    1993-05-01

    A multiyear, multidisciplinary project concerning the toxicity of former Manufactured Gas Plant (MGP) tarry residues was initiated by EPRI under the Environmental Behavior of Organic Substances (EBOS) Program. This report concerns one portion of that work -- the collection and chemical characterization of tar samples from several former MGP sites. META Environmental, Inc. and Atlantic Environmental Services, Inc. were contracted by EPRI to collect several samples of tarry residues from former MGP sites with varied historical gas production processes and from several parts of the country. The eight tars collected during this program were physically very different. Some tars were fluid and easily pumped from existing wells, while other tars were thicker, semi-solid, or solid. Although care was taken to collect only tar, the nature of the residues at several sites made it impossible not to collect other material, such as soil, gravel, and plant matter. After the samples were collected, they were analyzed for 37 organic compounds, 8 metals, and cyanide. In addition, elemental analysis was performed on the tar samples for carbon, hydrogen, oxygen, sulfur and nitrogen content and several physical/chemical properties were determined for each tar. The tars were mixed together in different batches and distributed to researchers for use in animal toxicity studies. The results of this work show that, although the tars were produced from different processes and stored in different manners, they had some chemical similarities. All of the tars, with the exception of one unusual solid tar, contained similar relative abundances of polycyclic aromatic hydrocarbons (PAHs)

  2. Catalytic Pyrolysis of Tar Model Compound with Various Bio-Char Catalysts to Recycle Char from Biomass Pyrolysis

    Directory of Open Access Journals (Sweden)

    Jinmiao Liu

    2016-03-01

    Full Text Available Tar and char can be regarded as unwanted byproducts during the gasification process. In this study, three types of catalyst, i.e., biomass char (bio-char, nickel supported on biomass (Ni+bio-char, and nickel supported on bio-char (bio-char+Ni, were studied to compare the catalytic effects of different preparation methods on tar model compound removal. The structural characteristics of the three catalysts were also investigated by X-ray diffraction (XRD, scanning electron microscopy (SEM, and Brunauer-Emmett-Teller (BET methods. The results revealed that Ni+bio-char catalyst showed much higher activity for the reformation of toluene (C7H8 as a tar model compound than the other two catalysts. Toluene could be completely converted to small gas molecules at a conversion rate of 99.92% at 800 °C, and the maximum yield of gas was 432 mL/(mL C7H8. In particular, the H2 and CH4 yields were 339 and 85 mL/(mL C7H8 at 850 °C, respectively. An N2 absorption-desorption experiment demonstrated that the specific surface area of Ni+bio-char was 32.87 times that of bio-char and 8.39 times that of bio-char+Ni. Moreover, metallic nickel (Ni0 particles could be generated in the carbon matrix of Ni+bio-char catalyst. SEM analysis confirmed that the Ni+bio-char catalyst had a more porous structure. Nickel supported on biomass might be a promising catalyst for tar reformation because of its excellent catalytic activities.

  3. Effect of the rate of heating on the quality of the primary tar in low-temperature coal-carbonization process

    Energy Technology Data Exchange (ETDEWEB)

    Turskii, Y I

    1956-01-01

    Two stages are observed. The first stage yields products of the primary and partial decomposition of coal, mainly water, CO/sub 2/, and CO as decomposition products of functional groups (-COOH, > CO, - OH, and so forth). No tar is formed in this stage. The structural decomposition and tar formation occur in the second stage. The rate of heating is important for the quality of the tar obtained. The slow rate of heating with both stages following each other yields a good-quality tar, richer in C and H, with lower O content. In case of high rate of heating both stages overlap. The tar is of poorer quality with higher specific gravity, and contains more O and asphaltenes. The complete experimental data are given in detail.

  4. Bioremediation potential of coal-tar-oil-contaminated soil

    International Nuclear Information System (INIS)

    Lajoie, C.A.

    1991-01-01

    The bioremediation of coal tar oil contaminated soil was investigated in 90 day laboratory simulation experiments. The effect of soil moisture, humic acid amendment, and coal tar oil concentration on the rate of disappearance of individual coal tar oil constituents (PAHs and related compounds) was determined by methylene chloride extraction and gas chromatography. Mass balance experiments determined the fate of both the individual 14 C-labeled PAHs phenanthrene, pyrene, and benzo(a)pyrene, and the total coal tar oil carbon. Mineralization, volatilization, incorporation into microbial biomass, disappearance of individual coal tar oil constitutents, and the distribution of residual 14 C-activity in different soil fractions were measured. The rate of disappearance of coal tar oil constituents increased with increasing soil moisture over the experimental range. Humic acid amendment initially enhanced the rate of disappearance, but decreased the extent of disappearance. The amount of contamination removed decreased at higher coal tar oil concentrations. The practical limit for biodegradation in the system tested appeared to be between 1.0 and 2.5% coal tar oil. Mineralization accounted for 40 to 50% of the applied coal tar oil. Volatilization was a minor pathway of disappearance

  5. In situ recovery of oil from Utah tar sand: a summary of tar sand research at the Laramie Energy Technology Center

    Energy Technology Data Exchange (ETDEWEB)

    Marchant, L.C.; Westhoff, J.D.

    1985-10-01

    This report describes work done by the United States Department of Energy's Laramie Energy Technology Center from 1971 through 1982 to develop technology for future recovery of oil from US tar sands. Work was concentrated on major US tar sand deposits that are found in Utah. Major objectives of the program were as follows: determine the feasibility of in situ recovery methods applied to tar sand deposits; and establish a system for classifying tar sand deposits relative to those characteristics that would affect the design and operation of various in situ recovery processes. Contents of this report include: (1) characterization of Utah tar sand; (2) laboratory extraction studies relative to Utah tar sand in situ methods; (3) geological site evaluation; (4) environmental assessments and water availability; (5) reverse combustion field experiment, TS-1C; (6) a reverse combustion followed by forward combustion field experiment, TS-2C; (7) tar sand permeability enhancement studies; (8) two-well steam injection experiment; (9) in situ steam-flood experiment, TS-1S; (10) design of a tar sand field experiment for air-stream co-injection, TS-4; (11) wastewater treatment and oil analyses; (12) economic evaluation of an in situ tar sand recovery process; and (13) appendix I (extraction studies involving Utah tar sands, surface methods). 70 figs., 68 tabs.

  6. Experimental and theoretical evaluation of the performance of a tar solar water heater

    International Nuclear Information System (INIS)

    Ammari, H.D.; Nimir, Y.L.

    2003-01-01

    The paper presents an experimental and theoretical evaluation of the performance of a tar solar water heater and comparison with that of a conventional type collector. The performance of both collectors is assessed under the same conditions. Both of the collectors have the same surface area and are glazed. The conventional type has the water tubes welded to the absorber plate, whereas in the tar type, the tar acts as an absorber plate that covers the water tubes. The theoretical model for each collector type, with the transient effects taken into account, is based on a control volume and a time base in the related energy equations. By considering a small element of the collector in each case, three partial differential equations were developed for each collector and were solved numerically by the Runge-Kutta method of the fifth order. A good agreement was achieved between the numerical and experimental results for both the conventional and tar collectors, indicating the feasibility of employing the theoretical model in the design of flat plate solar collectors. The results also showed that the conventional collector is more efficient than the tar type during most of the daylight, but the tar collector had the added advantage of better conservation of energy in late afternoon and evening

  7. Monitoring of tar contents in gases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Finn [ChimneyLab Europe ApS, Hadsten (Denmark); Houmann Jakobsen, H. [BioSynergi Proces ApS, Hoersholm (Denmark)

    2012-08-15

    The purpose of this project is to develop and test a relative cheap and simple online tar measuring method, which can monitor the tar content in product gas from thermal gasification. The measuring principle is absorption of tar from sample gas in Isopropanol (IPA), and measuring on this solution by UV-spectrophotometer. Continuous sampling of tar containing producer gas turned out to be a larger problem than earlier foreseen. The best solution was decided to be sampling with higher flows, and afterwards cleaning the IPA in activated carbon. The ambitions for continuous sampling had to be decreased to 1 week, where the IPA and the activated carbon is contaminated by tar and has to be replaced. However this requires larger amounts of IPA and activated carbon. For IPA the weekly consumption was 12-15 Litres and for activated carbon 10 Litres. The whole analyzer unit turned out to be more complex than first projected, mainly because of the increased amounts of IPA. The best mist filter, with respect to pressure drop, efficiency and retention time is a combination of glass wool and quarts wool. The unit has been tested on gas; 20 kW pellets burner for 116 hours. Harbooere updraft gasifier for 519 hours. Skive fluid bed gasifier for 879 hours. There have during the project period been several simple practical problems such as bubbles in the IPA, increasing pressure drop over the activated carbon bed, dropout of UV data acquisition program and increasing baseline. The principle showed from the beginning some good results, with the limitation of 1 week continuous operation, but at the 5. period in Skive the baseline was increasing all the time, and it was not possible to solve this problem. (LN)

  8. Deciphering structure-activity relationships in a series of Tat/TAR inhibitors.

    Science.gov (United States)

    Pascale, Lise; González, Alejandro López; Di Giorgio, Audrey; Gaysinski, Marc; Teixido Closa, Jordi; Tejedor, Roger Estrada; Azoulay, Stéphane; Patino, Nadia

    2016-11-01

    A series of pentameric "Polyamide Amino Acids" (PAAs) compounds derived from the same trimeric precursor have been synthesized and investigated as HIV TAR RNA ligands, in the absence and in the presence of a Tat fragment. All PAAs bind TAR with similar sub-micromolar affinities but their ability to compete efficiently with the Tat fragment strongly differs, IC50 ranging from 35 nM to >2 μM. While NMR and CD studies reveal that all PAA interact with TAR at the same site and induce globally the same RNA conformational change upon binding, a comparative thermodynamic study of PAA/TAR equilibria highlights distinct TAR binding modes for Tat competitor and non-competitor PAAs. This led us to suggest two distinct interaction modes that have been further validated by molecular modeling studies. While the binding of Tat competitor PAAs induces a contraction at the TAR bulge region, the binding of non-competitor ones widens it. This could account for the distinct PAA ability to compete with Tat fragment. Our work illustrates how comparative thermodynamic studies of a series of RNA ligands of same chemical family are of value for understanding their binding modes and for rationalizing structure-activity relationships.

  9. Coal tar: past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Thami, G.P.; Sarkar, R. [Government Medical College & Hospital, Chandigarh (India). Dept. of Dermatology & Venerology

    2002-03-01

    Crude coal tar has been used in the treatment of dermatoses for many decades. In the last few years its use has been limited to skin diseases such as psoriasis and chronic dermatitis. Newer topical modalities for psoriasis are being used increasingly for treatment, but have failed to replace crude coal tar as a first-line treatment of psoriasis. The authors review the pharmacology, chemistry and use of crude coal tar in order to reappraise its role as a therapeutic agent in dermatology.

  10. A review of the primary measures for tar elimination in biomass gasification processes

    International Nuclear Information System (INIS)

    Devi, Lopamudra; Ptasinski, K.J.; Janssen, F.J.J.G.

    2003-01-01

    Tar formation is one of the major problems to deal with during biomass gasification. Tar condenses at reduced temperature, thus blocking and fouling process equipments such as engines and turbines. Considerable efforts have been directed on tar removal from fuel gas. Tar removal technologies can broadly be divided into two approaches; hot gas cleaning after the gasifier (secondary methods), and treatments inside the gasifier (primary methods). Although secondary methods are proven to be effective, treatments inside the gasifier are gaining much attention as these may eliminate the need for downstream cleanup. In primary treatment, the gasifier is optimized to produce a fuel gas with minimum tar concentration. The different approaches of primary treatment are (a) proper selection of operating parameters, (b) use of bed additive/catalyst, and (c) gasifier modifications. The operating parameters such as temperature, gasifying agent, equivalence ratio, residence time, etc. play an important role in formation and decomposition of tar. There is a potential of using some active bed additives such as dolomite, olivine, char, etc. inside the gasifier. Ni-based catalyst are reported to be very effective not only for tar reduction, but also for decreasing the amount of nitrogenous compounds such as ammonia. Also, reactor modification can improve the quality of the product gas. The concepts of two-stage gasification and secondary air injection in the gasifier are of prime importance. Some aspects of primary methods and the research and development in this area are reviewed and cited in the present paper

  11. Flash hydropyrolysis of bituminous coal . III. Research on flash hydropyrolysis tar

    Energy Technology Data Exchange (ETDEWEB)

    Dong, M.; Zhu, Z.; He, Y.; Ding, N.; Tang, L. [East China University of Science and Technology, Shanghai (China)

    2000-02-01

    Tar sample obtained by flash hydropyrolysis (FHP) from Dongshen coal at high pressure entrained reactor was investigated. An effect of flash hydropyrolysis temperature on the main components in tar was studied and the quality of the tar was compared with high temperature coke oven tar. The results showed that: the yields of liquid hydrocarbon in FHP tar were more than 15%, which is twofold of that in coke oven tar; the FHP tar has high oil fraction and low pitch; high phenol components and pure condensed polycyclic aromatic hydrocarbon, and low aliphatic hydrocarbon. The components of the FHP tar were simpler than that of high temperature coke oven tar. Therefore, FHP has improved the quantity and quality of tar. 11 refs., 3 figs., 5 tabs.

  12. Research and information needs for management of tar sands development. Interim report Apr-May 83

    Energy Technology Data Exchange (ETDEWEB)

    1983-05-01

    The report discusses important research and information needs for federal lease management of lands with tar sands resources. Short-term needs include more complete definition and characterization of deposits, hydrology, and regions downwind from tar sands areas. Longer-term needs include demonstration-scale operations to resolve production, waste management, and reclamation problems and to provide opportunities for measurement, analysis, and assessment of mining and processing wastes and emissions. Most of the known federal tar sands resource is in eastern Utah and contains about 25 billion barrels of bitumen. Recent legislation provides that existing mining claims and oil and gas leases may be converted to combined hydrocarbon leases including tar sands. Federal approval, which must be applied for by November 1983, is a condition for conversion.

  13. Steam reforming of different biomass tar model compounds over Ni/Al_2O_3 catalysts

    International Nuclear Information System (INIS)

    Artetxe, Maite; Alvarez, Jon; Nahil, Mohamad A.; Olazar, Martin; Williams, Paul T.

    2017-01-01

    Highlights: • Order of reactivity: anisole > furfural > indene > phenol > toluene > methyl naphthalene. • Higher coke deposition for oxygenates (1.5–2.8%) than for aromatics (0.5–0.8%). • Amorphous coke is deposited for oxygenates and filamentous carbon for aromatics. • Ni content of 20 wt.% shows the higher conversion (90%) and H_2 potential (63%). - Abstract: This work focuses on the removal of the tar derived from biomass gasification by catalytic steam reforming on Ni/Al_2O_3 catalysts. Different tar model compounds (phenol, toluene, methyl naphthalene, indene, anisole and furfural) were individually steam reformed (after dissolving each one in methanol), as well as a mixture of all of them, at 700 °C under a steam/carbon (S/C) ratio of 3 and 60 min on stream. The highest conversions and H_2 potential were attained for anisole and furfural, while methyl naphthalene presented the lowest reactivity. Nevertheless, the higher reactivity of oxygenates compared to aromatic hydrocarbons promoted carbon deposition on the catalyst (in the 1.5–2.8 wt.% range). When the concentration of methanol is decreased in the feedstock and that of toluene or anisole is increased, the selectivity to CO is favoured in the gaseous products, thus increasing coke deposition on the catalyst and decreasing catalyst activity for the steam reforming reaction. Moreover, an increase in Ni loading in the catalyst from 5 to 20% enhances carbon conversion and H_2 formation in the steam reforming of a mixture of all the model compounds studied, but these values decrease for a Ni content of 40%. Coke formation also increased by increasing Ni loading, attaining its maximum value for 40% Ni (6.5 wt.%).

  14. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  15. Characterization of acid tar waste from benzol purification | Danha ...

    African Journals Online (AJOL)

    The use of concentrated sulphuric acid to purify benzene, toluene and xylene produces acidic waste known as acid tar. The characterization of the acid tar to determine the composition and physical properties to device a way to use the waste was done. There were three acid tars two from benzene (B acid tar), toluene and ...

  16. A source mixing model to apportion PAHs from coal tar and asphalt binders in street pavements and urban aquatic sediments

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, M.J.; Depree, C.V. [National Institute of Water & Atmospheric Research, Hamilton (New Zealand)

    2010-12-15

    Present-day and more than 30 years old road and footpath pavements from Auckland, New Zealand were analysed for PAHs to test the hypothesis that coal tar based pavement binders contribute to unusually high PAH concentrations in adjacent stream and estuarine sediments Total PAH ({Sigma}{sub 28}PAH) concentrations in the dichloromethane-soluble fraction ('binder'), comprising 5-10% of pavement mass, were as high as 200 000 mg kg{sup -1}(10 000 mg kg{sup -1} in binder + aggregate) Older and deeper pavement layers were strongly pyrogenic, whereas pavement layers from recently sealed roads had a more petrogenic composition and more than 1000 times lower Sigma(28)PAH concentrations. Source identification analysis using three PAH isomer ratio pairs (benz(a)anthracene/(benz(a)anthracene + chrysene), benzo(a)pyrene/(benzo(a)pyrene + benzo(e)pyrene)), and indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene) revealed low PAH (bitumen) pavements to have consistently lower isomer ratios than high PAH (coal tar) samples. A concentration-weighted mixing model, with coal tar and bitumen as source materials, explained more than 80% of the variance in isomer ratios and enveloped the entire PAH compositional and concentration range encountered PAH composition and concentrations in adjacent stream sediments ({gt} 15 mg kg{sup -1} dry weight) were consistent with diluted coal tar material as a principal PAH source. Due to the very high PAH concentrations of coal tar, a coal tar content of as little as 0.01% of total sediment mass can account for more than 90% of PAH concentrations in adjacent stream sediments.

  17. The temporal relationship between advertising and sales of low-tar cigarettes.

    Science.gov (United States)

    Reed, Mark B; Anderson, Christy M; Burns, David M

    2006-12-01

    To determine whether a temporal relationship exists between the advertising and sales of low-tar cigarettes. It was hypothesised that increases in the advertising of low-tar cigarettes would precede increases in sales for these cigarettes. The themes of cigarette advertisements were reviewed and coded for 20 low-tar cigarette brands advertised in 13 widely read magazines in the US between 1960 and 1996. These 20 brands represented most of the low-tar cigarette advertisements and cigarette sales from 1967 to 1996. Cigarette sales data were obtained from the 1994 Maxwell report that summarises all cigarette sales from 1925 to 1990. If the advertisement referred to the low-tar attributes of the cigarette advertised, the advertisement was coded as having a low-tar theme and was included in the analysis. Five different graphical presentations of the relationship between the advertising and sales of the 20 low-tar cigarette brands showed a temporal relationship between low-tar advertising and sales for these brands. This relationship was observed for brands that introduced a low-tar alternative into an existing brand family (eg, Marlboro Light) and for new exclusively low-tar brands (eg, Carlton). Despite large increases in the advertising for the exclusively low-tar brands, sales of these brands remained low relative to sales of the low-tar alternative brands. Increases in print advertising of 20 of the most popular low-tar cigarette brands were followed by increases in sales for these cigarettes. Despite increases in the advertising of exclusively low-tar brands in the mid-1970s and early 1980s, the sales of these brands never matched the sales of the low-tar alternative brands. This suggests that it may have been easier to get smokers to switch to low-tar brands within a brand family compared with entirely new low-tar brands. Over the past 30 years, the marketing of low-tar cigarettes as a healthier alternative to higher-tar cigarettes has resulted in these brands

  18. Influence of cigarette filter ventilation on smokers' mouth level exposure to tar and nicotine.

    Science.gov (United States)

    Caraway, John W; Ashley, Madeleine; Bowman, Sheri A; Chen, Peter; Errington, Graham; Prasad, Krishna; Nelson, Paul R; Shepperd, Christopher J; Fearon, Ian M

    2017-12-01

    Cigarette filter ventilation allows air to be drawn into the filter, diluting the cigarette smoke. Although machine smoking reveals that toxicant yields are reduced, it does not predict human yields. The objective of this study was to investigate the relationship between cigarette filter ventilation and mouth level exposure (MLE) to tar and nicotine in cigarette smokers. We collated and reviewed data from 11 studies across 9 countries, in studies performed between 2005 and 2013 which contained data on MLE from 156 products with filter ventilation between 0% and 87%. MLE among 7534 participants to tar and nicotine was estimated using the part-filter analysis method from spent filter tips. For each of the countries, MLE to tar and nicotine tended to decrease as filter ventilation increased. Across countries, per-cigarette MLE to tar and nicotine decreased as filter ventilation increased from 0% to 87%. Daily MLE to tar and nicotine also decreased across the range of increasing filter ventilation. These data suggest that on average smokers of highly ventilated cigarettes are exposed to lower amounts of nicotine and tar per cigarette and per day than smokers of cigarettes with lower levels of ventilation. Copyright © 2017 British American Tobacco. Published by Elsevier Inc. All rights reserved.

  19. The temporal relationship between advertising and sales of low‐tar cigarettes

    Science.gov (United States)

    Reed, Mark B; Anderson, Christy M; Burns, David M

    2006-01-01

    Objective and hypothesis To determine whether a temporal relationship exists between the advertising and sales of low‐tar cigarettes. It was hypothesised that increases in the advertising of low‐tar cigarettes would precede increases in sales for these cigarettes. Methods The themes of cigarette advertisements were reviewed and coded for 20 low‐tar cigarette brands advertised in 13 widely read magazines in the US between 1960 and 1996. These 20 brands represented most of the low‐tar cigarette advertisements and cigarette sales from 1967 to 1996. Cigarette sales data were obtained from the 1994 Maxwell report that summarises all cigarette sales from 1925 to 1990. If the advertisement referred to the low‐tar attributes of the cigarette advertised, the advertisement was coded as having a low‐tar theme and was included in the analysis. Results Five different graphical presentations of the relationship between the advertising and sales of the 20 low‐tar cigarette brands showed a temporal relationship between low‐tar advertising and sales for these brands. This relationship was observed for brands that introduced a low‐tar alternative into an existing brand family (eg, Marlboro Light) and for new exclusively low‐tar brands (eg, Carlton). Despite large increases in the advertising for the exclusively low‐tar brands, sales of these brands remained low relative to sales of the low‐tar alternative brands. Conclusions Increases in print advertising of 20 of the most popular low‐tar cigarette brands were followed by increases in sales for these cigarettes. Despite increases in the advertising of exclusively low‐tar brands in the mid‐1970s and early 1980s, the sales of these brands never matched the sales of the low‐tar alternative brands. This suggests that it may have been easier to get smokers to switch to low‐tar brands within a brand family compared with entirely new low‐tar brands. Over the past 30 years, the marketing of low‐tar

  20. Brown carbon in tar balls from smoldering biomass combustion

    Science.gov (United States)

    R. K. Chakrabarty; H. Moosmuller; L.-W. A. Chen; K. Lewis; W. P. Arnott; C. Mazzoleni; M. K. Dubey; C. E. Wold; W. M. Hao; S. M. Kreidenweis

    2010-01-01

    We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Angstrom coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent...

  1. Chemical modification of a bitumen and its non-fuel uses. [Reactions of tar sand asphaltenes in synthesis of non-fuel products

    Energy Technology Data Exchange (ETDEWEB)

    Moschopedis, S.E.; Speight, J.G.

    1974-01-01

    Simple reactions are described whereby tar sand bitumen can be converted to a whole range of materials. Examples are given to illustrate the non-fuel uses of the products. The following reactions of Athabasca asphaltenes are considered: oxidation, halogenation, sulfonation and sulfomethylation, phosphorylation, hydrogenation, reactions with S and O, reactions with metal salts, and miscellaneous chemical conversions. (JGB)

  2. Tar sands showdown : Canada and the new politics of oil in an age of climate change

    International Nuclear Information System (INIS)

    Clarke, T.

    2009-01-01

    This book outlined the social and environmental issues facing the oil sands industry in Canada, including economic sovereignty, energy security, water rights and free trade. The tar sands have become vital to the Canadian economy, as they have the potential to increase Canada's foreign oil output by 4 to 5 times in the next 15 years. The author discussed the ecological and social impact of the Alberta tar sands and the real cost of development to Albertans and Canadians. Tar sands oil production generates more than 3 times the amount of greenhouse gas emissions than conventional oil production. The industry is also becoming a prime example of the abuse of water sources. The author emphasized the need to build an alternative energy future in an age of global warming. The main objective of this book was to help stimulate a nation-wide public debate about the tar sands and the critical issues at stake regarding Canada's energy future and an environmental strategy for more sustainable development. refs., tabs., figs.

  3. Tar Removal from Biomass Producer Gas by Using Biochar

    DEFF Research Database (Denmark)

    Ravenni, Giulia; Henriksen, Ulrik Birk; Ahrenfeldt, Jesper

    2017-01-01

    The biomass-derived char (biochar) produced in the gasifier as a residue, is a potential solution for removing tars from producer gas. This work investigates the interaction between tar compounds and biochar. Residual biochar from a TwoStage gasifier was tested as bed material in a laboratory setup....... Phenol and naphthalene were chosen as model tars, and entrained in a nitrogen flow. The gaseous stream was sampled before and after the biochar bed to evaluate the extent of conversion. The biochar bed (30g) was tested at 250°C, 500°C and 600°C, with for 3 consecutive hours. The compounds concentration...... in the gas phase was quantified by stable isotope dilution analysis, using Gas Chromatography-Mass Spectrometry (GC-MS). Results showed a significant effect of biochar on the removal of phenol, at all temperatures. Naphthalene was removed less efficiently at higher temperature, and this trend was even more...

  4. Ukrainian brown-coal tars recovered at low-temperature carbonization with solid heating medium

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, V I; Govorova, R P; Fadeicheva, A G; Kigel, T B; Chernykh, M K

    1955-01-01

    Three samples of tar were recovered in the laboratory from brown coals carbonized at 375/sup 0/ to 456/sup 0/ +- 25/sup 0/ in a retort with inner heating by solid circulating medium, namely, semicoke (ratio: 4 or 3:1) first heated to 700/sup 0/. One comparative (parallel) experiment was carried out in a retort with inner heating by inert gases entering the retort at 580/sup 0/ to 600/sup 0/ and leaving it at 115/sup 0/ to 120/sup 0/. The tars that were recovered from the retort with the solid heating medium contained a high percentage of coal dust and moisture, which were separated from the tars in supercentrifuges (15,000 rpm). Four samples of cleaned tars were fractionated in a Cu flask with a 2-ball fractional column. The tars from the retort with the solid-heating medium are characterized by increased yield of the petroleum-ether fraction (16.3 or 19.3%) and decreased yield of the paraffin fraction (15.1 to 21.2%) in comparison with those of tar from the retort with gas heating (5.9% of the petroleum ether fraction and 36.5% of paraffin fraction). The yield of paraffin from the paraffin fraction also decreased from 90.6% to 62.6-74.3%. This result shows that in the first case the carbonized products were cracked to a higher degree than those from the retort with gas heating. In raw phenols recovered from fractions of investigated tars, the yield of the phenol-cresol fraction (182/sup 0/ to 204/sup 0/) decreased from 25.9% to 13.0-18.9%.

  5. Relevance of carbon structure to formation of tar and liquid alkane during coal pyrolysis

    International Nuclear Information System (INIS)

    Liu, Peng; Le, Jiawei; Wang, Lanlan; Pan, Tieying; Lu, Xilan; Zhang, Dexiang

    2016-01-01

    Highlights: • Curve-fitting method was used to quantify the accurate contents of structural carbon. • Effect of carbon structure in coal with different rank on formation of pyrolysis tar was studied. • Numerical interrelation between carbon types in coal structure and tar yield is elaborated. • Effect of carbon structure on formation of liquid alkane during coal pyrolysis is discussed. - Abstract: The relevance of carbon structure to formation of tar and liquid alkane during coal pyrolysis were discussed extensively. The pyrolysis tests were carried out in a tube reactor at 873 K and keep 15 min. The carbon distribution in coals was investigated by solid state "1"3C nuclear magnetic resonance (N.M.R.). The curve-fitting method was used to quantify the accurate contents of structural carbon. The alkanes in coal tar were analyzed by Gas Chromatograph–Mass Spectrometer (GC–MS). The results show that oxygen-linked aromatic carbon decreases with the increasing of coal rank. The aliphatic carbon contents of Huainan (HN) coal are 44.20%, the highest among the four coals. The carbon types in coal structure have a significant influence on the formation of tar and liquid alkane. The coal tar yields are related to the aliphatic substituted aromatic carbon, CH_2/CH_3 ratio and oxygen-linked carbon in coal so that the increasing order of tar yield is Inner Mongolia lignite (IM, 6.30 wt.%) < Sinkiang coal (SK, 7.55 wt.%) < Shenmu coal (SM, 12.84 wt.%) < HN (16.29 wt.%). The highest contents of oxygen-linked aromatic carbon in IM lead to phenolic compound of 41.06% in IM-tar. The contents of alkane in SM-tar are the highest because the appropriate CH_2/CH_3 ratio and the highest aliphatic side chains on aromatic rings in SM leading to generate aliphatic hydrocarbon with medium molecular weight easily. The mechanism on formation of tar and liquid alkane plays an important role in guiding the industrialization of pyrolysis-based poly-generation producing tar with high

  6. UTILIZATION OF ACTIVATED ZEOLITE AS MOLECULAR SIEVE IN CHROMATOGRAPHIC COLUMN FOR SEPARATION OF COAL TAR COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Dwi Retno Nurotul Wahidiyah

    2010-06-01

    Full Text Available Application of activated zeolite (ZAA as molecular sieve to separate compounds of coal tar from vaccum fractional distillation, have been done. The size of zeolite was 10-20 mesh and used as solid phase in column chromatography with length of 30 cm. The first step of the research was coal pyrolisis and the product (tar was distillated by fractional column and vaccum system at reduced pressure 44 cmHg and maximum temperature at 200 oC. The distillate from this procedure was flowed to the column chromatography of zeolite (ZAA. The compound absorbed by zeolite was eluted with varying solvents, i.e: CCl4, acetone and ethanol. Each fraction was then analyzed by gas chromatography. The results showed, zeolite have a capability to separate the compounds of tar and it tends to absorb medium hydrocarbon. The nonpolar eluent [CCl4] gives the better result in eluting tar compound than polar (ethanol or medium polar eluents (acetone.   Keywords: zeolite, coal tar, column chromatography

  7. Preparation of pure phenols from tars

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J

    1929-06-18

    A process is disclosed for preparing pure phenols from brown coal and shale tar, characterized in that the alkaline extract obtained from the tar is oxidized and concurrently the alkaline solution is separated from the existing impurities by heating with steam at high temperature, which finally reaches at least 150/sup 0/C.

  8. New method for the exact determination of phenols in low-temperature tar and tar oils

    Energy Technology Data Exchange (ETDEWEB)

    Lambris, G; Haferkorn, H

    1949-01-01

    A 3-gram sample of water-free tar or tar oil containing approximately 50% phenols is dissolved in a mixture of benzene and xylene and a known excess of a 20% KOH solution of known normality saturated with benzene and xylene is added. Weight of the KOH is determined by difference. This mixture is shaken repeatedly in a 300-milliliter separatory funnel. After standing for 0.5 h, the dark or almost black phenolate solution containing the major portion is separated and weighed. Care must be taken to prevent the induction of solids. The phenolate in the residue is extracted with hot water and titrated with 0.2N HCl and 1 ml. Congo red (1:100). If water is present in the tar or tar oil, 100 ml of xylene is added immediately after weighing and the water separated by distillation the weight of which must be determined. Any phenols carried over are dissolved in the small quantity of xylene in the distillate. This quantity is added to the bulk of the xylene. After any remaining phenols are extracted from the tar residue with boiling benzene, the benzene-xylene mixture is treated with KOH as above. The accuracy of the method is estimated to be +-1% as shown by experiments with phenol; o-, m-, and p-cresol; cresol mixture; and pyrocatechol. The weight of the dissolved phenols X is determined by X = c - a + cd/(ab - d) where a = weight of KOH, b = HCl used per gram of KOH, C = weight of major portion of phenolate solution, which is formed by shaking the phenol solution with KOH, d = HCl used for titration of phenolate residue.

  9. Infrared absorption characteristics of hydroxyl groups in coal tars

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, S A; Chu, C J; Hange, R H; Margrave, J L

    1987-01-01

    Tar evolution was observed over a temperature range of 150-600 C for four coals. Pittsburgh bituminous, Illinois No.6, Rawhide subbituminous, and Texas lignite. Isolation of the evolved tars in a nitrogen matrix at 15 degrees K produced better resolved infrared spectra than those in a coal matrix, thus enhancing structural characterization of the tar molecules. Two distinct hydroxyl functional groups in the tar molecules free of hydrogen bonding were identified for the first time without interference from H/sub 2/O absorptions. These absorptions at 3626.5 cm/sup -1/ have been assigned to phenolic hydroxyls. It is suggested that carboxylic and aliphatic hydroxyl groups do not survive the vaporization process. Tars from Illinois No.6 were found to contain the largest amount of phenolic hydroxyl; Pittsburgh No. 8 tar contains approximately half of that for Illinois No.6 while Rawhide and Texas lignite contain much less phenolic than either of the other coals. 10 references, 6 figures, 1 table.

  10. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle [Emory University School of Medicine, Atlanta, GA (United States). Department of Dermatology

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  11. Sunflower oil in the treatment of hot tar burns.

    Science.gov (United States)

    Türegün, M; Oztürk, S; Selmanpakoğlu, N

    1997-08-01

    Hot tar burns compose a unique class of thermal injury, because removal of this highly sticky compound may be very difficult without inflicting additional tissue damage. Early removal of tar facilitates assessment of the burn and improves patient comfort. Although the use of many substances for the painless removal of tar has been described, we used sunflower oil effectively in the treatment of four tar burn patients. This first report describes the practical and successful use of sunflower oil which was easily obtained from the hospital kitchen.

  12. Tar dew point analyser as a tool in biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Vreugdenhil, B.J.; Kuipers, J. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

    2008-08-15

    Application of the Tar Dew point Analyzer (TDA) in different biomass based gasification systems and subsequent gas cleaning setups has been proven feasible. Such systems include BFB gasifiers, CFB gasifier and fixed bed gasifiers, with tar crackers or different scrubbers for tar removal. Tar dew points obtained with the TDA give direct insight in the performance of the gas cleaning section and help prevent any tar related problems due to condensation. The current TDA is capable of measuring tar dew points between -20 to 200C. This manuscript will present results from 4 different gasification setups. The range of measured tar dew points is -7 to 164C with comparable results from the calculated dew points based on the SPA measurements. Further detail will be presented on the differences between TDA and SPA results and explanations will be given for deviations that occurred. Improvements for the TDA regarding future work will be presented.

  13. HuMiTar: A sequence-based method for prediction of human microRNA targets

    Directory of Open Access Journals (Sweden)

    Chen Ke

    2008-12-01

    Full Text Available Abstract Background MicroRNAs (miRs are small noncoding RNAs that bind to complementary/partially complementary sites in the 3' untranslated regions of target genes to regulate protein production of the target transcript and to induce mRNA degradation or mRNA cleavage. The ability to perform accurate, high-throughput identification of physiologically active miR targets would enable functional characterization of individual miRs. Current target prediction methods include traditional approaches that are based on specific base-pairing rules in the miR's seed region and implementation of cross-species conservation of the target site, and machine learning (ML methods that explore patterns that contrast true and false miR-mRNA duplexes. However, in the case of the traditional methods research shows that some seed region matches that are conserved are false positives and that some of the experimentally validated target sites are not conserved. Results We present HuMiTar, a computational method for identifying common targets of miRs, which is based on a scoring function that considers base-pairing for both seed and non-seed positions for human miR-mRNA duplexes. Our design shows that certain non-seed miR nucleotides, such as 14, 18, 13, 11, and 17, are characterized by a strong bias towards formation of Watson-Crick pairing. We contrasted HuMiTar with several representative competing methods on two sets of human miR targets and a set of ten glioblastoma oncogenes. Comparison with the two best performing traditional methods, PicTar and TargetScanS, and a representative ML method that considers the non-seed positions, NBmiRTar, shows that HuMiTar predictions include majority of the predictions of the other three methods. At the same time, the proposed method is also capable of finding more true positive targets as a trade-off for an increased number of predictions. Genome-wide predictions show that the proposed method is characterized by 1.99 signal

  14. Chemical-composition studies of low-temperature-carbonization coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Edel' shtein, N G; Lanin, V A

    1955-01-01

    Pintsch-oven low-temperature tar was separated into its constituents by conventional methods, and the average of 2 results was neutral asphaltenes 12.56, basic asphaltenes 2.61, acid asphaltenes 18.82, phenols 13.23, bases 2.31, neutral oil 17.66, crystalline paraffins 7.34, silica-gel tars (I) (benzene extract) 15.40, I (acetone extract) 2.47, carbenes 0.45, and carbides and dust 1.44%. The low-temperature-tar asphaltenes and tars differ from shale-oil tars by being lower in C and higher in H, with a considerably higher C:H ratio. Their specific gravity is somewhat higher, and they are cyclic in structure. The asphaltenes and silica-gel tars of coal tar and shale oil were hydrogenated, molecular weights d/sub 4//sup 20/ and n/sub 4//sup 20/ of the separated compounds were determined, and empirical formulas of the hydrogenated compounds calculated. The neutral oil was separated into saturated, intermediate (iodine number 23), unsaturated (iodine number 51), a small quantity of a mixture of unsaturated and aromatic hydrocarbons, and 44.9% aromatic hydrocarbons. While naphthenes seem to be predominantly present in the neutral-oil fraction of shale oil, aromatic hydrocarbons are predominant in coal oil.

  15. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management.

    Science.gov (United States)

    Mahler, Barbara J; Metre, Peter C Van; Crane, Judy L; Watts, Alison W; Scoggins, Mateo; Williams, E Spencer

    2012-03-20

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments-including stormwater runoff, lake sediment, soil, house dust, and most recently, air-contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  16. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Crane, Judy L.; Watts, Alison W.; Scoggins, Mateo; Williams, E. Spencer

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  17. Estimating release of polycyclic aromatic hydrocarbons from coal tar at manufactured-gas plant sites

    International Nuclear Information System (INIS)

    Loehr, R.C.; Rao, P.S.C.; Lee, L.S.; Okuda, I.

    1992-08-01

    One component of the EPRI's research on Envirorunental Behavior of Organic Substances (EBOS) consists of developing information and models to predict releases of monocyclic and polycyclic aromatic hydrocarbons (MAHs and PAHs) to groundwater from coal tars and contaminated soils at MGP sites. The results of this report focus primarily on release of PAHs from coal tars. There are at least two approaches to predicting the release of organic chemicals from coal tar to water. The simplest method to estimate aqueous concentrations is to assume that water solubility of a PAH compound released from the tar can be defined by equilibrium precipitation-dissolution reactions. Application of Raoult's law is another method to predict aqueous concentrations, which requires the assumption of ''ideal'' behavior for partitioning of PAHs between the tar and water phases. To evaluate the applicability of these two methods for predicting PAH releases, laboratory experiments were conducted with eight coal tar samples from former MGP sites across the country. Migration of chemicals in the environment and resulting contaminant plumes in groundwater are determined by leachate concentrations of the chemicals. The use of equilibrium precipitation-dissolution reactions will usually result in an overestimation of PAH concentrations in the leachate from a coal tar source, and thus the resulting PAH concentrations in groundwater. Raoult's law appears to be a more accurate approach to predicting the release of several PAHs from coal tars. Furthermore, if nonequilibrium conditions prevail, aqueous-phase PAH concentrations will be even lower than those predicted using Raoult's law

  18. Acid Tar Lagoons: Management and Recovery

    Science.gov (United States)

    Bohers, Anna; Hroncová, Emília; Ladomerský, Juraj

    2017-04-01

    This contribution presents the issue with possibility of definitive removal of dangerous environmental burden in Slovakia - serious historical problem of two acid tar lagoons. In relation to their removal, no technology has been found so far - technologically and economically suitable, what caused problems with its management. Locality Predajná is well known in Slovakia by its character of contrasts: it is situated in the picturesque landscape of National Park buffer zone of Nízke Tatry, on the other site it is contaminated by 229 211m3 of acid tar with its characteristics of toxicity, carcinogenicity, teratogenicity, mutagenicity and toxicity especially for animals and plants. Acid tar in two landfills with depth of 1m in case of the first lagoon and 9,5m in case of the second lagoon is a waste product derived from operation of Petrochema Dubová - refinery and petrochemical plant whose activity was to process the crude oil through processes of sulfonation and adsorption technology for producing lubricating and special oils, synthetic detergents and special white oils for cosmetic and medical purposes. A part of acid tar was incinerated in two incineration plats. Concentration of SO2 in combustion gases was too high and it was not possible to decrease it under the value of 2000 mg.mn-3 [LADOMERSKÝ, J. - SAMEŠOVÁ, D.: Reduction in sulfur dioxide emissions waste gases of incineration plant. Acta facultatis ecologiae. 1999, p. 217-223]. That is why it was necessary to put them out of operation. Later, because of public opposition it was not possible to build a new incineration plat corresponding to the state of the art. Even though actual Slovak and European legislative for protection of environment against such impacts, neither of tried methods - bio or non-biologic treatment methods - was proved as suitable for processing or for recovery in the reason of different factors admission: i.e. strong aggressivity, difficulty with handling because of its sludgy and

  19. Analysis of the use of coal tar as a binder in bituminous mixtures, using Marshall and Ramcodes methodologies

    International Nuclear Information System (INIS)

    Ochoa-Díaz, R

    2013-01-01

    This paper presents an alternative use of coal tar, a by-product of the steel industry, given the problems of accumulation and negative environmental impact. Therefore, it is necessary to analyze the incorporation of coal tar as a binder in paving mixtures. First, this paper presents the origin, description of the main characteristics, and properties of tar. Then, this paper evaluates the mix of coal tar by means of the RAMCODES and Marshall methodologies to determine its resistance. The results of the tests explain the physical and mechanical properties of the mix. Taking into account the results of both methods, this paper makes a comparison to determine the suitability of the RAMCODES methodology in the mix design. Finally, it analyzes the alternatives to coal tar that can be used as binders in bituminous mixes for pavement and the advantages of their uses under some specific conditions

  20. Evaluation of the health risk resulting from exposure to polycyclic aromatic hydrocarbons in coal-tar shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Mennes, W.C.; Van Veen, M.P.; Kroese, E.D.; Speijers, G.J.A.

    1996-10-01

    Shampoos may contain as much as 56 mg benzo(a)pyrene (BaP)/kg product. Based on a human dermal uptake study, it is plausible that BaP and other PAHs become systemically available after a single use of coal-tar shampoos. Because several PAHs, among which BaP are considered to be carcinogenic substances, the safety of these products has been questioned. Dermal exposure results in skin tumours, but after inhalatory or oral exposure besides to local tumour formation, systemic tumours are found as well. In this report, an estimate of external dermal exposure to BaP has been generated by application of a mathematical model. This estimate was the starting point in an assessment of the additional risk on local skin tumours after contact with a coal-tar shampoo containing 56 mg BaP/kg product. In this assessment it was assumed that this shampoo was used three times weekly. Four different risk estimates were derived, namely for contact times of 1 or 5 minutes per event and for life-time or 40 years of use. 4 tabs., 3 appendices, 15 refs.

  1. Recovery of very viscous lubricating oils from shale-tar, etc

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, E

    1918-01-22

    A process is disclosed for the recovery of very viscous lubricating oils from brown-coal tar and shale tar, consisting in driving off from the crude tar or the tar freed from volatile constituents after removal of paraffin by precipitation with a volatile solvent such as acetone or one of its homologs, the light oils more or less completely with superheated steam from about 200 to 250/sup 0/C without any outside heating over a free flame.

  2. Microstructure and properties of lignite tar and pitch. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Walther, H

    1954-01-01

    Photomicrographs reveal the presence of crystalline wax which affects the working properties in lignite tars and pitch. The crystals are large needles after slow cooling and small after rapid cooling. The crystals are paraffinic in character. All samples were nonhomogeneous. Thus the properties of lignite tar and pitch are varied by the source of the lignite and history of the specimen, neither softening point nor dropping point seems to satisfactorily characterize these tars. The samples exhibit thixotropic behavior characteristic of a structural viscosity and show hysteresis loops on varying the working rate. The variations have hindered use of lignite tars and pitches except where solubility in a solvent such as coal tar oil can be used to advantage.

  3. Catalytic destruction of tar in biomass derived producer gas

    International Nuclear Information System (INIS)

    Zhang Ruiqin; Brown, Robert C.; Suby, Andrew; Cummer, Keith

    2004-01-01

    The purpose of this study is to investigate catalytic destruction of tar formed during gasification of biomass, with the goal of improving the quality of the producer gas. This work focuses on nickel based catalysts treated with alkali in an effort to promote steam gasification of the coke that deposits on catalyst surfaces. A tar conversion system consisting of a guard bed and catalytic reactor was designed to treat the producer gas from an air blown, fluidized bed biomass gasifier. The guard bed used dolomite to crack the heavy tars. The catalytic reactor was used to evaluate three commercial steam reforming catalysts. These were the ICI46-1 catalyst from Imperial Chemical Industry and Z409 and RZ409 catalysts from Qilu Petrochemical Corp. in China. A 0.5-3 l/min slipstream from a 5 tpd biomass gasifier was used to test the tar conversion system. Gas and tar were sampled before and after the tar conversion system to evaluate the effectiveness of the system. Changes in gas composition as functions of catalytic bed temperature, space velocity and steam/TOC (total organic carbon) ratio are presented. Structural changes in the catalysts during the tests are also described

  4. Characterization of acid tars

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Sunday A., E-mail: sunday.leonard@ucl.ac.uk [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Stegemann, Julia A. [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Roy, Amitava [J. Bennett Johnston, Sr., Centre for Advance Microstructures and Devices (CAMD), 6980 Jefferson Highway, Louisiana State University, Baton Rouge, LA, 70806 (United States)

    2010-03-15

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  5. Characterization of acid tars

    International Nuclear Information System (INIS)

    Leonard, Sunday A.; Stegemann, Julia A.; Roy, Amitava

    2010-01-01

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  6. Ultrasound assisted, thermally activated persulfate oxidation of coal tar DNAPLs.

    Science.gov (United States)

    Peng, Libin; Wang, Li; Hu, Xingting; Wu, Peihui; Wang, Xueqing; Huang, Chumei; Wang, Xiangyang; Deng, Dayi

    2016-11-15

    The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Application of organic geochemistry to coastal tar residues from central California

    Energy Technology Data Exchange (ETDEWEB)

    Kvenvolden, K.A.; Rosenbauer, R.J.; Hostettler, F.D.; Lorenson, T.D.

    2000-01-01

    Tar residues are common on the Monterey Bay National Marine Sanctuary. These coastal tar residues have been washed ashore and usually occur on headlands near the high-tide line. In this study, 18 coastal tar residues were collected and analyzed to determine their carbon isotopic compositions and values of selected biomarker ratios. All of the residues have very heavy ({sup 13}C-enriched) carbon isotopic compositions spanning a narrow range ({delta}{sup 13}C = {minus}22.2 to {minus}23.4{per{underscore}thousand}), and 28,30-bisnorhopane is present in all samples. These same geochemical characteristics are found in Monterey Formation oils from which the coastal tar residues were likely derived. These coastal residues could result from natural seeps or from accidental spills. Statistically the coastal tar residues can be organized into three groups, each of which may represent different spill or seep events. Seven samples of potential local representative sources for the tar residues were examined, but none could account for the coastal tars.

  8. A Mathematical Model of a Thermally Activated Roof (TAR Cooling System Using a Simplified RC-Thermal Model with Time Dependent Supply Water Temperature

    Directory of Open Access Journals (Sweden)

    Khalid Ahmed Joudi

    2017-01-01

    Full Text Available This paper presents a computer simulation model of a thermally activated roof (TAR to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time dependent with the variation of the ambient wet bulb temperature. Results from RC-thermal modeling were compared with experimental measurements for a second story room measuring 5.5 m x 4 m x 3 m at Amarah city/ Iraq (31.865 ˚N, 47.128 ˚E for 21 July, 2013. The roof was constructed of 200 mm concrete slab, 150 mm turf and 50 mm insulation. Galvanized 13 mm steel pipe coils were buried in the roof slab with a pipe occupation ratio of 0.12. The walls were constructed of 240 mm common brick with 10mm cement plaster on the inside and outside surfaces and 20 mm Styrofoam insulation on the inside surface and covered with PVC panel. Thermistors were used to measure the indoor and outdoor temperatures, TAR system water inlet and outlet temperatures and temperature distribution inside the concrete slab. The effect of pipe spacing and water mass flow rate were evaluated. Agreement was good between the experimental and RC-thermal model. Concrete core temperature reaches the supply water temperature faster for lower pipe spacing. Heat extracted from the space increased with water mass flow rate to an optimum of 0.0088 kg/s.m².

  9. Study on tar generated from downdraft gasification of oil palm fronds.

    Science.gov (United States)

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study.

  10. Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

    Directory of Open Access Journals (Sweden)

    Samson Mekbib Atnaw

    2014-01-01

    Full Text Available One of the most challenging issues concerning the gasification of oil palm fronds (OPF is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3 in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study.

  11. Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

    Science.gov (United States)

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study. PMID:24526899

  12. GC/MS analysis of coal tar composition produced from coal pyrolysis

    African Journals Online (AJOL)

    Coal tar is a significant product generated from coal pyrolysis. A detailed analytical study on its composition and chemical structure will be of great advantage to its further processing and utilization. Using a combined method of planigraphy-gas chromatograph/mass spectroscopy (GC/MS), this work presents a composition ...

  13. Cold Preparation of Heroin in a Black Tar Market.

    Science.gov (United States)

    Roth, Alexis M; Armenta, Richard F; Wagner, Karla D; Strathdee, Steffanie A; Goldshear, Jesse L; Cuevas-Mota, Jazmine; Garfein, Richard S

    2017-07-29

    Black tar heroin is typically prepared for injection with heat which decreases the risk of HIV transmission by inactivating the virus. We received reports that persons who inject drugs (PWID) in Tijuana, Baja California, Mexico, a black tar heroin market, were using only water to dissolve heroin. Because Tijuana abuts San Diego County, CA, United States, we undertook the present analyses to determine the prevalence of this practice among PWID in San Diego, California. PWID completed quarterly behavioral assessments and serological testing for blood-borne viruses. Bivariate and multivariable logistic regression models were constructed to assess for individual, social, and structural correlates of preparing heroin without heat within the preceding 6 months. Nearly half of black tar heroin users (149/305) reported they had prepared heroin without heat within 6 months. In multivariable analysis, cold preparation was independently associated with younger age (10 year decrease; AOR = 1.25; 95% CI 1.03, 1.53), more drug injecting acquaintances (per 5 acquaintance increase; AOR = 1.05; 95% CI 1.01, 1.09) and prefilled syringe use (injecting drugs from syringes that are already filled with drugs before purchase; AOR = 1.86; 95% CI 1.14, 3.02). Conclusions/Importance: To our knowledge, this is the first paper to report that PWID living in a black tar heroin market are preparing heroin without heat. Additional research is needed to determine whether this is an endemic practice or PWID are engaging in new forms of drug preparation in response to changes in the environment.

  14. Dandruff, seborrheic dermatitis, and psoriasis drug products containing coal tar and menthol for over-the-counter human use; amendment to the monograph. Final rule

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-03-15

    The Food and Drug Administration (FDA) is issuing a final rule amending the final monograph (FM) for over-the-counter (OTC) dandruff, seborrheic dermatitis, and psoriasis drug products to include the combination of 1.8 percent coal tar solution and 1.5 percent menthol in a shampoo drug product to control dandruff. FDA did not receive any comments or data in response to its previously proposed rule to include this combination. This final rule is part of FDA's ongoing review of OTC drug products.

  15. The impact of steam and current density on carbon formation from biomass gasification tar on Ni/YSZ, and Ni/CGO solid oxide fuel cell anodes

    Science.gov (United States)

    Mermelstein, Joshua; Millan, Marcos; Brandon, Nigel

    The combination of solid oxide fuel cells (SOFCs) and biomass gasification has the potential to become an attractive technology for the production of clean renewable energy. However the impact of tars, formed during biomass gasification, on the performance and durability of SOFC anodes has not been well established experimentally. This paper reports an experimental study on the mitigation of carbon formation arising from the exposure of the commonly used Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium-doped ceria) SOFC anodes to biomass gasification tars. Carbon formation and cell degradation was reduced through means of steam reforming of the tar over the nickel anode, and partial oxidation of benzene model tar via the transport of oxygen ions to the anode while operating the fuel cell under load. Thermodynamic calculations suggest that a threshold current density of 365 mA cm -2 was required to suppress carbon formation in dry conditions, which was consistent with the results of experiments conducted in this study. The importance of both anode microstructure and composition towards carbon deposition was seen in the comparison of Ni/YSZ and Ni/CGO anodes exposed to the biomass gasification tar. Under steam concentrations greater than the thermodynamic threshold for carbon deposition, Ni/YSZ anodes still exhibited cell degradation, as shown by increased polarization resistances, and carbon formation was seen using SEM imaging. Ni/CGO anodes were found to be more resilient to carbon formation than Ni/YSZ anodes, and displayed increased performance after each subsequent exposure to tar, likely due to continued reforming of condensed tar on the anode.

  16. Composition of coal tar from pyrolysis and hydropyrolysis of Shenmu coal macerals

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Q.; Li, W.; Chen, H.; Li, B. [Shandong Academy of Sciences, Jinan (China)

    2005-08-15

    To understand the relationship of the tar compositions and the coal macerals, the tars obtained from the pyrolysis and hydropyrolysis of Shenmu coal macerals in a fixed-bed reactor were analysed using GC-MS. And the effects of petrographic component, atmosphere and pressure on the yield of aromatic hydrocarbon, phenols, hydrocarbons, oxygen-containing heterocycle and PAHs were systematically investigated. The results show that there is great difference in the composition and the relative content of long chain hydrocarbons, aromatic hydrocarbons, phenols, oxygen-containing heterocycle and PAHs in tars from vitrinite and inertinite pyrolysis. Vitrinite tar contains high content of hydrocarbon with long chain, and inertinite tar contains high content of aromatic hydrocarbons, phenols, oxygen-containing heterocycle and PAHs. It suggests that vitrinite has lower aromaticity and longer chain in its structure than inertinite, which is in well agreement with the result from {sup 13}C NMR and FT-IR test. The tar yield of hydropyrolysis is higher than that of pyrolysis. With increasing the hydrogen pressure, the yield of tar increases greatly. The content of phenols and naphthalene in vitrinite tar form hydropyrolysis under 0.1 MPa is much lower than that form pyrolysis, while that of inertinite tar changes a little. The difference of tar compositions and relative content during pyrolysis and hydropyrolysis reflects the effect of hydrogenation and hydrocracking reactions and the structure characteristics of the macerals. 12 refs., 3 figs.

  17. 48 CFR Appendix to Part 1252 - Tar Matrix

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Tar Matrix Appendix to Part 1252 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Pt. 1252, App. Appendix to Part 1252—Tar Matrix ER27DE05.000...

  18. Evaluation of Gravimetric Tar Determination in Particle Samples

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik B.; Bentzen, Jens Dall

    2000-01-01

    A comparison of tar determination of particles from a down-draft gasifier using soxhlet extractions (with anisole, dichloromethane and acetone) and pyrolysis of the particles.......A comparison of tar determination of particles from a down-draft gasifier using soxhlet extractions (with anisole, dichloromethane and acetone) and pyrolysis of the particles....

  19. Catalytic decomposition of biomass tars: Use of dolomite and untreated olivine

    NARCIS (Netherlands)

    Devi, L.; Ptasinski, K.J.; Janssen, F.J.J.G.; Paasen, van S.V.B.; Bergman, P.C.A.; Kiel, J.H.A.

    2005-01-01

    Although biomass is getting increased attention as a renewable energy source, one of the remaining problems still to be solved is the reduction of the high level of tar present in the product gas from gasification of biomass. The purpose of the present work is to study the activity of olivine and

  20. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    International Nuclear Information System (INIS)

    Bryer, Pamela J.; Scoggins, Mateo; McClintock, Nancy L.

    2010-01-01

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, and 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments. - Coal-tar pavement sealants degrade stream invertebrate communities.

  1. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

  2. Athabasca tar sand reservoir properties derived from cores and logs

    International Nuclear Information System (INIS)

    Woodhouse, R.

    1976-01-01

    Log interpretation parameters for the Athabasca Tar Sand Lease No. 24 have been determined by careful correlation with Dean and Stark core analysis data. Significant expansion of Athabasca cores occurs as overburden pressure is removed. In the more shaly sands the core analysis procedures remove adsorbed water from the clays leading to further overestimation of porosity and free water volume. Log interpretation parameters (R/sub w/ = 0.5 ohm . m and m = n = 1.5) were defined by correlation with the weight of tar as a fraction of the weight of rock solids (grain or dry weight fraction of tar). This quantity is independent of the water content of the cores, whereas porosity and the weight of tar as a fraction of the bulk weight of fluids plus solids (bulk weight fraction) are both dependent on water content. Charts are provided for the conversion of bulk weight fraction of fluids to porosity; grain weight fraction of fluids to porosity; log derived porosity and core grain weight tar to water saturation. Example results show that the core analysis grain weight fraction of tar is adequately matched by the log analyses. The log results provide a better representation of the reservoir fluid volumes than the core analysis data

  3. Coal-tar pavement sealants might substantially increase children's PAH exposures

    Science.gov (United States)

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Dietary ingestion has been identified repeatedly as the primary route of human exposure to polycyclic aromatic hydrocarbons (PAHs), seven of which are classified as probable human carcinogens (B2 PAHs) by the U.S. EPA. Humans are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air, and absorption through skin. Although PAH sources are ubiquitous in the environment, one recently identified PAH source stands out: Coal-tar-based pavement sealant—a product applied to many parking lots, driveways, and even playgrounds primarily in the central, southern, and eastern U.S.—has PAH concentrations 100–1000 times greater than most other PAH sources. It was reported recently that PAH concentrations in house dust in residences adjacent to parking lots with coal-tar-based sealant were 25 times higher than in residences adjacent to unsealed asphalt parking lots.

  4. Plasma Gasification of Wood and Production of Gas with Low Content of Tar

    Czech Academy of Sciences Publication Activity Database

    Hlína, Michal; Hrabovský, Milan; Kopecký, Vladimír; Konrád, Miloš; Kavka, Tetyana; Skoblja, S.

    2006-01-01

    Roč. 56, suppl. B (2006), s. 1179-1184 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA ČR GA202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Keywords : tar * plasma * biomass gasification Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

  5. Corrosion test by low-temperature coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Ando, S; Yamamoto, S

    1952-01-01

    Corrosive actions of various fractions of low-temperature coal tar against mild steel or Cr 13-steel were compared at their boiling states. Corrosions became severe when the boiling points exceeded 240/sup 0/. The acidic fractions were more corrosive. In all instances, corrosion was excessive at the beginning of immersion testing and then gradually became mild; boiling accelerated the corrosion. Cr 13-steel was corrosion-resistant to low-temperature coal-tar fractions.

  6. Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement

    Science.gov (United States)

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10–4, as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10–5. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0–6 years of age).

  7. Marketing 'less harmful, low-tar' cigarettes is a key strategy of the industry to counter tobacco control in China.

    Science.gov (United States)

    Yang, Gonghuan

    2014-03-01

    While the 'low-tar' scheme has been widely recognised as a misleading tactic used by the tobacco industry to deceive the public about the true risks of cigarette smoking, a similar campaign using the slogan of 'less harmful, low tar' was launched by the Chinese tobacco industry, that is, State Tobacco Monopoly Administration/China National Tobacco Corporation and began to gain traction during the last decade. Despite the fact that no sufficient research evidence supports the claims made by the industry that these cigarettes are safer, the Chinese tobacco industry has continued to promote them using various health claims. As a result, the production and sales of 'less harmful, low-tar' cigarettes have increased dramatically since 2000. Recently, a tobacco industry senior researcher, whose main research area is 'less harmful, low-tar' cigarettes, was elected as an Academician to the prestigious Chinese Academy of Engineering for his contribution to developing 'less harmful, low-tar' cigarettes. The tobacco researcher's election caused an outcry from the tobacco control community and the general public in China. This paper discusses the Chinese tobacco industry's 'less harmful, low-tar' initiatives and calls for the Chinese government to stop the execution of this deceptive strategy for tobacco marketing.

  8. Sampling of tar from sewage sludge gasification using solid phase adsorption.

    Science.gov (United States)

    Ortiz González, Isabel; Pérez Pastor, Rosa Ma; Sánchez Hervás, José Ma

    2012-06-01

    Sewage sludge is a residue from wastewater treatment plants which is considered to be harmful to the environment and all living organisms. Gasification technology is a potential source of renewable energy that converts the sewage sludge into gases that can be used to generate energy or as raw material in chemical synthesis processes. But tar produced during gasification is one of the problems for the implementation of the gasification technology. Tar can condense on pipes and filters and may cause blockage and corrosion in the engines and turbines. Consequently, to minimize tar content in syngas, the ability to quantify tar levels in process streams is essential. The aim of this work was to develop an accurate tar sampling and analysis methodology using solid phase adsorption (SPA) in order to apply it to tar sampling from sewage sludge gasification gases. Four types of commercial SPA cartridges have been tested to determine the most suitable one for the sampling of individual tar compounds in such streams. Afterwards, the capacity, breakthrough volume and sample stability of the Supelclean™ ENVI-Carb/NH(2), which is identified as the most suitable, have been determined. Basically, no significant influences from water, H(2)S or NH(3) were detected. The cartridge was used in sampling real samples, and comparable results were obtained with the present and traditional methods.

  9. High-BTU gas production from tar-bearing hot coke oven gas over iron catalyst

    Energy Technology Data Exchange (ETDEWEB)

    L.Y. Li; K. Morishita; T. Takarada [Gunma University, Gunma (Japan). Department of Biological and Chemical Engineering

    2005-07-01

    To utilize the tar-bearing hot coke oven gas (the by-product of coke making process) more effectively, a process was developed by converting the hot coke oven gas into a methane rich high-BTU gas over iron-bearing catalysts. The catalytic behaviour of Indonesian limonite ore was mainly discussed. For a reference, a conventional nickel catalyst (Ni/Al{sub 2}O{sub 3}) was employed. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. A bituminous coal sample was heated at first stage, the volatiles was carried by feed gas and decomposed at second stage. The limonite promoted hydropyrolysis of coal volatiles similar to Ni/Al{sub 2}O{sub 3} catalyst. High yields of total product gas and methane were obtained at 50 vol.% hydrogen atmosphere with a feed gas of 60 ml min{sup -1} hydrogen and 60 ml min{sup -1} nitrogen. After experiments, hydrocarbons heavier than ethane were not observed. Also that, carbon balance was more than 99.8% in coal char, product gases and carbon deposits. It was considered that coal volatiles converted into light gases and carbon almost completely in catalyst bed. Yields of product gas and methane depended upon catalytic temperature. At 923 K, the maximum yield of product gas was achieved at 74.3% for limonite catalyst on carbon balance with methane 83.2 vol.% of the carbonaceous gas products. Comparing with limonite, Fe/Al{sub 2}O{sub 3} and BOF dust samples showed low activities on coal volatiles catalytic decomposition. 21 refs., 5 figs., 3 tabs.

  10. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Dady Dadyburjor; Philip R. Biedler; Chong Chen; L. Mitchell Clendenin; Manoj Katakdaunde; Elliot B. Kennel; Nathan D. King; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2004-08-31

    This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon foam and carbon fibers. The focus of this effort was on development of lower cost solvents, milder hydrogenation conditions and improved yield in order to enable practical production of these products. This technology is needed because of the long-term decline in production of domestic feedstocks such as petroleum pitch and coal tar pitch. Currently, carbon products represents a market of roughly 5 million tons domestically, and 19 million tons worldwide. Carbon products are mainly derived from feedstocks such as petroleum pitch and coal tar pitch. The domestic supply of petroleum pitch is declining because of the rising price of liquid fuels, which has caused US refineries to maximize liquid fuel production. As a consequence, the long term trend has a decline in production of petroleum pitch over the past 20 years. The production of coal tar pitch, as in the case of petroleum pitch, has likewise declined significantly over the past two decades. Coal tar pitch is a byproduct of metallurgical grade coke (metcoke) production. In this industry, modern metcoke facilities are recycling coal tar as fuel in order to enhance energy efficiency and minimize environmental emissions. Metcoke production itself is dependent upon the production requirements for domestic steel. Hence, several metcoke ovens have been decommissioned over the past two decades and have not been replaced. As a consequence sources of coal tar are being taken off line and are not being replaced. The long-term trend is a reduction in coal tar pitch production. Thus import of feedstocks, mainly from Eastern Europe and China, is on the rise despite the relatively large transportation cost. To reverse this trend, a new process for producing carbon products is needed. The process must be

  11. Occupational coal tar dermatitis

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Salazar, L; Guimaraens, D; Romero, L V; Gonzalez, M A

    1987-04-01

    The paper describes the allergic reaction to coal tar of a man handling it in a factory. The reaction appeared in the form of eczema on his trunk, arms and legs, but his hands were not affected as he had been wearing gloves. 1 ref.

  12. 179 Extraction of Coal-tar Pitch by Supercritical Carbon Dioxide ...

    African Journals Online (AJOL)

    Meyer

    Several extractions of coal-tar pitch were performed using supercritical fluid ..... pressure and temperature, unlike exhaustive extraction, which involves a change in ... mechanism that is operative on extracting coal-tar pitch components with.

  13. Structural evolution of Eucalyptus tar pitch-based carbons during carbonization

    International Nuclear Information System (INIS)

    Prauchner, Marcos J.; Pasa, Vanya M.D.; Molhallem, Nelcy D.S.; Otani, Choyu; Otani, Satika; Pardini, Luiz C.

    2005-01-01

    Wood tar pitches are generated as by-products by the charcoal manufacturing industry. They have a macromolecular structure constituted mainly by phenolic, guaiacylic, and siringylic units common to lignin. Due to their characteristics, biopitches are been investigated as precursors of carbon materials such as carbon fibers, bioelectrodes and activated carbons. In the present work the structural evolution of Eucalyptus tar pitches under carbonization is investigated, which is important for the improvement of planning and control of pitch processing and end-product properties during carbon material production. The studies involve X-ray diffraction and infrared analyses, besides helium density, BET surface area and BJH pore volume measurements. The results showed that the conversion of pitch into carbon basically involves three steps: (1) Up to around 600 deg C the material has an highly disordered structure, being the release of aliphatic side chains and volatiles the main events taking place. (2) Between 600 deg C and 800 deg C, condensation of aromatic rings occurs to form bi-dimensional hexagonal networks so that micro- and mesoporosity are developed. The 800 deg C-coke is constituted by two phases: one highly disordered and another more crystalline. (3) Over 800 deg C, both phases are gradually ordered. As defects are gradually removed, surface area and porosity decrease, approaching zero for the 2100 deg C-coke

  14. Stuck in the tar sands : how the federal government's proposed climate change strategy lets oil companies off the hook

    International Nuclear Information System (INIS)

    2008-10-01

    The credibility of any federal climate change strategy must be measured against its ability to reduce emissions from the tar sands. However, the federal government has proposed a climate change strategy that would allow tar sands producers to double their total emissions over the next decade. This report discussed how the federal government's proposed climate change strategy lets oil companies off the hook. The report discussed the problems and harmful effects associated with tar sands development, including greenhouse gas emissions; water depletion and pollution; toxic air emissions; destruction of the boreal forest; violation of native rights; threat to energy security; and negative socio-economic spin-off from an overheated economy. The federal government's proposed strategy was also assessed in terms of its weak greenhouse gas targets; ignoring the recent growth in tar sands emissions; adopting intensity-based targets instead of hard caps on greenhouse gas pollution, allowing total emissions from the tar sands to keep climbing; putting off critical measures until 2018; awarding oil companies hundreds of millions of dollars in credits for meeting targets they have already adopted voluntarily; lowballing the price of oil and downplaying future growth in tar sands emissions; ignoring huge portions of the oil industry's greenhouse gas pollution; letting oil companies buy their way out at rockbottom prices instead of forcing them to reduce their own emissions; and subsidizing increased tar sands production. It was concluded that the federal government's proposed plan to reduce greenhouse gas emissions was inadequate, because it failed to crack down on rising greenhouse gas emissions from the tar sands, one of Canada's most carbon intensive and fastest growing industries. 29 refs., 1 appendix

  15. Comparison of Bayesian and frequentist approaches in modelling risk of preterm birth near the Sydney Tar Ponds, Nova Scotia, Canada

    Directory of Open Access Journals (Sweden)

    Canty Angelo

    2007-09-01

    Full Text Available Abstract Background This study compares the Bayesian and frequentist (non-Bayesian approaches in the modelling of the association between the risk of preterm birth and maternal proximity to hazardous waste and pollution from the Sydney Tar Pond site in Nova Scotia, Canada. Methods The data includes 1604 observed cases of preterm birth out of a total population of 17559 at risk of preterm birth from 144 enumeration districts in the Cape Breton Regional Municipality. Other covariates include the distance from the Tar Pond; the rate of unemployment to population; the proportion of persons who are separated, divorced or widowed; the proportion of persons who have no high school diploma; the proportion of persons living alone; the proportion of single parent families and average income. Bayesian hierarchical Poisson regression, quasi-likelihood Poisson regression and weighted linear regression models were fitted to the data. Results The results of the analyses were compared together with their limitations. Conclusion The results of the weighted linear regression and the quasi-likelihood Poisson regression agrees with the result from the Bayesian hierarchical modelling which incorporates the spatial effects.

  16. Production and investigation of low-temperature coal tar. [Book in German

    Energy Technology Data Exchange (ETDEWEB)

    1953-01-01

    Research into low-temperature carbonization has recently been stimulated because this process can be applied to coals that are not suitable for treatment by the usual high-temperature method. However, in spite of the value of the coke produced by low-temperature carbonization as a smokeless fuel, this process has not proved economical in Germany. Research has therefore been directed towards a more profitable utilization of the tar, and this government publication reports experiments on its detailed analysis by distillation and other methods. The book also includes descriptions of the various types of plant used for low-temperature carbonization and presents a brief history of the process.

  17. Coal tar phototoxicity: characteristics of the smarting reaction

    International Nuclear Information System (INIS)

    Diette, K.M.; Gange, R.W.; Stern, R.S.; Arndt, K.A.; Parrish, J.A.

    1985-01-01

    The properties and ultraviolet exposure parameters of tar smarts were examined in an effort to elucidate the mechanisms involved. It was show that irradiation with 1 minimal smarting dose (MSD) of UVA immediately following tar removal lowered the MSD for 6 h, demonstrated by subsequent challenge with UVA. Following 3 MSDs this memory effect was demonstrable for 24 h. The smarting reaction was area dependent--smaller areas of exposure require higher doses of UVA to induce smarting. Smarting followed reciprocity over a 6-fold range of irradiances (2-12.5 mW/cm2) but higher irradiances required higher doses of UVA, perhaps due to a delay in the recognition and reporting of smarting. The smarting reaction and delayed erythema due to UVA and tar were equally blocked by sunscreen

  18. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Bryer, P.J.; Scoggins, M.; McClintock, N.L. [Lamar University, Beaumont, TX (United States). Dept. of Biology

    2010-05-15

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P < 0.0001) between treatments in addition to specific taxa responses, displaying a clear negative relationship with the amount of coal-tar sealant flake. These results support the hypothesis that coal-tar pavement sealants contain bioavailable PAHs that may harm aquatic environments.

  19. Gasification of Rice Husk in a Downdraft Gasifier: The Effect of Equivalence Ratio on the Gasification Performance, Properties, and Utilization Analysis of Byproducts of Char and Tar

    Directory of Open Access Journals (Sweden)

    Zhongqing Ma

    2015-03-01

    Full Text Available Rice husks (RH are a potential biomass source for bio-energy production in China, such as bio-gas production by gasification technology. In this paper, a bench-scale downdraft fixed bed gasifier (DFBG and a tar sampling system were designed. The effect of equivalence ratio (ER on gasification performance in terms of the temperature in the gasifier, the composition distribution of the producer gas, and the tar content in the producer gas was studied. The maximum lower heating value of 4.44 MJ/Nm3, minimum tar content of 1.34 g/Nm3, and maximum cold gas efficiency of 50.85% were obtained at ER of 0.211. In addition, the characteristics of gasification byproducts, namely bio-char and bio-tar, were analyzed. The proximate and ultimate analysis (especially of the alkali metal, the surface morphology, the surface area, and the pore size distribution of the rice husk char (RHC were obtained by the use of X-ray fluorescence (XRF and scanning electron microscopy (SEM, as well as by using the Brunauer-Emmett-Teller (BET method. The components of light tar and heavy tar were obtained by using gas chromatography-mass spectrometry (GC-MS.

  20. How do different cigarette design features influence the standard tar yields of popular cigarette brands sold in different countries?

    Science.gov (United States)

    O'Connor, R J; Hammond, D; McNeill, A; King, B; Kozlowski, L T; Giovino, G A; Cummings, K M

    2008-09-01

    To examine the associations among cigarette design features and tar yields of leading cigarette brands sold in the United States, Canada, Australia and the United Kingdom. Government reports and numbers listed on packs were used to obtain data on International Organization for Standardization (ISO)/Federal Trade Commission (FTC) yields for the tar of 172 cigarette varieties sold in the United States, Canada, Australia and the United Kingdom. We used standardised methods to measure the following 11 cigarette design parameters: filter ventilation, cigarette pressure drop, filter pressure drop, tobacco rod length, filter length, cigarette diameter, tipping paper length, tobacco weight, filter weight, rod density and filter density. Filter ventilation was found to be the predominant design feature accounting for the variations between brands in ISO/FTC tar yields in each of the four countries. After accounting for filter ventilation, design parameters such as overwrap length, tobacco weight and rod density played comparatively minor roles in determining tar yields. Variation in ISO/FTC tar yields are predicted by a limited set of cigarette design features, especially filter ventilation, suggesting that governments should consider mandatory disclosure of cigarette design parameters as part of comprehensive tobacco product regulations.

  1. The search for a source rock for the giant Tar Sand triangle accumulation, southeastern Utah

    Science.gov (United States)

    Huntoon, J.E.; Hansley, P.L.; Naeser, N.D.

    1999-01-01

    A large proportion (about 36%) of the world's oil resource is contained in accumulations of heavy oil or tar. In these large deposits of degraded oil, the oil in place represents only a fraction of what was present at the time of accumulation. In many of these deposits, the source of the oil is unknown, and the oil is thought to have migrated over long distances to the reservoirs. The Tar Sand triangle in southeastern Utah contains the largest tar sand accumulation in the United States, with 6.3 billion bbl of heavy oil estimated to be in place. The deposit is thought to have originally contained 13-16 billion bbl prior to the biodegradation, water washing, and erosion that have taken place since the middle - late Tertiary. The source of the oil is unknown. The tar is primarily contained within the Lower Permian White Rim Sandstone, but extends into permeable parts of overlying and underlying beds. Oil is interpreted to have migrated into the White Rim sometime during the Tertiary when the formation was at a depth of approximately 3500 m. This conclusion is based on integration of fluid inclusion analysis, time-temperature reconstruction, and apatite fission-track modeling for the White Rim Sandstone. Homogenization temperatures cluster around 85-90??C for primary fluid inclusions in authigenic, nonferroan dolomite in the White Rim. The fluid inclusions are associated with fluorescent oil-bearing inclusions, indicating that dolomite precipitation was coeval with oil migration. Burial reconstruction suggests that the White Rim Sandstone reached its maximum burial depth from 60 to 24 Ma, and that maximum burial was followed by unroofing from 24 to 0 Ma. Time-temperature modeling indicates that the formation experienced temperatures of 85-90??C from about 35 to 40 Ma during maximum burial. Maximum formation temperatures of about 105-110??C were reached at about 24 Ma, just prior to unroofing. Thermal modeling is used to examine the history of potential source rocks

  2. Pelagic tar and plastic in the Gulf of Alaska and Bering Sea: 1975

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, D G

    1977-07-01

    Seventy-one tows of 740 m/sup 2/ each were made in search of pelagic tar and plastics in the Gulf of Alaska and Bering Sea during the period October 1974 to October 1975. Tar was observed on nine occasions while plastics were found six times. The arithmetic mean value of tar abundance, 3.3 x 10/sup -3/ mg/m/sup 2/, is considerably lower than most other oceanic areas for which values have been reported. Gas chromatographic analysis of this tar indicates that it is more extensively weathered than tar from the north Atlantic. An estimate of the abundance of tar lumps too small to be sampled by net tows is made based on the assumption that there are equal weights of particles in logarithmetically equal size intervals. The abundance of pelagic plastics is also low.

  3. Extraction of low-temperature tar by various alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Hara, N; Osawa, M; Azuma, H

    1948-01-01

    MeOH was the most effective of the alcohols tested (MeOH to pentanol) in extracting acid components from low-temperature tar. The optimum concentrations of MeOH were 70 to 80% for 1 extraction and 70 to 75% for repeated or continuous extractions when the solvent-tar ratio was 1:1. By 2 to 3 extractions neutral oil could be separated in about 90% yield including > 3% acidic oil.

  4. Dermal uptake of polycyclic aromatic hydrocarbons after hairwash with coal-tar shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Schooten, F.-J. van; Moonen, E.J.C.; Rhijnsburger, E.; Agen, B. van; Thijssen, H.H.W.; Kleinjans, J.C.S. [University of Limburg, Maastricht (Netherlands). Dept. of Health Risk Analysis and Toxicology

    1994-11-26

    Describes an experiment to assess the dermal uptake of polycyclic aromatic hydrocarbons (PAHs) after hairwashing with coal tar antidandruff shampoo. The urinary excretion of 1-hydroxypyrene (1-OH-P), a PAH metabolile was used to assess internal dose of PAH. A single use of coal tar shampoo resulted in increased 1-OH-P excretion in all members of the experimental group compared with the control group using a non-coal tar antidandruff shampoo. It is suggested that repeated use of coal tar shampoo would result in a high internal dose of carcinogenic PAH. 5 refs., 1 fig.

  5. Iron-based materials as tar cracking catalyst in waste gasification

    Energy Technology Data Exchange (ETDEWEB)

    Nordgreen, Thomas

    2011-07-01

    The treatment of municipal solid waste (MSW) in Sweden has changed during the past decades due to national legislation and European Union directives. The former landfills have more or less been abandoned in favour of material recycling and waste incineration. On a yearly basis approximately 2.2 million tonnes waste are incinerated in Sweden with heat recovery and to some extent also with electricity generation, though at a low efficiency. It is desirable to alter this utilisation and instead employ MSW as fuel in a fluid bed gasification process. Then electrical energy may be produced at a much higher efficiency. However, MSW contain about 1 % chlorine in the form of ordinary table salt (NaCl) from food scraps. This implies that the tar cracking catalyst, dolomite, which is normally employed in gasification, will suffer from poisoning if applied under such conditions. Then the tar cracking capacity will be reduced or vanish completely with time. Consequently, an alternative catalyst, more resistant to chlorine, is needed. Preliminary research at KTH has indicated that iron in its metallic state may possess tar cracking ability. With this information at hand and participating in the project 'Energy from Waste' an experimental campaign was launched. Numerous experiments were conducted using iron as tar cracking catalyst. First iron sinter pellets from LKAB were employed. They were reduced in situ with a stream of hydrogen before they were applied. Later iron-based granules from Hoeganaes AB were tested. These materials were delivered in the metallic state. In all tests the KTH atmospheric fluidised bed gasifier with a secondary catalytic reactor housing the catalytic material was deployed. Mostly, the applied fuel was birch. The results show that metallic iron possesses an intrinsic ability, almost in the range of dolomite, to crack tars. Calculations indicate that iron may be more resistant to chlorine than dolomite. The exploration of metallic iron

  6. You're standing on it! Coal-tar-based pavement sealcoat and environmental and human health

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.

    2013-01-01

    Coal-tar-based sealcoat—a product marketed to protect and beautify asphalt pavement—is a potent source of polycyclic aromatic hydrocarbons (PAHs) to air, soils, streams and lakes, and homes. Does its use present a risk to human health?

  7. Tar loads on Omani beaches

    International Nuclear Information System (INIS)

    Badawy, M.I.; Al-Harthy, F.T.

    1991-01-01

    Owing to Oman's geographic position and long coastal line, the coastal areas of Oman are particularly vulnerable to oil pollution from normal tanker operations, illegal discharges, and accidental spills as well as local sources of oil input. UNEP carried out a survey on the coasts of Oman to determine the major sources of oil pollution and concluded that the major shoreline pollution problems in Oman arose from operational discharges of oil from passing vessels traffic. The oil, because of the high sea and air temperatures in the area, was subjected to relatively high rates of evaporation and photo-oxidation and tended to arrive at the coast as heavy petroleum particulate residues (tar balls). The aim of the present study was to measure the loads of tar balls in Omani coastal areas and to identify the source of oil pollutants on beaches

  8. PAH volatilization following application of coal-tar-based pavement sealant

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  9. Decomposition of tar in gas from updraft gasifier by thermal cracking

    DEFF Research Database (Denmark)

    Brandt, Peder; Henriksen, Ulrik Birk

    2000-01-01

    Continuing earlier work with tar reduction by partial oxidation of pyrolysis gas [1] thermal cracking has been evaluated as a gas cleaning process. The work has been focusing on cleaning gas from updraft gasifiers, and the long term purpose is to develop a tar cleaning unit based on thermal...... cracking. An experimental set-up has been built, in which a flow of contaminated gas can be heated up to 1290°C in a reactor made of pure Al2O3. Four measurements were made. Three with gas from a pyrolysis unit simulating updraft gasifier, and one with gas from an updraft gasifier. Cracking temperatures...... was 1200, 1250 and 1290°C, and the residence time at this temperature was 0.5 second. The measurements show that at the selected residence time of 0.5 second, the gas flow in a thermal tar cracking unit has to be heated to at least 1250°C to achieve sufficient tar cleaning. At 1290°C, a tar content as low...

  10. Use of advanced chemical fingerprinting in PAH source identification and allocation at a coal tar processing site

    International Nuclear Information System (INIS)

    Brown, J.S.; Boehm, P.D.; Douglas, G.S.

    1995-01-01

    Advanced chemical fingerprinting analyses were used to determine source allocation at a former coal tar processing facility which had been converted to a petroleum recycling site. Soil samples from the site had high petroleum hydrocarbon concentrations and elevated levels of polynuclear aromatic hydrocarbons (PAH). Comparisons of PAH distributions were used to differentiate the coal tar hydrocarbons from the petroleum hydrocarbons in soil samples. A more specific technique was needed to accurately allocate the contribution of the two sources to the observed PAH contamination in the soil. Petroleum biomarkers (steranes and triterpanes) which are present in crude oils and many refined petroleum products but are absent in coal tar were used to quantitatively allocate the source of the PAH contamination based on the relative ratio of the PAH to the biomarkers in soil samples. Using the resulting coal tar/petroleum source ratio the contribution of petroleum to the overall PAH contamination at the site was calculated. A multivariate statistical technique (principal component analysis or PCA) was used to provide an independent validation of the source allocation. The results of the source allocation provided a foundation for the site clean-up and remediation costs

  11. Understanding the fate and transport of petroleum hydrocarbons from coal tar within gasholders.

    Science.gov (United States)

    Coulon, Frédéric; Orsi, Roberto; Turner, Claire; Walton, Chris; Daly, Paddy; Pollard, Simon J T

    2009-02-01

    Coal tars have been identified as posing a threat to human health due to their toxic, mutagenic and carcinogenic characteristics. Workers involved in former gasholders decommissioning are potentially exposed to relevant concentrations of volatile and semi-volatile hydrocarbons upon opening up derelict tanks and during tar excavation/removal. While information on contaminated sites air-quality and its implications on medium-long term exposure is available, acute exposure issues associated with the execution of critical tasks are less understood. Calculations indicated that the concentration of a given contaminant in the gasholder vapour phase only depends on the coal tar composition, being only barely affected by the presence of water in the gasholder and the tar volume/void space ratio. Fugacity modelling suggested that risk-critical compounds such as benzene, naphthalene and other monocyclic and polycyclic aromatic hydrocarbons may gather in the gasholder air phase at significant concentrations. Gasholder emissions were measured on-site and compared with the workplace exposure limits (WELs) currently in use in UK. While levels for most of the toxic compounds were far lower than WELs, benzene air-concentrations where found to be above the accepted threshold. In addition due to the long exposure periods involved in gasholder decommissioning and the significant contribution given by naphthalene to the total coal tar vapour concentration, the adoption of a WEL for naphthalene may need to be considered to support operators in preventing human health risk at the workplace. The Level I fugacity approach used in this study demonstrated its suitability for applications to sealed environments such as gasholders and its further refining could provide a useful tool for land remediation risk assessors.

  12. Structural and dynamic characterization of the upper part of the HIV-1 cTAR DNA hairpin

    OpenAIRE

    Zargarian, Loussin?; Kanevsky, Igor; Bazzi, Ali; Boynard, Jonathan; Chaminade, Fran?oise; Foss?, Philippe; Mauffret, Olivier

    2009-01-01

    First strand transfer is essential for HIV-1 reverse transcription. During this step, the TAR RNA hairpin anneals to the cTAR DNA hairpin; this annealing reaction is promoted by the nucleocapsid protein and involves an initial loop?loop interaction between the apical loops of TAR and cTAR. Using NMR and probing methods, we investigated the structural and dynamic properties of the top half of the cTAR DNA (mini-cTAR). We show that the upper stem located between the apical and the internal loop...

  13. Criteria for selection of dolomites and catalysts for tar elimination from biomass gasification gas. Kinetic constants

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J; Narvaez, I; Orio, A [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1997-12-31

    Calcined dolomites and commercial steam reforming catalysts are used downstream biomass gasifiers for hot catalytic raw gas cleaning. To further compare these solids under a rigorous basis, a reaction network and a kinetic model are presented. The apparent kinetic constant for the tar reduction is here proposed as a basis of comparison. Tar sampling and analysis, and the units used for the space-time in the catalytic reactor affect the kinetic constants observed. (author) (2 refs.)

  14. Criteria for selection of dolomites and catalysts for tar elimination from biomass gasification gas. Kinetic constants

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1996-12-31

    Calcined dolomites and commercial steam reforming catalysts are used downstream biomass gasifiers for hot catalytic raw gas cleaning. To further compare these solids under a rigorous basis, a reaction network and a kinetic model are presented. The apparent kinetic constant for the tar reduction is here proposed as a basis of comparison. Tar sampling and analysis, and the units used for the space-time in the catalytic reactor affect the kinetic constants observed. (author) (2 refs.)

  15. Creating fluid injectivity in tar sands formations

    Science.gov (United States)

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2010-06-08

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

  16. The separate effects of tar and nicotine on the cigarette smoking manoeuvre

    International Nuclear Information System (INIS)

    Woodman, G.; Newman, S.P.; Paiva, D.; Clarke, S.W.

    1987-01-01

    The separate effects of tar and nicotine on the cigarette smoking manoeuvre were investigated. Each of ten asymptomatic habitual smokers smoked three different commercially available cigarettes in a randomised order. The brands were chosen such that two had the same tar yield (10 mg) and two had the same nicotine yield (1.4 mg). The volume of smoke inhaled into the lungs was measured by tracing the smoke with the inert gas 81 Kr m . Puffing indices were recorded using an electronic smoking analyser and flowhead/cigarette holder. There was no difference in the total volume of smoke puffed from each of the cigarette brands. With cigarettes of the samme tar level, the total inhaled smoke volume was lower with the higher nicotine cigarette (P<0.05): by contrast, with cigarettes of the same nicotine level, the toal inhaled smoke volume was lower with the lower tar cigarette (P<0.02). Tar and nicotine appear to exercise independent control over the volume of smoke inhaled. (author)

  17. Characterization of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) in tar-balls collected from the East Coast of Peninsular Malaysia.

    Science.gov (United States)

    Chandru, Kuhan; Zakaria, Mohamad Pauzi; Anita, Sofia; Shahbazi, Azadeh; Sakari, Mahyar; Bahry, Pourya Shahpoury; Mohamed, Che Abd Rahim

    2008-05-01

    The East Coast of Peninsular Malaysia faces the South China Sea and is vulnerable to oil pollution because of intense petroleum production activities in the area. The South China Sea is also a favored route for supertankers carrying crude oil to the Far East. Consequently, oil spills can occur, causing pollution and contamination in the surrounding areas. Residual oil spills stranded on coastal beaches usually end up as tar-balls. Elucidating the sources of tar-balls using a molecular marker approach is essential in assessing environmental impacts and perhaps settling legal liabilities for affected parties. This study utilizes a multimodal molecular marker approach through the use of diagnostic ratios of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) to determine the source, distribution and weathering of tar-balls. Hopane ratios (e.g., C29/C30, and summation C31-C35/C30 ratios) were used to identify the sources of tar-balls. The weathering effects were distinguished by using alkanes, namely the unresolved complex mixture (UCM) and low molecular weight/high molecular weight (L/H) ratios. Similarly, PAHs were also used for the determination of weathering processes undergone by the tar-balls. This multimodal molecular marker gave a very strong indication of the sources of tar-balls in this study. For example, 16 out of 17 samples originated from South East Asian Crude Oil (SEACO) with one sample from Merang, Terengganu originating from North Sea Oil (Troll). The TRME-2 sample may have come from a supertanker's ballast water discharge. The second possibility is that the tar-ball may have been transported via oceanographic currents. All 'weathered' sample characterizations were based on the presence of UCM and other ratios. The multimodal molecular marker approach applied in this study has enabled us to partially understand the transport behavior of tar-balls in the marine environment and has revealed insights into the weathering process of tar-balls.

  18. Physical properties and component contents of brown coal tars obtained in semicoking with a solid heat transfer semicoke

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, V I; Bobrova, A A

    1955-01-01

    Tar obtained in low-temperature carbonization of brown coals with brown-coal semicoke as a heat-transfer medium contains more water and dust, has a lower drop point, and a higher specific gravity, and contains more asphaltene and less paraffin than does tar from the same coal produced in rotating retorts or in shaft kilns. The brown-coal semicoke used as a heat-transfer medium produces partial thermal cracking of the fuel and polymerization of the products of secondary decompositions. The yield of asphaltenes is lowered when the carbonization temperature is raised.

  19. Gasification of municipal solid waste in a downdraft gasifier: Analysis of tar formation

    Directory of Open Access Journals (Sweden)

    Tabitha Geoffrey Etutu

    2016-04-01

    Full Text Available In this study, municipal solid waste (MSW from a dumpsite was converted into refuse derived fuel (RDF and used as feedstock for an air-blown gasification process. The gasification process was conducted in a 10 kg.hr -1 downdraft gasifier at different air flow rates of 300, 350, 400, 450 and 550 NL.min1 at atmospheric pressure in order to investigate the quantity and quality of tar formed. It was shown that the increase in the air flow rate from 300 NL.min1 to 550 NL.min1 led to an increase in the oxidation temperature from 719°C to 870°C and an increase in the reduction temperature from 585°C to 750°C, respectively. Tar was reduced from 15 g.Nm3 to 4.7 g.Nm3 respectively. Heavy tar compounds (>C17 e.g. pyrene and phenathrene, decreased with the increase in the light tar compounds (tar reduction through a tar cracking process.

  20. Catalytic reforming of toluene as tar model compound: effect of Ce and Ce-Mg promoter using Ni/olivine catalyst.

    Science.gov (United States)

    Zhang, Ruiqin; Wang, Huajian; Hou, Xiaoxue

    2014-02-01

    Tar produced by biomass gasification as a route of renewable energy must be removed before the gas can be used. This study was undertaken using toluene as a model tar compound for evaluating its steam reforming conversion with three Ni-based catalysts, Ni/olivine, Ni-Ce/olivine and Ni-Ce-Mg/olivine. Effects of Ce and Mg promoters on the reaction activity and coke deposition were studied. Overall the performance of Ce and Mg promoted Ni/olivine catalysts is better than that of only Ce promoter and Ni/olivine alone. The experimental results indicate that Ni-Ce-Mg/olivine catalysts could improve the resistance to carbon deposition, enhance energy gases yield and resist 10ppm H2S poison at 100mLmin(-1) for up to 400min. Furthermore, the activity of catalysts was related to the steam/carbon (S/C) ratios; at S/C ratio=5, T=790°C, space velocity=782h(-1) and t=2h, the Ni-Ce-Mg/olivine system yielded 89% toluene conversion, 5.6Lh(-1) product gas rate, 62.6mol% H2 content and 10% (mol useful gas mol(-1) toluene) energy yield. Moreover, at low S/C ratio, it had higher reaction activity and better ability to prevent coking. There is a small amount of carbon deposition in the form of amorphous carbon after 7h. Various characterization techniques such as XRD, FTIR and thermogravimetric were performed to investigate the coke deposition of Ni/olivine, Ni-Ce/olivine and Ni-Ce-Mg/olivine. It is suggested that 3% Ni-1% Ce-1% Mg/olivine was the most promising catalyst due to its minimum coke amount and the lower activation energy of coke burning. Copyright © 2014. Published by Elsevier Ltd.

  1. Recovery of very viscous lubricating oils from shale-tar, etc

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, E

    1919-09-10

    Modification of the process covered by German Patent 335,190 for recovering very viscous lubricating oils, consisting, in place of brown-coal tar, deparafinned peat tar being subjected to the treatment with superheated steam from about 200 to 250/sup 0/C or to heating in vacuum at a temperature below 250/sup 0/C.

  2. Inhaled smoke volume and puff indices with cigarettes of different tar and nicotine levels

    International Nuclear Information System (INIS)

    Woodman, G.; Newman, S.P.; Pavia, D.; Clarke, S.W.

    1987-01-01

    Ten asymptomatic smokers each smoked a low, low-to-middle and a middle tar cigarette with approximately the same tar-to-nicotine ratio, in a randomised order. The inhaled smoke volume was measured by tracing the smoke with the inert gas 81 Kr m . Puffing indices were recorded using an electronic smoking analyser and flowhead/cigarette holder. Throughout the study neither the mean inhaled smoke volume per puff nor the total inhaled smoke volume per cigarette changed significantly; however, the mean and total puff volumes were largest with the low tar cigarette and decreased with the higher tar brands. Puff volume was related to puff work (r s =0.83,P s =0.10,P>0.1). It is concluded that when switched between brands with the same tar-to-nicotine ratio, smokers increase their puff volumes with a lower tar cigarette but do not change the volume of smoke inhaled. Puff work and puff resistance were significantly correlated (r s =0.45,P<0.02). (author)

  3. Changes in tar yields and cigarette design in samples of Chinese cigarettes, 2009 and 2012.

    Science.gov (United States)

    Schneller, Liane M; Zwierzchowski, Benjamin A; Caruso, Rosalie V; Li, Qiang; Yuan, Jiang; Fong, Geoffrey T; O'Connor, Richard J

    2015-11-01

    China is home to the greatest number of smokers as well as the greatest number of smoking-related deaths. An active and growing market of cigarettes marketed as 'light' or 'low tar' may keep health-concerned smokers from quitting, wrongly believing that such brands are less harmful. This study sought to observe changes in cigarette design characteristics and reported tar, nicotine and carbon monoxide (TNCO) levels in a sample of cigarette brands obtained in seven Chinese cities from 2009 to 2012. Cigarettes were purchased and shipped to Roswell Park Cancer Institute, where 91 pairs of packs were selected for physical cigarette design characteristic testing and recording of TNCO values. Data analysis was conducted using SPSS, and was initially characterised using descriptive statistics, correlations and generalised estimating equations to observe changes in brand varieties over time. Reported TNCO values on packs saw mean tar, nicotine and CO levels decrease from 2009 to 2012 by 7.9%, 4.5% and 6.0%, respectively. Ventilation was the only cigarette design feature that significantly changed over time (p<0.001), with an increase of 31.7%. Significant predictors of tar and CO yield overall were ventilation and per-cigarette tobacco weight, while for nicotine tobacco moisture was also an independent predictor of yield. The use of ventilation to decrease TNCO emissions is misleading smokers to believe that they are smoking a 'light/low' tar cigarette that is healthier, and is potentially forestalling the quitting behaviours that would begin to reduce the health burden of tobacco in China, and so should be prohibited. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Assessment of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    Science.gov (United States)

    Hult, M.F.

    1984-01-01

    Operation of a coal-tar distillation and wood-preserving facility in St. Louis Park, Minnesota, during 1918-72 contaminated ground water with coal-tar derivatives and inorganic chemicals. Coal-tar derivatives entered the groundwater system through three major paths: (1) Spills and drippings that percolated to the water table, (2) surface runoff and plant process water that was discharged to wetlands south of the former plant site, and (3) movement of coal tar directly into bedrock aquifers through a multiaquifer well on the site.

  5. Simulation of Trajectories of Tar Ball Transport to the Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Vethamony, P.; VinodKumar, K.; Babu, M.T.; Prasad, V.S.R.

    Arrival of tar balls to the Goa coast during pre- and southwest monsoon seasons has been a regular phenomenon in the past few years. In one such event, we observed tar ball deposits along the Goa coast during August 2010, April 2011 and May 2011...

  6. Ensamblajes urbanos: la TAR y el examen de la ciudad

    Directory of Open Access Journals (Sweden)

    Ignacio Farías

    2011-03-01

    Full Text Available Este artículo presenta nuevas perspectivas de investigación y desafíos analíticos que la teoría del actor-red (TAR abre para los estudios urbanos. En primer lugar, se revisan cómo los principios de relacionalidad híbrida y asociatividad plana de la TAR están siendo adoptados en los estudios urbanos para ampliar simétricamente la ecología urbana a no-humanos e impugnar concepciones escalares del espacio y economías urbanas. A continuación, se propone que la TAR trae consigo un desafío más fundamental relativo a la concepción de la ciudad como objeto de estudio. Mientras su comprensión habitual como objeto espacial, entidad político-económica y/o forma sociocultural subraya su carácter singular, estable y delimitado, la TAR permite pensar la ciudad como un objeto múltiple y decentrado. La noción de ensamblajes urbanos se introduce entonces para dar cuenta de la circulación y devenir de la ciudad en múltiples redes híbridas y translocales. El artículo concluye sopesando algunas de las consecuencias de este exámen de la ciudad, especialmente el reposicionamiento del problema de la complejidad, urbana en este caso, como punto, si no de partida, entonces al menos de llegada para la TAR.

  7. Copyrolysis of coal with coke-oven gas. III. Analysis of tar

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Sun, C.; Li, B.; Liu, Z. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion, Institute of Coal Chemistry

    1998-02-01

    Tars from copyrolysis of Xianfeng lignite with coke-oven gas (COG) at different pressures (0.1-5 MPa) and heating rates (5-25{degree}C/min) to a final temperature of 650{degree}C were analyzed and compared with hydropyrolysis under the same H{sub 2} partial pressure. The results indicated that high contents of BTX, PCX and naphthalene were found in the tar from copyrolysis of Xianfeng lignite with COG. Pressure and heating rate have important effects on tar yields and the contents of BTX, PCX and naphthalene in oil. Increasing pressure and decreasing heating rate enhance the tar yields and result in high yields of BTX and PCX. When compared with hydropyrolysis under the same H{sub 2} partial pressure, the tar yield increases by 1.2 times and the yields of BTX, PCX and naphthalene by about 1.6, 1.3 and 1.6 times, respectively. At the same total pressure (3MPa), the yields of BTX and naphthalene from copyrolysis are equal to those from hydropyrolysis. The results reveal that other components in COG, such as methane, carbon monoxide etc., are of importance for pyrolysis behaviour of coal under COG and improvement of oil qualities. 5 refs., 5 figs., 2 tabs.

  8. Evaluation of different oxygen carriers for biomass tar reforming

    DEFF Research Database (Denmark)

    Mendiara, Teresa; Johansen, Joakim Myung; Utrilla, Rubén

    2011-01-01

    , in a concentration of 600–2000ppmv, was chosen as a tar model compound. Experiments were performed in a TGA apparatus and a fixed bed reactor. Four oxygen carriers (60% NiO/MgAl2O4 (Ni60), 40% NiO/NiAl2O4 (Ni40), 40% Mn3O4/Mg–ZrO2 (Mn40) and FeTiO3 (Fe)) were tested under alternating reducing/oxidizing cycles...

  9. Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques

    International Nuclear Information System (INIS)

    Suneel, V.; Vethamony, P.; Zakaria, M.P.; Naik, B.G.; Prasad, K.V.S.R.

    2013-01-01

    Highlights: ► This is first fingerprinting study in India on identification of source of tar balls. ► Tar balls were formed from tanker-wash spills and they resemble floating tar ball. ► δ 13 C values of Bombay High crude oil and the present tar balls do not match. ► Compound specific stable carbon isotope analysis confirmed the source of tar balls. ► Source is confirmed as the South East Asian Crude Oil and not the Bombay High crude. -- Abstract: Deposition of tar balls along the coast of Goa, India is a common phenomenon during the southwest monsoon. Representative tar ball samples collected from various beaches of Goa and one Bombay High (BH) crude oil sample were subjected to fingerprint analysis based on diagnostic ratios of n-alkane, biomarkers of pentacyclic tri-terpanes and compound specific stable carbon isotope (δ 13 C) analysis to confirm the source. The results were compared with the published data of Middle East Crude Oil (MECO) and South East Asian Crude Oil (SEACO). The results revealed that the tar balls were from tanker-wash derived spills. The study also confirmed that the source is not the BH, but SEACO. The present study suggests that the biomarkers of alkanes and hopanes coupled with stable carbon isotope analysis act as a powerful tool for tracing the source of tar balls, particularly when the source specific biomarkers fail to distinguish the source

  10. 29 CFR 1926.1102 - Coal tar pitch volatiles; interpretation of term.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1926.1102 Section 1926.1102 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Hazardous Substances § 1926.1102 Coal tar pitch volatiles; interpretation of term. Note: The requirements...

  11. 29 CFR 1915.1002 - Coal tar pitch volatiles; interpretation of term.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1915.1002 Section 1915.1002 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... Toxic and Hazardous Substances § 1915.1002 Coal tar pitch volatiles; interpretation of term. Note: The...

  12. Acute toxicity of birch tar oil on aquatic organisms

    Directory of Open Access Journals (Sweden)

    M. HAGNER

    2008-12-01

    Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

  13. Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene

    International Nuclear Information System (INIS)

    Gaylor, D.W.; Culp, S.J.; Goldstein, L.S.; Beland, F.A.

    2000-01-01

    Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk -4 (ppm coal tar in total diet) + 240 x 10 -4 (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk -4 (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10 -3 per microg per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10 -3 per microg per kg body weight per day listed in the US EPA Integrated Risk Information System

  14. Forensic assessment of polycyclic aromatic hydrocarbons at the former Sydney Tar Ponds and surrounding environment using fingerprint techniques

    International Nuclear Information System (INIS)

    MacAskill, N. Devin; Walker, Tony R.; Oakes, Ken; Walsh, Margaret

    2016-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were assessed spatially and temporally within and adjacent to a former coking and steel manufacturing facility in Sydney, Nova Scotia, Canada. Concentrations of PAHs were measured in surface soils, marine and estuary sediments prior to and during remediation of the Sydney Tar Ponds (STPs) site which was contaminated by nearly a century of coking and steel production. Previous studies identified PAHs in surficial marine sediments within Sydney Harbour, which were considered to be derived from STP discharges. Numerous PAH fingerprint techniques (diagnostic ratios, principal component analysis, quantitative and qualitative analysis) were applied to soil and sediment samples from the STPs and surrounding area to identify common source apportionment of PAHs. Results indicate coal combustion (from historical residential, commercial and industrial uses) and coal handling (from historic on-site stockpiling and current coal transfer and shipment facilities) are likely the principal source of PAHs found in urban soils and marine sediments, consistent with current and historical activities near these sites. However, PAH fingerprints associated with STP sediments correlated poorly with those of urban soils and marine sediments, but were similar to coal tar, historically consistent with by-products produced by the former coking operations. This study suggests PAH contamination of Sydney Harbour sediments and urban soils is largely unrelated to historic coking operations or recent remediation of the STPs site, but rather a legacy of extensive use of coal for a variety of activities. - Highlights: • PAHs were measured in soils and sediments near a former coking and steel facility. • Previous studies identified tar residues as main source of PAHs in marine sediments. • PAH fingerprint techniques were used to identify common source apportionment. • Fingerprint techniques indicated common sources derived from coal, not tar residues

  15. Extraction of tar acids with methanol from low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Funasaka, W; Yokogawa, C; Suga, S

    1948-01-01

    From 20 grams crude middle oil, boiling at 200/sup 0/ to 250/sup 0/, acid content 40%, tar acids were extracted at 20/sup 0/ to 30/sup 0/ with MeOH for comparison with EtOH, NMe/sub 3/, and ethylene glycol. When 80% MeOH is used, the oil extracted amounts to 61%, including 9% acids, if the ratio of crude oil and solvent is kept at 1:2. EtOH is inferior to MeOH. The properties of the crude oil and the purified oil extracted with 80% MeOH are described.

  16. Solvent refining of low-temperature tar with liquid ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, K

    1953-01-01

    The middle fractions of low-temperature tar were treated with mixed solutions of H/sub 2/O and liquid NH/sub 3/ at 0/sup 0/ and 20/sup 0/, and with liquid NH/sub 3/ at -10, 0, + 10, and 20/sup 0/, and phase equilibrium between tar acids, neutral oil, and solvents were studied. The distribution ratio ranged from less than 1 to greater than 1 when the solvent contained about 20 percent (by weight) H/sub 2/O. When the solvent contained less than 85 percent (by weight) NH/sub 3/, the yield of extract was small but the purity of phenols in the extracted oil was above 90 percent. Solvent containing about 85 percent NH/sub 3/ (by weight) is considered optimum for separating tar acids from oils. A novel definition is proposed for solvent selectivity as the difference between the concentration of the solute in the extract layer, on a solvent-free basis, and the concentration in the raffinate layer.

  17. Characterization and utilization of hydrotreated products produced from the Whiterocks (Utah) tar sand bitumen-derived liquid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.H.; Longstaff, D.C.; Deo, M.D.; Hanson, F.V.; Oblad, A.G.

    1991-12-31

    The bitumen-derived liquid produced in a 4-inch diameter fluidized-bed reactor from the mined and crushed ore from the Whiterocks tar sand deposit has been hydrotreated in a fixed-bed reactor. The purpose was to determine the extent of upgrading as a function of process operating variable. A sulfided nickel-molybendum on alumina hydrodenitrogenation catalyst was used in all experiments. Moderately severe operating conditions were employed; that is, high reaction temperature (617--680 K) high reactor pressure (11.0--17.1 MPa) and low liquid feed rate (0.18--0.77 HSV); to achieve the desired reduction in heteroatom content. Detailed chemical structures of the bitumen-derived liquid feedstock and the hydrotreated total liquid products were determined by high resolution gas chromatography - mass spectrometry analyses. The compounds identified in the native bitumen included isoprenoids; bicyclic, tricycle, and tetracyclic terpenoids; steranes; hopanes; and perhydro-{beta}-carotenes. In addition, normal and branched alkanes and alkenes and partially dehydrogenated hydroaromatics were identified in the bitumen-derived liquid. The dominant pyrolysis reactions were: (1) the dealkylation of long alkyl side chains to form {alpha} - and isoolefins; and (2) the cleavage of alkyl chains linking aromatic and hydroaromatic clusters. Olefinic bonds were not observed in the hydrotreated product and monoaromatic hydrocarbons were the predominant aromatic species. The properties of the jet fuel fractions from the hydrotreated products met most of the jet fuel specifications. The cetane indices indicated these fractions would be suitable for use as diesel fuels.

  18. Characterization and utilization of hydrotreated products produced from the Whiterocks (Utah) tar sand bitumen-derived liquid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.H.; Longstaff, D.C.; Deo, M.D.; Hanson, F.V.; Oblad, A.G.

    1991-01-01

    The bitumen-derived liquid produced in a 4-inch diameter fluidized-bed reactor from the mined and crushed ore from the Whiterocks tar sand deposit has been hydrotreated in a fixed-bed reactor. The purpose was to determine the extent of upgrading as a function of process operating variable. A sulfided nickel-molybendum on alumina hydrodenitrogenation catalyst was used in all experiments. Moderately severe operating conditions were employed; that is, high reaction temperature (617--680 K) high reactor pressure (11.0--17.1 MPa) and low liquid feed rate (0.18--0.77 HSV); to achieve the desired reduction in heteroatom content. Detailed chemical structures of the bitumen-derived liquid feedstock and the hydrotreated total liquid products were determined by high resolution gas chromatography - mass spectrometry analyses. The compounds identified in the native bitumen included isoprenoids; bicyclic, tricycle, and tetracyclic terpenoids; steranes; hopanes; and perhydro-{beta}-carotenes. In addition, normal and branched alkanes and alkenes and partially dehydrogenated hydroaromatics were identified in the bitumen-derived liquid. The dominant pyrolysis reactions were: (1) the dealkylation of long alkyl side chains to form {alpha} - and isoolefins; and (2) the cleavage of alkyl chains linking aromatic and hydroaromatic clusters. Olefinic bonds were not observed in the hydrotreated product and monoaromatic hydrocarbons were the predominant aromatic species. The properties of the jet fuel fractions from the hydrotreated products met most of the jet fuel specifications. The cetane indices indicated these fractions would be suitable for use as diesel fuels.

  19. Preparation, Characterization, and Activation of Co-Mo/Y Zeolite Catalyst for Coal Tar Conversion to Liquid Fuel

    Directory of Open Access Journals (Sweden)

    Didi Dwi Anggoro

    2017-05-01

    Full Text Available One of many efforts to convert coal tar into alternative liquid fuel is by hydrocracking. This research aims to determine the impregnation of Co-Mo/Y zeolite, its characteristics, the effect of impregnation temperature and time, and also the best Co-Mo/Y zeolite impregnation condition for the conversion of coal tar. This research was conducted in several steps, impregnating Co from Co(NO32.6H2O and Mo from (NH46Mo7O24.4H2O into Zeolite Y in liquid media, drying at 100 °C for 24 hours, and calcination at 550 °C for 3 hours. Coal tar was then reacted with hydrogen gas (as a reactant, and Co-Mo/Zeolite Y (as a catalyst was conducted at 350 °C. Characteristic analysis showed that Co and Mo had impregnated into the Y zeolite, as well as it made no change of catalyst’s structure and increased the total acidity. The higher of impregnation temperature was increased the catalyst crystallinity, total acidity, and yield of gasoline. The longer impregnation time was reduced crystallinity value, but total acidity and yield were increased. GC analysis showed that products included into the gasoline product (C8, C9, and C10. Copyright © 2017 BCREC Group. All rights reserved Received: 13rd November 2016; Revised: 12nd February 2017; Accepted: 16th February 2017 How to Cite: Anggoro, D.D., Buchori, L., Silaen, G.C., Utami, R.N. (2017. Preparation, Characterization, and Activation of Co-Mo/Y Zeolite Catalyst for Coal Tar Conversion to Liquid Fuel. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2: 219-226 (doi:10.9767/bcrec.12.2.768.219-226 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.768.219-226

  20. Analysis of the environmental control technology for tar sand development

    Energy Technology Data Exchange (ETDEWEB)

    de Nevers, N.; Glenne, B.; Bryner, C.

    1979-06-01

    The environmental technology for control of air pollution, water pollution, and for the disposal, stabilization, and vegetation of the waste tar sand were thoroughly investigated. Although some difficulties may be encountered in any of these undertakings, it seems clear that the air and water pollution problems can be solved to meet any applicable standard. Currently there are two large-scale plants producing liquid fuels from tar sands in Alberta, Canada which use similar technology involving surface mining, hot water extraction, and surface disposal of waste sand. These projects all meet the Canadian environmental control regulations in force at the time they began. The largest US deposits of tar sands are much smaller than the Canadian; 95 percent are located in the state of Utah. Their economics do not appear as attractive as the Canadian deposits. The environmental control costs are not large enough to make an otherwise economic project uneconomic. The most serious environmental conflict likely to occur over the recovery of liquid fuels from the US deposits of tar sands is that caused by the proximity of the deposits to national parks, national monuments, and a national recreation area in Utah. These areas have very stringent air pollution requirements; and even if the air pollution control requirements can be met, there may still be adequate opposition to large-scale mining ventures in these areas to prevent their commercial exploitation. Another environmental constraint may be water rights availability.Essentially all of the water running in the Colorado river basin is now legally allocated. Barring new interpretations of the legality of water rights purchase, Utah tar sands developments should be able to obtain water by purchasing existing irrigation water rights.

  1. Properties of gasification-derived char and its utilization for catalytic tar reforming

    Science.gov (United States)

    Qian, Kezhen

    Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon. The overall goal of the proposed research was to develop novel methods to use char derived from gasification for high-value applications in syngas conditioning. The first objective was to investigate effects of gasification condition and feedstock on properties of char derived from fluidized bed gasification. Results show that the surface areas of most of the char were 1--10 m 2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The next objective was to study the properties of sorghum and red cedar char derived from downdraft gasifier. Red cedar char contained more aliphatic carbon and o-alkyl carbon than sorghum char. Char derived from downdraft gasification had higher heating values and lower ash contents than char derived from fluidized bed gasification. The gasification reactivity of red cedar char was higher than that of sorghum char. Then, red cedar char based catalysts were developed with different preparation method to reform toluene and naphthalene as model tars. The catalyst prepared with nickel nitrate was found to be better than that with nickel acetate. The nickel particle size of catalyst impregnated with nickel nitrate was smaller than that of catalyst impregnated with nickel acetate. The particle size of catalyst impregnated with nickel acetate decreased by hydrazine reduction. The catalyst impregnated with nickel nitrate had the highest toluene removal efficiency, which was 70%--100% at 600--800 °C. The presence of naphthalene in tar reduced the catalyst efficiency. The toluene conversion was 36--99% and the naphthalene conversion was 37%--93% at 700--900 °C. Finally, effects of atmosphere and pressure on catalytic reforming of lignin-derived tars over the developed catalyst

  2. Process from removing benzine, toluene, etc. , from petroleum residues, coal tar, and shale tar, etc

    Energy Technology Data Exchange (ETDEWEB)

    Hlawaty, F

    1888-08-11

    A process is described for the preparation of ligroin and its homologs as well as naphthalene and anthracene consisting in leading superheated water vapor into a mixture of petroleum residues (or mineral coal tar, etc.) heated to about 400/sup 0/C with cellulosic substances as sage shreds, sea grass, or straw, with addition of caustic alkali.

  3. Simulation of the influence of tar formation in wood gasification processes on the cost of the purified process gas; Simulation des Einflusses der Teerbildung bei der Vergasung von Holz auf die Kosten des gereinigten Produktgases

    Energy Technology Data Exchange (ETDEWEB)

    Saller, G; Krumm, W [Siegen Univ. (Gesamthochschule) (Germany). Inst. fuer Energietechnik

    1998-09-01

    The influence of the gasification process and the related tar formation rate on the cost of gas production is investigated with the aid of process models. The processes of gasification, gas purification and adsorptive treatment of waste water were modelled mathematically with a view to process mechanisms and cost. Simulations of the overall process helped to obtain a quantitative assessment of the cost of product gas as a function of process parameters like gasification process and tar formation. (orig./SR) [Deutsch] Mit Hilfe von Prozessmodellen wird untersucht, welchen Einfluss das Vergasungsverfahren und die damit verbundene Teerbildung mit entsprechenden Reinigungsverfahren auf die Produktionskosten des gereinigten Produktgases besitzt. Hierfuer werden die Prozesse der Vergasung, Gasreinigung und adsorptiven Abwasseraufbereitung hinsichtlich verfahrenstechnischer Zusammenhaenge und Kosten mathematisch modelliert. Durch Simulation des Gesamtprozesses werden quantitativ die Kosten des Produktgases in Abhaengigkeit von Prozessparametern wie Vergasungsverfahren und Teerbildung ermittelt. (orig./SR)

  4. Natural attenuation of aged tar-oil in soils: A case study from a former gas production site

    Science.gov (United States)

    Ivanov, Pavel; Eickhorst, Thilo; Wehrer, Markus; Georgiadis, Anna; Rennert, Thilo; Eusterhues, Karin; Totsche, Kai Uwe

    2017-04-01

    Contamination of soils with tar oil occurred on many industrial sites in Europe. The main source of such contamination has been former manufactured gas plants (MGP). As many of them were destroyed during the World War II or abandoned in the second half of the XXth century, the contamination is depleted in volatile and degradable hydrocarbons (HC) but enriched in the heavy oil fractions due to aging processes. We studied a small tar-oil spill in a former MGP reservoir basin. The tar-oil had a total petroleum hydrocarbon (TPH) content of 245 mg/g. At the margin of the spill, vegetation has started to overgrow and intensively root the tar-oil layer. This zone comprised the uppermost 5-7 cm of our profile and contained 28 mg/g of TPH (A-layer)- The layer below the root zone (7-15 cm) was the most contaminated, with 90 mg/g TPH (B-layer). The layer underneath (15-22 cm) had smaller concentrations of 16 mg/g TPH (C-layer). Further down in the profile (D-layer) we found only slightly higher TPH content than in the control samples (1,4 mg/g vs 0,6 mg/g). The polycyclic aromatic hydrocarbons analysis showed the same distribution throughout all layers with highest contents of the PAHs with 4-6 condensed aromatic rings. Direct cell count and extraction of microbial biomass showed that the highly contaminated soil layers A and B had 2-3 times more bacteria than the control soils. CARD-FISH analysis revealed that in samples from layers A and B Archaea were more abundant (12% opposing to 6-7% in control soil). Analysis of bacteria (tested for Alpha-, Beta-, Gamma- and Epsilonproteobacteria and Actinobacteria) showed the dominance of Alphaproteobacteria in the layer A and C both beneath and above the most contaminated layer B. The primers covered the whole microbial consortia in these two layers, leaving almost no unidentified cells. In the most contaminated layer B Alphaproteobacteria amounted only to 20% of the microbial consortium, and almost 40% of the cells remained

  5. Effective conversion of biomass tar into fuel gases in a microwave reactor

    Energy Technology Data Exchange (ETDEWEB)

    Anis, Samsudin, E-mail: samsudin-anis@yahoo.com [Department of Mechanical Engineering, Universitas Negeri Semarang, Kampus Sekaran, Gunungpati, 50229 Semarang, 8508101 (Indonesia); Zainal, Z. A., E-mail: mezainal@usm.my [School of Mechanical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang (Malaysia)

    2016-06-03

    This work deals with conversion of naphthalene (C{sub 10}H{sub 8}) as a biomass tar model compound by means of thermal and catalytic treatments. A modified microwave oven with a maximum output power of 700 W was used as the experimental reactor. Experiments were performed in a wide temperature range of 450-1200°C at a predetermined residence time of 0.24-0.5 s. Dolomite and Y-zeolite were applied to convert naphthalene catalytically into useful gases. Experimental results on naphthalene conversion showed that conversion efficiency and yield of gases increased significantly with the increase of temperature. More than 90% naphthalene conversion efficiency was achieved by thermal treatment at 1200°C and 0.5 s. Nevertheless, this treatment was unfavorable for fuel gases production. The main product of this treatment was soot. Catalytic treatment provided different results with that of thermal treatment in which fuel gases formation was found to be the important product of naphthalene conversion. At a high temperature of 900°C, dolomite had better conversion activity where almost 40 wt.% of naphthalene could be converted into hydrogen, methane and other hydrocarbon gases.

  6. The use of coal-tar pitches of very high softening point and low carcinogen content as binders for industrial carbon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    It has been demonstrated that the content of known carcinogenic polynuclear aromatic hydrocarbons (PAH) in coal-tar pitches may be reduced to levels which comply with existing and/or proposed environmental legislation, typically by distillation at low pressures, and preferably using a form of thin-film evaporation apparatus. However, the immediate products of such distillations usually have very high softening points, typically above 200{degree}C, and are unsuitable for direct utilization in conventional commercial carbon manufacturing processes as a result of the need for very high mixing temperatures. Advantage has been taken of the of a low-PAH coal-tar pitch, supplied in powder form, which has a softening point above 200{degree}C. Methods were examined which might allow mixing and forming of the hard pitch and a petroleum coke aggregate blend either at room temperature or at conventional processing temperature, and hot-pressuring or sintering procedures in which mixtures of the hard pitch and petroleum coke aggregate were formed at or above the softening temperature of the pitch. All the formed products were baked to give carbons which were evaluated for the major properties of density, electrical resistivity and strength. A comparison was also made between the volatiles evolved during the baking of products made with the low-PAH pitch and those made with a conventional coal-tar binder pitch.

  7. Co-carcinogenesis: Human Papillomaviruses, Coal Tar Derivatives, and Squamous Cell Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Harry W. Haverkos

    2017-11-01

    Full Text Available Cervical cancer (CC is the fourth most common cancers among women worldwide. Human papillomaviruses (HPVs play a major role in the etiology of CC, with several lines of epidemiologic and experimental evidence supporting a role for non-viral (co-carcinogens and host genetic factors in controlling the risk for progression to neoplasia among HPV-infected individuals. The role of co-carcinogens in the development of CC is significant in the developing world where poor sanitation and other socio-economic conditions increase the infectious cancer burden. Here, we discuss how exposure to environmental factors such as coal tar derivatives from cigarette smoking, tar-based sanitary products, and inhaled smoke from biomass-burning stoves, could activate host pathways involved in development of HPV-associated squamous cell cancers in resource-limited settings. Understanding interactions between these pathways with certain oncogenic HPV genotypes may guide implementation of strategies for control and treatment of HPV-associated cancers that develop in populations at high risk of exposure to various co-carcinogens.

  8. Creating and maintaining a gas cap in tar sands formations

    Science.gov (United States)

    Vinegar, Harold J.; Karanikas, John Michael; Dinkoruk, Deniz Sumnu; Wellington, Scott Lee

    2010-03-16

    Methods for treating a tar sands formation are disclosed herein. Methods for treating a tar sands formation may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. Pressure may be allowed to increase in an upper portion of the formation to provide a gas cap in the upper portion. At least some hydrocarbons are produced from a lower portion of the formation.

  9. The documentation of tar balls on oiled shorelines : lessons from the New Carissa, Oregon

    International Nuclear Information System (INIS)

    Owens, E.H.; Zimlicki-Owens, L.M.; Lamarche, A.; Reimer, P.D.; Martin, C.A.

    2000-01-01

    The New Carissa, carrying approximately 400,000 gallons of fuel oils ran aground on the outer shore of North Spit, in the vicinity of Coos Bay, Oregon, on February 4, 1999. The oil was released directly into the nearshore surf zone. Following the spill, a stretch of approximately 300 km of the coast of Oregon was surveyed and monitored. The need for the documentation of stranded tar balls in the neighbourhood of the spill site prompted the implementation of a long-term observation program. Initially, Shoreline Clean-up and Assessment Technique (SCAT) reporting procedures were required. Heavy oiling was followed by stranded oil taking the form of tar balls. The amount of oil on the shoreline decreased and the SCAT procedures alone were no longer adequate. They provided estimations of oil quantities that were too high and failed to provide any discrimination between amounts of oil observed on the beaches. A new reporting technique called Beach Assessment Reporting was designed to overcome the difficulties and record adequately the character and frequency of stranded tar balls. Maps, tables and histograms of stranded tar ball volumes and concentrations were discussed. Since the data spanned nine orders of magnitude at times, the semi-logarithmic scale time series plots of the concentration of the tar balls was used in order to identify trends. Conventional histograms only identified large values and camouflaged smaller trends in the time series. A direct method for describing tar ball concentrations geographically proved to be the use of weekly maximum tar ball concentration maps by segment. 10 refs., 2 tabs., 9 figs

  10. Comparative assessment of coal tars obtained from 10 former manufactured gas plant sites in the eastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.G.; Gupta, L.; Kim, T.H.; Moo-Young, H.K.; Coleman, A.J. [Lehigh University, Bethlehem, PA (United States). Dept. of Civil & Environmental Engineering

    2006-11-15

    A comparative analysis was performed on eleven coal tars obtained from former manufactured gas plant sites in the eastern United States. Bulk properties analyzed included percent ash, Karl Fisher water content, viscosity and average molecular weight. Chemical properties included monocyclic- and polycyclic-aromatic hydrocarbon (PAH) concentrations, alkylated aromatic concentrations, and concentrations of aliphatic and aromatic fractions. It was found that there was at least an order-of-magnitude variation in all properties measured between the eleven coal tars. Additionally, two coal tars obtained from the same manufactured gas plant site had very different properties, highlighting that there can be wide variations in coal tar properties from different samples obtained from the same site. Similarities were also observed between the coal tars. The relative chemical distributions were similar for all coal tars, and the coal tars predominantly consisted of PAHs, with naphthalene being the single-most prevalent compound. The C{sub 9-22} aromatic fraction, an indicator of all PAHs up to a molecular weight of approximately 276 g mole{sup -1}, showed a strong power-law relationship with the coal tar average molecular weight (MWct). And the concentrations of individual PAHs decreased linearly as MWct increased up to ca. 1000 g mole{sup -1}, above which they remained low and variable. Implications of these properties and their variation with MWct on groundwater quality are discussed. Ultimately, while these similarities do allow generalities to be made about coal tars, the wide range of coal tar bulk and chemical properties reported here highlights the complex nature of coal tars.

  11. A CFD model for biomass fast pyrolysis in fluidized-bed reactors

    Science.gov (United States)

    Xue, Qingluan; Heindel, T. J.; Fox, R. O.

    2010-11-01

    A numerical study is conducted to evaluate the performance and optimal operating conditions of fluidized-bed reactors for fast pyrolysis of biomass to bio-oil. A comprehensive CFD model, coupling a pyrolysis kinetic model with a detailed hydrodynamics model, is developed. A lumped kinetic model is applied to describe the pyrolysis of biomass particles. Variable particle porosity is used to account for the evolution of particle physical properties. The kinetic scheme includes primary decomposition and secondary cracking of tar. Biomass is composed of reference components: cellulose, hemicellulose, and lignin. Products are categorized into groups: gaseous, tar vapor, and solid char. The particle kinetic processes and their interaction with the reactive gas phase are modeled with a multi-fluid model derived from the kinetic theory of granular flow. The gas, sand and biomass constitute three continuum phases coupled by the interphase source terms. The model is applied to investigate the effect of operating conditions on the tar yield in a fluidized-bed reactor. The influence of various parameters on tar yield, including operating temperature and others are investigated. Predicted optimal conditions for tar yield and scale-up of the reactor are discussed.

  12. Physicochemical Approaches for the Remediation of Former Manufactured Gas Plant Tars

    Science.gov (United States)

    Hauswirth, S.; Miller, C. T.

    2014-12-01

    Former manufactured gas plant (FMGP) tars are one of the most challenging non-aqueous phase liquid (NAPL) contaminants to remediate due to their complex chemical composition, high viscosities, and ability to alter wettability. In this work, we investigate several in situ remediation techniques for the removal of tar from porous media. Batch and column experiments were conducted to test the effectiveness of mobilization, solubilization, and chemical oxidation remediation approaches. Alkaline (NaOH), surfactant (Triton X-100), and polymer (xanthan gum) agents were used in various combinations to reduce tar-water interfacial tension, increase flushing solution viscosity, and increase the solubilities of tar components. Base-activated sodium persulfate was used alone and in combination with surfactant to chemically oxidized tar components. The effectiveness of each method was assessed in terms of both removal of PAHs from the system and reduction of dissolved-phase effluent polycyclic aromatic hydrocarbon (PAH) concentrations. In column studies, alkaline-polymer (AP) and alkaline-surfactant-polymer (ASP) solutions efficiently mobilized 81-93% and 95-96% of residual PAHs, respectively, within two pore volumes. The impact of AP flushing on dissolved-phase PAH concentrations was relatively low; however, the concentrations of several low molar mass PAHs were significantly reduced after ASP flushing. Surfactant-polymer (SP) solutions removed over 99% of residual PAHs through a combination of mobilization and solubilization, and reduced the post-remediation, dissolved-phase total PAH concentration by 98.4-99.1%. Degradation of residual PAHs by base-activated sodium persulfate was relatively low (30-50%), and had little impact on dissolved-phase PAH concentrations.

  13. Mechanical characterization of Portland cement mortars containing petroleum or coal tar

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-08-01

    Full Text Available This article discusses experimental data on the flexural and compressive strength of Portland cement mortars containing additions or cement replacements consisting in petroleum or coal tar, by-products of the oil and coal industries. The materials studied were two coal (BACA and BACB and two petroleum (BPP and BPT tars. The results show that it is feasible to use such materials as a partial replacement for cement in mortar manufacture. This should lead to the design of a new sustainable product that will contribute to lowering the environmental impact of construction materials while at the same time opening up an avenue for the re-use of this type of industrial by-products.En este artículo se presentan datos experimentales de resistencia a flexión y a compresión de morteros de cemento Portland con adición y sustitución de breas de petróleo y de alquitrán de carbón, que son subproductos de la industria del carbón o del petróleo. Los materiales estudiados son breas de alquitrán de carbón A (BACA y B (BACB, y dos breas de petróleo (BPP y (BPT. Los datos demuestran la viabilidad del uso de estas breas en la fabricación de morteros con menores contenidos de cemento, permitiendo diseñar un nuevo material sostenible con el medio ambiente y que contribuya a reducir el impacto ambiental de los materiales de construcción, hecho que permite abrir una nueva vía de valorización de estos subproductos.

  14. The purification of coal tar by the addition of quinoline and Zn(oh)/sub 2/

    International Nuclear Information System (INIS)

    Zhou, P.; Chen, Q.L.; Ao, X.Q.; Kang, C

    2017-01-01

    The coal tar was purified by the addition of quinoline and Zn(OH)2, in order to decrease the content of carbon and inorganic oxide particles. The effect on the viscosity and ash content of the coal tar were investigated by altering temperature, time, and the amount of quinolone and Zn(OH)2 . When the volume ratio between quinolone and coal tar was 20:1 and the static time was 24 h. The viscosity of three layers decreased with rising temperature. When the static temperature and time was 45 °C and 24 h, respectively. The viscosity of three layers decreased with the arising amount of quinoline. And when the volume ratio between quinolone and coal tar was 20:1 and the temperature was 45 °C. The viscosity of three layers decreased first and then increased with the prolonging of static time. And when the static time of coal tar was 24 h, the viscosity of coal tar is the lowest. Because of the lower viscosity of coal tar, decreasing the content of carbon and ash particles in upper and middle layer, the ash content decreased from 0.168% to 0.092%. The addition of Zn(OH)2 can lead ash content in middle layer decrease to 0.058%. Zn2SiO4 and ZnAl2O4 may be produced due to the reaction between Zn (OH) 2 and SiO2 or Al2O3, which can settle down easily. The results show that the content of carbon and inorganic oxide particles in upper-middle-class (the middle 4/5 of the whole volume) decreased with the addition of quinolone and Zn(OH)2 . When the volume ratio between quinolone and coal tar was 50:2, quality ratio between coal tar and Zn(OH)2 was 20000:1, the mixture were heated up to 45 °C at atmospheric pressure and keeping this constant temperature for 24 h, the ash content in upper-middle-class can decreased to 0.058%. (author)

  15. Opening of the TAR hairpin in the HIV-1 genome causes aberrant RNA dimerization and packaging

    Directory of Open Access Journals (Sweden)

    Das Atze T

    2012-07-01

    Full Text Available Abstract Background The TAR hairpin is present at both the 5′ and 3′ end of the HIV-1 RNA genome. The 5′ element binds the viral Tat protein and is essential for Tat-mediated activation of transcription. We recently observed that complete TAR deletion is allowed in the context of an HIV-1 variant that does not depend on this Tat-TAR axis for transcription. Mutations that open the 5′ stem-loop structure did however affect the leader RNA conformation and resulted in a severe replication defect. In this study, we set out to analyze which step of the HIV-1 replication cycle is affected by this conformational change of the leader RNA. Results We demonstrate that opening the 5′ TAR structure through a deletion in either side of the stem region caused aberrant dimerization and reduced packaging of the unspliced viral RNA genome. In contrast, truncation of the TAR hairpin through deletions in both sides of the stem did not affect RNA dimer formation and packaging. Conclusions These results demonstrate that, although the TAR hairpin is not essential for RNA dimerization and packaging, mutations in TAR can significantly affect these processes through misfolding of the relevant RNA signals.

  16. Material Properties and Characteristics for Development of an Expert System for Coal-Tar Sealers

    National Research Council Canada - National Science Library

    Shoenberger, James

    2001-01-01

    .... Several coal-tar mixtures that varied with source of the coal-tar emulsion, amount of aggregate, and amount of polymer used in the mixtures were evaluated for their field performance and material properties...

  17. Paleontological overview of oil shale and tar sands areas in Colorado, Utah, and Wyoming.

    Energy Technology Data Exchange (ETDEWEB)

    Murphey, P. C.; Daitch, D.; Environmental Science Division

    2009-02-11

    In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the ''Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005,'' Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. In addition, Congress declared that both research- and commercial-scale development of oil shale and tar sands should (1) be conducted in an environmentally sound manner using management practices that will minimize potential impacts, (2) occur with an emphasis on sustainability, and (3) benefit the United States while taking into account concerns of the affected states and communities. To support this declaration of policy, Congress directed the Secretary of the Interior to undertake a series of steps, several of which are directly related to the development of a commercial leasing program for oil shale and tar sands. One of these steps was the completion of a programmatic environmental impact statement (PEIS) to analyze the impacts of a commercial leasing program for oil shale and tar sands resources on public lands, with an emphasis on the most geologically prospective lands in Colorado, Utah, and Wyoming. For oil shale, the scope of the PEIS analysis includes public lands within the Green River, Washakie, Uinta, and Piceance Creek Basins. For tar sands, the scope includes Special Tar Sand Areas (STSAs) located in Utah. This paleontological resources overview report was prepared in support of the Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and PEIS, and it is intended to be used by Bureau of Land Management (BLM) regional paleontologists and field office staff to support future

  18. Pan Am tar sand bid revealed

    Energy Technology Data Exchange (ETDEWEB)

    Gray, E

    1968-12-16

    Muskeg Oil Co., wholly-owned subsidiary of Pan American Canada Oil Co. Ltd., hopes to expand its proposed initial 8,000 bpd in situ Athabasca tar sand production scheme to an ultimate rate of 60,000 bpd. The Muskeg recovery process involves an in situ combustion technique developed by Pan American and applied successfully in experimental work in the Athabasca area. The underground burning process develops heat in the formation, reduces crude bitumen viscosity, and displaces the bitumen to the producing wells. Core analyses have been used to determine bitumen in place, wherever possible. Values for uncored wells were based on logs, through development of an empirical relationship between formation resistivity measured by focused logging devices and bitumen content determined by core analysis. The proposed recovery process is a 10-acre well spacing with 9-spot configuration. The McMurray Formation will be fractured hydraulically and preheated by a combustion process. The bitumen will be recovered by a combustion displacement process utilizing air and water.

  19. Biomass Gasifier ''Tars'': Their Nature, Formation, and Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Milne, T. A.; Evans, R. J. (National Renewable Energy Laboratory); Abatzaglou, N. (Kemestrie, Inc.)

    1998-11-01

    The main purpose of this review is to update the information on gasification tar, the most cumbersome and problematic parameter in any gasification commercialization effort. The work aims to present to the community the scientific and practical aspects of tar formation and conversion (removal) during gasification as a function of the various technological and technical parameters and variables.

  20. Catalytic Steam Reforming of Toluene as a Model Compound of Biomass Gasification Tar Using Ni-CeO2/SBA-15 Catalysts

    Directory of Open Access Journals (Sweden)

    Erik Dahlquist

    2013-07-01

    Full Text Available Nickel supported on SBA-15 doped with CeO2 catalysts (Ni-CeO2/SBA-15 was prepared, and used for steam reforming of toluene which was selected as a model compound of biomass gasification tar. A fixed-bed lab-scale set was designed and employed to evaluate the catalytic performances of the Ni-CeO2/SBA-15 catalysts. Experiments were performed to reveal the effects of several factors on the toluene conversion and product gas composition, including the reaction temperature, steam/carbon (S/C ratio, and CeO2 loading content. Moreover, the catalysts were subjected to analysis of their carbon contents after the steam reforming experiments, as well as to test the catalytic stability over a long experimental period. The results indicated that the Ni-CeO2/SBA-15 catalysts exhibited promising capabilities on the toluene conversion, anti-coke deposition and catalytic stability. The toluene conversion reached as high as 98.9% at steam reforming temperature of 850 °C and S/C ratio of 3 using the Ni-CeO2(3wt%/SBA-15 catalyst. Negligible coke formation was detected on the used catalyst. The gaseous products mainly consisted of H2 and CO, together with a little CO2 and CH4.

  1. Dual vapor extraction on acidic sludge tar at a former refinery

    International Nuclear Information System (INIS)

    Lear, P.R.; Beall, P.; Townsend, S.

    1996-01-01

    OHM Remediation Services Corp conducted a pilot-scale demonstration for a novel application of dual vapor extraction technology for the pretreatment of the acid tar sludge material. The acid tar sludge comprised of approximately 60% asphaltene hydrocarbon material, 20% clay, and up to 20% sulfuric acid (H 2 SO 4 ). The liquid layer in the bottom of the pits has a low pH ( 2 ) gas which is released with the sludge material is excavated or handled. The objective of the dual vapor extraction was to remove the SO 2 vapors and liquid layer containing sulfuric acid prior to any further treatment. The dual vapor extraction would reduce the amount of alkaline reagent required for neutralization while eliminating the health and safety concerns. Overall, the DVE pilot demonstration successfully showed that both liquids and vapors could be removed from the acid tar sludge material. The liquid present in the lower portions of the pits will have pH values of 1.0 or less and acidities on the order of 5% H 2 SO 4 . The liquid removed from the acid tar sludge material by a DVE system will have slightly higher pH (∼1.5) and lower alkalinities (∼3% H 2 SO 4 ). The SO 2 concentration in the vapors removed by the DVE system will be variable with initial levels approaching 1,200 ppmv SO 2 . The SO 2 concentration in the vapor phase should decrease with time. A caustic scrubber solution will remove any SO 2 from the vapor phase. After DVE treatment, the acid tar sludge material would have a slightly increased pH and a decreased SO 2 concentration

  2. Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens

    Energy Technology Data Exchange (ETDEWEB)

    Bommarito, T.; Sparling, D.W.; Halbrook, R.S. [South Illinois University, Carbondale, IL (United States). Cooperative Wildlife Research Laboratory

    2010-09-15

    Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg{sup -1}, much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg{sup -1} to 1500 mg kg{sup -1} under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

  3. Tar ball concentrations in the ocean around the Cape of Good Hope before and after a major oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Eagle, G A; Green, A; Williams, J

    1979-11-01

    From August 1977 to August 1978, tar ball concentrations around the southwestern coast of South Africa were sampled. Prior to a tanker collision on December 16, 1977, the area was relatively free of floating tar. Following the collision, tar ball concentrations increased; tar was transported by wind and currents, at average speeds of about 1 km/hr. In areas of slack currents, tar was observed for as long as 8 months after the spill. Results provided information about surface current trends.

  4. Skin cancer in patients with psoriasis treated with coal tar. A 25-year follow-up study

    International Nuclear Information System (INIS)

    Pittelkow, M.R.; Perry, H.O.; Muller, S.A.; Maughan, W.Z.; O'Brien, P.C.

    1981-01-01

    For many years, crude coal tar has been used for the treatment of psoriasis. The possible carcinogenic effect of crude coal tar and ultraviolet (UV) radiation (Goeckerman regimen), considered individually or in combination, has been of some concern to physicians. A 25-year follow-up study was completed on 280 patients with psoriasis who were hospitalized and treated with crude coal tar and UV radiation at the Mayo Clinic, Rochester, Minn, during the years 1950 through 1954. The results of this study suggest that the incidence of skin cancer is not appreciably increased above the expected incidence for the general population when patients are treated with coal tar ointments. It seems that the Goeckerman regimen (topical crude coal tar combined with UV radiation) can be used with minimal risk for skin cancer in the treatment of psoriasis

  5. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

  6. Do increases in cigarette prices lead to increases in sales of cigarettes with high tar and nicotine yields?

    Science.gov (United States)

    Farrelly, Matthew C; Loomis, Brett R; Mann, Nathan H

    2007-10-01

    We used scanner data on cigarette prices and sales collected from supermarkets across the United States from 1994 to 2004 to test the hypothesis that cigarette prices are positively correlated with sales of cigarettes with higher tar and nicotine content. During this period the average inflation-adjusted price for menthol cigarettes increased 55.8%. Price elasticities from multivariate regression models suggest that this price increase led to an increase of 1.73% in sales-weighted average tar yields and a 1.28% increase in sales-weighted average nicotine yields for menthol cigarettes. The 50.5% price increase of nonmenthol varieties over the same period yielded an estimated increase of 1% in tar per cigarette but no statistically significant increase in nicotine yields. An ordered probit model of the impact of cigarette prices on cigarette strength (ultra-light, light, full flavor, unfiltered) offers an explanation: As cigarette prices increase, the probability that stronger cigarette types will be sold increases. This effect is larger for menthol than for nonmenthol cigarettes. Our results are consistent with earlier population-based cross-sectional and longitudinal studies showing that higher cigarette prices and taxes are associated with increasing consumption of higher-yield cigarettes by smokers.

  7. Detailed grouping and functional composition of neutral substances in low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Kalechits, I V; Salimgareeva, F G; Popova, N I; Kurbangaleeva, D K; Klykova, G G

    1955-01-01

    The grouping and the functional composition of the neutral substances in coal tar were characterized by means of adsorption on silica gel with subsequent chemical analysis of each fraction. The neutral materials were obtained by consecutive treatment of a C/sub 6/H/sub 6/ solution of coal tar with 10 percent alkali and 5 percent H/sub 2/SO/sub 4/ to remove the phenols and the bases. The data show that of the neutral substances (only 75% were identified) 40.5% were aromatic hydrocarbons. Based on a study of all of the data, it was proposed that 90% of the composition of coal tars is aromatic. The physical constants of the separated fractions were determined and are presented in tabular form.

  8. Investigation of sulfur-polycyclic aromatic hydrocarbon in coal derived tars of pyrolysis and hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

    1999-07-01

    A study was undertaken to characterize sulphur forms in coal derived tars from pyrolysis and hydropyrolysis of bituminous coal and lignite. The pyrolysis tars were analyzed for content of polycyclic aromatic sulfur hydrocarbons (PASH). 5 refs., 3 figs., 3 tabs.

  9. Crystallization and preliminary X-ray diffraction analysis of the periplasmic domain of the Escherichia coli aspartate receptor Tar and its complex with aspartate

    Energy Technology Data Exchange (ETDEWEB)

    Mise, Takeshi; Matsunami, Hideyuki; Samatey, Fadel A.; Maruyama, Ichiro N., E-mail: ichi@oist.jp [Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495 (Japan)

    2014-08-27

    The periplasmic domain of the E. coli aspartate receptor Tar was cloned, expressed, purified and crystallized with and without bound ligand. The crystals obtained diffracted to resolutions of 1.58 and 1.95 Å, respectively. The cell-surface receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni{sup 2+}. To understand the molecular mechanisms underlying the induction of Tar activity by its ligands, the Escherichia coli Tar periplasmic domain with and without bound aspartate (Asp-Tar and apo-Tar, respectively) were each crystallized in two different forms. Using ammonium sulfate as a precipitant, crystals of apo-Tar1 and Asp-Tar1 were grown and diffracted to resolutions of 2.10 and 2.40 Å, respectively. Alternatively, using sodium chloride as a precipitant, crystals of apo-Tar2 and Asp-Tar2 were grown and diffracted to resolutions of 1.95 and 1.58 Å, respectively. Crystals of apo-Tar1 and Asp-Tar1 adopted space group P4{sub 1}2{sub 1}2, while those of apo-Tar2 and Asp-Tar2 adopted space groups P2{sub 1}2{sub 1}2{sub 1} and C2, respectively.

  10. Potential contributions of asphalt and coal tar to black carbon quantification in urban dust, soils, and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Mahler, B.J.; Van Metre, P.C.; Ligouis, B.; Werth, C.J. [University of Illinois Urbana Champaign, Urbana, IL (USA). Dept. of Civil & Environmental Engineering

    2010-12-01

    Measurements of black carbon (BC) using either chemical or thermal oxidation methods are generally thought to indicate the amount of char and/or soot present in a sample. In urban environments, however, asphalt and coal-tar particles worn from pavement are ubiquitous and, because of their pyrogenic origin, could contribute to measurements of BC. Here we explored the effect of the presence of asphalt and coal-tar particles on the quantification of BC in a range of urban environmental sample types, and evaluated biases in the different methods used for quantifying BC. Samples evaluated were pavement dust, residential and commercial area soils, lake sediments from a small urban watershed, and reference materials of asphalt and coal tar. Total BC was quantified using chemical treatment through acid dichromate (Cr{sub 2}O{sub 7}) oxidation and chemo-thermal oxidation at 375{sup o}C (CTO-375). BC species, including soot and char/charcoal, asphalt, and coal tar, were quantified with organic petrographic analysis. Comparison of results by the two oxidation methods and organic petrography indicates that both coal tar and asphalt contribute to BC quantified by Cr{sub 2}O{sub 7} oxidation, and that coal tar contributes to BC quantified by CTO-375. These results are supported by treatment of asphalt and coal-tar reference samples with Cr2O7 oxidation and CTO-375. The reference asphalt is resistant to Cr{sub 2}O{sub 7} oxidation but not to CTO-375, and the reference coal tar is resistant to both Cr2O7 oxidation and CTO-375. These results indicate that coal tar and/or asphalt can contribute to BC measurements in samples from urban areas using Cr{sub 2}O{sub 7} oxidation or CTO-375, and caution is advised when interpreting BC measurements made with these methods.

  11. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement.

    Science.gov (United States)

    Van Metre, Peter C; Majewski, Michael S; Mahler, Barbara J; Foreman, William T; Braun, Christopher L; Wilson, Jennifer T; Burbank, Teresa L

    2012-06-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH(8)) in the 0.03-m samples above sealed lots (1320 ng m(-3)) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m(-3)). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m(-3)) was five times greater than above unsealed lots (26.0 ng m(-3)). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m(-2) h(-1), respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces. Published by Elsevier Ltd.

  12. Development of secondary chamber for tar cracking-improvement of wood pyrolysis performance in pre-vacuum chamber

    Science.gov (United States)

    Siahaan, S.; Homma, H.; Homma, H.

    2018-02-01

    Energy crisis and global warming, in other words, climate change are critical topics discussed in various parts of the world. Global warming primarily result from too much emission of carbon dioxide (CO2) in the atmosphere. To mitigate global warming, or climate change and improve electrification in rural areas, wood pyrolysis technology is developed in a laboratory scale, of which gases are directly applicable to the gas engine generator. Our laboratory has developed a prototype of wood pyrolysis plant with a pre-vacuum chamber. However, tar yield was around 40 wt% of feedstock. This research aims to reduce tar yield by secondary tar cracking. For the secondary tar cracking, a secondary pre-vacuum chamber is installed after primary pre-vacuum chamber. Gases generated in the primary pre-vacuum chamber are lead into the secondary chamber that is heated up to 1000 K. This paper reports performance of the secondary chamber for secondary tar cracking in homogeneous mode and heterogeneous mode with char.

  13. IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    M. Amzad Hossain

    2010-06-01

    Full Text Available A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC: n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate column was used, followed by glass fiber filter (GFF paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh.   Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS

  14. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates.

    Science.gov (United States)

    Bryer, Pamela J; Scoggins, Mateo; McClintock, Nancy L

    2010-05-01

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P pavement sealants contain bioavailable PAHs that may harm aquatic environments. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C. [Institute of Marine Biology of Crete, Iraklio (Greece). Environmental Dept.

    1998-12-01

    During the first cruise of R/V `Philia` in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 {mu}g/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 {mu}g/m{sup 2}, respectively. Mean pelagic tar concentration was 318 {mu}g/m{sup 2}, more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  16. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C. [Institute of Marine Biology of Crete, Iraklio (Greece). Environmental Dept.

    1998-12-01

    During the first cruise of R/V 'Philia' in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 {mu}g/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 {mu}g/m{sup 2}, respectively. Mean pelagic tar concentration was 318 {mu}g/m{sup 2}, more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  17. Pelagic tar, dissolved/dispersed petroleum hydrocarbons and plastic distribution in the Cretan Sea, Greece

    International Nuclear Information System (INIS)

    Kornilios, S.; Drakopoulos, P.G.; Dounas, C.

    1998-01-01

    During the first cruise of R/V 'Philia' in July 1997 within the framework of the TALOS programme supported by the Greek Ministry of Physical Planning and Public Works, the sampling of floating tar, litter and sea water for dissolved/dispersed petroleum hydrocarbons (DDPH) was carried out in the Cretan Sea. Analysis of these data has allowed a first assessment of the status of floating marine pollution in the region. DDPH measurements showed a mean concentration of 0.145 μg/l of chrysene equivalents (n = 24). Tar and plastics concentrations were in the range of 1-4280 and 0-1160 μg/m 2 , respectively. Mean pelagic tar concentration was 318 μg/m 2 , more than two times higher than what was reported for the area in previous studies. Based on in situ hydrographic observations there is strong evidence that most of the floating tar enters the Cretan Sea through the Ionian Sea. (author)

  18. 77 FR 48431 - Safety Zone for Fireworks Display, Pamlico and Tar Rivers; Washington, NC

    Science.gov (United States)

    2012-08-14

    ... near the Pamlico and Tar Rivers to commemorate Beaufort County's 300th anniversary. The temporary... 1625-AA00 Safety Zone for Fireworks Display, Pamlico and Tar Rivers; Washington, NC AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on...

  19. The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1992-04-01

    Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.

  20. Selected constituents in the smokes of U. S. commercial cigaretts: tar, nicotine, carbon monoxide and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    One hundred twenty-one brands of United States commercial cigarettes were analyzed for their deliveries of tar, nicotine, carbon monoxide, and carbon dioxide under standard analytical smoking conditions. The sample included both filter and nonfilter cigarettes. Comparisons of carbon monoxide deliveries over the range of observed tar deliveries indicated a very high correlation between CO and tar for filter cigarettes, but nonfilter cigarettes tended to produce much less CO than would have been predicted from their tar deliveries. Comparison of ORNL nicotine values for specific brands with those determined by the Federal Trade Commission yield no statistically significant differences between laboratories. 4 figures, 6 tables.

  1. Some studies on tar pillets at Veraval coast (Gujarat)

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A.N.

    Infrared spectroscopic (IR) analysis indicated that the tar pillets contain saturated hydrocarbons particularly higher homologues of n-paraffins, unsaturated and carbonyl type of polar compounds. Gas chromatographic (GLC) fingerprint pattern...

  2. Luminescence monitoring of oil or tar contamination for industrial hygiene

    International Nuclear Information System (INIS)

    Gammage, R.B.; Vo-Dinh, T.

    1980-01-01

    Synfuel plants produce potentially carcinogenic oils and tars. Exposure of workers to these tars and oils is difficult to avoid completely and occurs via direct contact with dirty surfaces or condensation of escaped fumes onto or within the body. Surface skin, measurements are made directly with a near-ultraviolet luminoscope employing a fiber optics lightguide and a stethoscopic cap pressed against the skin. This instrument is especially suitable for measuring ng to μg/cm 2 amounts of residual contamination remaining on the surface of the skin after washing. To minimize the potential for carcinogenicity, the excitating ultraviolet light intensity is only 1/100th that of sunlight. (orig.)

  3. Pyrolysis kinetics of phenols from lignite semicoking tar

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Polovetskaya, O.S.; Proskuryakov, V.A.; Shavyrina, O.A. [Leo Tolstoy Tula State Pedag University, Tula (Russian Federation)

    2002-11-01

    The features of pyrolysis of phenols from lignite semicoking tar were studied. The activation energy and order of the reactions of accumulation of methane, hydrogen, carbon monoxide and dioxide, naphthalene and its methyl homologs, phenols, and isomeric cresols and dimethylphenols were determined.

  4. Machine-smoking studies of cigarette filter color to estimate tar yield by visual assessment and through the use of a colorimeter.

    Science.gov (United States)

    Morton, Michael J; Williams, David L; Hjorth, Heather B; Smith, Jennifer H

    2010-04-01

    This paper explores using the intensity of the stain on the end of the filter ("filter color") as a vehicle for estimating cigarette tar yield, both by instrument reading of the filter color and by visual comparison to a template. The correlation of machine-measured tar yield to filter color measured with a colorimeter was reasonably strong and was relatively unaffected by different puff volumes or different tobacco moistures. However, the correlation of filter color to machine-measured nicotine yield was affected by the moisture content of the cigarette. Filter color, as measured by a colorimeter, was generally comparable to filter extraction of either nicotine or solanesol in its correlation to machine-smoked tar yields. It was found that the color of the tar stain changes over time. Panelists could generally correctly order the filters from machine-smoked cigarettes by tar yield using the intensity of the tar stain. However, there was considerable variation in the panelist-to-panelist tar yield estimates. The wide person-to-person variation in tar yield estimates, and other factors discussed in the text could severely limit the usefulness and practicality of this approach for visually estimating the tar yield of machine-smoked cigarettes. Copyright 2009 Elsevier Inc. All rights reserved.

  5. Family physicians and youth tobacco-free education: outcomes of the Colorado Tar Wars program.

    Science.gov (United States)

    Cain, Jeffrey J; Dickinson, W Perry; Fernald, Douglas; Bublitz, Caroline; Dickinson, L Miriam; West, David

    2006-01-01

    Tar Wars is a national school-based tobacco-free education program operated by the American Academy of Family Physicians. The Tar Wars lesson uses an interactive 45-min session taught by volunteer family physicians in 4th- and 5th-grade classrooms and focuses on the short-term image-based consequences of tobacco use. In this study, we evaluated the effectiveness of the Tar Wars program in Colorado with both quantitative and qualitative measures. Students participating in the quantitative evaluation were tested before and after a Tar Wars teaching session using a 14-question test covering the short-term and image-based consequences of tobacco use, cost of smoking, tobacco advertising, and social norms of tobacco use. Qualitative evaluation of the program included guided telephone interviews and focus groups with participating students, teachers, and presenters. Quantitative evaluation showed statistically significant improvement in correct responses for the 14 questions measured with an average increase in correct responses from 8.95 to 10.23. Three areas recommended by the Centers for Disease Control (CDC) for youth tobacco prevention showed greater change in correct responses, including cost of smoking, truth of tobacco advertising, and peer norms of tobacco use. Qualitative evaluation found that the overall message of the session was well received, that previously known tobacco information was reinforced by its presentation in a novel format, and that new information learned included cost of smoking, truth of tobacco advertising, and peer norms of tobacco use. The Tar Wars lesson plan is effective in increasing students' understanding about the short-term consequences of tobacco use, cost of tobacco use, truth of tobacco advertising, and peer norms. Tar Wars meets the CDC guidelines as one component of effective comprehensive youth tobacco prevention.

  6. No Increased Risk of Cancer after Coal Tar Treatment in Patients with Psoriasis or Eczema

    NARCIS (Netherlands)

    Roelofzen, Judith H. J.; Aben, Katja K. H.; Oldenhof, Ursula T. H.; Coenraads, Pieter-Jan; Alkemade, Hans A.; van de Kerkhof, Peter C. M.; van der Valk, Pieter G. M.; Kiemeney, Lambertus A. L. M.

    Coal tar is an effective treatment for psoriasis and eczema, but it contains several carcinogenic compounds. Occupational and animal studies have shown an increased risk of cancer after exposure to coal tar. Many dermatologists have abandoned this treatment for safety reasons, although the risk of

  7. Tar removal from biomass derived fuel gas by pulsed corona discharges: chemical kinetic study II

    NARCIS (Netherlands)

    Nair, S.A.; Yan, K.; Pemen, A.J.M.; Heesch, van E.J.M.; Ptasinski, K.J.; Drinkenburg, A.A.H.

    2005-01-01

    Tar (heavy hydrocarbon or poly aromatic hydrocarbon (PAH)) removal from biomass derived fuel gas is one of the biggest obstacles in its utilization for power generation. We have investigated pulsed corona as a method for tar removal. Our previous experimental results indicate the energy consumption

  8. Abating coal tar seepage into surface water bodies using sheet piles with sealed interlocks

    International Nuclear Information System (INIS)

    Collingwood, B.I.; Boscardin, M.D.; Murdock, R.F.

    1995-01-01

    A former coal tar processing facility processed crude coal tar supplied from manufactured gas plants in the area. Coal-tar-contaminated ground water from the site was observed seeping through an existing timber bulkhead along a tidal river and producing a multicolored sheen on the surface of the river. As part of a short-term measure to abate the seepage into the river, 64-m long anchored sheet pile wall with sheet pile wing walls at each end was constructed inland of the of the timber bulkhead. The sheet piles extended to low-permeability soils at depth and the interlocks of the sheet piles were provided with polyurethane rubber seals. Based on postconstruction observations for leakage and sheens related to leakage, the steel sheet piles with polyurethane rubber interlock seals appeared to provide a successful seal and abate coal-tar-contaminated ground water seepage into the river. The tie rod penetration sealing proved to be a more problematic detail, but through several postconstruction grouting episodes, an effective seal was produced

  9. Modeling the effects of climate and land use change on instream temperature in the Upper Tar River, North Carolina

    Science.gov (United States)

    Daraio, J. A.; Bales, J. D.

    2011-12-01

    Freshwater mussels are among the most imperiled groups of organisms in the world. Declines in abundance and diversity in North America have been attributed to a wide range of human activities, and many species occur in habitats close to their upper thermal tolerance. We are modeling instream temperature (T) as part of an effort to understand the response of imperiled freshwater mussels to anthropogenically induced changes in water T, habitat, and flow. We used the Precipitation-Runoff Modeling System (PRMS) to model projected changes in stream discharge, and the Stream Network Temperature Model (SNTEMP) to model changes in instream T due to climate and land-use change in the Upper Tar River, North Carolina, which has a drainage area of 2200 mi^2. Down-scaled gridded 12km Global Circulation Models were used for precipitation and T inputs to PRMS simulations from the present through 2060. Land-use change through 2060 in the Upper Tar basin was estimated from SLEUTH, a model that estimates land-use change using the probability of urbanization, (results available from NC State University) and incorporated into PRMS for long term simulations. Stream segment discharge and lateral and groundwater flow into each stream segment from PRMS were used as input for SNTEMP. Groundwater T was assumed equal to the average annual air T for the basin. Lateral inflow T was estimated from physical characteristics of the basin (e.g. impervious area, cover density, cover type, solar radiation, air T) when possible, or from a regression with air T based on empirical field data at 20 sites throughout the basin. In addition to T, data on mussel and fish populations (e.g., density and species composition?) and microhabitat have been collected at these sites. The SNTEMP model was calibrated using the mean daily T at each site. Nash-Sutcliffe efficiency values ranged from 0.86 to 0.94 for mean daily T, and from 0.80 to 0.93 for maximum daily T. Ensemble simulations were run for a range of

  10. Smokers' sensory beliefs mediate the relation between smoking a light/low tar cigarette and perceptions of harm.

    Science.gov (United States)

    Elton-Marshall, Tara; Fong, Geoffrey T; Yong, Hua-Hie; Borland, Ron; Xu, Steve Shaowei; Quah, Anne C K; Feng, Guoze; Jiang, Yuan

    2015-11-01

    The sensory belief that 'light/low tar' cigarettes are smoother can also influence the belief that 'light/low tar' cigarettes are less harmful. However, the 'light' concept is one of several factors influencing beliefs. No studies have examined the impact of the sensory belief about one's own brand of cigarettes on perceptions of harm. The current study examines whether a smoker's sensory belief that their brand is smoother is associated with the belief that their brand is less harmful and whether sensory beliefs mediate the relation between smoking a 'light/low tar' cigarette and relative perceptions of harm among smokers in China. Data are from 5209 smokers who were recruited using a stratified multistage sampling design and participated in Wave 3 of the International Tobacco Control (ITC) China Survey, a face-to-face survey of adult smokers and non-smokers in seven cities. Smokers who agreed that their brand of cigarettes was smoother were significantly more likely to say that their brand of cigarettes was less harmful (pmarketing can have in capitalising on the smoker's natural associations between smoother sensations and lowered perceptions of harm. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  11. Utilisation of the binders prepared from coal tar pitch and phenolic resins for the production metallurgical quality briquettes from coke breeze and the study of their high temperature carbonization behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Benk, Ayse [University of Erciyes, Faculty of Art and Science, Department of Chemistry, 38039, Kayseri (Turkey)

    2010-09-15

    To reduce the cost of the formed coke briquettes which can be used as a substitute fuel to the metallurgical coke for the blast furnace from the coke breeze alternative binders and their blends were used. The high temperature behavior was investigated. The binders tested were: the nitrogen blown, air blown coal tar pitch and the blend of air blown coal tar pitch with the phenolic resins blends. The phenolic resin blends were prepared by mixing equal amount of resole and novalac. From the results, nitrogen blowing resulted in the weakest briquettes. The air blowing procedure should be preferred in place of nitrogen blowing for this purpose. When the air blown coal tar pitch was used alone as a binder, the briquettes must be cured at 200 C for 2 h, then carbonized at a temperature above 670 C. Since it requires higher temperature at carbonization stage, using air blown coal tar pitch alone as a binder was not economical. Therefore, the briquettes were prepared from the blended binder, containing air blown coal tar pitch and phenolic resins blend. The optimum amount of air blown coal tar pitch was found to be 50% w/w in the blended binder. Curing the briquettes at 200 C for 2 h was found to be sufficient for producing strong briquettes with a tensile strength of 50.45 MN/m{sup 2}. When these cured briquettes were carbonized at temperatures 470 C, 670 C and 950 C, their strength were increasing continuously, reaching to 71.85 MN/m{sup 2} at the carbonization temperature of 950 C. These briquettes can be used as a substitute for the metallurgical coke after curing; the process might not require un-economical high temperature carbonization stage. (author)

  12. The effects of higher cigarette prices on tar and nicotine consumption in a cohort of adult smokers.

    Science.gov (United States)

    Farrelly, M C; Nimsch, C T; Hyland, A; Cummings, M

    2004-01-01

    The objective of this paper is to estimate the demand for tar and nicotine in cigarettes as a function of cigarette prices in a cohort of cigarette 11,966 smokers followed for 5 years. Data for the analysis come from a longitudinal telephone survey of 11,966 smokers who were interviewed in 1988 and 1993 as part of the Community Intervention Trial for Smoking Cessation (COMMIT). Separate models are estimated for three age groups to account for differences in levels of addiction and brand loyalty across age. We found that smokers respond to higher cigarette prices by reducing the number of cigarettes smoked per day but also by switching to cigarettes that are higher in tar and nicotine per cigarette. Copyright 2003 John Wiley & Sons, Ltd.

  13. Evidence for conformational flexibility in the Tat-TAR recognition motif of cyclin T1

    International Nuclear Information System (INIS)

    Das, Chandreyee; Edgcomb, Stephen P.; Peteranderl, Ralph; Chen, Lily; Frankel, Alan D.

    2004-01-01

    Cyclin T1 (CycT1) is a cellular transcription elongation factor that also participates in Tat-mediated activation of several lentiviral promoters. In human immunodeficiency virus (HIV), CycT1 is required for Tat to bind tightly to TAR and interacts in the ternary complex via its Tat-TAR recognition motif (TRM). In the related bovine immunodeficiency virus (BIV), Tat recognizes its cognate TAR element with high affinity and specificity in the absence of CycT1. At both promoters, CycT1 recruits the Cdk9 kinase, which phosphorylates RNA polymerase II to generate processive transcription complexes. To examine the physical properties of CycT1, we purified a functional domain corresponding to residues 1-272 and found that it possesses a stably folded core, as judged by partial proteolysis and circular dichroism experiments. Interestingly, the C-terminal 20 residues corresponding to the TRM appear conformationally flexible or disordered. The TRM of the bovine CycT1 (bCycT1) is similarly sensitive to proteolysis yet differs in sequence from the human protein. In particular, bCycT1 lacks a cysteine at residue 261 known to be critical for HIV but not BIV ternary complex formation, and mutagenesis data are consistent with a proposed role for this cysteine in metal binding. The apparent flexibility of the TRM suggests that conformational rearrangements may accompany formation of CycT1-Tat-TAR ternary complexes and may contribute to different TAR recognition strategies in different lentiviruses

  14. Quantitative analysis of phenol and alkylphenols in Brazilian coal tar

    Directory of Open Access Journals (Sweden)

    Elina Bastos Caramão

    2004-04-01

    Full Text Available The main purpose of this work is the identification and quantification of phenolic compounds in coal tar samples from a ceramics factory in Cocal (SC, Brazil. The samples were subjected to preparative scale liquid chromatography, using Amberlyst A-27TM ion-exchange resin as stationary phase. The fractions obtained were classified as "acids" and "BN" (bases and neutrals. The identification and quantification of phenols, in the acid fraction, was made by gas chromatography coupled to mass spectrometry (GC/MS. Nearly twenty-five phenols were identified in the samples and nine of them were also quantified. The results showed that coal tar has large quantities of phenolic compounds of industrial interest.

  15. Composition and Dissolution of a Migratory, Weathered Coal Tar Creosote DNAPL

    Directory of Open Access Journals (Sweden)

    Kerstin E. Scherr

    2016-09-01

    Full Text Available Opaque, viscous tars derived from the carbonization of fossile carbon feedstocks, such coal tars and creosote, are long-term sources of groundwater contamination, predominantly with poly- and heterocyclic aromatic hydrocarbons (PAH. The dissolution, ageing and migratory behavior of dense, non aqueous phase liquid (DNAPL coal tar blobs and pools forming at the aquitard is not sufficiently understood to estimate the risk and adequately design groundwater treatment measures at a contaminated site. In this study, we investigate the composition and dissolution of a migrated, aged creosote DNAPL and corresponding experimental and groundwater profiles using comprehensive two-dimensional gas chromatography (GCxGC-MS. GC-FID unresolved compounds were attributed to methylated homocyclic species using GCxGC-MS in the Methylanthracene weight range. Equilibrium concentrations were estimated using Raoult’s law, assuming non-ideal behavior. Low molecular weight compounds were found to be prevalent even after decades of weathering, with Naphthalene (8% by mass representing the most abundant identified compound, contrary to the expected preferential depletion of hydrophilic compounds. Morevoer, dimethylnaphthalenes were relatively more abundant in the aqueous boundary layer than in the DNAPL. DNAPL migration over 400m with the groundwater flow effected lower viscosity and specific gravity of the migrated phase body in a superposition of weathering, transport and aquifer chromatography effects. Based on a decomposition of analysed and estimated constituents using the group contribution approach, reference DNAPL values for activity coefficients γi were used to model aqueous solubilities for selected compounds. Anthracene was close to its theoretical precipitation limit in the bulk DNAPL. While laboratory and modelled DNAPL dissolution behavior agree well, field data imply the presence of specific interfacial in situ processes significantly impacting dissolution

  16. DeepMirTar: a deep-learning approach for predicting human miRNA targets.

    Science.gov (United States)

    Wen, Ming; Cong, Peisheng; Zhang, Zhimin; Lu, Hongmei; Li, Tonghua

    2018-06-01

    MicroRNAs (miRNAs) are small noncoding RNAs that function in RNA silencing and post-transcriptional regulation of gene expression by targeting messenger RNAs (mRNAs). Because the underlying mechanisms associated with miRNA binding to mRNA are not fully understood, a major challenge of miRNA studies involves the identification of miRNA-target sites on mRNA. In silico prediction of miRNA-target sites can expedite costly and time-consuming experimental work by providing the most promising miRNA-target-site candidates. In this study, we reported the design and implementation of DeepMirTar, a deep-learning-based approach for accurately predicting human miRNA targets at the site level. The predicted miRNA-target sites are those having canonical or non-canonical seed, and features, including high-level expert-designed, low-level expert-designed, and raw-data-level, were used to represent the miRNA-target site. Comparison with other state-of-the-art machine-learning methods and existing miRNA-target-prediction tools indicated that DeepMirTar improved overall predictive performance. DeepMirTar is freely available at https://github.com/Bjoux2/DeepMirTar_SdA. lith@tongji.edu.cn, hongmeilu@csu.edu.cn. Supplementary data are available at Bioinformatics online.

  17. Source identification of a tar residue from Mumbai Beach

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A; Rokade, M.A

    A tar residue from Mumbai Beach, Maharashtra, India was matched with the suspected source sample from a tanker using UV, IR and GLC techniques. Negligible differences in several ratios of UV absorbances and ratios of infrared transmittances...

  18. Anomalous capillary flow of coal tar pitches

    Energy Technology Data Exchange (ETDEWEB)

    Saint Romain, J.L.; Lahaye, J.; Ehrburger, P.; Couderc, P.

    1986-06-01

    Capillary flow of liquid coal tar pitch into a coke bed was studied. Anomalies in the flow could not be attributed to a plugging effect for mesophase content lower than 20 wt%. The flow behaviour of small pitch droplets can be correlated with the change in physicochemical properties, as measured by the glass transition temperature, on penetration into the coke bed. 4 references.

  19. Structural determinants of HIV-1 nucleocapsid protein for cTAR DNA binding and destabilization, and correlation with inhibition of self-primed DNA synthesis.

    Science.gov (United States)

    Beltz, Hervé; Clauss, Céline; Piémont, Etienne; Ficheux, Damien; Gorelick, Robert J; Roques, Bernard; Gabus, Caroline; Darlix, Jean-Luc; de Rocquigny, Hugues; Mély, Yves

    2005-05-20

    The nucleocapsid protein (NC) of human immunodeficiency virus type 1 (HIV-1) is formed of two highly conserved CCHC zinc fingers flanked by small basic domains. NC is required for the two obligatory strand transfers in viral DNA synthesis through its nucleic acid chaperoning properties. The first DNA strand transfer relies on NC's ability to bind and destabilize the secondary structure of complementary transactivation response region (cTAR) DNA, to inhibit self-priming, and to promote the annealing of cTAR to TAR RNA. To further investigate NC chaperone properties, our aim was to identify by fluorescence spectroscopy and gel electrophoresis, the NC structural determinants for cTAR binding and destabilization, and for the inhibition of self-primed DNA synthesis on a model system using a series of NC mutants and HIV-1 reverse transcriptase. NC destabilization and self-priming inhibition properties were found to be supported by the two fingers in their proper context and the basic (29)RAPRKKG(35) linker. The strict requirement of the native proximal finger suggests that its hydrophobic platform (Val13, Phe16, Thr24 and Ala25) is crucial for binding, destabilization and inhibition of self-priming. In contrast, only partial folding of the distal finger is required, probably for presenting the Trp37 residue in an appropriate orientation. Also, Trp37 and the hydrophobic residues of the proximal finger appear to be essential for the propagation of the melting from the cTAR ends up to the middle of the stem. Finally, both N-terminal and C-terminal basic domains contribute to cTAR binding but not to its destabilization.

  20. A role for nuclear energy in the recovery of oil from the tar sands of Alberta

    International Nuclear Information System (INIS)

    Puttagunta, V.R.; Sochaski, R.O.; Robertson, R.F.S.

    1976-12-01

    Techniques of oil recovery from the tar sands and the energy requirements of this operation are described. Fossil fuels, and CANDU reactors are examined as competitive sources of energy for the tar sands plants. The CANDU-OCR reactor appears to have the necessary flexibility to fit into many of the possible methods of recovering oil from the tar sands. Cost comparisons of fossil and nuclear sources show that, for the supply of process steam, the nuclear source is competitive under the criteria of debt financing or low discount rates on capital, continued escalation, and long plant capital write-off period. (author)

  1. Preparation of thermo-sensitive slow releasing material and its application in low tar tobacco

    Directory of Open Access Journals (Sweden)

    Tian Zhong

    2017-04-01

    Full Text Available To solve some sensory defects such as fragrance deficiency,strong dry sense,poor satisfaction in the development of ultra-low tar tobacco products,we prepared a new thermo sensitive slow releasing composite material with tobacco aroma.The characterization results showed that the as-prepared thermosensitive particles have better aroma enhancing and slow releasing effects.Also,the aroma components of the tip stick containing thermosensitive particles were detected and its sensory quality was evaluated.The results showed that composite tip stick could enhance the aroma and improve the sensory quality of the cigarettes.

  2. Recovery of naphthalene, anthracene, etc. , from tar

    Energy Technology Data Exchange (ETDEWEB)

    1920-12-25

    A process is described for the recovery of naphthalene, anthracene, and the like from tar oils and similar liquors, characterized in that the oil is treated in a rapidly rotating hammer mill, such as a colloid mill, with water sufficient, in the presence or absence of suitable solvents, for the only portion preferably in the presence of emulsifiers; and is filtered through a filter with fine pores.

  3. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    International Nuclear Information System (INIS)

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. - Highlights: • We compare PAH and azaarene concentrations in runoff from coal-tar- and asphalt-sealed pavement. • Concentrations in coal-tar-sealcoat runoff greatly exceeded those in asphalt-sealcoat runoff. • Decreases in azaarenes and LMW PAHs were offset by increases in HMW PAHs. • PAH concentrations in coal-tar-sealcoat runoff remained high for months after application. - Concentrations of PAHs in runoff from pavement with coal-tar-based sealcoat continue to be elevated for at least 3 months following sealcoat application

  4. Site-selective probing of cTAR destabilization highlights the necessary plasticity of the HIV-1 nucleocapsid protein to chaperone the first strand transfer

    Science.gov (United States)

    Godet, Julien; Kenfack, Cyril; Przybilla, Frédéric; Richert, Ludovic; Duportail, Guy; Mély, Yves

    2013-01-01

    The HIV-1 nucleocapsid protein (NCp7) is a nucleic acid chaperone required during reverse transcription. During the first strand transfer, NCp7 is thought to destabilize cTAR, the (−)DNA copy of the TAR RNA hairpin, and subsequently direct the TAR/cTAR annealing through the zipping of their destabilized stem ends. To further characterize the destabilizing activity of NCp7, we locally probe the structure and dynamics of cTAR by steady-state and time resolved fluorescence spectroscopy. NC(11–55), a truncated NCp7 version corresponding to its zinc-finger domain, was found to bind all over the sequence and to preferentially destabilize the penultimate double-stranded segment in the lower part of the cTAR stem. This destabilization is achieved through zinc-finger–dependent binding of NC to the G10 and G50 residues. Sequence comparison further revealed that C•A mismatches close to the two G residues were critical for fine tuning the stability of the lower part of the cTAR stem and conferring to G10 and G50 the appropriate mobility and accessibility for specific recognition by NC. Our data also highlight the necessary plasticity of NCp7 to adapt to the sequence and structure variability of cTAR to chaperone its annealing with TAR through a specific pathway. PMID:23511968

  5. PAH/Aromatic Tar and Coke Precursor Formation in the Early Stages of Triglyceride (Triolein) Pyrolysis.

    Science.gov (United States)

    Alhroub, Ibrahim; Kozliak, Evguenii; Kubátová, Alena; Sulkes, Mark

    2018-03-29

    There has been a limited understanding of high MW polycyclic aromatic hydrocarbon (PAH) product chemistry in the pyrolysis of triglycerides (TGs), though the subject has important implications for both fuel production from TGs and food science. Previous TG pyrolysis studies have been able to identify only relatively low MW GC-elutable aromatics occurring in the bulk liquid phase; products occurring in the solid phase have remained inaccessible to chemical analysis. In contrast, cold gas expansion molecular beam methods, where pyrolysis products are analyzed in real time as they are entrained in gas expansions, remove product collection difficulties, thereby allowing for analysis of coke/tar PAH precursors. In this study, the model TG triolein was heated and the ensuing products in the molecular beam were soft photoionized, enabling time-of-flight mass detection. Use of 266 nm pulses enabled selective photoionization of aromatic products. Unlike previous work on analysis of the liquid phase TG cracking products, a different and distinct pattern of rather large PAHs, up to 444 amu, was observed, at nontrivial relative product fractions. With an increase of temperature to ∼350 °C, a small number of PAHs with MW ≥ 276 amu increasingly dominated the aromatic product distribution. Surprisingly, PAH product detection ensued at rather low temperatures, as low as ∼260 °C. For tentative PAH product identification and product chemistry rationalization, we observed the product homology pattern and applied a stoichiometric analysis. The latter, combined with the known homology profiles of TG cracking products, indicated specific patterns of intermediate fragment association that facilitated large-MW PAH formation as a result of TG cracking.

  6. A process for briquetting coal with the production of briquets with high resistance to crushing

    Energy Technology Data Exchange (ETDEWEB)

    Ono, M; Ito, S; Nakagava, K

    1983-02-08

    Finely ground coal is mixed with a binder with a softening point of greater than or equal to 30 degrees and with heavy coal tar products, the mixture is molded with the formation of briquets in a two roller press. The mixing is conducted in heated steam or waste gases from a horizontal, helical mixer. The coal is subsequently irrigated by the melted binder and heavy coal tar products. The heavy coal tar products are a bottom residue formed by condensation of volatile products in a gas stream from coking which contains particles of coal and coke. Briquets with a point compression strength of 50 plus or minus 4 kilograms per sq. cur. and a bulk tensity of 1.17 grams per cubic centimeter are produced from a mixture which contains 6 percent binder, 80 percent coal and 20 percent heavy coal tar products.

  7. Quantitative determination of acid oils in low-temperature coal tar by means of fractional distillation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, A

    1950-01-01

    The aromatic hydroxy compounds in low-temperature tar were separated, and 75 compounds in the boiling range 180/sup 0/ to 320/sup 0/ isolated by means of fractional distillation in packed columns of at least 45 theoretical plates. Mixtures not separable by fractionation were separated by means of other physicochemical or chemical methods. Hydroxy compounds with boiling point up to 230/sup 0/C were detemined quantitatively, as were the phenols present in low-temperature carbonization liquors. With the Krupp-Lurgi process of low-temperature carbonization, 1.8% phenol, 1.8% o-cresol, and 3.6% m-p-cresols were formed. The tar contained up to 1.3% 1:3:5-xylenol and up to 0.9% 1:2:4-xylenol. Of the 12.1% v/v of phenol, cresols, and xylenols present in tar, 11.2% were determined quantitatively, and 9 hydroxy compounds were identified in the remaining 0.9%. On the basis of these investigations, a technical plant that permitted the recovery of pure low-temperature tar phenols and the preparation of a number of different phenol resins from the mixtures was erected.

  8. Studies estimating the dermal bioavailability of polynuclear aromatic hydrocarbons from manufactured plant tar-contaminated soils

    International Nuclear Information System (INIS)

    Roy, T.A.; Krueger, A.J.; Taylor, B.B.; Mauro, D.M.; Goldstein, L.S.

    1998-01-01

    In vitro percutaneous absorption studies were performed with contaminated soils or organic extracts of contaminated soils collected at manufactured gas plant (MGP) sites. The MGP tar contaminated soils were found to contain a group of targeted polynuclear aromatic hydrocarbons (PAH) at levels ranging from 10 to 2400 mg/kg. The soil extracts contained target PAH at levels ranging from 12 000 - 34 000 mg/kg. Dermal penetration rates of target PAH from the MGP tar-contaminated soils/soil extracts were determined experimentally through human skin using 3 H-benzo(a)pyrene (BaP) as a surrogate. Results from three MGP sites showed reductions of 2-3 orders of magnitude in PAH absorption through human skin from the most contaminated soils in comparison to the soil extracts. Reduction in PAH penetration can be attributed to PAH concentration and (soil) matrix properties. PAH dermal flux values are used to determine site-specific dermally absorbed dose (DAD) and chronic daily intake (CDI) which are essential terms required to estimate risk associated with human exposure to MGP tar and MGP tar-contaminated soils. 21 refs., 4 figs., 3 tabs

  9. Tar removal from biomass gasification streams: processes and catalysts; Remocao do alcatrao de correntes de gaseificacao de biomassa: processos e catalisadores

    Energy Technology Data Exchange (ETDEWEB)

    Quitete, Cristina P.B. [Centro de Pesquisa e Desenvolvimento Leopoldo Americo Miguez de Mello (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Processos de Conversao de Biomassa; Souza, Mariana M.V.M., E-mail: mmattos@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Escola de Quimica

    2014-07-01

    Biomass gasification is a technology that has attracted great interest in synthesis of biofuels and oxo alcohols. However, this gas contains several contaminants, including tar, which need to be removed. Removal of tar is particularly critical because it can lead to operational problems. This review discusses the major pathways to remove tar, with a particular focus on the catalytic steam reforming of tar. Few catalysts have shown promising results; however, long-term studies in the context of real biomass gasification streams are required to realize their potential. (author)

  10. Human papillomavirus and tar hypothesis for squamous cell cervical ...

    Indian Academy of Sciences (India)

    2010-08-09

    Aug 9, 2010 ... Keywords. Cervical cancer; co-factors; human papillomavirus; tar-based vaginal douche; tobacco smoke; wood smoke. Author Affiliations. Christina Bennett1 Allen E Kuhn2 Harry W Haverkos3. Indiana University School of Medicine, Indianapolis, Indiana 46202-5149, USA; Suite 300, Hamilton Mason Road ...

  11. Coal-tar-based sealcoated pavement: A major PAH source to urban stream sediments

    International Nuclear Information System (INIS)

    Witter, Amy E.; Nguyen, Minh H.; Baidar, Sunil; Sak, Peter B.

    2014-01-01

    We used land-use analysis, PAH concentrations and assemblages, and multivariate statistics to identify sediment PAH sources in a small (∼1303 km 2 ) urbanizing watershed located in South-Central, Pennsylvania, USA. A geographic information system (GIS) was employed to quantify land-use features that may serve as PAH sources. Urban PAH concentrations were three times higher than rural levels, and were significantly and highly correlated with combined residential/commercial/industrial land use. Principal components analysis (PCA) was used to group sediments with similar PAH assemblages, and correlation analysis compared PAH sediment assemblages to common PAH sources. The strongest correlations were observed between rural sediments (n = 7) and coke-oven emissions sources (r = 0.69–0.78, n = 5), and between urban sediments (n = 22) and coal-tar-based sealcoat dust (r = 0.94, n = 47) suggesting that coal-tar-based sealcoat is an important urban PAH source in this watershed linked to residential and commercial/industrial land use. -- Highlights: • Total PAH concentrations were measured at 35 sites along an urbanizing land-use gradient. • PAH concentrations increased with increasing urban land-use. • Urban land-use metrics were measured at three spatial scales using GIS. • PAH assemblages indicate coal-tar-based sealcoat is a major urban PAH source. • PAH assemblages indicate coke-oven emissions are an important rural PAH source. -- Coal-tar-based sealcoated pavement is a major PAH source to urban freshwater stream sediments in south-central Pennsylvania, USA

  12. Social-cognitive remediation in schizophrenia: generalization of effects of the Training of Affect Recognition (TAR).

    Science.gov (United States)

    Wölwer, Wolfgang; Frommann, Nicole

    2011-09-01

    In the last decade, several social cognitive remediation programs have been developed for use in schizophrenia. Though existing evidence indicates that such programs can improve social cognition, which is essential for successful social functioning, it remains unclear whether the improvements generalize to social cognitive domains not primarily addressed by the intervention and whether the improved test performance transfers into everyday social functioning. The present study investigated whether, beyond its known effects on facial affect recognition, the Training of Affect Recognition (TAR) has effects on prosodic affect recognition, theory of mind (ToM) performance, social competence in a role-play task, and more general social and occupational functioning. Thirty-eight inpatients with a diagnosis of schizophrenia or schizoaffective disorder were randomly assigned to 6 weeks of treatment with the TAR--primarily targeted at facial affect recognition-or Cognitive Remediation Training (CRT)--primarily targeted at neurocognition. Intention-to-treat analyses found significantly larger pre-post improvements with TAR than with CRT in prosodic affect recognition, ToM, and social competence and a trend effect in global social functioning. However, the effects on ToM and social competence were no longer significant in the smaller group of patients who completed treatment according to protocol. Results suggest that TAR effects generalize to other social cognitive domains not primarily addressed. TAR may also enhance social skills and social functioning, although this has to be confirmed. Results are discussed with regard to the need to improve functional outcome in schizophrenia against the background of current evidence from other social cognitive remediation approaches.

  13. 1170-MW(t) HTGR-PS/C plant application study report: tar sands oil recovery application

    International Nuclear Information System (INIS)

    Rao, R.; McMain, A.T. Jr.

    1981-05-01

    This report summarizes a study to apply an 1170-MW(t) high-temperature gas-cooled reactor - process steam/cogeneration (HTGR-PS/C) to tar sands oil recovery and upgrading. The raw product recovered from the sands is a heavy, sour bitumen; upgrading, which involves coking and hydrodesulfurization, produces a synthetic crude (refinable by current technology) and petroleum coke. Steam and electric power are required for the recovery and upgrading process. Proposed and commercial plants would purchase electric power from local utilities and obtain from boilers fired with coal and with by-product fuels produced by the upgrading. This study shows that an HTGR-PS/C represents a more economical source of steam and electric power

  14. Gc/ms analysis of coal tar composition produced from coal

    African Journals Online (AJOL)

    Coal pyrolysis is one of the significant approaches for the comprehensive utilization ... planigraphy-GC/MS; therefore a satisfactory analytical result obtained, which .... Among the aliphatic group of the coal tar, the proportion of alkene is larger ...

  15. In situ heat treatment of a tar sands formation after drive process treatment

    Science.gov (United States)

    Vinegar, Harold J.; Stanecki, John

    2010-09-21

    A method for treating a tar sands formation includes providing a drive fluid to a hydrocarbon containing layer of the tar sands formation to mobilize at least some hydrocarbons in the layer. At least some first hydrocarbons from the layer are produced. Heat is provided to the layer from one or more heaters located in the formation. At least some second hydrocarbons are produced from the layer of the formation. The second hydrocarbons include at least some hydrocarbons that are upgraded compared to the first hydrocarbons produced by using the drive fluid.

  16. Modeling of hydrogen production methods: Single particle model and kinetics assessment

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.S.; Bellan, J. [California Institute of Technology, Pasadena, CA (United States)

    1996-10-01

    The investigation carried out by the Jet Propulsion Laboratory (JPL) is devoted to the modeling of biomass pyrolysis reactors producing an oil vapor (tar) which is a precursor to hydrogen. This is an informal collaboration with NREL whereby JPL uses the experimentally-generated NREL data both as initial and boundary conditions for the calculations, and as a benchmark for model validation. The goal of this investigation is to find drivers of biomass fast-pyrolysis in the low temperature regime. The rationale is that experimental observations produce sparse discrete conditions for model validation, and that numerical simulations produced with a validated model are an economic way to find control parameters and an optimal operation regime, thereby circumventing costly changes in hardware and tests. During this first year of the investigation, a detailed mathematical model has been formulated for the temporal and spatial accurate modeling of solid-fluid reactions in biomass particles. These are porous particles for which volumetric reaction rate data is known a priori and both the porosity and the permeability of the particle are large enough to allow for continuous gas phase flow. The methodology has been applied to the pyrolysis of spherically symmetric biomass particles by considering previously published kinetics schemes for both cellulose and wood. The results show that models which neglect the thermal and species boundary layers exterior to the particle will generally over predict both the pyrolysis rates and experimentally obtainable tar yields. An evaluation of the simulation results through comparisons with experimental data indicates that while the cellulose kinetics is reasonably accurate, the wood pyrolysis kinetics is not accurate; particularly at high reactor temperatures. Current effort in collaboration with NREL is aimed at finding accurate wood kinetics.

  17. Cigarettes, lung cancer, and coronary heart disease: the effects of inhalation and tar yield.

    Science.gov (United States)

    Higenbottam, T; Shipley, M J; Rose, G

    1982-06-01

    Ten-year mortality rates for lung cancer and coronary heart disease have been related to cigarette smoking habits in 17 475 male civil servants aged 40-64 and in sample of 8089 male British residents aged 35-69. Both diseases were more frequent in smokers. Lung cancer rates were higher overall for "non-inhalers", particularly in heavy smokers. Tar yield correlated with the risk of lung cancer in non-inhalers but less so in inhalers. Conversely, coronary deaths were more common among inhalers, and the effect of tar/nicotine yield (such as it was) was confined to inhalers. It appears that there are subtle interactions between the amount smoked, the tar/nicotine yield of the cigarette, and the style of smoking. Thus the effects of a change in cigarette characteristics are hard to predict, and they may be different for respiratory and cardiovascular disease.

  18. Biogeochemical gradients above a coal tar DNAPL

    Energy Technology Data Exchange (ETDEWEB)

    Scherr, Kerstin E., E-mail: kerstin.brandstaetter-scherr@boku.ac.at [University of Natural Resources and Life Sciences Vienna (BOKU), Department IFA-Tulln, Institute for Environmental Biotechnology, Konrad Lorenz Strasse 20, 3430 Tulln (Austria); Backes, Diana [University of Natural Resources and Life Sciences Vienna (BOKU), Department IFA-Tulln, Institute for Environmental Biotechnology, Konrad Lorenz Strasse 20, 3430 Tulln (Austria); Scarlett, Alan G. [University of Plymouth, Petroleum and Environmental Geochemistry Group, Biogeochemistry Research Centre, Drake Circus, Plymouth, Devon PL4 8AA (United Kingdom); Lantschbauer, Wolfgang [Government of Upper Austria, Directorate for Environment and Water Management, Division for Environmental Protection, Kärntner Strasse 10-12, 4021 Linz (Austria); Nahold, Manfred [GUT Gruppe Umwelt und Technik GmbH, Ingenieurbüro für Technischen Umweltschutz, Plesching 15, 4040 Linz (Austria)

    2016-09-01

    Naturally occurring distribution and attenuation processes can keep hydrocarbon emissions from dense non aqueous phase liquids (DNAPL) into the adjacent groundwater at a minimum. In a historically coal tar DNAPL-impacted site, the de facto absence of a plume sparked investigations regarding the character of natural attenuation and DNAPL resolubilization processes at the site. Steep vertical gradients of polycyclic aromatic hydrocarbons, microbial community composition, secondary water quality and redox-parameters were found to occur between the DNAPL-proximal and shallow waters. While methanogenic and mixed-electron acceptor conditions prevailed close to the DNAPL, aerobic conditions and very low dissolved contaminant concentrations were identified in three meters vertical distance from the phase. Comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS) proved to be an efficient tool to characterize the behavior of the present complex contaminant mixture. Medium to low bioavailability of ferric iron and manganese oxides of aquifer samples was detected via incubation with Shewanella alga and evidence for iron and manganese reduction was collected. In contrast, 16S rDNA phylogenetic analysis revealed the absence of common iron reducing bacteria. Aerobic hydrocarbon degraders were abundant in shallow horizons, while nitrate reducers were dominating in deeper aquifer regions, in addition to a low relative abundance of methanogenic archaea. Partial Least Squares – Canonical Correspondence Analysis (PLS-CCA) suggested that nitrate and oxygen concentrations had the greatest impact on aquifer community structure in on- and offsite wells, which had a similarly high biodiversity (H’ and Chao1). Overall, slow hydrocarbon dissolution from the DNAPL appears to dominate natural attenuation processes. This site may serve as a model for developing legal and technical strategies for the treatment of DNAPL-impacted sites where contaminant plumes are

  19. Characterisation and catalytic upgrading of tars from coal-tyre hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Murillo, R.; Callen, M.S.; Garcia, T. [Instituto de Carboquimica, Zaragoza (Spain)

    1999-07-01

    Tars from coal-tyre hydropyrolysis obtained in a swept fixed bed reactor were upgraded with catalysts. Upgraded oils were characterized, and naphtha, kerosene, gas oil, heavy gas oil and vacuum residue percentages were quantified. 7 refs., 3 tabs.

  20. Class I cultural resource overview for oil shale and tar sands areas in Colorado, Utah and Wyoming.

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, D.; Kullen, D.; Gierek, L.; Wescott, K.; Greby, M.; Anast, G.; Nesta, M.; Walston, L.; Tate, R.; Azzarello, A.; Vinikour, B.; Van Lonkhuyzen, B.; Quinn, J.; Yuen, R.; Environmental Science Division

    2007-11-01

    In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the 'Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005', Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. The Bureau of Land Management (BLM) is developing a Programmatic Environmental Impact Statement (PEIS) to evaluate alternatives for establishing commercial oil shale and tar sands leasing programs in Colorado, Wyoming, and Utah. This PEIS evaluates the potential impacts of alternatives identifying BLM-administered lands as available for application for commercial leasing of oil shale resources within the three states and of tar sands resources within Utah. The scope of the analysis of the PEIS also includes an assessment of the potential effects of future commercial leasing. This Class I cultural resources study is in support of the Draft Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and Programmatic Environmental Impact Statement and is an attempt to synthesize archaeological data covering the most geologically prospective lands for oil shale and tar sands in Colorado, Utah, and Wyoming. This report is based solely on geographic information system (GIS) data held by the Colorado, Utah, and Wyoming State Historic Preservation Offices (SHPOs). The GIS data include the information that the BLM has provided to the SHPOs. The primary purpose of the Class I cultural resources overview is to provide information on the affected environment for the PEIS. Furthermore, this report provides recommendations to support planning decisions and the management of cultural resources that could be impacted by future

  1. Guideline for Sampling and Analysis of Tar and Particles in Biomass Producer Gases. Version 3.3

    Energy Technology Data Exchange (ETDEWEB)

    Neeft, J.P.A.; Knoef, H.A.M.; Zielke, U.; Sjoestroem, K.; Hasler, P.; Simell, P.A.; Dorrington, M.A.; Thomas, L.; Abatzoglou, N.; Deutch, S.; Greil, C.; Buffinga, G.J.; Brage, C.; Suomalainen, M.

    2002-07-01

    This Guideline provides a set of procedures for the measurement of organic contaminants and particles in producer gases from biomass gasifiers. The procedures are designed to cover different gasifier types (updraft or downdraft fixed bed or fluidised bed gasifiers), operating conditions (0 - 900C and 0.6-60 bars) and concentration ranges (1 mg/m{sub n}{sup 3} to 300 g/m{sub n}{sup 3}). The Guideline describes a modular sampling train, and a set of procedures, which include: planning and preparation of the sampling, sampling and post-sampling, analysis, calculations, error analysis and reporting. The modular sampling train consists of 4 modules. Module 1 is a preconditioning module for isokinetic sampling and gas cooling. Module 2 is a particle collection module including a heated filter. Module 3 is a tar collection module with a gas quench (optionally by circulating a liquid), impinger bottles and a backup adsorber. Module 4 is a volume-sampling module consisting of a pump, a rotameter, a gas flow meter and pressure and temperature indicators. The equipment and materials that are required for procuring this modular sampling train are given in the Guideline. The sampling procedures consist of a description for isokinetic sampling, a leakage test prior to sampling, the actual sampling and its duration, how the equipment is cleaned after the sampling, and how the samples are prepared and stored. Analysis of the samples is performed via three procedures. Prior to these procedures, the sample is prepared by Soxhlet extraction of the tars on the particle filter and by collection of all tars in one bulk solution. The first procedure describes the weighing of the particle filter to obtain the concentration of particles in the biomass producer gas. The bulk tar solution is used for two purposes: for determination of gravimetric tar and for analysis of individual compounds. The second procedure describes how to determine the gravimetric tar mass from the bulk solution. The

  2. Treatment of low-temperature tar-gas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Schick, F

    1928-07-04

    Process for the treating and conversion of low-temperature tar-vapor and gas mixtures in the presence of metals or metal oxides as well as bodies of large surface, without previous condensation of the liquid material to be treated, characterized by the treatment taking place with a mixture of desulfurizing metals and metal oxides which, if necessary, are precipitated on carriers and large surface nonmetal cracking catalysts, such as active carbon and silica gel.

  3. Radiocarbon dating of extinct fauna in the Americas recovered from tar pits

    International Nuclear Information System (INIS)

    Jull, A.J.T.; Iturralde-Vinent, M.; O'Malley, J.M.; MacPhee, R.D.E.; McDonald, H.G.; Martin, P.S.; Moody, J.; Rincon, A.

    2004-01-01

    We have obtained radiocarbon dates by accelerator mass spectrometry on bones of extinct large mammals from tar pits. Results on some samples of Glyptodon and Holmesina (extinct large mammals similar to armadillos) yielded ages of >25 and >21 ka, respectively. We also studied the radiocarbon ages of three different samples of bones from the extinct Cuban ground sloth, Parocnus bownii, which yielded dates ranging from 4960 ± 280 to 11 880 ± 420 yr BP. In order to remove the tar component pretreat the samples sufficiently to obtain reliable dates, we cleaned the samples by Soxhlet extraction in benzene. Resulting samples of collagenous material were often small

  4. Mass Transfer Coefficientin Stirred Tank for p -Cresol Extraction Process from Coal Tar

    International Nuclear Information System (INIS)

    Fardhyanti, D S; Tyaningsih, D S; Afifah, S N

    2017-01-01

    Indonesia is a country that has a lot of coal resources. The Indonesian coal has a low caloric value. Pyrolysis is one of the process to increase the caloric value. One of the by-product of the pyrolysis process is coal tar. It contains a lot of aliphatic or aromatic compounds such as p -cresol (11% v/v). It is widely used as a disinfectant. Extractionof p -Cresol increases the economic value of waste of coal. The aim of this research isto study about mass tranfer coefficient in the baffled stirred tank for p -Cresolextraction from coal tar. Mass transfer coefficient is useful for design and scale up of industrial equipment. Extraction is conducted in the baffled stirred tank equipped with a four-bladed axial impeller placed vertically in the vessel. Sample for each time processing (5, 10, 15, 20, 25 and 30minutes) was poured into a separating funnel, settled for an hour and separated into two phases. Then the two phases were weighed. The extract phases and raffinate phases were analyzed by Spectronic UV-Vis. The result showed that mixing speed of p -Cresol extraction increasesthe yield of p -Cresol and the mass transfer coefficient. The highest yield of p -Cresol is 49.32% and the highest mass transfer coefficient is 4.757 x 10 -6 kg/m 2 s. (paper)

  5. Mass Transfer Coefficientin Stirred Tank for p-Cresol Extraction Process from Coal Tar

    Science.gov (United States)

    Fardhyanti, D. S.; Tyaningsih, D. S.; Afifah, S. N.

    2017-04-01

    Indonesia is a country that has a lot of coal resources. The Indonesian coal has a low caloric value. Pyrolysis is one of the process to increase the caloric value. One of the by-product of the pyrolysis process is coal tar. It contains a lot of aliphatic or aromatic compounds such asp-cresol (11% v/v). It is widely used as a disinfectant. Extractionof p-Cresol increases the economic value of waste of coal. The aim of this research isto study about mass tranfer coefficient in the baffled stirred tank for p-Cresolextraction from coal tar. Mass transfer coefficient is useful for design and scale up of industrial equipment. Extraction is conducted inthe baffled stirred tank equipped with a four-bladed axial impeller placed vertically in the vessel. Sample for each time processing (5, 10, 15, 20, 25 and 30minutes) was poured into a separating funnel, settled for an hour and separated into two phases. Then the two phases were weighed. The extract phases and raffinate phases were analyzed by Spectronic UV-Vis. The result showed that mixing speed of p-Cresol extraction increasesthe yield of p-Cresol and the mass transfer coefficient. The highest yield of p-Cresol is 49.32% and the highest mass transfer coefficient is 4.757 x 10-6kg/m2s.

  6. Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar

    Energy Technology Data Exchange (ETDEWEB)

    Fassinou, Wanignon Ferdinand; Toure, Siaka [Laboratoire d' Energie Solaire-UFR-S.S.M.T. Universite de Cocody, 22BP582 Abidjan 22 (Ivory Coast); Van de Steene, Laurent; Volle, Ghislaine; Girard, Philippe [CIRAD-Foret, TA 10/16, 73, avenue J.-F. Breton, 34398 Montpellier, Cedex 5 (France)

    2009-01-15

    A new two-stage gasifier with fixed-bed has recently been installed on CIRAD facilities in Montpellier. The pyrolysis and the gasifier units are removable. In order to characterise the pyrolysis products before their gasification, experiments were carried out, for the first time only with the pyrolysis unit and this paper deals with the results obtained. The biomass used is Pinus pinaster. The parameters investigated are: temperature, residence time and biomass flow rate. It has been found that increasing temperature and residence time improve the cracking of tars, gas production and char quality (fixed carbon rate more than 90%, volatile matter rate less than 4%). The increase of biomass flow rate leads to a bad char quality. The efficiency of tar cracking, the quality and the heating value of the charcoal and the gases, indicate that: temperature between 650 C and 750 C, residence time of 30 min, biomass flow rate between 10 and 15 kg/h should be the most convenient experimental conditions to get better results from the experimental device and from the biomass pyrolysis process. The kinetic study of charcoal generation shows that the pyrolysis process, in experimental conditions, is a first-order reaction. The kinetic parameters calculated are comparable with those found by other researchers. (author)

  7. Hydrogen-Rich Gas Production by Sorption Enhanced Steam Reforming of Woodgas Containing TAR over a Commercial Ni Catalyst and Calcined Dolomite as CO2 Sorbent

    Directory of Open Access Journals (Sweden)

    Vincenzo Naso

    2013-07-01

    Full Text Available The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR and CH4 and to produce pure H2 by means of a CO2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite (CaO/MgO. The bed material simultaneously acts as reforming catalyst and CO2 sorbent. The experimental investigations have been carried out in a fixed bed micro-reactor rig using a slipstream from the gasifier to evaluate gas cleaning and upgrading options. The reforming/sorption tests were carried out at 650 °C while regeneration of the sorbent was carried out at 850 °C in a nitrogen environment. Both combinations of catalyst and sorbent are very effective in TAR and CH4 removal, with conversions near 100%, while the simultaneous CO2 sorption effectively enhances the water gas shift reaction producing a gas with a hydrogen volume fraction of over 90%. Multicycle tests of reforming/CO2 capture and regeneration were performed to verify the stability of the catalysts and sorbents to remove TAR and capture CO2 during the duty cycle.

  8. Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, Smilodon

    OpenAIRE

    Carbone, Chris; Maddox, Tom; Funston, Paul J.; Mills, Michael G.L.; Grether, Gregory F.; Van Valkenburgh, Blaire

    2008-01-01

    Inferences concerning the lives of extinct animals are difficult to obtain from the fossil record. Here we present a novel approach to the study of extinct carnivores, using a comparison between fossil records (n=3324) found in Late Pleistocene tar seeps at Rancho La Brea in North America and counts (n=4491) from playback experiments used to estimate carnivore abundance in Africa. Playbacks and tar seep deposits represent competitive, potentially dangerous encounters where multiple predators ...

  9. Traditional African Religions (TARs): on HIV/AIDS, health and ...

    African Journals Online (AJOL)

    This is because the moral guidance put forward by. African religions is underestimated; hence making HIV/AIDS more of a moral problem. Rethinking the dialogue with TARs, will help in setting appropriate means of enhancing health in a broad sense and living in human dignity in Africa. Mtafiti Mwafrika Vol. 15 2005: pp.

  10. Class III Mid-Term Project, "Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies"

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2007-03-31

    The overall objective of this project was to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involved improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective has been to transfer technology that can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The first budget period addressed several producibility problems in the Tar II-A and Tar V thermal recovery operations that are common in SBC reservoirs. A few of the advanced technologies developed include a three-dimensional (3-D) deterministic geologic model, a 3-D deterministic thermal reservoir simulation model to aid in reservoir management and subsequent post-steamflood development work, and a detailed study on the geochemical interactions between the steam and the formation rocks and fluids. State of the art operational work included drilling and performing a pilot steam injection and production project via four new horizontal wells (2 producers and 2 injectors), implementing a hot water alternating steam (WAS) drive pilot in the existing steamflood area to improve thermal efficiency, installing a 2400-foot insulated, subsurface harbor channel crossing to supply steam to an island location, testing a novel alkaline steam completion technique to control well sanding problems, and starting on an advanced reservoir management system through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation. The second budget period phase (BP2) continued to implement state-of-the-art operational work to optimize thermal recovery processes, improve well drilling and completion practices, and evaluate the

  11. Performance Evaluation of Linear (ARMA and Threshold Nonlinear (TAR Time Series Models in Daily River Flow Modeling (Case Study: Upstream Basin Rivers of Zarrineh Roud Dam

    Directory of Open Access Journals (Sweden)

    Farshad Fathian

    2017-01-01

    Full Text Available Introduction: Time series models are generally categorized as a data-driven method or mathematically-based method. These models are known as one of the most important tools in modeling and forecasting of hydrological processes, which are used to design and scientific management of water resources projects. On the other hand, a better understanding of the river flow process is vital for appropriate streamflow modeling and forecasting. One of the main concerns of hydrological time series modeling is whether the hydrologic variable is governed by the linear or nonlinear models through time. Although the linear time series models have been widely applied in hydrology research, there has been some recent increasing interest in the application of nonlinear time series approaches. The threshold autoregressive (TAR method is frequently applied in modeling the mean (first order moment of financial and economic time series. Thise type of the model has not received considerable attention yet from the hydrological community. The main purposes of this paper are to analyze and to discuss stochastic modeling of daily river flow time series of the study area using linear (such as ARMA: autoregressive integrated moving average and non-linear (such as two- and three- regime TAR models. Material and Methods: The study area has constituted itself of four sub-basins namely, Saghez Chai, Jighato Chai, Khorkhoreh Chai and Sarogh Chai from west to east, respectively, which discharge water into the Zarrineh Roud dam reservoir. River flow time series of 6 hydro-gauge stations located on upstream basin rivers of Zarrineh Roud dam (located in the southern part of Urmia Lake basin were considered to model purposes. All the data series used here to start from January 1, 1997, and ends until December 31, 2011. In this study, the daily river flow data from January 01 1997 to December 31 2009 (13 years were chosen for calibration and data for January 01 2010 to December 31 2011

  12. Corrosão de parafusos fixados à madeira tratada com soluções de creosoto vegetal Corrosion of screws fixed into wood treated with wood tar creosote solutions

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2002-05-01

    Full Text Available O objetivo desta pesquisa foi avaliar a corrosão de parafusos auto-rosqueáveis fixados à madeira tratada com soluções preservativas preparadas com creosoto vegetal, em condições de campo. Obteve-se o creosoto vegetal bruto por meio da destilação à temperatura de 110 - 255ºC do alcatrão vegetal. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tubutil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Estacas confeccionadas com madeira de alburno de Eucalyptus grandis foram tratadas pelo processo de célula- cheia (processo Bethell. Após o tratamento, parafusos auto-rosquéaveis de ferro zincado foram fixados às estacas. O ensaio foi instalado em três localidades da Zona da Mata de Minas Gerais (Viçosa, Ponte Nova e Leopoldina. A corrosividade das soluções de creosoto vegetal foi comparada à causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, assemelhando-se ao creosoto mineral.The objective of this research was to evaluate the corrosion of screws fixed into wood treated with preservative solutions of wood tar creosote. The crude wood tar creosote was obtained through distillation of wood tar at 110 - 255ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood tar creosote. Both fractions were enriched with 3% of copper naphtenate, 3% of zinc naphtenate, 3% of cobalt naphtenate, 2% of TBTO, 2% of tributhyl-tin tribromophenate, 2% of pentachlorophenol, or with 0.4% of arsenic trioxide. A total

  13. Catalytic upgrading of gas from biofuels and implementation of electricity production. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Espenaes, Bengt-Goeran; Frostaeng, Sten [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-04-01

    components concerned are typically aromatic hydrocarbons. These investigations were done using basic oxides (e.g. dolomite), and nickel-based catalysts. Data were collected at different gas compositions and temperatures. Interdependence of reaction rates of some most stable tar components was investigated with dolomite as catalyst. New insights were obtained concerning the reaction mechanism of the decomposition of aromatic compounds catalysed by dolomite. Among issues studied were relations between pore structure and catalytic ability, and influences from the conditions during calcination. The role of intermediate carbon formation on dolomite during decomposition of aromatic hydrocarbons was investigated. Several suggested kinetic rate model equations were evaluated. Internal surface areas of calcined dolomite of different origin were investigated and correlated to their catalytic activity. Kinetics of tar conversion with dolomite and nickel catalysts was included in reactor models. Different models were formulated and tested for different types of reactors. A model for the physical degradation behaviour of dolomite and carry-over of fines in fluidized beds was formulated. A number of new suggested catalysts and catalyst combinations were tested. One interesting new approach is to use a SiO{sub 2} material with large surface area in combination with another catalyst, e.g. dolomite. Another novel catalyst gave very good conversion of benzene at 480 deg C in a 'clean' synthetic gas mixture. Further testing of this catalyst at realistic conditions will be needed. Relations between raw materials and tar formation was investigated in experiments with thermal and catalytic treatment in a secondary reactor after a pyrolyser and comparisons were done with results from gasification. Tar products distribution and amounts were found to be influenced by feedstock. These differences decrease with increasing cracking temperature and efficiency of the catalyst. The sampling and

  14. Controllable growth of nanostructured carbon from coal tar pitch by chemical vapor deposition

    International Nuclear Information System (INIS)

    Liu Xuguang; Yang Yongzhen; Ji Weiyun; Liu Hongyan; Zhang Chunyi; Xu Bingshe

    2007-01-01

    The direct synthesis of vapor grown carbon fibers with different diameters was achieved by the pyrolysis of coal tar pitch by chemical vapor deposition. The products were characterized by field-emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The experimental results demonstrated that ferrocene content, reaction temperature and Ar flow rate strongly influenced the yield and nature of nanostructured carbon materials, pure carbon microbeads, with diameter distribution ranging from 450 to 650 nm, were also obtained in the absence of catalyst, uniform and straight carbon nanofibers with the outer diameter of about 115 nm were obtained and curl and thick carbon fibers with narrow diameter distribution of 300-350 nm were produced

  15. Perversities of Extreme Dependence and Unequal Growth in the TAR

    NARCIS (Netherlands)

    A.M. Fischer (Andrew Martín)

    2007-01-01

    textabstractThe official Chinese press recently came out with a series of articles reporting the latest statistics on the phenomenally rapid economic growth that has been taking place in the Tibet Autonomous Region (TAR) since the mid-1990s through sheer force of Central Government subsidies.

  16. PAHs underfoot: Contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    Science.gov (United States)

    Van Metre, P.C.; Mahler, B.J.; Wilson, J.T.

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U. S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat Dust was swept from parking lots in six cities in the central and eastern U. S., where coal-tar-based sealcoat dominates use, and three cities in the western U. S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median ?? PAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2. 1 and 0. 8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  17. Application of adsorption analysis to the investigation of phenols and bases in low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Kalechts, I V; Salimgareeva, F G; Tumbusova, Z P

    1955-01-01

    The use of chromatographic adsorption for the separation of mono- and bicyclic phenols and bases from coal tar and from its hydrogenation products were studied with o-cresol, ..beta..-naphthol, pyridine, and quinoline. Experimental data show that Al/sub 2/O/sub 3/ was preferable for separating phenols, but that silica gel was better for the bases. The best order of use of the developers was as follows: C/sub 6/H/sub 6/, Et/sub 2/O, EtOH. The data show that the destructive hydrogenation process degrades the higher series phenols to lower ones.

  18. Geology and resources of the Tar Sand Triangle, southeastern Utah

    Energy Technology Data Exchange (ETDEWEB)

    Dana, G.F.; Oliver, R.L.; Elliott, J.R.

    1984-05-01

    The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyonlands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well-sorted sandstone which was deposited in a shallow marine environment. Resources were calculated from analytical data from the three coreholes drilled by the Laramie Energy Technology Center and other available data. The total in-place resources, determined from this study, are 6.3 billion barels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses will be necessary before a more accurate determination of resources can be attempted. 8 references, 11 figures, 7 tables.

  19. PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana.

    Science.gov (United States)

    Blenau, Wolfgang; Balfanz, Sabine; Baumann, Arnd

    2017-10-30

    The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP] i ) whereas type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . Here; we report that the American cockroach ( Periplaneta americana ) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP] i . Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana ; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.

  20. PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

    Directory of Open Access Journals (Sweden)

    Wolfgang Blenau

    2017-10-01

    Full Text Available The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G protein-coupled receptors (GPCRs. Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP]i whereas type 2 tyramine receptors can mediate Ca2+ signals or both Ca2+ signals and effects on [cAMP]i. Here; we report that the American cockroach (Periplaneta americana expresses a second type 1 tyramine receptor (PeaTAR1B in addition to PeaTAR1A (previously called PeaTYR1. When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP]i. Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.

  1. Calcipotriol versus coal tar: a prospective randomized study in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.; Kaur, I.; Kumar, B. [Postgraduate Institute of Medicinal Education & Research, Chandigarh (India)

    2003-10-01

    Topical therapies are the first line of treatment for patients with stable plaque psoriasis (SPP) affecting a limited body surface area. Very few trials comparing newer agents, such as 0.005% topical calcipotriol, with conventional modes of therapy, such as coal tar ointment, have been reported. A prospective, right-left randomized, investigator-blinded study with a 12-week treatment period and an 8-week follow-up period was performed. It was found that 0.005% calcipotriol ointment produced a faster initial response and had better cosmetic acceptability in patients, although after a long period of treatment, i.e. 12 weeks, 5% coal tar ointment had comparable efficacy. There was no statistically significant difference in the relapse rates between the two modalities.

  2. Heating tar sands formations to visbreaking temperatures

    Science.gov (United States)

    Karanikas, John Michael [Houston, TX; Colmenares, Tulio Rafael [Houston, TX; Zhang, Etuan [Houston, TX; Marino, Marian [Houston, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX; Ryan, Robert Charles [Houston, TX; Beer, Gary Lee [Houston, TX; Dombrowski, Robert James [Houston, TX; Jaiswal, Namit [Houston, TX

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  3. Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

    KAUST Repository

    Li, Yongxin

    2015-03-24

    Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning plug-and-playa approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

  4. Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

    Science.gov (United States)

    Li, Yongxin; Li, Zhongrui; Yamanaka, Kazuya; Xu, Ying; Zhang, Weipeng; Vlamakis, Hera; Kolter, Roberto; Moore, Bradley S.; Qian, Pei-Yuan

    2015-03-01

    Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning ``plug-and-play'' approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

  5. Topical coal tar alone and in combination with oral methotrexate in management of psoriasis : a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Prasad PVS

    1997-01-01

    Full Text Available Thirty five patients admitted with psoriasis were analysed. 16 patients received 20% crude coal tar and 19 patients received 20% crude coal tar along with methotrexate in a weekly oral schedule (15mg/wk. After 4 weeks of therapy there was total clearence in 52.6% of the patients with combination therapy, whereas only 12.5% of the patients with conventional therapy achieved this.

  6. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  7. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Van Metre; Barbara J. Mahler; Jennifer T. Wilson [U.S. Geological Survey, Austin, TX (USA)

    2009-01-15

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of {Sigma}PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo(a)pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. 30 refs., 4 figs., 2 tabs.

  8. A proteomic study of TAR-RNA binding protein (TRBP-associated factors

    Directory of Open Access Journals (Sweden)

    Chi Ya-Hui

    2011-02-01

    Full Text Available Abstract Background The human TAR RNA-binding protein, TRBP, was first identified and cloned based on its high affinity binding to the small hairpin trans-activation responsive (TAR RNA of HIV-1. TRBP has more recently been found to be a constituent of the RNA-induced silencing complex (RISC serving as a Dicer co-factor in the processing of the ~70 nucleotide pre-microRNAs(miRNAs to 21-25 nucleotide mature miRNAs. Findings Using co-immunoprecipitation and protein-identification by mass spectrometry, we characterized intracellular proteins that complex with TRBP. These interacting proteins include those that have been described to act in protein synthesis, RNA modifications and processing, DNA transcription, and cell proliferation. Conclusions Our findings provide a proteome of factors that may cooperate with TRBP in activities such as miRNA processing and in RNA interference by the RISC complex.

  9. Isolation of biosurfactant-producing bacteria from the Rancho La Brea Tar Pits.

    Science.gov (United States)

    Belcher, Richard W; Huynh, Kelvin V; Hoang, Timothy V; Crowley, David E

    2012-12-01

    This research was conducted to identify culturable surfactant-producing bacterial species that inhabit the 40,000-year-old natural asphalt seep at the Rancho La Brea Tar Pits in Los Angeles, CA. Using phenanthrene, monocyclic aromatic hydrocarbons, and tryptic soy broth as growth substrates, culturable bacteria from the tar pits yielded ten isolates, of which three species of gamma-proteobacteria produced biosurfactants that accumulated in spent culture medium. Partially purified biosurfactants produced by these strains lowered the surface tension of water from 70 to 35-55 mN/m and two of the biosurfactants produced 'dark halos' with the atomized oil assay, a phenomenon previously observed only with synthetic surfactants. Key findings include the isolation of culturable biosurfactant-producing bacteria that comprise a relatively small fraction of the petroleum-degrading community in the asphalt.

  10. PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.

    2013-01-01

    Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected in 1998, 2000, 2001, 2012, and 2014 from Lady Bird Lake, the principal receiving water body for Austin urban runoff. The sum concentration of the 16 EPA Priority Pollutant PAHs (∑PAH16) in dated core intervals and surficial bottom-sediment samples collected from sites in the lower lake declined about 44% from 1998–2005 to 2006–2014 (means of 7980 and 4500 μg kg–1, respectively), and by 2012–2014, the decline was about 58% (mean of 3320 μg kg–1). Concentrations of ∑PAH16 in bottom sediment from two of three mid-lake sites decreased by about 71 and 35% from 2001 to 2014. Concentrations at a third site increased by about 14% from 2001 to 2014. The decreases since 2006 reverse a 40-year (1959–1998) upward trend. Despite declines in PAH concentrations, PAH profiles and source-receptor modeling results indicate that coal-tar sealants remain the largest PAH source to the lake, implying that PAH concentrations likely will continue to decline as stocks of previously applied sealant gradually become depleted.

  11. Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Prausnitz, J.M.

    1980-05-01

    This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

  12. Microporous Organic Polymers Based on Hyper-Crosslinked Coal Tar: Preparation and Application for Gas Adsorption.

    Science.gov (United States)

    Gao, Hui; Ding, Lei; Bai, Hua; Li, Lei

    2017-02-08

    Hyper-crosslinked polymers (HCPs) are promising materials for gas capture and storage, but high cost and complicated preparation limit their practical application. In this paper, a new type of HCPs (CTHPs) was synthesized through a one-step mild Friedel-Crafts reaction with low-cost coal tar as the starting material. Chloroform was utilized as both solvent and crosslinker to generate a three-dimensional crosslinked network with abundant micropores. The maximum BET surface area of the prepared CTHPs could reach up to 929 m 2  g -1 . Owing to the high affinity between the heteroatoms on the coal-tar building blocks and the CO 2 molecules, the adsorption capacity of CTHPs towards CO 2 reached up to 14.2 wt % (1.0 bar, 273 K) with a high selectivity (CO 2 /N 2 =32.3). Furthermore, the obtained CTHPs could adsorb 1.27 wt % H 2 at 1.0 bar and 77.3 K, and also showed capacity for the capture of high organic vapors at room temperature. In comparison with other reported porous organic polymers, CTHPs have the advantages of low-cost, easy preparation, and high gas-adsorption performance, making them suitable for mass production and practical use in the future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  14. Effects of varying marijuana potency on deposition of tar and delta9-THC in the lung during smoking.

    Science.gov (United States)

    Matthias, P; Tashkin, D P; Marques-Magallanes, J A; Wilkins, J N; Simmons, M S

    1997-12-01

    To determine whether smoking more, compared to less, potent marijuana (MJ) cigarettes to a desired level of intoxication ("high") reduces pulmonary exposure to noxious smoke components, in 10 habitual smokers of MJ, we measured respiratory delivery and deposition of tar and delta9-tetrahydrocannabinol (THC), carboxyhemoglobin (COHb) boost, smoking topography, including cumulative puff volume (CPV) and breathholding time, change in heart rate (deltaHR) and "high" during ad lib smoking of 0, 1.77, and 3.95% MJ cigarettes on 3 separate days. At each session, subjects had access to only a single MJ cigarette. On average, smoking topography and COHb boost did not differ across the different strengths of MJ, while THC delivery, as well as HR, were significantly greater (p studies using a standardized smoking technique revealed a mean 25% lower tar yield from 3.95% than 1.77% MJ (p marijuana. Under the conditions of this study, we conclude that tar delivery is reduced relative to THC content in a minority of subjects, and this reduction appears to be due to a reduced intake of smoke (decreased CPV) and/or a reduced tar yield from the stronger MJ preparation.

  15. Coal tar induces AHR-dependent skin barrier repair in atopic dermatitis

    NARCIS (Netherlands)

    Bogaard, E.H. van den; Bergboer, J.G.M.; Vonk-Bergers, M.; Vlijmen-Willems, I.M. van; Hato, S.V.; Valk, P.G. van der; Schroder, J.M.; Joosten, I.; Zeeuwen, P.L.J.M.; Schalkwijk, J.

    2013-01-01

    Topical application of coal tar is one of the oldest therapies for atopic dermatitis (AD), a T helper 2 (Th2) lymphocyte-mediated skin disease associated with loss-of-function mutations in the skin barrier gene, filaggrin (FLG). Despite its longstanding clinical use and efficacy, the molecular

  16. A cost comparison of nuclear and fossil power for the Alberta tar sands

    International Nuclear Information System (INIS)

    Sochaski, R.O.; Smith, D.W.

    1977-04-01

    One technique envisaged for commercial development of the Alberta tar sands is in-situ removal of bitumen by injection of steam into the formation at high temperature and pressure. The 3000 MW of thermal power required for a typical 20 Gg/d plant could be supplied by a nuclear reactor. Accordingly, an economic comparison was made between a CANDU organic-cooled reactor and a conventional coal-fired station, using a variety of financial ground rules. This analysis shows that for debt-financed cases, nuclear power has essentially no economic competition from coal. For equity cases, the competitive position of a coal-fired station is heavily dependent on the cost of coal delivered to the tar sands area, discount rate, amortization period and inflation rate. (author)

  17. Polycyclic aromatic hydrocarbons (PAHs) and hopanes in stranded tar-balls on the coasts of peninsular Malaysia: applications of biomarkers for identifying sources of oil pollution

    International Nuclear Information System (INIS)

    Zakaria, Mohamad Pauzi; Okuba, Tomoaki; Takada, Hideshige

    2001-01-01

    Malaysian coasts are subjected to various threats of petroleum pollution including routine and accidental oil spill from tankers, spillage of crude oils from inland and offshore oil fields, and run-off from land-based human activities. Due to its strategic location, the Straits of Malacca serves as a major shipping lane. This paper expands the utility of biomarker compounds, hopanes, in identifying the source of tar-balls stranded on Malaysian coasts. 20 tar-ball samples collected from the east and west coast were analysed for hopanes and polycylic aromatic hydrocarbons (PAHs). Four of the 13 tar-ball samples collected from the west coast of Peninsular Malaysia were identified as the Middle East crude oil (MECO) based on their biomarker signatures, suggesting tanker-derived sources significantly contributing the petroleum pollution in the Straits of Malacca. The tar-balls found on the east cost seem to originate from the offshore oil platforms in the South China Sea. The presence of South East Asian crude oil (SEACO) tar-balls on the west coast carry several plausible explanations. Some of the tar-balls could have been transported via sea currents from the east coast. The tankers carrying SEACO to other countries could have accidentally spilt the oil as well. Furthermore, discharge of tank washings and ballast water from the tankers were suggested based on the abundance in higher molecular weight n-alkanes and the absence of unresolved complex mixture (UCM) in the tar-ball samples. The other possibilities are that the tar-balls may have originated from the Sumatran oil fields and spillage of domestic oil from oil refineries in Port Dickson and Malacca. The results of PAHs analysis suggest that all the tar-ball samples have undergone various extent of weathering through evaporation, dissolution and photo-oxidation. (Author)

  18. Polycyclic aromatic hydrocarbon (PAHs) and hopanes in stranded tar-balls on the coasts of Peninsular Malaysia: applications of biomarkers for identifying sources of oil pollution.

    Science.gov (United States)

    Zakaria, M P; Okuda, T; Takada, H

    2001-12-01

    Malaysian coasts are subjected to various threats of petroleum pollution including routine and accidental oil spill from tankers, spillage of crude oils from inland and off-shore oil fields, and run-off from land-based human activities. Due to its strategic location, the Straits of Malacca serves as a major shipping lane. This paper expands the utility of biomarker compounds, hopanes, in identifying the source of tar-balls stranded on Malaysian coasts. 20 tar-ball samples collected from the east and west coast were analyzed for hopanes and polycyclic aromatic hydrocarbons (PAHs). Four of the 13 tar-ball samples collected from the west coast of Peninsular Malaysia were identified as the Middle East crude oil (MECO) based on their biomarker signatures, suggesting tanker-derived sources significantly contributing the petroleum pollution in the Straits of Malacca. The tar-balls found on the east coast seem to originate from the offshore oil platforms in the South China Sea. The presence of South East Asian crude oil (SEACO) tar-balls on the west coast carry several plausible explanations. Some of the tar-balls could have been transported via sea currents from the east coast. The tankers carrying SEACO to other countries could have accidentally spilt the oil as well. Furthermore, discharge of tank washings and ballast water from the tankers were suggested based on the abundance in higher molecular weight n-alkanes and the absence of unresolved complex mixture (UCM) in the tar-ball samples. The other possibilities are that the tar-balls may have been originated from the Sumatran oil fields and spillage of domestic oil from oil refineries in Port Dickson and Malacca. The results of PAHs analysis suggest that all the tar-ball samples have undergone various extent of weathering through evaporation, dissolution and photooxidation.

  19. Dissolution and transport of coal tar compounds in fractured clay-rich residuum

    DEFF Research Database (Denmark)

    Vulava, Vijay M.; McKay, Larry D.; Broholm, Mette Martina

    2012-01-01

    the importance of rapid dissolution and transport through the fracture networks. The concentrations continued to rise but did not reach the corresponding effective solubility limit in most cases. Compounds that were less soluble and those that were more susceptible to sorption or matrix diffusion eluted...... at a much slower rate. Analysis of contaminant concentrations in microcore residuum samples indicated that all 10 compounds had spread throughout the entire monolith and had diffused into the fine-grained matrix between fractures. These data suggest that the predominantly fine pore structure did not appear......We investigated the dissolution and transport of organic contaminants from a crude coal tar mixture in a monolith of fractured clay-rich residuum. An electrolyte solution was eluted through the residuum monolith containing a small emplaced source of coal tar under biologically inhibited and mildly...

  20. Heating tar sands formations while controlling pressure

    Science.gov (United States)

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  1. 48 CFR 1201.301-70 - Amendment of (TAR) 48 CFR chapter 12.

    Science.gov (United States)

    2010-10-01

    ...) 48 CFR chapter 12 is maintained by the SPE through the TAR/TAM change process. This process consists... (C) To issue guidance which may be effective for a period of 1 year or less. (ii) Each TN will expire...

  2. Thermal remediation of tar-contaminated soil and oil-contaminated gravel

    International Nuclear Information System (INIS)

    Anthony, E.J.; Wang, J.

    2005-01-01

    High temperature treatments are commonly considered for the decontamination of soil as they have the advantages of reliability, high capacity, and effective destruction of hazardous materials with reduced long-term liability. This paper examined the remediation of soil contaminated by coal tar as well as gravel contaminated by oil. Pilot plant studies were conducted using 2 representative incineration technologies: rotary kiln and fluidized bed. The coal tar contaminated soil had accumulated over a few decades at a calcination plant in western Canada. The soil was sticky and could not be handled by conventional feeding and combustion systems. Crushed lignite was mixed with the soil as an auxiliary fuel and to reduce stickiness. A pilot plant furnace was used to evaluate the potential of decontamination in a rotary calciner. An analysis of both a modelling study and the test results showed that complete decontamination could be achieved in the targeted calciner. The results suggested that energy recovery was also possible, which could in turn make the remediation process more cost-effective. Decontamination of oil-contaminated gravel was conducted with a pilot plant fluidized bed combustor to study the feasibility of using incineration technology in the remediation of gravel and debris contaminated by oil spills. Results indicated that the gravel was decontaminated with acceptable emission performance. It was concluded that the study will be valuable to the application of commercial incineration processes for the remediation of polluted soils. It was observed that the weathering of the oiled gravel lowered the rate of decontamination. A small amount of salt water resulted in lowered decontamination rates, which may be an important factor for situations involving the remediation of shoreline gravel contaminated by oil. 24 refs., 6 tabs., 7 figs

  3. Low Temperature Particle Filtration of Wood Gas with Low Tar Content

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik Birk; Bentzen, Jens Dall

    2002-01-01

    Baghouse filters and cartridge filters were tested online with wood gas from a two stage down draft gasifier. The gas contained soot and very low levels (10-30 mg/Nm³) of tar. Particle collection efficiencies were above 95%. Continuous operation with cheap self cleaning baghouse filters were test...

  4. Identifying the source of tar balls deposited along the beaches of Goa in 2013 and comparing with historical data collected along the West Coast of India

    Energy Technology Data Exchange (ETDEWEB)

    Suneel, V., E-mail: vasimallas@nio.org [CSIR-National Institute of Oceanography, Dona Paula, Goa 403004 (India); Vethamony, P., E-mail: mony@nio.org [CSIR-National Institute of Oceanography, Dona Paula, Goa 403004 (India); Naik, B.G., E-mail: bgnaik@nio.org [CSIR-National Institute of Oceanography, Dona Paula, Goa 403004 (India); Krishna, M.S., E-mail: moturi@nio.org [CSIR-National Institute of Oceanography, Regional Centre, Visakhapatnam, 530 017 (India); Jadhav, Lakshmikant, E-mail: lakshya87.0@gmail.com [CSIR-National Institute of Oceanography, Dona Paula, Goa 403004 (India)

    2015-09-15

    Deposition of oil residues, also known as tar balls, is a seasonal phenomenon, and it occurs only in the southwest monsoon season along the west coast of India. This has become a serious environmental issue, as Goa is a global tourist destination. The present work aims at identifying the source oil of the tar balls that consistently depositing along the Goa coast using multi-marker fingerprint technique. In this context, the tar ball samples collected in May 2013 from 9 beaches of Goa coast and crude oils from different oil fields and grounded ship were subject to multi-marker analyses such as n-alkanes, pentacyclic terpanes, regular steranes, compound specific isotope analysis (CSIA) and principle component analysis (PCA). The n-alkane weathering index shows that samples have been weathered to various degrees, and the status of weathering is moderate. Since the international tanker route passes closer to the west coast of India (WCI), it is generally presumed that tanker wash is the source of the tar balls. We found that 2010/2011 tar balls are as tanker wash, but the present study demonstrates that the Bombay High (BH) oil fields can also contribute to oil contamination (tar balls) along ≈ 650 km stretch of the WCI, running from Gujarat in the north to Goa in the south. The simulated trajectories show that all the particles released in April traveled in the southeast direction, and by May, they reached the Goa coast with the influence of circulation of Indian monsoon system. - Highlights: • Multi-marker approach was effective in identifying the source of tar balls. • n-Alkane DRs show weathering effects even within the core of the tar ball. • Tar balls of the west coast of India since 2012 were derived from Bombay High crude. • Tanker-wash is not the only source of tar balls deposited on the beaches of Goa.

  5. Identifying the source of tar balls deposited along the beaches of Goa in 2013 and comparing with historical data collected along the West Coast of India

    International Nuclear Information System (INIS)

    Suneel, V.; Vethamony, P.; Naik, B.G.; Krishna, M.S.; Jadhav, Lakshmikant

    2015-01-01

    Deposition of oil residues, also known as tar balls, is a seasonal phenomenon, and it occurs only in the southwest monsoon season along the west coast of India. This has become a serious environmental issue, as Goa is a global tourist destination. The present work aims at identifying the source oil of the tar balls that consistently depositing along the Goa coast using multi-marker fingerprint technique. In this context, the tar ball samples collected in May 2013 from 9 beaches of Goa coast and crude oils from different oil fields and grounded ship were subject to multi-marker analyses such as n-alkanes, pentacyclic terpanes, regular steranes, compound specific isotope analysis (CSIA) and principle component analysis (PCA). The n-alkane weathering index shows that samples have been weathered to various degrees, and the status of weathering is moderate. Since the international tanker route passes closer to the west coast of India (WCI), it is generally presumed that tanker wash is the source of the tar balls. We found that 2010/2011 tar balls are as tanker wash, but the present study demonstrates that the Bombay High (BH) oil fields can also contribute to oil contamination (tar balls) along ≈ 650 km stretch of the WCI, running from Gujarat in the north to Goa in the south. The simulated trajectories show that all the particles released in April traveled in the southeast direction, and by May, they reached the Goa coast with the influence of circulation of Indian monsoon system. - Highlights: • Multi-marker approach was effective in identifying the source of tar balls. • n-Alkane DRs show weathering effects even within the core of the tar ball. • Tar balls of the west coast of India since 2012 were derived from Bombay High crude. • Tanker-wash is not the only source of tar balls deposited on the beaches of Goa

  6. Diversity of 16S rRNA and dioxygenase genes detected in coal-tar-contaminated site undergoing active bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M; Khanna, S [NIIT Univ, Neemrana (India). Dept. of Biotechnology & Bioinformation

    2010-04-15

    In order to develop effective bioremediation strategies for polyaromatic hydrocarbons (PAHs) degradation, the composition and metabolic potential of microbial communities need to be better understood, especially in highly PAH contaminated sites in which little information on the cultivation-independent communities is available. Coal-tar-contaminated soil was collected, which consisted of 122-122.5 mg g{sup -1} total extractable PAH compounds. Biodegradation studies with this soil indicated the presence of microbial community that is capable of degrading the model PAH compounds viz naphthalene, phenanthrene and pyrene at 50 ppm each. PCR clone libraries were established from the DNA of the coal-tar-contaminated soil, targeting the 16S rRNA to characterize (I) the microbial communities, (ii) partial gene fragment encoding the Rieske iron sulfur center {alpha}-subunit) common to all PAH dioxygenase enzymes and (iii) {beta}-subunit of dioxygenase. Phylotypes related to Proteobacteria ({Alpha}-, {Epsilon}- and Gammaproteobacteria), Acidobacteria, Actinobacteria, Firmicutes, Gemmatimonadetes and Deinococci were detected in 16S rRNA derived clone libraries. Many of the gene fragment sequences of alpha-subunit and beta-subunit of dioxygenase obtained from the respective clone libraries fell into clades that are distinct from the reference dioxygenase gene sequences. Presence of consensus sequence of the Rieske type (2Fe2S) cluster binding site suggested that these gene fragments encode for {alpha}-subunit of dioxygenase gene. Sequencing of the cloned libraries representing {alpha}-subunit gene fragments (Rf1) and beta-subunit of dioxygenase showed the presence of hitherto unidentified dioxygenase in coal-tar-contaminated soil.

  7. Effect of Carbon and Nitrogen Sources on Polygalacturonase Production by Trichoderma viride (BITRS-1001 Isolated from Tar Sand in Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ogunmolu, F. E.

    2011-01-01

    Full Text Available The effects of the various carbon and nitrogen substrates on the growth and polygalacturonase activity of Trichoderma viride (BITRS-1001 isolated from the tar sand deposit in Gbelejuloda-Irele Ondo State, Nigeria were investigated in submerged cultivation at 30 °C ± 2 °C. The commercial carbon and nitrogen substrates included sucrose, fructose, starch, maltose, lactose and peptone, sodium nitrate, urea and casein respectively. All the carbon substrates used supported the growth of T. viride (0.566 to 0.156 g/50 mL of culture medium with starch supporting the highest biomass yield and sucrose the least biomass yield. Maximum polygalacturonase activity of 3033 U/mL was recorded in maltose medium. Maximum biomass yield on the nitrogen sources was observed in the organic nitrogen namely peptone and casein with values not significantly different from each other at p ≤ 0.05. In the determination of the crude enzyme activity on the nitrogen sources, maximum polygalacturonase activity of 12,400 U/mL was recorded in peptone medium. Hence, a careful manipulation of these nutrient substrates could help to optimise the production of this enzyme on a large scale.

  8. Low Temperature Particle Filtration of Producer Gas with Low Tar Content

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    This report describes the tests of different techniques for removing the particulates from producer gas from the 100 kW two-stage down-draft gasifier at DTU1 . The goal of the tests was to identify and implement methods to remove soot particles from producer gas with low tar content. During the f...

  9. Trace metals in heavy crude oils and tar sand bitumens

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.G.

    1990-11-28

    Fe, Ni, and V are considered trace impurities in heavy crude oils and tar sand bitumens. In order to understand the importance of these metals, we have examined several properties: (1) bulk metals levels, (2) distribution in separated fractions, (3) size behavior in feeds and during processing, (4) speciation as a function of size, and (5) correlations with rheological properties. Some of the results of these studies show: (1) V and Ni have roughly bimodal size distributions, (2) groupings were seen based on location, size distribution, and Ni/V ratio of the sample, (3) Fe profiles are distinctively different, having a unimodal distribution with a maximum at relatively large molecular size, (4) Fe concentrations in the tar sand bitumens suggest possible fines solubilization in some cases, (5) SARA separated fractions show possible correlations of metals with asphaltene properties suggesting secondary and tertiary structure interactions, and (6) ICP-MS examination for soluble ultra-trace metal impurities show the possibility of unexpected elements such as U, Th, Mo, and others at concentrations in the ppB to ppM range. 39 refs., 13 figs., 5 tabs.

  10. Polycyclic aromatic hydrocarbons (PAHs) in a coal tar standard reference material - SRM 1597a updated

    Energy Technology Data Exchange (ETDEWEB)

    Wise, Stephen A.; Poster, Dianne L.; Rimmer, Catherine A.; Schubert, Patricia; Sander, Lane C.; Schantz, Michele M. [National Institute of Standards and Technology (NIST), Analytical Chemistry Division, Gaithersburg, MD (United States); Leigh, Stefan D. [National Institute of Standards and Technology (NIST), Statistical Engineering Division, Gaithersburg, MD (United States); Moessner, Stephanie [National Institute of Standards and Technology (NIST), Analytical Chemistry Division, Gaithersburg, MD (United States); GMP/Comparator Labs, Werthenstein Chemie AG, Industrie Nord, Schachen (Switzerland)

    2010-09-15

    SRM 1597 Complex Mixture of Polycyclic Aromatic Hydrocarbons from Coal Tar, originally issued in 1987, was recently reanalyzed and reissued as SRM 1597a with 34 certified, 46 reference, and 12 information concentrations (as mass fractions) for polycyclic aromatic hydrocarbons (PAHs) and polycyclic aromatic sulfur heterocycles (PASHs) including methyl-substituted PAHs and PASHs. The certified and reference concentrations (as mass fractions) were based on results of analyses of the coal tar material using multiple analytical techniques including gas chromatography/mass spectrometry on four different stationary phases and reversed-phase liquid chromatography. SRM 1597a is currently the most extensively characterized SRM for PAHs and PASHs. (orig.)

  11. Durability and regeneration of catalysts of the iron family in hydrogenation of low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Funasaka, W; Yokogawa, C; Hayashi, K; Kawamura, T; Fujita, H; Suga, S

    1949-01-01

    The low-temperature tar consisting of neutral and acidic oils has been reduced under atmospheric pressure between 400/sup 0/ and 500/sup 0/ by using catalysts prepared from Fe-Cr-kieselguhr, yellow ocher, and other material. When the reduction was performed at 480/sup 0/ with the yellow ocher from Niwasaka, Fukushima Prefacture, Japan, the low-temperature tar was easily converted to neutral and light oils and the catalysts could be regenerated by repeated baking and reduction. It is concluded that the commercialization of this reduction process is possible by using a cycle (each takes 20 minutes) composed of catalytic reaction, baking, and reduction of the catalysts.

  12. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    International Nuclear Information System (INIS)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R.; Vala, David; Reese, Barbara K.; Freedman, Dina R.; Stenten, Christina J.; Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J.

    2015-01-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  13. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States); Vala, David [Murray High School, Murray, UT 84107 (United States); Reese, Barbara K. [Butler Middle School, Cottonwood Heights, UT 84121 (United States); Freedman, Dina R. [Hillside Middle School, Salt Lake City, UT 84108 (United States); Stenten, Christina J. [Draper Park Middle School, Draper, UT 84020 (United States); Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States)

    2015-11-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  14. Source targeting tar balls along the southern Louisiana coastline

    International Nuclear Information System (INIS)

    Boerts, P.O.; Henry, C.B. Jr.; Overton, E.B.

    1993-01-01

    Stranded oil and tarballs deposited along the southern coast of Louisiana were source targeted, or compared for petroleum similarities, during 1992. The distribution, frequency, and composition of the stranded oil was assessed for specific study sites covering about 200 miles of the Louisiana coastline. Petroleum transportation off Louisiana shores is in the millions of barrels; with the Louisiana Offshore Oil Port receiving more than 200 million barrels per year. Also contributing to this transportation system are the outer continental shelf production activities, transporting 98 percent of their production by pipeline and 2 percent by barge. The questions addressed here are: What are the sources of the stranded oil and tar found upon the beaches? Are they primarily from small unrelated events, or are they from chronic discharges of identifiable sources? Preliminary data indicates a wide range of petroleum sources, with bunker oils most abundant. The petroleum has undergone varying degrees of weathering, or degradation by environmental processes. Preliminary data indicate relatively undegraded as well as extremely degraded petroleum, with no apparent correlation with study stations. Stations selected along the coastline were biannually surveyed, and petroleum samples collected were quantitatively assessed for petroleum per square meter per station. For a complete chemical assessment, the samples were qualitatively analyzed by detailed gas chromatography/mass spectrometry (GC/MS) characterization and source fingerprinting using selective ion monitoring (SIM). The results were plotted in a cluster matrix to highlight the number of possible sources and the chemical characteristics of the petroleum found

  15. Product analysis of catalytic multi-stage hydropyrolysis of lignite

    Energy Technology Data Exchange (ETDEWEB)

    Wen Li; Na Wang; Baoqing Li [Chinese Academy of Science, Taiyuan (China). State Key Lab of Coal Conversion, Institute of Coal Chemistry

    2003-03-01

    A lignite added with 0.2% MoS{sub 2} as catalyst was pyrolyzed under H{sub 2} using multi-stage heating method (MHyPy) which means holding a suitable time near the peak temperature. The product distribution and detailed analysis of products were performed. The results show that the tar yield increased to 63.9% during MHyPy compared with that of 51.8% in traditional hydropyrolysis (HyPy), while the gas yield decreased to a half. This suggests the effective utilization of hydrogen during MHyPy. The light aromatics in the tar from MHyPy increased remarkably 42, 37.8 and 115.4% for BTX, PCX and naphthalenes, respectively. Biphenyls were also observed in the tar from MHyPy, which indicated the effective hydrogenation occurs during catalytic MHyPy. The rich pore structure of the char from MHyPy hints its high reactivity in the subsequent conversion process such as gasification and combustion. 15 refs., 7 figs., 2 tabs.

  16. Composition of phenols in the primary tar of bituminous brown coal of the Ukrainian S. S. R

    Energy Technology Data Exchange (ETDEWEB)

    Karavaev, N M; Fadeicheva, A G; Kuznetsov, V I

    1957-01-01

    The phenol content in the low-temperature carbonizatin tar of brown coal is higher than in high-temperature coking tar, and the tar obtained in the carbonization of briquets in the Pintsch ovens was investigated after its separation at the carbonization plant. The phenol-containing fraction was extracted with 13 percent NaOH. The phenols were fractionated into narrow fractions at 8- to 9-millimeter pressure, and the fractions were identified by their melting point, n, OH content, analysis, and the melting point of their arylglycolic acids. Lower phenols (44 percent) wre found in the crude-phenol fraction, including 6 percent of crystalline PhOH, melting point 34/sup 0/; o-C/sub 6/H/sub 4/(Me)OH, melting point 27/sup 0/; 9.25 percent m- and o-cresols, with 32 percent m-cresol in the mixture EtC/sub 6/H/sub 4/OH formed 4.5 percent of the crude phenols, and consisted of o-, m-, and p-ethylphenols, 1,4,2-, 1,3,4-, 1,3,5-, and 1,2,4-xylenols.

  17. Kinetic study and syngas production from pyrolysis of forestry waste

    International Nuclear Information System (INIS)

    Hu, Mian; Wang, Xun; Chen, Jian; Yang, Ping; Liu, Cuixia; Xiao, Bo; Guo, Dabin

    2017-01-01

    Highlights: • Pyrolysis process can be divided into three stages using differential DTG method. • A modified discrete DAEM model fitted experimental data well. • Fe/biochar catalyst showed a good performance on catalytic reforming process. - Abstract: Kinetic study and syngas production from pyrolysis of forestry waste (pine sawdust (PS)) were investigated using a thermogravimetric analyzer (TGA) and a fixed-bed reactor, respectively. In TGA, it was found that the pyrolysis of PS could be divided into three stages and stage II was the major mass reduction stage with mass loss of 73–74%. The discrete distributed activation energy model (DAEM) with discrete 200 first-order reactions was introduced to study the pyrolysis kinetic. The results indicated that the DAEM with 200 first-order reactions could approximate the pyrolysis process with an excellent fit between experimental and calculated data. The apparent activation energies of PS ranged from 147.86 kJ·mol −1 to 395.76 kJ·mol −1 , with corresponding pre-exponential factors of 8.30 × 10 13 s −1 to 3.11 × 10 25 s −1 . In the fixed-bed reactor, char supported iron catalyst was prepared for tar cracking. Compared with no catalyst which the gas yield and tar yield were 0.58 N m 3 /kg biomass and 201.23 g/kg biomass, the gas yield was markedly increased to 1.02 N m 3 /kg biomass and the tar yield was decreased to only 26.37 g/kg biomass in the presence of char supported iron catalyst. These results indicated that char supported iron catalyst could potentially be used to catalytically decompose tar molecules in syngas generated via biomass pyrolysis.

  18. Synthesis of nanoporous carbons from mixtures of coal tar pitch and furfural and their application as electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Petrova, B.; Tsyntsarski, B.; Budinova, T.; Petrov, N.; Ania, C.O.; Parra, J.B.; Mladenov, M.; Tzvetkov, P.

    2010-11-15

    Synthetic nanoporous carbons are prepared by polymerization of mixtures containing coal tar pitch and furfural in different proportions, followed by carbonization of obtained solid product and steam activation of the carbonizate. The chemical composition of the initial mixture significantly affects the physicochemical properties (surface area, pore structure, electro resistance and amount of oxygen-containing groups on the surface) of the obtained materials. The incorporation of oxygen in the precursor mixture by means of furfural, has a strong influence in the synthetic step; increasing the furfural content facilitates the formation of a solid product characterized by a large oxygen content. Moreover, the solid product is more reactive towards activation as the furfural content increases, giving rise to nanoporous carbons with large surface areas and unique chemical features (high density of oxygen functionalities of basic nature). These nanoporous carbons have been investigated as electrodes in electrochemical applications. (author)

  19. Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method

    International Nuclear Information System (INIS)

    Boyer, N.W.; Taylor, R.S.

    1980-01-01

    A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications

  20. Síndrome de TAR y estado de heterocigosis para anemia falciforme

    Directory of Open Access Journals (Sweden)

    Pilar Garavito

    2004-01-01

    Full Text Available Presentación de un paciente con el cuadro clínico del síndrome de TAR, quien presenta además un estado de heterocigosis para anemia falciforme. El síndrome de TAR, descrito por primera vez en 1959 por Shaw y Oliver, es un trastorno genético no común que ocurre con una prevalencia aproximada de 1: 500.000 a 1: 1.000.000 de nacidos vivos. En 1969 Hall y col. delinearon los criterios diagnósticos de este síndrome que incluyen ausencia bilateral del radio con presencia de ambos pulgares y trombocitopenia. Otras anomalías descritas en menor frecuencia son: Alteraciones óseas del húmero y cúbito, en los casos severos, focomelia, malformaciones de expresión variable en extremidades inferiores, malformaciones cardiacas e intolerancia a la leche de vaca (1, 2. Los hallazgos encontrados en este caso se comparan con los de la literatura y se discute su posible etiología, además de resaltar la importancia de realizar un diagnóstico y tratamiento precoz y preciso especialmente de la trombocitopenia

  1. Influence of temperature on products yield of Eucalyptus microcorys carbonization

    Directory of Open Access Journals (Sweden)

    Renato da Silva Vieira

    2013-03-01

    Full Text Available During charcoal production different products are formed. These products are influenced primarily by the temperature of carbonization. Given that charcoal is the main input in the production of pig iron in Brazil, this study evaluated the influence of final temperature of carbonization of the products generated and also the influence of the radial and longitudinal sampling on the yield of each product. Samples were taken from internal and external position along the radius and also from three different heights from four Eucalyptus microcorys trees. The samples were carbonized in an electric furnace with an experimental water-cooled condenser and a collecting bottle of condensable volatile materials. The final temperatures of carbonization were 500, 600, 700, 800 and 900°C. The gravimetric yield, tar and non-condensable gases were calculated. The results showed no difference in the gravimetric yield in the longitudinal and radial positions studied, while the tar yield and non-condensable gases showed temperature variations of 700°C and 800°C and the variation of the gravimetric yield temperatures between 500°C to 900°C was 15%, the change of yield of tar from the radial direction of sampling was on average 8%, the variation of the yield of non-condensable gases in a radial sampling was on average 16%.

  2. From Product Models to Product State Models

    DEFF Research Database (Denmark)

    Larsen, Michael Holm

    1999-01-01

    A well-known technology designed to handle product data is Product Models. Product Models are in their current form not able to handle all types of product state information. Hence, the concept of a Product State Model (PSM) is proposed. The PSM and in particular how to model a PSM is the Research...

  3. The migration and monitoring of viscous NAPLs (coal tar and creosote) in the subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, R. [Intera Engineering Ltd., Heidelberg, ON (Canada)

    2009-07-01

    The high viscosity of nonaqueous phase liquids (NAPLs) such as creosote and coal tar complicates efforts to monitor their mobility at contaminated sites. Viscous NAPLs can remain mobile for many decades after their application as a wood preservative, or after the closure of the facilities in which they were generated. NAPL-wet pathways in the subsurface can also lead to errors in residual saturation measurements. This abstract discussed issues related to creeping flow and the low seepage rates that are not accounted for using traditional measuring methods. Examples of creeping flow and the monitoring techniques used to assess it were presented for sites in British Columbia and Florida. The drainage of viscous NAPLs during water table declines was also considered, and a case study of a coal tar-removal procedures using polymer surfactant flooding was presented.

  4. Microscopic charcoal and tar (CHAT particles in peat: a 6500-year record of palaeo-fires in southern Sweden

    Directory of Open Access Journals (Sweden)

    B.A. Malmgren

    2012-01-01

    Full Text Available Peat stratigraphies of eleven raised bogs in southern Sweden were investigated. Measurements included the occurrence of charcoal and various tar particles. Most of the particles found were microscopic, i.e. 5–100 µm in diameter. Two distinctly different groups of particles were distinguished: (A charred fragments of plant tissue and (B objects formed from tar, which were classified into five sub-groups on the basis of morphology. Both charcoal and tar are indicative of mire and forest fires. We suggest that it is possible to use the different groups of particles as fire regime indicators. Hence, the high frequency of charcoal and tar (CHAT in the lower parts of the stratigraphies, i.e. in the lower strongly decomposed fen and carr peats that were formed before ca. 4000 cal 14C BP, could be indicative of intense and frequent local fires. The decreasing abundance of CHAT and the lower relative share of Type A particles within the lower strongly decomposed Sphagnum peat ca. 4000–2500 cal 14C BP signify a transition from local to regional fires. With a few exceptions, the uppermost weakly decomposed ombrotrophic peats formed after ca. 2500 cal 14C BP, in which both charcoal and tar are rare, indicate a period of low fire frequency at both local and regional scales. There is no regional variation in the lower material, and it seems that wildfires were common phenomena throughout southern Sweden during the first few thousand years after peat formation began 6–8000 years ago. From a climatological point of view, the mass occurrence of CHAT in the lower parts of the profiles indicates a warm and dry Mid Holocene with frequent and widespread wildfires, and a moist and cool Late Holocene with more sporadic fires. Spectral analysis of the entire dataset shows significant periodicities of 610, 70, 30, 21, 17 and 14 years, the two most significant being 14 and 70 years.

  5. Formulation of Pine Tar Antidandruff Shampoo Assessment and Comparison With Some Commercial Formulations

    Directory of Open Access Journals (Sweden)

    M. Gharavi

    1990-07-01

    Full Text Available In this study a pine tar shampoo as a new antidandruff formulation is presented. Assessment of antidandruff preparations has been hampered by the lack of standardized schedules, and reliable methods of evaluation.Some antidandruff agents such as : Zinc pyri-thione pine tar, selenium sulphide and (sulfure were used in shampoos. Samples were coded as numbers 1,2 formulated by us and 3,4 formulated commercially. The grading scheme based on 10 point scale, and corneocyte count was carried out on 50 selected volunte¬ers. Corneocyte count and fungal study proved that pine tor shampoo is effective against pityrosporum ovale. Draize lest was used for determination of the irritancy potential of the samples. Results showed that samples numbered 1,2 were relatively innocous in comparison with the others. I urthermore,s kin sensitination test on rabbit also confirmed the results obtained by Draize test. Consumer judgments proved that all formulations were acceptable.

  6. Coal-tar-based sealcoated pavement: a major PAH source to urban stream sediments.

    Science.gov (United States)

    Witter, Amy E; Nguyen, Minh H; Baidar, Sunil; Sak, Peter B

    2014-02-01

    We used land-use analysis, PAH concentrations and assemblages, and multivariate statistics to identify sediment PAH sources in a small (~1303 km(2)) urbanizing watershed located in South-Central, Pennsylvania, USA. A geographic information system (GIS) was employed to quantify land-use features that may serve as PAH sources. Urban PAH concentrations were three times higher than rural levels, and were significantly and highly correlated with combined residential/commercial/industrial land use. Principal components analysis (PCA) was used to group sediments with similar PAH assemblages, and correlation analysis compared PAH sediment assemblages to common PAH sources. The strongest correlations were observed between rural sediments (n = 7) and coke-oven emissions sources (r = 0.69-0.78, n = 5), and between urban sediments (n = 22) and coal-tar-based sealcoat dust (r = 0.94, n = 47) suggesting that coal-tar-based sealcoat is an important urban PAH source in this watershed linked to residential and commercial/industrial land use. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    Science.gov (United States)

    Mahler, B.J.; Van Metre, P.C.

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  8. The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Egsgaard, Helge; Stelte, Wolfgang

    2013-01-01

    adsorption and determined by stable isotope dilution analysis. The results have shown that partial oxidation reduces and converts primary tars into low molecular weight, polycyclic aromatic hydrocarbons (PAHs), primarily naphthalene. At temperatures above 950°C practically all phenol is converted...

  9. Inhibition of HIV Replication by Cyclic and Hairpin PNAs Targeting the HIV-1 TAR RNA Loop

    Science.gov (United States)

    Upert, Gregory; Di Giorgio, Audrey; Upadhyay, Alok; Manvar, Dinesh; Pandey, Nootan; Pandey, Virendra N.; Patino, Nadia

    2012-01-01

    Human immunodeficiency virus-1 (HIV-1) replication and gene expression entails specific interaction of the viral protein Tat with its transactivation responsive element (TAR), to form a highly stable stem-bulge-loop structure. Previously, we described triphenylphosphonium (TPP) cation-based vectors that efficiently deliver nucleotide analogs (PNAs) into the cytoplasm of cells. In particular, we showed that the TPP conjugate of a linear 16-mer PNA targeting the apical stem-loop region of TAR impedes Tat-mediated transactivation of the HIV-1 LTR in vitro and also in cell culture systems. In this communication, we conjugated TPP to cyclic and hairpin PNAs targeting the loop region of HIV-1 TAR and evaluated their antiviral efficacy in a cell culture system. We found that TPP-cyclic PNAs containing only 8 residues, showed higher antiviral potency compared to hairpin PNAs of 12 or 16 residues. We further noted that the TPP-conjugates of the 8-mer cyclic PNA as well as the 16-mer linear PNA displayed similar antiviral efficacy. However, cyclic PNAs were shown to be highly specific to their target sequences. This communication emphasizes on the importance of small constrained cyclic PNAs over both linear and hairpin structures for targeting biologically relevant RNA hairpins. PMID:23029603

  10. Inhibition of HIV Replication by Cyclic and Hairpin PNAs Targeting the HIV-1 TAR RNA Loop

    Directory of Open Access Journals (Sweden)

    Gregory Upert

    2012-01-01

    Full Text Available Human immunodeficiency virus-1 (HIV-1 replication and gene expression entails specific interaction of the viral protein Tat with its transactivation responsive element (TAR, to form a highly stable stem-bulge-loop structure. Previously, we described triphenylphosphonium (TPP cation-based vectors that efficiently deliver nucleotide analogs (PNAs into the cytoplasm of cells. In particular, we showed that the TPP conjugate of a linear 16-mer PNA targeting the apical stem-loop region of TAR impedes Tat-mediated transactivation of the HIV-1 LTR in vitro and also in cell culture systems. In this communication, we conjugated TPP to cyclic and hairpin PNAs targeting the loop region of HIV-1 TAR and evaluated their antiviral efficacy in a cell culture system. We found that TPP-cyclic PNAs containing only 8 residues, showed higher antiviral potency compared to hairpin PNAs of 12 or 16 residues. We further noted that the TPP-conjugates of the 8-mer cyclic PNA as well as the 16-mer linear PNA displayed similar antiviral efficacy. However, cyclic PNAs were shown to be highly specific to their target sequences. This communication emphasizes on the importance of small constrained cyclic PNAs over both linear and hairpin structures for targeting biologically relevant RNA hairpins.

  11. A real-time view of the TAR:Tat:P-TEFb complex at HIV-1 transcription sites

    Directory of Open Access Journals (Sweden)

    Knezevich Anna

    2007-05-01

    Full Text Available Abstract HIV-1 transcription is tightly regulated: silent in long-term latency and highly active in acutely-infected cells. Transcription is activated by the viral protein Tat, which recruits the elongation factor P-TEFb by binding the TAR sequence present in nascent HIV-1 RNAs. In this study, we analyzed the dynamic of the TAR:Tat:P-TEFb complex in living cells, by performing FRAP experiments at HIV-1 transcription sites. Our results indicate that a large fraction of Tat present at these sites is recruited by Cyclin T1. We found that in the presence of Tat, Cdk9 remained bound to nascent HIV-1 RNAs for 71s. In contrast, when transcription was activated by PMA/ionomycin, in the absence of Tat, Cdk9 turned-over rapidly and resided on the HIV-1 promoter for only 11s. Thus, the mechanism of trans-activation determines the residency time of P-TEFb at the HIV-1 gene, possibly explaining why Tat is such a potent transcriptional activator. In addition, we observed that Tat occupied HIV-1 transcription sites for 55s, suggesting that the TAR:Tat:P-TEFb complex dissociates from the polymerase following transcription initiation, and undergoes subsequent cycles of association/dissociation.

  12. Alternative coke production from unconventional feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Smoot, D.; Eatough, C.N.; Heaton, J.S.; Eatough, S.R.; Miller, A.B. [Combustion Resources, Provo, UT (US)

    2004-07-01

    This presentation reports on US Department of Energy and company sponsored research and development to develop a technology and process for making metallurgical-quality coke from alternate feedstocks, including by-product and waste carbonaceous materials. The basic patent-pending process blends and presses these carbon-containing materials into briquettes of specified size. This product is referred to as CR Clean Coke because pollutant emission levels are carefully controlled to low levels with little or no vagrant emissions during processing. A wide range of feedstock materials has been investigated in over 600 tests for run-of-mine and waste coal fines of various rank with blends of coal tars and pitches, coal and biomass chars, met-coke breeze or petroleum coke. For various coal/pet-coke/tar feedstocks, CR has produced uniform-sized briquettes in commercial-scale briquettes in three nominal sizes: one inch, two inch, and three inch. These products have been successfully qualified according to stringent requirements for conventional met-coke use in a blast furnace. Several formulation have met and frequently exceeded these established met-coke specifications. One specific product containing coal, tar and pet-coke was selected as a base formulation for which preliminary process design and cost estimates have been completed for construction and operation of a demonstration plant capable of producing 120,000 tons per year of CR Clean Coke. Plant design elements and blast furnace test plans are presented. Tailoring of CR Clean Coke products to other prospective end users including foundry, sugar, soda ash, and ferrometals industries presents additional opportunities. The text is accompanied by 30 slides/overheads. 14 refs., 3 figs., 9 tabs.

  13. Aromatic oxygen compounds boiling from 180/sup 0/ to 225/sup 0/ from acid oils in low-temperature tar

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, A; Kattwinkel, G

    1950-01-01

    To determine the composition of the Krupp-Lurgi low-temperature coal tar and to develop methods for isolating the various compounds, a quantitative investigation was made of the dry tar acid mixture. The aromatic O compounds boiling up to 225/sup 0/ were secured by fractionation with one of the several columns that are described. Large volumes of tar were fractionated under vacuum in an apparatus with a 10-liter flask, electrically heated, and provided with a fractionating column (packed) with a jacket supplied by recirculated oil, externally heated. Large volumes were fractionated to give sufficient quantities of the O compounds. The method of fractional extraction, not described herein, made the separation of the acid oils by fractional distillation much easier. The aromatic O compounds present in greatest proportion are relatively easily isolated; those present in small quantities and more difficult to separate can be removed as a mixture, which can be hydrogenated directly to solvents. Phenols and cresols are formed in about equal fractions in low-temperature carbonization. Of the various xylenols, the sym-xylenol is present to the greatest extent. O compounds with longer side chains than C/sub 2/ were present only to a very slight extent. At the temperature of formation of these tars, side chains of three or more C atoms formed closed ring compounds (indan derivatives, etc.). Little change appears to occur up to 225/sup 0/ in the fractionation of these acid oils.

  14. The effects of topical corticosteroids and a coal tar preparation on dithranol-induced irritation in patients with psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Swinkels, O.Q.J.; Kucharekova, M.; Prins, M.; Gerritsen, M.J.P.; van der Valk, P.G.M.; van de Kerkhof, P.C.M. [University of Nijmegen, Nijmegen (Netherlands). Medical Center

    2003-02-01

    Dithranol has been a mainstay in the treatment of psoriasis for more than 80 years. Although a safe approach, the irritation of the clinically uninvolved perilesional skin remains a major limitation of this treatment. Corticosteroids and coal tar solution have an anti-inflammatory potential. The aim of the present study was to investigate the clinical and cell-biological effects of two topical corticosteroids and a coal tar preparation on dithranol-irritated skin. The expression of epidermal proliferation, differentiation and inflammation markers and the clinical irritation scores indicate that the application of a high potency corticosteroid is the best approach to minimise dithranol irritation.

  15. Engineering New Catalysts for In-Process Elimination of Tars

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Larry G. [Gas Technology Inst., Des Plaines, IL (United States)

    2012-09-30

    The key objective of this project was to develop a new and more efficient methodology for engineering and economically producing optimized robust catalysts for the reduction or elimination of tars in biomass gasification. Whereas current catalyst technology typically disposes thin layers of catalytically-active material onto rigid supports via wet chemistry-based methods, this project investigated novel thermal methods for directly incorporating catalytically active materials onto robust supports as well as novel approaches for incorporating catalytically active materials on and/or within an otherwise inert refractory support material which is then subsequently formed and processed to create a catalytically-active material on all exposed surfaces. Specifically, the focus of this engineered catalyst development was on materials which were derived from, or otherwise related to, olivine-like minerals, due to the inherent attrition resistance and moderate catalytic properties exhibited by natural olivine when used in a fluidized bed biomass gasifier. Task 1 of this project successfully demonstrated the direct thermal impregnation of catalytically-active materials onto an olivine substrate, with the production of a Ni-olivine catalyst. Nickel and nickel oxide were thermally impregnated onto an olivine substrate and when reduced were shown to demonstrate improved catalytic activity over the baseline olivine material and equal the tar-decomposing performance of Ni-olivine catalysts prepared by conventional wet impregnation. Task 2 involved coordination with our subcontracted project partners to further develop and characterize catalyst formulations and to optimize activity and production methods. Within this task, several significant new materials were developed. NexTech Materials developed a sintered ceramic nickel-magnesium-silicate catalyst that demonstrated superb catalytic activity and high resistance to deactivation by H2S. Alfred University developed both supported

  16. Possibility study of gasifier with axial circulating flue gas for reducing Tar

    Science.gov (United States)

    Poowadin, T.; Polsongkram, M.; Khantikomol, P.

    2018-01-01

    This present research article aims to study the possibility of gasification by axial core flue gas circulating kiln and find the efficiency of syngas production. An axial core flue gas circulating tube was installed in the center of the updraft gasifier in purposing of tar reducing. In the present study, the eucalyptus wood chip 4, 8, and 10 kg with the moisture content 16% were examined. Several type-K thermocouples were employed to measure the temperatures at preheat, combustion, reduction, pyrolysis, drying, and gas outlet zone. The results showed that the temperatures in the combustion and the reduction zone of the kiln with the axial core flue gas recirculating were lower than the kiln without the core owing to installing the core would reduce the combustion zone area in biomass burning. Obviously, the temperature in the pyrolysis and drying zone were nearly the same as both with and without the core. In consideration of syngas components, it was found that CO production from the gasifier with the core was higher than the gasifier without the core about 25%. Other gases, however, were almost same. The syngas production efficiency obtained from the gasifier with the core decreased with increasing the mass of biomass. It showed that the highest efficiency was 30% at 4 kg supplying biomass. In comparison, the efficiencies of both the kilns with and without the core were not different. For liquid product, the amount of liquid decreased about 47.23% comparing with the gasifier without the core.

  17. Catalytic steam reforming of tar derived from steam gasification of sunflower stalk over ethylene glycol assisting prepared Ni/MCM-41

    International Nuclear Information System (INIS)

    Karnjanakom, Surachai; Guan, Guoqing; Asep, Bayu; Du, Xiao; Hao, Xiaogang; Samart, Chanatip; Abudula, Abuliti

    2015-01-01

    Highlights: • Ni/MCM-41 was prepared by EG-assisted co-impregnation method. • EG-assisted co-impregnation method resulted in Ni particles well dispersed on MCM-41. • Ni/MCM-41-EG catalyst had high catalytic activity for tar reforming. • The highest H 2 gas yield was obtained when using 20 wt.% Ni/MCM-41-EG. • The catalysts were reused up to 5 cycles without any serious deactivation. - Abstract: Ethylene glycol (EG) assisted impregnation of nickel catalyst on MCM-41 (Ni/MCM-41-EG) was performed and applied for steam reforming of tar derived from biomass. The catalyst was characterized by SEM–EDX, BET, XRD, and TPR. It is found that smaller nickel particles were well dispersed on MCM-41 and better catalytic activity was shown for the Ni/MCM-41-EG when compared with the catalyst of Ni/MCM-41 prepared by using the conventional impregnation method. H 2 yield increased approximately 8% when using 20 wt.% Ni/MCM-41-EG instead of 20 wt.% Ni/MCM-41 for the steam reforming of tar derived from sunflower stalk. The catalyst reusability was also tested up to five cycles, and no obvious activity reduction was observed. It indicates that EG assisted impregnation method is a good way to prepare metal loaded porous catalyst with high catalytic activity, high loading amount and long-term stability for the tar reforming

  18. Tar in road system wastes - bibliographic study - quick characterization methods; Le goudron dans les dechets du reseau routier - etude bibliographique - methodes de caracterisation rapides

    Energy Technology Data Exchange (ETDEWEB)

    Brazillet, C.; Domas, J.; Pepin, G.

    2001-12-15

    In the framework of the european regulations on the wastes management, the road structure wastes present a particularly problem because of the tar content and of the toxic associated polycyclic aromatic hydrocarbons. In order to chose the elimination or the valorization of these roads wastes, it is necessary to measure the tar content. After a presentation of the study objectives, a bibliographic study of the context, the challenges, the hydrocarbons, the tar characterization and the today situation of the french road network, the author presents the methods of PAH detection with a special attention on the well known methods: the PAK marker, the TSE and the toluene spot. (A.L.B.)

  19. Performance Measurement Model A TarBase model with ...

    Indian Academy of Sciences (India)

    rohit

    Model A 8.0 2.0 94.52% 88.46% 76 108 12 12 0.86 0.91 0.78 0.94. Model B 2.0 2.0 93.18% 89.33% 64 95 10 9 0.88 0.90 0.75 0.98. The above results for TEST – 1 show details for our two models (Model A and Model B).Performance of Model A after adding of 32 negative dataset of MiRTif on our testing set(MiRecords) ...

  20. Distribution of sulphur into products from waste tire pyrolysis

    International Nuclear Information System (INIS)

    Susa, D.; Haydary, J.; Markos, J.

    2012-01-01

    Tire pyrolysis is getting growing attention as an effective waste tire disposal method in comparison to environmentally less friendly methods like dumping or incineration. But the scrap tire sulphur content can be a potential obstacle to scrap tire utilization as a fuel. In this paper the distribution of sulphur into tire pyrolysis yields, solid (char) and liquid (tar), was investigated. The pyrolysis experiments were carried out under different conditions to determine the partitioning of sulphur into pyrolysis products. The influence of different temperatures and reaction times was investigated in a laboratory flow reactor under nitrogen atmosphere. Solid and liquid residues were collected and analyzed by elemental analysis. The sulphur content in residual char and tar was determined using an elemental analyzer and the sulphur forms in tar were characterized by the X-ray photoelectron spectroscopy (XPS). (Authors)

  1. Identifying the source of tar balls deposited along the beaches of Goa in 2013 and comparing with historical data collected along the West Coast of India.

    Science.gov (United States)

    Suneel, V; Vethamony, P; Naik, B G; Krishna, M S; Jadhav, Lakshmikant

    2015-09-15

    Deposition of oil residues, also known as tar balls, is a seasonal phenomenon, and it occurs only in the southwest monsoon season along the west coast of India. This has become a serious environmental issue, as Goa is a global tourist destination. The present work aims at identifying the source oil of the tar balls that consistently depositing along the Goa coast using multi-marker fingerprint technique. In this context, the tar ball samples collected in May 2013 from 9 beaches of Goa coast and crude oils from different oil fields and grounded ship were subject to multi-marker analyses such as n-alkanes, pentacyclic terpanes, regular steranes, compound specific isotope analysis (CSIA) and principle component analysis (PCA). The n-alkane weathering index shows that samples have been weathered to various degrees, and the status of weathering is moderate. Since the international tanker route passes closer to the west coast of India (WCI), it is generally presumed that tanker wash is the source of the tar balls. We found that 2010/2011 tar balls are as tanker wash, but the present study demonstrates that the Bombay High (BH) oil fields can also contribute to oil contamination (tar balls) along ≈ 650 km stretch of the WCI, running from Gujarat in the north to Goa in the south. The simulated trajectories show that all the particles released in April traveled in the southeast direction, and by May, they reached the Goa coast with the influence of circulation of Indian monsoon system. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Thermodynamic studies of a series of homologous HIV-1 TAR RNA ligands reveal that loose binders are stronger Tat competitors than tight ones.

    Science.gov (United States)

    Pascale, Lise; Azoulay, Stéphane; Di Giorgio, Audrey; Zenacker, Laura; Gaysinski, Marc; Clayette, Pascal; Patino, Nadia

    2013-06-01

    RNA is a major drug target, but the design of small molecules that modulate RNA function remains a great challenge. In this context, a series of structurally homologous 'polyamide amino acids' (PAA) was studied as HIV-1 trans-activating response (TAR) RNA ligands. An extensive thermodynamic study revealed the occurence of an enthalpy-entropy compensation phenomenon resulting in very close TAR affinities for all PAA. However, their binding modes and their ability to compete with the Tat fragment strongly differ according to their structure. Surprisingly, PAA that form loose complexes with TAR were shown to be stronger Tat competitors than those forming tight ones, and thermal denaturation studies demonstrated that loose complexes are more stable than tight ones. This could be correlated to the fact that loose and tight ligands induce distinct RNA conformational changes as revealed by circular dichroism experiments, although nuclear magnetic resonance (NMR) experiments showed that the TAR binding site is the same in all cases. Finally, some loose PAA also display promising inhibitory activities on HIV-infected cells. Altogether, these results lead to a better understanding of RNA interaction modes that could be very useful for devising new ligands of relevant RNA targets.

  3. Fuel production from microwave assisted pyrolysis of coal with carbon surfaces

    International Nuclear Information System (INIS)

    Mushtaq, Faisal; Mat, Ramli; Ani, Farid Nasir

    2016-01-01

    Highlights: • MW heating of coal was carried out with uniformly distributed carbon surfaces. • The effects of carbon loading, MW power and N 2 flow rate were investigated. • Heating profile, pyrolysis products are influenced by the process variables. • Highest coal-tar obtained when final temperature sustained for longer duration. • Coal-tar is mainly composed of aromatics and saturated aliphatics hydrocarbons. - Abstract: In this study, coal solids were subjected to Microwave (MW) pyrolysis conditions. Coconut Activated Carbon (CAC) solids used as a MW absorber was distributed uniformly over coal solids to reduce hotspots. Three process parameters; CAC loading, MW power and N 2 flow rate were studies on pyrolysis heating performance. The highest coal-tar yield of 18.59 wt% was obtained with 600 W, 75 wt% CAC loading and 4 Liter per Minute (LPM) of N 2 flow rate. This improved coal-tar yield is mainly of the fact that higher MW power and CAC loading produced sustained pyrolysis conditions for longer duration for the complete conversion of pyrolysis solids. The coal-tar was composed mainly of aromatics (naphthalenes, benzenes and xylene) and saturated aliphatics (alkanes and alkenes) hydrocarbons. The gas produced from pyrolysis of coal is mainly of H 2 40.23–65.22 vol%.

  4. AmTAR2: Functional characterization of a honeybee tyramine receptor stimulating adenylyl cyclase activity.

    Science.gov (United States)

    Reim, Tina; Balfanz, Sabine; Baumann, Arnd; Blenau, Wolfgang; Thamm, Markus; Scheiner, Ricarda

    2017-01-01

    The biogenic monoamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. Insects such as honeybees do not synthesize these neuroactive substances. Instead, they employ octopamine and tyramine for comparable physiological functions. These biogenic amines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Based on pharmacological data obtained on heterologously expressed receptors, α- and β-adrenergic-like octopamine receptors are better activated by octopamine than by tyramine. Conversely, GPCRs forming the type 1 tyramine receptor clade (synonymous to octopamine/tyramine receptors) are better activated by tyramine than by octopamine. More recently, receptors were characterized which are almost exclusively activated by tyramine, thus forming an independent type 2 tyramine receptor clade. Functionally, type 1 tyramine receptors inhibit adenylyl cyclase activity, leading to a decrease in intracellular cAMP concentration ([cAMP] i ). Type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . We here provide evidence that the honeybee tyramine receptor 2 (AmTAR2), when heterologously expressed in flpTM cells, exclusively causes an increase in [cAMP] i . The receptor displays a pronounced preference for tyramine over octopamine. Its activity can be blocked by a series of established antagonists, of which mianserin and yohimbine are most efficient. The functional characterization of two tyramine receptors from the honeybee, AmTAR1 (previously named AmTYR1) and AmTAR2, which respond to tyramine by changing cAMP levels in opposite direction, is an important step towards understanding the actions of tyramine in honeybee behavior and physiology, particularly in comparison to the effects of octopamine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. General toxic effects of shale tars on the human body

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, H; Sillam, A

    1972-01-01

    Of 115 workers in close contact with oil shale tars, 80 percent complained of headache, fatigue, and stomach aches. Vegetative dystonia, asthenovegetative, or asthenic syndromes were diagnosed in 32 percent of the cases. An excessive excretion of free phenols was found in the urine of 13 percent of the patients and an excess of sulfates and coproporphyrin in 27 and 29 percent, respectively. The statistical analysis of clinical data indicates a relation to biochemical changes. The immunological reactivity studies showed that in 60 percent of the cases the immunological resistance decreased markedly.

  6. Protection Performance Simulation of Coal Tar-Coated Pipes Buried in a Domestic Nuclear Power Plant Using Cathodic Protection and FEM Method

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H. Y.; Lim, B. T.; Kim, K. S.; Kim, J. W.; Park, H. B. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of); Kim, Y. S.; Kim, K. T. [Andong National University, Andong (Korea, Republic of)

    2017-06-15

    Coal tar-coated pipes buried in a domestic nuclear power plant have operated under the cathodic protection. This work conducted the simulation of the coating performance of these pipes using a FEM method. The pipes, being ductile cast iron have been suffered under considerably high cathodic protection condition beyond the appropriate condition. However, cathodic potential measured at the site revealed non-protected status. Converting from 3D CAD data of the power plant to appropriate type for a FEM simulation was conducted and cathodic potential under the applied voltage and current was calculated using primary and secondary current distribution and physical conditions. FEM simulation for coal tar-coated pipe without defects revealed over-protection condition if the pipes were well-coated. However, the simulation for coal tar-coated pipes with many defects predict that the coated pipes may be severely degraded. Therefore, for high risk pipes, direct examination and repair or renewal of pipes are strongly recommended.

  7. Synthesis Of 2- (1- Naphthyl) Ethanoic Acid ( Plant Growth Regulator ) From Coal Tar And Its Application

    International Nuclear Information System (INIS)

    Khin Mooh Theint; Tin Myint Htwe

    2011-12-01

    Plant growth regulators, which are commonly called as plant hormones, naturally produced non-nutrient chemical compounds involved in growth and development. Among the various kinds of plant growth regulators, 2- (1- Naphthyl ) ethanoic acid especially encourages the root development of the plant. In this work, NAA was successfuly synthesized from naphthalene which was extracted from coal tar. The purity of naphthalene, -Chloromethyl naphthalene, -Naphthyl acetonitrile, - Naphthyl acetic acid or 2 - ( 1-Naphthyl ) ethanoic acid were also confirmed by Thin Layer Chromatography, and by spectroscopy methods. The yield percent of NAA based on naphthalene was found to be 2.1%. The yield percent of naphthaleneFrom coal tar is found to be 4.09%. The effect of NAA on root development was also studied in different concentrations of soy bean (Glycine max)and cow pea (Vigna catjang walp).

  8. Removal of phenol by powdered activated carbon prepared from coal gasification tar residue.

    Science.gov (United States)

    Wang, Xiong-Lei; Shen, Jun; Niu, Yan-Xia; Wang, Yu-Gao; Liu, Gang; Sheng, Qing-Tao

    2018-03-01

    Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m 2 /g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater.

  9. Inhibition of both HIV-1 reverse transcription and gene expression by a cyclic peptide that binds the Tat-transactivating response element (TAR RNA.

    Directory of Open Access Journals (Sweden)

    Matthew S Lalonde

    2011-05-01

    Full Text Available The RNA response element TAR plays a critical role in HIV replication by providing a binding site for the recruitment of the viral transactivator protein Tat. Using a structure-guided approach, we have developed a series of conformationally-constrained cyclic peptides that act as structural mimics of the Tat RNA binding region and block Tat-TAR interactions at nanomolar concentrations in vitro. Here we show that these compounds block Tat-dependent transcription in cell-free systems and in cell-based reporter assays. The compounds are also cell permeable, have low toxicity, and inhibit replication of diverse HIV-1 strains, including both CXCR4-tropic and CCR5-tropic primary HIV-1 isolates of the divergent subtypes A, B, C, D and CRF01_AE. In human peripheral blood mononuclear cells, the cyclic peptidomimetic L50 exhibited an IC(50 ∼250 nM. Surprisingly, inhibition of LTR-driven HIV-1 transcription could not account for the full antiviral activity. Timed drug-addition experiments revealed that L-50 has a bi-phasic inhibition curve with the first phase occurring after HIV-1 entry into the host cell and during the initiation of HIV-1 reverse transcription. The second phase coincides with inhibition of HIV-1 transcription. Reconstituted reverse transcription assays confirm that HIV-1 (- strand strong stop DNA synthesis is blocked by L50-TAR RNA interactions in-vitro. These findings are consistent with genetic evidence that TAR plays critical roles both during reverse transcription and during HIV gene expression. Our results suggest that antiviral drugs targeting TAR RNA might be highly effective due to a dual inhibitory mechanism.

  10. The pentane- and toluene-soluble fractions of a petroleum residue and three coal tars by size exclusion chromatography and UV-fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Karaca, F.; Millan-Agorio, M.; Morgan, T.J.; Bull, I.D.; Herod, A.A.; Kandiyoti, R. [University of London Imperial College Science Technology & Medicine, London (United Kingdom). Dept. of Chemical Engineering

    2008-01-15

    A petroleum atmospheric pressure distillate residue and three tars derived from different coals using different severities of thermal treatment were separated into seven fractions using column chromatography on silica and sequential elution by the solvent sequence pentane, toluene, acetonitrile, pyridine, 1-methyl-2-pyrrolidinone (NMP) and water. The fractions from the four extractions have been compared using size exclusion chromatography (SEC) in NMP as eluent and by synchronous ultra-violet-fluorescence (UV-F). This paper concerns the pentane and toluene soluble fractions only since these are the least polar fractions. By SEC, the size of the aromatic molecules increased from the first pentane soluble fractions to the toluene-soluble fractions, with the petroleum residue fractions of larger size than the equivalent fractions from coal liquids. The three coal tars showed significant differences, indicating that temperature of pyrolysis had a significant effect on the molecular size. Synchronous UV-F spectra of the four sets of fractions, in solution in NMP, again showed significant differences between the petroleum residue and the coal tars, as well as amongst the three coal tars. In general, the petroleum residue fractions contained smaller aromatic clusters than the coal liquid fractions. These low-polarity fractions contained material excluded from the column porosity in SEC that was unlikely to consist of aggregates of polar molecules.

  11. Investigating Efficient Tar Management from Biomass and Waste to Energy Gasification Processes

    Science.gov (United States)

    2015-04-01

    internal combustion engine (ICE) can mean spark ignition or diesel ( compression ignition ). It is likely that the light tars could be made to burn in...filled with methyl chloroform to allow rapid acquisition and analysis via an auto handler on the gas chromatography machine. An additional test...flare and venturi are lost. If the venturi were lost air can draw back into the process pipe creating an air fuel mixture that may ignite . PLASMA

  12. Tar sand extraction by steam stimulation and steam drive: measurement of physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Linberg, W.R.

    1980-09-10

    The measurement of the following thermophysical properties of Utah tar sands is in progress: thermal conductivity, specific heat relative permeability, and viscosity (of the recovered bitumen). During the report period (October 1, 1978 to November 1, 1979), experimental procedures have been developed and a basic data set has been measured. Additionally, standard core analysis has been performed for four drill sites in the Asphalt Ridge, Utah area.

  13. Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, Barbara J.

    2010-01-01

    Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) has increased in the United States during the past 40 years. We evaluated sources of PAHs in post-1990 sediments in cores from 40 lakes in urban areas across the United States using a contaminant mass-balance receptor model and including as a potential source coal-tar-based (CT) sealcoat, a recently recognized source of urban PAH. Other PAH sources considered included several coal- and vehicle-related sources, wood combustion, and fuel-oil combustion. The four best modeling scenarios all indicate CT sealcoat is the largest PAH source when averaged across all 40 lakes, contributing about one-half of PAH in sediment, followed by vehicle-related sources and coal combustion. PAH concentrations in the lakes were highly correlated with PAH loading from CT sealcoat (Spearman's rho=0.98), and the mean proportional PAH profile for the 40 lakes was highly correlated with the PAH profile for dust from CT-sealed pavement (r=0.95). PAH concentrations and mass and fractional loading from CT sealcoat were significantly greater in the central and eastern United States than in the western United States, reflecting regional differences in use of different sealcoat product types. The model was used to calculate temporal trends in PAH source contributions during the last 40 to 100 years to eight of the 40 lakes. In seven of the lakes, CT sealcoat has been the largest source of PAHs since the 1960s, and in six of those lakes PAH trends are upward. Traffic is the largest source to the eighth lake, located in southern California where use of CT sealcoat is rare.

  14. Product analysis of catalytic multi-stage hydropyrolysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.; Wang, N.; Li, B. [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

    2002-05-01

    Multi-stage hydropyrolysis (MHyPy) and hydropyrolysis (HyPy) of Xundian lignite, with MoS{sub 2} as the catalyst, were performed in a fixed bed reactor. The product distribution and property were investigated in detail. The results show that the tar yield increases to 63.9% during MHyPy compared with that of 51.8% in HyPy, while the gas yield decreases by 50%. The tar composition does not make big difference between MHyPy and HyPy. However, the light aromatics in the tar from MHyPy increase remarkably by 42%, 37.8% and 115.4% for BTX, PCX and naphthalene respectively. The specific surface area of char from MHyPy is larger than that from HyPy. The average pore diameter of char from MHyPy is smaller than that from HyPy, while the pore volume increases by 100% compared with that from HyPy. The catalytic MHyPy has an obvious advantage over HyPy. 10 refs., 8 figs., 3 tabs.

  15. Concerted motions in HIV-1 TAR RNA may allow access to bound state conformations: RNA dynamics from NMR residual dipolar couplings.

    Science.gov (United States)

    Al-Hashimi, Hashim M; Gosser, Yuying; Gorin, Andrey; Hu, Weidong; Majumdar, Ananya; Patel, Dinshaw J

    2002-01-11

    Ground-state dynamics in RNA is a critical precursor for structural adaptation observed ubiquitously in protein-RNA recognition. A tertiary conformational analysis of the stem-loop structural element in the transactivation response element (TAR) from human immunodeficiency virus type 1 (HIV-I) RNA is presented using recently introduced NMR methods that rely on the measurement of residual dipolar couplings (RDC) in partially oriented systems. Order matrix analysis of RDC data provides evidence for inter-helical motions that are of amplitude 46(+/-4) degrees, of random directional character, and that are executed about an average conformation with an inter-helical angle between 44 degrees and 54 degrees. The generated ensemble of TAR conformations have different organizations of functional groups responsible for interaction with the trans-activator protein Tat, including conformations similar to the previously characterized bound-state conformation. These results demonstrate the utility of RDC-NMR for simultaneously characterizing RNA tertiary dynamics and average conformation, and indicate an avenue for TAR complex formation involving tertiary structure capture. Copyright 2001 Academic Press.

  16. Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    Science.gov (United States)

    Hult, Marc F.; Schoenberg, Michael E.

    1984-01-01

    Operation of a coal-tar distillation and wood-preserving plant from 1918 to 1972 in St. Louis Park, a suburb of Minneapolis, Minn., resulted in ground-water contamination. This preliminary evaluation presents an overview of the problem based on the results of the first year (1979) of an ongoing study.

  17. A Tat-grafted anti-nucleic acid antibody acquires nuclear-localization property and a preference for TAR RNA

    International Nuclear Information System (INIS)

    Jeong, Jong-Geun; Kim, Dong-Sik; Kim, Yong-Sung; Kwon, Myung-Hee

    2011-01-01

    Highlights: → We generate ' H3 Tat-3D8' by grafting Tat 48-60 peptide to VH CDR of 3D8 scFv antibody. → H3 Tat-3D8 antibody retains nucleic acid binding and hydrolyzing activities. → H3 Tat-3D8 acquires a preference for TAR RNA structure. → Properties of Tat 48-60 is transferred to an antibody via Tat-grafting into a CDR. -- Abstract: The 3D8 single chain variable fragment (3D8 scFv) is an anti-nucleic acid antibody that can hydrolyze nucleic acids and enter the cytosol of cells without reaching the nucleus. The Tat peptide, derived from the basic region of the HIV-1 Tat protein, translocates to cell nuclei and has TAR RNA binding activity. In this study, we generated a Tat-grafted antibody ( H3 Tat-3D8) by replacing complementarity-determining region 3 (CDR3) within the VH domain of the 3D8 scFv with a Tat 48-60 peptide (GRKKRRQRRRPPQ). H3 Tat-3D8 retained the DNA-binding and DNA-hydrolyzing activity of the scFv, and translocated to the nuclei of HeLa cells and preferentially recognized TAR RNA. Thus, the properties associated with the Tat peptide were transferred to the antibody via Tat-grafting without loss of the intrinsic DNA-binding and hydrolyzing activities of the 3D8 scFv antibody.

  18. Functional analysis of a Wheat Homeodomain protein, TaR1, reveals that host chromatin remodelling influences the dynamics of the switch to necrotrophic growth in the phytopathogenic fungus Zymoseptoria tritici.

    Science.gov (United States)

    Lee, Jack; Orosa, Beatriz; Millyard, Linda; Edwards, Martin; Kanyuka, Kostya; Gatehouse, Angharad; Rudd, Jason; Hammond-Kosack, Kim; Pain, Naomi; Sadanandom, Ari

    2015-04-01

    A distinguishing feature of Septoria leaf blotch disease in wheat is the long symptomless growth of the fungus amongst host cells followed by a rapid transition to necrotrophic growth resulting in disease lesions. Global reprogramming of host transcription marks this switch to necrotrophic growth. However no information exists on the components that bring about host transcriptional reprogramming. Gene-silencing, confocal-imaging and protein-protein interaction assays where employed to identify a plant homeodomain (PHD) protein, TaR1 in wheat that plays a critical role during the transition from symptomless to necrotrophic growth of Septoria. TaR1-silenced wheat show earlier symptom development upon Septoria infection but reduced fungal sporulation indicating that TaR1 is key for prolonging the symptomless phase and facilitating Septoria asexual reproduction. TaR1 is localized to the nucleus and binds to wheat Histone 3. Trimethylation of Histone 3 at lysine 4 (H3K4) and lysine 36 (H3K36) are found on open chromatin with actively transcribed genes, whereas methylation of H3K27 and H3K9 are associated with repressed loci. TaR1 specifically recognizes dimethylated and trimethylated H3K4 peptides suggesting that it regulates transcriptional activation at open chromatin. We conclude that TaR1 is an important component for the pathogen life cycle in wheat that promotes successful colonization by Septoria. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  19. Effect of the polymerization with formaldehyde on the thermal reactivity of a low-temperature coal tar pitch

    Energy Technology Data Exchange (ETDEWEB)

    Jose L. Crespo; Ana Arenillas; Jose A. Vin; Roberto Garcia; Colin E. Snape; Sabino R. Moinelo [Instituto Nacional del Carbon (CSIC), Oviedo (Spain)

    2005-04-01

    The influence of polymerization with formaldehyde on the thermal reactivity of a low-temperature coal tar pitch has been investigated. The mechanism and extent of the polymerization depends on the catalyst used, the greatest extent of polymerization being achieved under basic catalytic conditions. After the polymerization treatment, samples were carbonized at 420{sup o}C and the products were characterized by optical microscopy. According to the results, polymerization with formaldehyde increases the reactivity of the pitch, giving rise to increased carbonization yields and leading to the formation of the mesophase with milder conditions. The polymerization process also affects the morphology of the resultant anisotropic material, giving rise to the formation of irregularly shaped mesophase particles and reducing the optical texture size of the anisotropic domains, giving mosaic texture, especially when basic catalysis is used. 36 refs., 11 figs., 5 tabs.

  20. Cashing in on Tar Sands. RBS, UK banks and Canada's 'blood oil'

    Energy Technology Data Exchange (ETDEWEB)

    Evans, M.; Howarth, C.; Kellay, A.; Laboucan, B.J.; Mercredi, M.; Minio-Paluelo, M.; Schling, H.; Smith, K.; Thomas-Muller, C.; Wood, A.

    2010-03-15

    Tar sands extraction in Canada is devastating Indigenous communities, wildlife and vast areas of boreal forests, as well as being many times more carbon-intensive to produce than 'conventional' oil. The higher oil prices in recent years have meant that it's become a more attractive prospect for oil companies to expand their operations in the costly process of obtaining and processing the thick bitumen into a usable form. It's estimated that the industry is looking for a capital investment of 120-220 billion USD over the next 20 years to build the new pipelines, mines, refineries and upgraders that are necessary to sustain the boom. This report looks at the role that UK banks are playing in providing the necessary capital, and how RBS (Royal Bank of Scotland), which is 84% owned by the UK public, has been the bank the most heavily involved in underwriting loans to companies engaging in tar sands extraction.

  1. Researching the technology of tar removal from coke-chemical plants’ wastewater by reagent flotation method

    Directory of Open Access Journals (Sweden)

    Anna V. Ivanchenko

    2015-03-01

    Full Text Available The study aims to identify process patterns of tars and oils removal from phenolic wastewater by reagent flotation with bringing those components’ content to acceptable concentrations. For the first time established is the effect of Al2(SO43, AlCl3, FeSO4, Fe2(SO43, Al2(OH5Cl and FeCl3 doses onto residual tar content in phenolic wastewater. Results obtained give the possibility to prevent air pollution resulting from the toxic substances emission at the wet quenching with water containing excessive oils and to increase the quality of wastewater biological treatment. It is shown experimentally that the most efficient are Fe2(SO43, FeCl3 and Al2(OH5Cl at optimum concentrations of 50, 30 and 30 mg/dm3 respectively. The Al2(OH5Cl can be recommended for implementation at industry on existing coking plants and municipal wastewater treatment plants to improve the environmental air and water resources condition in Ukraine.

  2. Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

    Science.gov (United States)

    Engle, Mark A; Radke, Lawrence F; Heffern, Edward L; O'Keefe, Jennifer M K; Hower, James C; Smeltzer, Charles D; Hower, Judith M; Olea, Ricardo A; Eatwell, Robert J; Blake, Donald R; Emsbo-Mattingly, Stephen D; Stout, Scott A; Queen, Gerald; Aggen, Kerry L; Kolker, Allan; Prakash, Anupma; Henke, Kevin R; Stracher, Glenn B; Schroeder, Paul A; Román-Colón, Yomayra; ter Schure, Arnout

    2012-03-15

    Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires. Published by Elsevier B.V.

  3. The structure and pyrolysis product distribution of lignite from different sedimentary environment

    International Nuclear Information System (INIS)

    Liu, Peng; Zhang, Dexiang; Wang, Lanlan; Zhou, Yang; Pan, Tieying; Lu, Xilan

    2016-01-01

    Highlights: • Carbon structure of three lignites was measured by solid "1"3C NMR. • Effect of carbon structure on pyrolysis product distribution was studied. • Tar yield is influenced by aliphatic carbon and oxygen functional group. • C1–C4 content of pyrolysis gas is related to CH_2/CH_3 ratio. - Abstract: Low-temperature pyrolysis is an economically efficient method for lignite to obtain coal tar and improve its combustion calorific value. The research on the distribution of pyrolysis product (especially coal tar yield) plays an important role in energy application and economic development in the now and future. Pyrolysis test was carried out in a tube reactor at 873 K for 15 min. The structure of the lignite was measured by solid "1"3C nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The thermal analysis was analyzed by thermo-gravimetric (TG) analyzer. The results show that the pyrolysis product distribution is related to the breakage of branch structures of aromatic ring in lignites from different sedimentary environment. The gas yield and composition are related to the decomposition of carbonyl group and the breakage of aliphatic carbon. The tar yield derived from lignite pyrolysis follows the order: Xianfeng lignite (XF, 13.67 wt.%) > Xiaolongtan lignite (XLT, 7.97 wt.%) > Inner Mongolia lignite (IM, 6.30 wt.%), which is mainly influenced by the aliphatic carbon contents, the CH_2/CH_3 ratio and the oxygen functional groups in lignite. The pyrolysis water yield depends on the decomposition of oxygen functional groups. IM has the highest content of oxygen-linked carbon so that the pyrolysis water yield derived from IM is the highest (9.20 wt.%), and is far more than that from the other two lignites.

  4. Co-pyrolysis of low rank coals and biomass: Product distributions

    Energy Technology Data Exchange (ETDEWEB)

    Soncini, Ryan M.; Means, Nicholas C.; Weiland, Nathan T.

    2013-10-01

    Pyrolysis and gasification of combined low rank coal and biomass feeds are the subject of much study in an effort to mitigate the production of green house gases from integrated gasification combined cycle (IGCC) systems. While co-feeding has the potential to reduce the net carbon footprint of commercial gasification operations, the effects of co-feeding on kinetics and product distributions requires study to ensure the success of this strategy. Southern yellow pine was pyrolyzed in a semi-batch type drop tube reactor with either Powder River Basin sub-bituminous coal or Mississippi lignite at several temperatures and feed ratios. Product gas composition of expected primary constituents (CO, CO{sub 2}, CH{sub 4}, H{sub 2}, H{sub 2}O, and C{sub 2}H{sub 4}) was determined by in-situ mass spectrometry while minor gaseous constituents were determined using a GC-MS. Product distributions are fit to linear functions of temperature, and quadratic functions of biomass fraction, for use in computational co-pyrolysis simulations. The results are shown to yield significant nonlinearities, particularly at higher temperatures and for lower ranked coals. The co-pyrolysis product distributions evolve more tar, and less char, CH{sub 4}, and C{sub 2}H{sub 4}, than an additive pyrolysis process would suggest. For lignite co-pyrolysis, CO and H{sub 2} production are also reduced. The data suggests that evolution of hydrogen from rapid pyrolysis of biomass prevents the crosslinking of fragmented aromatic structures during coal pyrolysis to produce tar, rather than secondary char and light gases. Finally, it is shown that, for the two coal types tested, co-pyrolysis synergies are more significant as coal rank decreases, likely because the initial structure in these coals contains larger pores and smaller clusters of aromatic structures which are more readily retained as tar in rapid co-pyrolysis.

  5. Johannes Hindi tütar Pille Pae : inimlik headus ei sõltu rezhiimist / Pille Pae ; interv. Anneli Ammas

    Index Scriptorium Estoniae

    Pae, Pille

    2006-01-01

    Desintegraatori juhi Johannes Hindi tütar Pille Pae vastab küsimustele, mis puudutavad tema isa armuandmispalve esitamist, isale toetusallkirjade kogumist ning Arnold Rüütli suhteid Johannes Hindiga. Lisa: Kes oli Johannes Hint ja mis Desintegraator?

  6. Using fuzzy logic to control the power of a biomass gasifier ventilation system motor to ensure suitable oxidation temperature for tar cracking; Uso da logica fuzzy para controle da potencia do motor do sistema de ventilacao de um gaseificador de biomassa que assegure temperatura de oxidacao adequada para craqueamento do alcatrao

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Oscar L.T.; Kulitz, Hans H. [Instituto Federal de Educacao, Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)], email: oscar@ifes.edu.br; Silva, Jadir N.; Galvarro, Svetlana F.S. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola; Martin, Samuel [Universidade de Brasilia (FAV/UNB), DF (Brazil). Fac. de Agronomia e Medicina Veterinaria

    2011-07-01

    There are several models of biomass gasifier. The one used in this study was the concurrent model, in which fuel is fed through the top and air feed occurs in descending flow through combustion and reduction zones, producing low-tar gas. Nevertheless, total tar burning must be ensured in order to produce a gas, suitable for several applications. This study aimed at developing a fuzzy-based algorithm to control the active power applied to a gasifier ventilation system motor, which can ensure adequate oxidation temperature for cracking tar that may be present in the gas produced. The input variables of the fuzzy controller were oxidation zone temperature and the variation rate of this temperature. The output variable was active power. The rule base was created using experimental data. The tests performed with this algorithm allowed observing that the oxidation temperature can be set to a value desired, which does not occur in gasification processes without ventilation system control. (author)

  7. Influence of supports on catalytic behavior of nickel catalysts in carbon dioxide reforming of toluene as a model compound of tar from biomass gasification.

    Science.gov (United States)

    Kong, Meng; Fei, Jinhua; Wang, Shuai; Lu, Wen; Zheng, Xiaoming

    2011-01-01

    A series of supported Ni catalysts including Ni/MgO, Ni/γ-Al2O3, Ni/α-Al2O3, Ni/SiO2 and Ni/ZrO2 was tested in CO2 reforming of toluene as a model compound of tar from biomass gasification in a fluidized bed reactor, and characterized by the means of temperature programmed reduction with hydrogen (H2-TPR), XRD, TEM and temperature programmed oxidation (TPO). Combining the characterization results with the performance tests, the activity of catalyst greatly depended on Ni particles size, and the stability was affected by the coke composition. Both of them (Ni particle size and coke composition) were closely related to the interaction between nickel and support which would determine the chemical environment where Ni inhabited. The best catalytic performance was observed on Ni/MgO due to the strong interaction between NiO and MgO via the formation of Ni-Mg-O solid solution, and the highest dispersion of Ni particle in the basic environment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Development of a modified equilibrium model for biomass pilot-scale fluidized bed gasifier performance predictions

    International Nuclear Information System (INIS)

    Rodriguez-Alejandro, David A.; Nam, Hyungseok; Maglinao, Amado L.; Capareda, Sergio C.; Aguilera-Alvarado, Alberto F.

    2016-01-01

    The objective of this work is to develop a thermodynamic model considering non-stoichiometric restrictions. The model validation was done from experimental works using a bench-scale fluidized bed gasifier with wood chips, dairy manure, and sorghum. The model was used for a further parametric study to predict the performance of a pilot-scale fluidized biomass gasifier. The Gibbs free energy minimization was applied to the modified equilibrium model considering a heat loss to the surroundings, carbon efficiency, and two non-equilibrium factors based on empirical correlations of ER and gasification temperature. The model was in a good agreement with RMS <4 for the produced gas. The parametric study ranges were 0.01 < ER < 0.99 and 500 °C < T < 900 °C to predict syngas concentrations and its LHV (lower heating value) for the optimization. Higher aromatics in tar were contained in WC gasification compared to manure gasification. A wood gasification tar simulation was produced to predict the amount of tars at specific conditions. The operating conditions for the highest quality syngas were reconciled experimentally with three biomass wastes using a fluidized bed gasifier. The thermodynamic model was used to predict the gasification performance at conditions beyond the actual operation. - Highlights: • Syngas from experimental gasification was used to create a non-equilibrium model. • Different types of biomass (HTS, DM, and WC) were used for gasification modelling. • Different tar compositions were identified with a simulation of tar yields. • The optimum operating conditions were found through the developed model.

  9. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement.

    Science.gov (United States)

    Mahler, Barbara J; Van Metre, Peter C; Foreman, William T

    2014-05-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. Published by Elsevier Ltd.

  10. Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

    2014-01-01

    Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 μg/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

  11. Studies on the applicability of biomarkers in estimating the systematic bioavailability of polynuclear aromatic hydrocarbons from manufactured gas plant tar-contaminated soils

    International Nuclear Information System (INIS)

    Koganti, A.; Spina, D.A.; Rozett, K.; Ma, B.-L.; Weyand, E.; Taylor, B.B.; Mauro, D.M.

    1998-01-01

    The systematic bioavailability of polynuclear aromatic hydrocarbons (PAH) from ingested soils containing manufactured gas plant (MGP) tar was evaluated in mice. Soil and organic extract of each soil were incorporated into a diet and fed to mice for two weeks. 1-Hydroxypyrene levels in urine and chemical:DNA adduct levels in lungs were used as biomarkers of PAH systematic bioavailability. Estimates of PAH relative bioavailability were determined by comparing the bioavailability observed between each soil and corresponding organic extract. In all but one case, bioavailiablity estimates based on 1-hydroxypyrene levels in urine indicate that the presence of MGP tar on soil results in a considerable decrease in PAH systemic bioavailablity (9-75%). Similarly, PAH bioavailability estimates based on chemical:DNA adduct formation ranged from nondetectable to 76%. These results clearly indicate that the bioavailiablity of PAH is less than 100% when soil contaminated with MGP tar is ingested by nice. In addition, the experimental methods employed in this study appear suitable for evaluating the effects of soil on the gastrointestinal absorption and systemic bioavailability of PAH from soil containing complex organic mixtures. 44 refs., 1 fig., 5 tabs

  12. Biomass Waste Gasification – Can Be the Two Stage Process Suitable for Tar Reduction and Power Generation?

    Czech Academy of Sciences Publication Activity Database

    Šulc, J.; Štojdl, J.; Richter, M.; Popelka, J.; Svoboda, Karel; Smetana, J.; Vacek, J.; Skoblia, S.; Buryan, P.

    2012-01-01

    Roč. 32, č. 4 (2012), s. 692-700 ISSN 0956-053X Grant - others:RFCR(XE) CT-2010-00009 Institutional research plan: CEZ:AV0Z40720504 Keywords : waste biomass * gasification * tar Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use Impact factor: 2.485, year: 2012

  13. Are PAHS the Right Metric for Assessing Toxicity Related to Oils, Tars, Creosote and Similar Contaminants in Sediments?

    Science.gov (United States)

    Oils, tars, and other non-aqueous phase hydrocarbon liquids (NAPLs) are common sources of contamination in aquatic sediments, and the toxicity of such contamination has generally been attributed to component chemicals, particularly PAHs. While there is no doubt PAHs can be toxic ...

  14. Análisis de cambio de régimen en series de tiempo no lienales utilizando modelos TAR

    Directory of Open Access Journals (Sweden)

    Hermilson Velásquez

    2004-12-01

    Full Text Available En muchas situaciones, la teoría recomienda un determinado modelo predictivo para una serie de tiempo financiera. Sin embargo, algunos comportamientos de estas series hacen que el modelo no sea apropiado. Una de las razones para ello puede ser la no linealidad de esos comportamientos. Se propone tratar estas series con modelos TAR (modelo autorregresivo por tramos; dichos modelos se definen por una variable umbral, por lo que en general resulta ser un modelo temporal no lineal. Un modelo de este tipo se formula como una serie temporal con su rezago como variable umbral, donde d es un entero positivo denominado retardo umbral. La variable umbral se desconoce en la práctica, y es importante saber cómo determinarla; en este artículo se explica cómo. Los modelos TAR se ilustran haciendo una modelación del PIB de España.

  15. Análisis de cambio de régimen en series de tiempo no lineales utilizando modelos TAR

    Directory of Open Access Journals (Sweden)

    Fredy Pérez

    2004-01-01

    Full Text Available En muchas situaciones, la teoría recomienda un determinado modelo predictivo para una serie de tiempo financiera. Sin embargo, algunos comportamientos de estas series hacen que el modelo no sea apropiado. Una de las razones para ello puede ser la no linealidad de esos comportamientos. Se propone tratar estas series con modelos TAR (modelo autorregresivo por tramos; dichos modelos se definen por una variable umbral, por lo que en general resulta ser un modelo temporal no lineal. Un modelo de este tipo se formula como una serie temporal con su rezago como variable umbral, donde d es un entero positivo denominado retardo umbral. La variable umbral se desconoce en la práctica, y es importante saber cómo determinarla; en este artículo se explica cómo. Los modelos TAR se ilustran haciendo una modelación del PIB de España.

  16. production and cost of cold patch road mats with bitumen extracted

    African Journals Online (AJOL)

    Jamiu

    This paper reports the production of bituminous road mats with bitumen sourced from the Nigerian Tar sand, recycled .... scrap tires are produced every year, which makes the disposal of ..... particles will be round or nearly round and will pass.

  17. Hydrogen and syngas production by catalytic gasification of algal biomass (Cladophora glomerata L.) using alkali and alkaline-earth metals compounds.

    Science.gov (United States)

    Ebadi, Abdol Ghaffar; Hisoriev, Hikmat; Zarnegar, Mohammad; Ahmadi, Hamed

    2018-01-02

    The steam gasification of algal biomass (Cladophora glomerata L.) in presence of alkali and alkaline-earth metal compounds catalysts was studied to enhance the yield of syngas and reduce its tar content through cracking and reforming of condensable fractions. The commercial catalysts used include NaOH, KHCO 3 , Na 3 PO 4 and MgO. The gasification runs carried out with a research scale, biomass gasification unit, show that the NaOH has a strong potential for production of hydrogen, along with the added advantages of char converting and tar destruction, allowing enhancement of produced syngas caloric value. When the temperature increased from 700°C to 900°C, the tar content in the gas sharply decreased, while the hydrogen yield increased. Increasing steam/biomass ratio significantly increased hydrogen yield and tar destruction; however, the particle size in the range of 0.5-2.5 mm played a minor role in the process.

  18. Phase I study of concurrent radiotherapy with TS-1 and vitamin A (TAR therapy) for head and neck cancer

    International Nuclear Information System (INIS)

    Nakashima, Torahiko; Kuratomi, Yuichiro; Yamamoto, Tomoya; Masuda, Muneyuki; Hirakawa, Naoya; Nakamura, Kazumasa; Shioyama, Yoshiyuki; Umezaki, Toshiro; Komune, Shizuo

    2005-01-01

    The triple combination of 5-fluorouracil (5-FU), vitamin A and radiation (FAR therapy) has been effectively used to treat head and neck cancer. The biological anti-tumor effect of 5-FU depends on the activity of its metabolizing enzyme, dihydropyrimidine dehydrogenase (DPD). TS-1 is a novel oral DPD inhibitory fluoropyrimidine (DIF). To improve the anti-tumor effect of FAR therapy, we have applied TS-1 in place of 5-FU injection in the combination of Vitamin A and radiation (TAR therapy). In this study, we have examined the appropriate duration of TS-1 medication and the clinical efficacy and safety of TAR therapy. TS-1 was administered orally at a dose of 65 mg/m 2 twice a day. Vitamin A (Retinol Palmitate: 50,000 U/day) was administered intra-musculary on each day of radiation. Radiation was given (1.5∼2 Gy/day: 5 days/week) for 30∼40 Gy. The levels were divided according to the length of TS-1 application as follows: level 1, 2 weeks; level 2, 3 weeks; level 4, 4 weeks. Grade 4 toxicity of anorexia was observed in one case of level 3. We decided that level 2 (3 weeks of TS-1 administration) was the appropriate length of TS-1 application. TAR therapy is a useful concurrent chemo-radiotherapy which might improve the response rate and quality of life (QOL) of patients with head and neck squamous cell carcinoma (HNSCC). (author)

  19. Industrial production of products like petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Baurier, P J.H.

    1925-02-25

    This invention has as its object a process for separating tars, oils, or gases coming from the distillation of carbonaceous materials, such as lignities or shales, to separate all other substances of the same kind and to prepare products like petroleum. The process for present consideration consists essentially in achieving simultaneously hydrogenation of the material (treated for conversion to stable products) and desulfurization of the materials showing the following characteristics: The substances to be treated are fed in the gaseous state, as vapors or pulverized and made to react at a temperature of 300 to 450/sup 0/C in the presence of excess water vapor, on divided metals capable of decomposing the water with release of hydrogen, at a temperature below 450/sup 0/C.

  20. Refining of the cracked products of mineral oils, etc

    Energy Technology Data Exchange (ETDEWEB)

    Seelig, S

    1928-06-02

    A process is disclosed for the refining of the distilled or cracked products from mineral oil, shale oil, or brown-coal-tar oil, with the aid of alkali-plumbite solution, characterized by adding to the plumbite solution from oxide, iron hydroxide, basic oxide, or an iron salt.

  1. Effects of biomass-generated producer gas constituents on cell growth, product distribution and hydrogenase activity of Clostridium carboxidivorans P7T

    International Nuclear Information System (INIS)

    Ahmed, Asma; Cateni, Bruno G.; Huhnke, Raymond L.; Lewis, Randy S.

    2006-01-01

    In our previous work, we demonstrated that biomass-generated producer gas can be converted to ethanol and acetic acid using a microbial catalyst Clostridium carboxidivorans P7 T . Results showed that the producer gas (1) induced cell dormancy, (2) inhibited H 2 consumption, and (3) affected the acetic acid/ethanol product distribution. Results of this work showed that tars were the likely cause of cell dormancy and product redistribution and that the addition of a 0.025μm filter in the gas cleanup negated the effects of tars. C. carboxidivorans P7 T can adapt to the tars (i.e. grow) only after prolonged exposure. Nitric oxide, present in the producer gas at 150ppm, is an inhibitor of the hydrogenase enzyme involved in H 2 consumption. We conclude that significant conditioning of the producer gas will be required for the successful coupling of biomass-generated producer gas with fermentation to produce ethanol and acetic acid. (author)

  2. Rebound of a coal tar creosote plume following partial source zone treatment with permanganate.

    Science.gov (United States)

    Thomson, N R; Fraser, M J; Lamarche, C; Barker, J F; Forsey, S P

    2008-11-14

    The long-term management of dissolved plumes originating from a coal tar creosote source is a technical challenge. For some sites stabilization of the source may be the best practical solution to decrease the contaminant mass loading to the plume and associated off-site migration. At the bench-scale, the deposition of manganese oxides, a permanganate reaction byproduct, has been shown to cause pore plugging and the formation of a manganese oxide layer adjacent to the non-aqueous phase liquid creosote which reduces post-treatment mass transfer and hence mass loading from the source. The objective of this study was to investigate the potential of partial permanganate treatment to reduce the ability of a coal tar creosote source zone to generate a multi-component plume at the pilot-scale over both the short-term (weeks to months) and the long-term (years) at a site where there is >10 years of comprehensive synoptic plume baseline data available. A series of preliminary bench-scale experiments were conducted to support this pilot-scale investigation. The results from the bench-scale experiments indicated that if sufficient mass removal of the reactive compounds is achieved then the effective solubility, aqueous concentration and rate of mass removal of the more abundant non-reactive coal tar creosote compounds such as biphenyl and dibenzofuran can be increased. Manganese oxide formation and deposition caused an order-of-magnitude decrease in hydraulic conductivity. Approximately 125 kg of permanganate were delivered into the pilot-scale source zone over 35 days, and based on mass balance estimates 35% reduction for all monitored compounds except for biphenyl, dibenzofuran and fluoranthene 150 days after treatment, which is consistent with the bench-scale experimental results. Pre- and post-treatment soil core data indicated a highly variable and random spatial distribution of mass within the source zone and provided no insight into the mass removed of any of the

  3. TAR (Theatre as Representation) as a Provocative Teaching Tool in School Administration: A Dramatized Inclusive Classroom Scenario

    Science.gov (United States)

    Meyer, Matthew J.; Young, David C.

    2013-01-01

    The following dramatized classroom scenario depicts a teacher struggling with the nature of an inclusive learning environment, with instructional leadership and supervision of instruction as the theoretical and practical backdrop. The purpose of this article is to demonstrate how the use of a TAR (theatre as representation) case study can be used…

  4. Towards nuclear energy applications other than electricity production

    International Nuclear Information System (INIS)

    Lecomte, M.

    2007-01-01

    Use of nuclear energy relies on operation of a boiler, involving practically no greenhouse gas emission. Whereas production of electricity is, nowadays, virtually its sole purpose, demand for heat production could equally arise, particularly with the emergence of high-temperature, or even very-high-temperature reactors. With the abilities this involves, as regards the recovery of heavy crude oils from tar sands, seawater desalination, or, most importantly, production of hydrogen by electrolysis, or thermochemistry, this being the energy carrier of tomorrow. (authors)

  5. Nakamura Ryûtarô’s Anime, Serial Experiments, Lain (1998

    Directory of Open Access Journals (Sweden)

    Tamae KOBAYASHI PRINDLE

    2015-07-01

    Full Text Available This paper introduces Nakamura Ryūtarō’s anime, Serial Experiments, Lain (1998 as a new type of anime, a genre nameable as an “expository anime”, for the reason that it creates a diachronic story out of a synchronic aspect of a certain field of science. The overarching topic of Experiments is electronics, focusing on the comparison between digital and analogue communication systems. Experiments unfolds the rationales, potentials, and effects of the two types of communication systems using the perceptions of the major character, a thirteen-year old girl, Rein, as well as other supporting characters.

  6. Robotic Transversus Abdominis Release (TAR: is it possible to offer minimally invasive surgery for abdominal wall complex defects?

    Directory of Open Access Journals (Sweden)

    MARIA VITÓRIA FRANÇA DO AMARAL

    Full Text Available ABSTRACT We describe the preliminary national experience and the early results of the use of robotic surgery to perform the posterior separation of abdominal wall components by the Transversus Abdominis Release (TAR technique for the correction of complex defects of the abdominal wall. We performed the procedures between 04/2/2015 and 06/15/2015 and the follow-up time was up to six months, with a minimum of two months. The mean surgical time was five hours and 40 minutes. Two patients required laparoscopic re-intervention, since one developed hernia by peritoneal migration of the mesh and one had mesh extrusion. The procedure proved to be technically feasible, with a still long surgical time. Considering the potential advantages of robotic surgery and those related to TAR and the results obtained when these two techniques are associated, we conclude that they seem to be a good option for the correction of complex abdominal wall defects.

  7. Urban assemblages: ANT and the examination of the city Ensamblajes urbanos: la TAR y el examen de la ciudad

    Directory of Open Access Journals (Sweden)

    Ignacio Farías

    2011-03-01

    Full Text Available

    This article presents new research perspectives and analytical challenges that actor-network theory opens for urban studies. First, it reviews how the ANT principles of hybrid relationality and flat associativity are being adopted in urban studies to symmetrically expand the urban ecology to nonhumans and contest scalar conceptions of urban space and economy. Second, it proposes that ANT brings along an even more fundamental challenge related to the understanding of the city as a research object. While common understandings as a spatial object, political-economical entity and/or sociocultural form underlie its singular, stable and bounded character, ANT allows thinking the city as a multiple and decentered object. The notion of urban assemblages is introduced to account for the circulation and becoming of the city in multiple hybrid and translocal networks. Finally, it concludes by discussing some consequences of this examination of the city, especially the reassertion of the problem of complexity, especially urban complexity, if not as a starting point, then at least as a point of arrival for ANT.

    Este artículo presenta nuevas perspectivas de investigación y desafíos analíticos que la teoría del actor-red (TAR abre para los estudios urbanos. En primer lugar, se revisan cómo los principios de relacionalidad híbrida y asociatividad plana de la TAR están siendo adoptados en los estudios urbanos para ampliar simétricamente la ecología urbana a no-humanos e impugnar concepciones escalares del espacio y economías urbanas. A continuación, se propone que la TAR trae consigo un desafío más fundamental relativo a la

  8. Trash-to-Gas: Converting Space Trash into Useful Products

    Science.gov (United States)

    Caraccio, Anne J.; Hintze, Paul E.

    2013-01-01

    NASA's Logistical Reduction and Repurposing (LRR) project is a collaborative effort in which NASA is determined to reduce total logistical mass through reduction, reuse and recycling of various wastes and components of long duration space missions and habitats. LRR is focusing on four distinct advanced areas of study: Advanced Clothing System, Logistics-to-Living, Heat Melt Compactor and Trash to Supply Gas (TtSG). The objective of TtSG is to develop technologies that convert material waste, human waste and food waste into high-value products. High-value products include life support oxygen and water, rocket fuels, raw material production feedstocks, and other energy sources. There are multiple pathways for converting waste to products involving single or multi-step processes. This paper discusses thermal oxidation methods of converting waste to methane. Different wastes, including food, food packaging, Maximum Absorbent Garments (MAGs), human waste simulants, and cotton washcloths have been evaluated in a thermal degradation reactor under conditions promoting pyrolysis, gasification or incineration. The goal was to evaluate the degradation processes at varying temperatures and ramp cycles and to maximize production of desirable products and minimize high molecular weight hydrocarbon (tar) production. Catalytic cracking was also evaluated to minimize tar production. The quantities of CO2, CO, CH4, and H2O were measured under the different thermal degradation conditions. The conversion efficiencies of these products were used to determine the best methods for producing desired products.

  9. Effects of biomass-generated producer gas constituents on cell growth, product distribution and hydrogenase activity of Clostridium carboxidivorans P7{sup T}

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Asma [Oklahoma State University, Stillwater, OK (United States). School of Chemical Engineering; Cateni, Bruno G.; Huhnke, Raymond L. [Oklahoma State University, Stillwater, OK (United States). Department of Biosystems and Agricultural Engineering; Lewis, Randy S. [Brigham Young University, Provo, UT (United States). Chemical Engineering Department

    2006-07-15

    In our previous work, we demonstrated that biomass-generated producer gas can be converted to ethanol and acetic acid using a microbial catalyst Clostridium carboxidivorans P7{sup T}. Results showed that the producer gas (1) induced cell dormancy, (2) inhibited H{sub 2} consumption, and (3) affected the acetic acid/ethanol product distribution. Results of this work showed that tars were the likely cause of cell dormancy and product redistribution and that the addition of a 0.025{mu}m filter in the gas cleanup negated the effects of tars. C. carboxidivorans P7{sup T} can adapt to the tars (i.e. grow) only after prolonged exposure. Nitric oxide, present in the producer gas at 150ppm, is an inhibitor of the hydrogenase enzyme involved in H{sub 2} consumption. We conclude that significant conditioning of the producer gas will be required for the successful coupling of biomass-generated producer gas with fermentation to produce ethanol and acetic acid. (author)

  10. Hydropyrolysis of a Turkish lignite (Tuncbilek) and effect of temperature and pressure on product distribution

    Energy Technology Data Exchange (ETDEWEB)

    Canel, M.; Misirlioglu, Z.; Sinag, A. [Ankara University, Ankara (Turkey). Faculty of Science

    2005-08-01

    The hydropyrolysis of a Turkish lignite (Tuncbilek) in a swept fixed bed reactor connected with a thermo-balance was performed at a heating rate of 3 C/min up to 950 C under 0.5MPa, 1MPa and 10MPa hydrogen pressures. The formation rates of gaseous hydrocarbons, carbon oxides, water and tar were determined. The difference between the weight loss due to tar formation of the non-condensable total and the weight loss of the sample recorded continuously with the thermo-balance showed the corresponding curve of tar formation rate as a function of temperature. It was shown that the total conversion and the formation rate of the products during hydropyrolysis could be influenced by varying the pressure. On the other hand, the volatile matter evolved during pyrolysis was substantially increased in the presence of hydrogen and especially when elevated hydrogen pressure was used.

  11. Johannes Hindi tütar Pille Pae : inimlik headus ei sõltu režiimist / Pille Pae ; interv. Anneli Ammas

    Index Scriptorium Estoniae

    Pae, Pille

    2006-01-01

    Desintegraatori juhi Johannes Hindi tütar Pille Pae vastab küsimustele, mis puudutavad tema isa armuandmispalve esitamist, isale toetusallkirjade kogumist, Arnold Rüütli suhteid Johannes Hindiga. Lisa: Kes oli Johannes Hint ja mis Desintegraator?

  12. Process and apparatus for recovering of oil, bitumen, tar, resins, etc

    Energy Technology Data Exchange (ETDEWEB)

    1921-11-06

    A process for recovering oil, bitumen, tar, and resins from oil shale, oil sands, Fuller's earth, peat, brown coal, mineral coal, and wood, through direct action of superheated steam on the material, is characterized by the fact that superheated steam with or without mixing of inert gases at a temperature, which lies below the decomposition temperature of the material being treated, is passed through the material with a high velocity. It leaves through nozzles, used in steam turbines. A method of carrying out the process in which solution medium is used for action on the material is characterized by the fact that solvents such as benzine and benzol are mixed with steam in different quantities.

  13. Preparation and Characterization of Malaysian Dolomites as a Tar Cracking Catalyst in Biomass Gasification Process

    Directory of Open Access Journals (Sweden)

    M. A. A. Mohammed

    2013-01-01

    Full Text Available Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites underwent two stages of decomposition during the calcination process. The X-ray diffraction and Fourier-transform infrared spectra analyses showed that thermal treatment of dolomite played a significant role in the disappearance of the CaMg(CO32 phase, producing the MgO-CaO form of dolomite. The scanning electron microscopy microphotographs of dolomite indicated that the morphological properties were profoundly affected by the calcination process, which led to the formation of a highly porous surface with small spherical particles. In addition, the calcination of dolomite led to the elimination of carbon dioxide and increases in the values of the specific surface area and average pore diameter, as indicated by surface area analysis. The results showed that calcined Malaysian dolomites have great potential to be applied as tar-cracking catalysts in the biomass gasification process based on their favorable physical properties.

  14. Method for production of fuel oils and diesel motor oils free of sediments and with unlimited miscibility

    Energy Technology Data Exchange (ETDEWEB)

    1942-01-13

    A method is described for the production of fuel and diesel oils free of sediments and with unlimited miscibility by their recovery from substances poor in hydrogen, such as tars of fossil carbon, from lignite, from peat, from schist oils, from wood, or tar oils of corresponding extracts, poorly hydrogenated carbohydrates and the like, characterized by the fact that these substances are being subjected without mixing with selective solvents to a chemical purification and then immediately subjected to a redistillation and the obtained distillates being cut with hydrogen-rich oils to obtain normal diesel oils.

  15. Production of nuclear graphite in France

    International Nuclear Information System (INIS)

    Legendre, P.; Mondet, L.; Arragon, Ph.; Cornuault, P.; Gueron, J.; Hering, H.

    1955-01-01

    The graphite intended for the construction of the reactors is obtained by the usual process: confection of a cake from coke of oil and tar, cooked (in a electric oven) then the product of cook is graphitized, also by electric heating. The use of the air transportation and the control of conditions cooking and graphitization have permitted to increase the nuclear graphite production as well as to better control their physical and mechanical properties and to reduce to the minimum the unwanted stains. (M.B.) [fr

  16. Genetic relationship of organic bases of the quinoline and isoquinoline series from lignite semicoking tars with the initial biological material

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Podshibyakin, S.I.; Domogatskii, V.V.; Shvykin, A.Y.; Shavyrina, O.A.; Chilachava, K.B. [Leo Tolstoy State Pedagog University, Tula (Russian Federation)

    2002-07-01

    The genetic relationship of quinoline and isoquinoline compounds present in semicoking tars of Kimovsk lignites (near-Moscow fields) with the initial vegetable material is discussed. Transformation pathways of the native compounds in the course of lignite formation are suggested.

  17. Catalytic hydroprocessing of simulated coal tars. 1. Activity of a sulphided Ni-Mo/Al/sub 2/O/sub 3/ catalyst for the hydroconversion of model compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lemberton, J.L.; Touzeyidio, M.; Guisnet, M. (Laboratoire de Catalyse en Chimie Organique CNRS, Poitiers (France))

    1989-09-15

    The conversion of tars from coal pyrolysis into light aromatics, such as BTX (benzene-toluene-xylenes) and naphthalene, requires the hydrocracking of heavy polyaromatics in the presence of nitrogen- and oxygen-containing compounds. The hydroconversion of phenanthrene, which occurs through bifunctional catalysis, was chosen as a model reaction. It was carried out over a sulphided Ni-Mo/Al/sub 2/O/sub 3/ catalyst (Ketjen 153) in the presence of carbazole and 1-naphthol. Carbazole poisons slightly through coking both the hydrogenating and the acid sites of the catalyst. 1-Naphthol has a more significant deactivating effect: the hydrogenating sites of the catalyst are poisoned by the water eliminated from 1-naphthol and the acid sites by coke generated by 1-naphthol. Lastly, the hydrogenating activity of the catalyst is not substantially affected in the presence of carbazole and 1-naphthol, but its cracking activity is much reduced, making it impossible for the catalyst to achieve the hydrocracking of phenanthrene into into light aromatics. 5 figs, 21 refs., 1 tab.

  18. A two-stage fixed-bed reactor for direct hydrotreatment of volatiles from the hydropyrolysis of biomass: effect of catalyst temperature, pressure and catalyst ageing time on product characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pindoria, R.V.; Megaritis, A.; Herod, A.A.; Kandiyoti, R. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Chemical Engineering and Chemical Technology

    1998-12-01

    This investigation involved the hydropyrolysis of biomass (eucalyptus globulus) and the immediate catalytic hydrocracking of pyrolytic oils in the second stage of the reactor. The effects of temperature, pressure and the catalyst ageing time on the final product tar have been studied using the catalyst Zeolite H-ZSM5. The catalytically hydrocracked tar/oil products were characterised and compared with the hydropyrolysis product from the first stage of the reactor to determine the effect of catalytic hydrocracking. The carbon deposition on the catalyst has been examined using thermogravimetric analysis. The tar yields after catalytic hydrocracking decreased with increasing pressure and temperature of the cracking stage. The tar yields at 10 bar pressure were greater than those at 40 bar pressure. The fresh zeolite catalyst trapped more than 40% of the product from the hydropyrolysis stage and TGA evidence indicated that this was not as carbon deposition but as volatiles trapped in the zeolite matrix. Reuse of the catalyst resulted in little more uptake of volatiles; however, extended use of the catalyst did not result in increased yields of liquid products but in increased production of light volatiles or gas. The H-ZSM5 catalyst appeared to act as a more active cracking catalyst rather than to promote hydrogenation or deoxygenation of the liquids produced in the hydropyrolysis stage. Characterisation of the liquids by SEC and UV fluorescence indicated that structural changes were relatively minor despite the significant changes in yields of liquids with process conditions. Available reaction routes do not appear to allow specific deoxygenation pathways to predominate without disintegration of parent molecules to lighter volatiles, under the conditions used here. 41 refs., 10 figs., 4 tabs.

  19. Sustainable Production of Bio-Combustibles from Pyrolysis of Agro-Industrial Wastes

    Directory of Open Access Journals (Sweden)

    Maurizio Volpe

    2014-11-01

    Full Text Available Evaluation of the sustainability of biomass pyrolysis requires a thorough assessment of the product yields and energy densities. With this purpose, a laboratory scale fixed bed reactor (FBR was adapted from the standard Gray-King (GK assay test on coal to conduct fixed bed pyrolysis experiments on agricultural and agro-industrial by-products. The present study provides results on the pyrolysis of two types of biomass: chipped olive tree trimmings (OT and olive pomace (OP. Solid (char and liquid (tar product yields are reported. Mass yields are determined and compared with values obtained in similar works. Results indicate that char yield decreases from 49% (OT-db and 50% (OP-db at 325 °C to 26% (OT db and 30% (OP-db at 650 °C. Tar yield is almost constant (42% at different reaction temperatures for OT, while it decreases slightly from 42% to 35% for OP. Energy density of the products at different peak temperatures is almost constant for OT (1.2, but slightly increases for OP (from a value of 1.3 to a value of 1.4.

  20. Studies of RF sheaths and diagnostics on IShTAR

    Energy Technology Data Exchange (ETDEWEB)

    Crombé, K., E-mail: Kristel.Crombe@UGent.be [Department of Applied Physics, Ghent University, Ghent (Belgium); LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. [YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France); D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. [LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, Ghent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

  1. Modelling Product Families for Product Configuration Systems with Product Variant Master

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik; Hvam, Lars; Haug, Anders

    2010-01-01

    This article presents an evaluation of applying a suggested method for modelling product families for product configuration based on theory for modelling mechanical products,systems theory and object-oriented modelling. The modelling technique includes a so-called product variant master and CRC-cards...... the three views. Modelling of characteristics of the product variants in a product family Modelling of constraints between parts in the product family Visualisation of the entire product family on a poster e.g. 1x2 meters The product variant master and CRC-cards are means to bridge the gap between domain...... experts and IT-developers, thus making it possible for the domain experts (e.g. engineers from product development) to express their knowledge in a form that is understandable both for the domain experts and the IT-developers. The product variant master and CRC-cards have currently been tested and further...

  2. iTAR: a web server for identifying target genes of transcription factors using ChIP-seq or ChIP-chip data.

    Science.gov (United States)

    Yang, Chia-Chun; Andrews, Erik H; Chen, Min-Hsuan; Wang, Wan-Yu; Chen, Jeremy J W; Gerstein, Mark; Liu, Chun-Chi; Cheng, Chao

    2016-08-12

    Chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) or microarray hybridization (ChIP-chip) has been widely used to determine the genomic occupation of transcription factors (TFs). We have previously developed a probabilistic method, called TIP (Target Identification from Profiles), to identify TF target genes using ChIP-seq/ChIP-chip data. To achieve high specificity, TIP applies a conservative method to estimate significance of target genes, with the trade-off being a relatively low sensitivity of target gene identification compared to other methods. Additionally, TIP's output does not render binding-peak locations or intensity, information highly useful for visualization and general experimental biological use, while the variability of ChIP-seq/ChIP-chip file formats has made input into TIP more difficult than desired. To improve upon these facets, here we present are fined TIP with key extensions. First, it implements a Gaussian mixture model for p-value estimation, increasing target gene identification sensitivity and more accurately capturing the shape of TF binding profile distributions. Second, it enables the incorporation of TF binding-peak data by identifying their locations in significant target gene promoter regions and quantifies their strengths. Finally, for full ease of implementation we have incorporated it into a web server ( http://syslab3.nchu.edu.tw/iTAR/ ) that enables flexibility of input file format, can be used across multiple species and genome assembly versions, and is freely available for public use. The web server additionally performs GO enrichment analysis for the identified target genes to reveal the potential function of the corresponding TF. The iTAR web server provides a user-friendly interface and supports target gene identification in seven species, ranging from yeast to human. To facilitate investigating the quality of ChIP-seq/ChIP-chip data, the web server generates the chart of the

  3. A Comparative Study Of Stock Price Forecasting Using Nonlinear Models

    Directory of Open Access Journals (Sweden)

    Diteboho Xaba

    2017-03-01

    Full Text Available This study compared the in-sample forecasting accuracy of three forecasting nonlinear models namely: the Smooth Transition Regression (STR model, the Threshold Autoregressive (TAR model and the Markov-switching Autoregressive (MS-AR model. Nonlinearity tests were used to confirm the validity of the assumptions of the study. The study used model selection criteria, SBC to select the optimal lag order and for the selection of appropriate models. The Mean Square Error (MSE, Mean Absolute Error (MAE and Root Mean Square Error (RMSE served as the error measures in evaluating the forecasting ability of the models. The MS-AR models proved to perform well with lower error measures as compared to LSTR and TAR models in most cases.

  4. Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Vethamony, P.; Zakaria, M.P.; Naik, B.G.; Prasad, K.V.

    . Christensen et al (2007) reviewed the practical aspects of chemometrics for oil spill fingerprinting and provided a basis for the use of chemometric 3    methods in tiered oil spill fingerprinting. Biomarker compounds such as isoprenoid alkanes, hopanes... deposited along the Malaysian beaches. Low molecular weight/high molecular weight ratios (L/H) of both alkanes and PAHs together are useful in categorizing the weathering effects of tar balls (Chandru et al., 2008). However, in cases...

  5. Modeling of Volatility with Non-linear Time Series Model

    OpenAIRE

    Kim Song Yon; Kim Mun Chol

    2013-01-01

    In this paper, non-linear time series models are used to describe volatility in financial time series data. To describe volatility, two of the non-linear time series are combined into form TAR (Threshold Auto-Regressive Model) with AARCH (Asymmetric Auto-Regressive Conditional Heteroskedasticity) error term and its parameter estimation is studied.

  6. Mineralization of PAHs in coal-tar impacted aquifer sediments and associated microbial community structure investigated with FISH

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, S W; Ong, S K; Moorman, T B [Iowa State University, Ames, IA (USA)

    2007-11-15

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detected microbial populations in the contaminated sediments were three orders of magnitude greater than nearby uncontaminated sediments, suggesting growth on coal-tar constituents in situ. Actinobacteria, {beta}- and {gamma}-Proteobacteria, and Flavobacteria dominated the in situ aerobic (> 1 mg l{sup -1} dissolved oxygen) microbial community, whereas sulfate-reducing bacteria comprised 37% of the microbial community in the sulfidogenic region of the aquifer. Rapid mineralization of naphthalene and phenanthrene were observed in aerobic laboratory microcosms and resulted in significant enrichment of {beta}- and {gamma}-Proteobacteria potentially explaining their elevated presence in situ. Nitrate- and sulfate-limited mineralization of naphthalene in laboratory microcosms occurred to a small degree in aquifer sediments from locations where groundwater chemistry indicated nitrate- and sulfate-reduction, respectively. The results of this study suggest that FISH may be a useful tool for providing a link between laboratory microcosms and groundwater measurements made in situ necessary to better demonstrate the potential for natural attenuation at complex PAH contaminated sites.

  7. Environmental survey - tar sands in situ processing research program (Vernal, Uintah County, Utah). [Reverse-forward combustion; steam injection

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Q.

    1980-03-01

    Research will be done on the reverse-forward combustion and steam injection for the in-situ recovery of oil from tar sands. This environmental survey will serve as a guideline for the consideration of environmental consequences of such research. It covers the construction phase, operational phase, description of the environment, potential impacts and mitigations, coordination, and alternatives. (DLC)

  8. Determination of aromatic fragment content in phenol-containing fractions of solid fuel conversion products using nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kanitskaya, L.V.; Kushnarev, D.F.; Polonov, V.M.; Kalabin, G.A.

    1986-03-01

    Optimum conditions are determined for obtaining quantitative nuclear magnetic resonance /sup 13/C spectra of fragments in phenol-containing fraction of coal products. Causes are analyzed of residual signals in spectra of un-protonized carbon atoms. The tests were carried out on: low-temperature carbonization tar and phenol fraction obtained during medium-temperature coking of Cherenkhovskii coal (which contains 84.13% C; 9.68% H; 1.23% S; 4.96% O); products of tar hydrogenation with various phenol content; standard phenol mixture. It was found that quantitative determination of aromatic fraction content in coal conversion products and other phenol- and amine-containing complex mixtures, using NMR spectroscopy requires the addition of dimethylsulfide or acetone in order to suppress specific interactions of phenols (amines) with relaxants and obtain quantitative subspectra of Tertiary and Quaternary aromatic carbon atoms. 16 references.

  9. Process for treating the dialyzed spent liquor from sulphonic acid containing sulfur minerals or tar oils or ammonium salts

    Energy Technology Data Exchange (ETDEWEB)

    Wernicke, E A

    1936-08-09

    Process for working up the dialyzate from sulfonic acid, sulfur-containing mineral or tar oils, or their ammonium salts, characterized by the combination of known steps, in the dialyzate being reacted with alkaline-earth oxide, hydroxide, or carbonate, and the resulting slightly soluble sulfate being filtered off and evaporated if necessary.

  10. Sampling of contaminants from product gases of biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Staahlberg, P.; Lappi, M.; Kurkela, E.; Simell, P.; Oesch, P.; Nieminen, M. [VTT Energy, Espoo (Finland). New Energy Technologies

    1998-12-01

    Reliable sampling and analysis of products from biomass gasification are essential for the successful process development and economical operation of commercial gasifiers. One of the most important and most difficult analytical tasks is to characterise the emissions from the gasifiers. This report presents a review of the sampling and analytical systems employed and developed when doing research on coal and biomass gasification. In addition to the sampling systems published in the literature, experiences obtained in various biomass gasification R and D projects of VTT in 1985-1995 are described. The present sampling methods used for different gas contaminants at VTT are also briefly presented. This report focuses mainly on the measurement of tars, nitrogen compounds and sulphur gases. Isokinetic and non-isokinetic sampling train systems are described and, in addition, special sampling apparatus based on liquid-quenched probe and gas dilution is briefly outlined. Sampling of tars with impinger systems and sampling of heavy tars with filter techniques are described in detail. Separate sampling of particulates is briefly discussed. From inorganic compounds the sampling systems used for H{sub 2}S and other sulphur gases, NH{sub 3} and HCN and HCl are presented. Proper storage of the samples is also included in the report. (orig.) 90 refs.

  11. The Search for the Lost Cultural Identity——The Interpretation of Toni Morrison's Novel Tar Baby

    Institute of Scientific and Technical Information of China (English)

    郑艺

    2011-01-01

    Toni Morrison's novel Tar Baby is a novel with the theme on the search for cultural identity,from which it suggests Toni Morrison's attitude towards cultural identity and her answer to the search for the lost cultural identity.The paper is divided into three parts to reveal the African Americans' state of cultural marginalization,the importance of getting a balanced point between two different cultures and the way to search for cultural identity.

  12. Extending product modeling methods for integrated product development

    DEFF Research Database (Denmark)

    Bonev, Martin; Wörösch, Michael; Hauksdóttir, Dagný

    2013-01-01

    Despite great efforts within the modeling domain, the majority of methods often address the uncommon design situation of an original product development. However, studies illustrate that development tasks are predominantly related to redesigning, improving, and extending already existing products...... and PVM methods, in a presented Product Requirement Development model some of the individual drawbacks of each method could be overcome. Based on the UML standard, the model enables the representation of complex hierarchical relationships in a generic product model. At the same time it uses matrix....... Updated design requirements have then to be made explicit and mapped against the existing product architecture. In this paper, existing methods are adapted and extended through linking updated requirements to suitable product models. By combining several established modeling techniques, such as the DSM...

  13. Optimal processing conditions for a dolomite cracker for cracking of tar from gasification of biomass fuels. Optimale procesbetingelser for en dolomitkrakker til krakning af tjaere fra forgasning af biobraendsler

    Energy Technology Data Exchange (ETDEWEB)

    Fjellerup, J.

    1989-08-15

    Gasification of fuels derived from biomass is of interest in connection with combined cycle systems. During gasification tar compounds can be produced, and these can block further stages of the process. As gas turbines are very sensitive to tar compounds it is necessary to remove the tar completely from the gas. The most effective method appears to be catalytic cracking and it is suggested that dolomite is an effective and cheap catalysator. Based on a survey of relevant literature, the aim was to discover optimal conditions for the process of dolomite cracking. It is concluded that it is important to decarbonate the dolomite before use, that dolomite is not suitable for use in fluidized beds as it can become eroded and is subsequently very quickly blown out, and that it is important to hold the temperature at a level of ca. 800 deg. C. Conditions for fixed bed cracking both with and without steam are also desderibed. (AB) 15 refs.

  14. Porous carbon nanosheets from coal tar for high-performance supercapacitors

    Science.gov (United States)

    He, Xiaojun; Ma, Hao; Wang, Jingxian; Xie, Yuanyang; Xiao, Nan; Qiu, Jieshan

    2017-07-01

    A hydroxide-template strategy coupled with in-situ chemical activation is reported for the first time to fabricate porous carbon nanosheets (PCNSs) from coal tar. The thin PCNSs feature abundant short pores accessible for fast ion transport and high specific surface area up to 3235 m2 g-1 for ion adsorption. As electrodes for supercapacitors, the PCNSs show a high capacitance of 296.2 F g-1 at 0.05 A g-1 in 6 M KOH electrolyte, an excellent rate performance with a capacitance of 220.7 F g-1 at 20 A g-1 and a superior cycle stability with over 97.2% capacitance retention after 11000 charge-discharge cycles at 3.5 A g-1. This work paves a new way for efficient fabrication of sheet-like carbon materials with tuned porous structure from polycyclic aromatic hydrocarbons for high performance supercapacitors.

  15. First experimental results on the IShTAR testbed

    Energy Technology Data Exchange (ETDEWEB)

    D’Inca, R.; Jacquot, J.; Ochoukov, R.; Morgal, I.; Fünfgelder, H.; Faugel, H. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Crombe, K.; Louche, F.; Van Eester, D. [LPP-ERM-KMS, TEC partner, Brussels (Belgium); Heuraux, S.; Devaux, S.; Moritz, J.; Faudot, E. [Institut Jean Lamour UMR 7198 CNRS-Université de Lorraine, Nancy (France); Noterdaeme, J.-M. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Department of Applied Physics, Ghent University (Belgium)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetized plasma test facility dedicated to the investigation of RF wave/plasma interaction [1] in the Ion Cyclotron Range of Frequencies (ICRF). It provides a better accessibility for the instrumentation than tokamaks while being representative of the neighboring region of the wave emitter. It is equipped with a magnetized plasma source (1 m long, 0.4 m diameter) powered by a helical antenna up to 3 kW at 11 MHz. We present the results of the first analysis of the plasma characteristics (plasma density, electron temperature) in function of the operating parameters (injected power, neutral pressure and magnetic field) as measured with fixed and movable Langmuir probes, spectrometer and cameras. The plasma is presently produced only by the helical antenna (no ICRF). We show that the plasma exists in three regime depending on the power level: the first two ones are stable and separated by a jump in density; a first spatial profile of the plasma density has been established for these modes; The third mode is unstable, characterized by strong oscillations of the plasma tube position.

  16. Shoreline erosion and decadal sediment accumulation in the Tar-Pamlico estuary, North Carolina, USA: A source-to-sink analysis

    Science.gov (United States)

    Eulie, Devon O.; Corbett, D. Reide; Walsh, J. P.

    2018-03-01

    Estuaries contain vital habitats and it is important to understand how these areas respond to human activities and natural processes such as sea-level rise and wave attack. As estuarine shorelines erode or become modified with hard structures, there is potential for significantly altering the availability of sediment and the filling of coastal systems. This study used a source-to-sink approach and quantified rates of shoreline erosion in the Tar-Pamlico sub-estuary, a tributary of the larger Albemarle-Pamlico Estuarine System (APES). The average shoreline change rate (SCR) determined using an end-point method was -0.5 ± 0.9 m yr-1 for the Tar-Pamlico. Incorporating bulk density estimates, this contributes 0.6 × 105 tons of fine sediment to the system annually, or after accounting for fluvial input, about 40% of the total sediment supply to the sub-estuary. The role of the Tar-Pamlico as a sink for these sediments was addressed using the radionuclide tracers 210Pb and 137Cs. Radionuclide activities and sediment accumulation rates identified several depositional regions, in particular in the middle of the estuary. Linear sediment accumulation rates ranged from 0.10 ± 0.02 to 0.38 ± 0.02 g cm-2 yr-1, and total storage of fine sediment in the system was 1.6 × 105 t yr-1. It was not possible to confidently discern a change in the rate of shoreline erosion or seabed accumulation. A preliminary budget for fine sediments (grain-size <63 μm) was then calculated to compare erosional sources with sedimentary sinks. Almost all (∼93.0%) of the fine sediment entering the system was accumulated and stored, while only about 7.0% was exported to Pamlico Sound.

  17. Production of heavy greases from lignite

    Energy Technology Data Exchange (ETDEWEB)

    1921-03-18

    A process is described for the extraction of heavy greases and wagon greases and their equivalents, by separation from bitumins, resins, and waxes contained in lignite, peat, bituminous shale, fossil wax, paraffin, etc., characterized by the fact that for the extraction are used solvents of high boiling point, such as mineral oils, grease oils, tar oils, and other equivalents, which are not eliminated and at the same time constitute a part of the product obtained.

  18. Oro taršos lakiaisiais organiniais junginiais tyrimas ir jos mažinimas naftos terminaluose

    OpenAIRE

    Paulauskienė, Tatjana

    2008-01-01

    Disertacijoje nagrinėjama naftos ir jos produktų garavimo terminaluose problema. Pagrindinis disertacijos tikslas – įvertinti atmosferos taršą lakiaisiais organiniais junginiais (LOJ) naftos terminaluose, nustatyti meteorologinių elementų ir krovos indikatoriaus įtaką LOJ koncentracijos kitimui pažemės atmosferos sluoksnyje. Darbe sprendžiami keli pagrindiniai uždaviniai: ištirti LOJ pasiskirstymą pažemės atmosferos sluoksnyje už naftos terminalų teritorijos skirtingais metų sezonais atsižvel...

  19. Nuclear graphite based on coal tar pitch; behavior under neutron irradiation between 400 and 14000C

    International Nuclear Information System (INIS)

    Mottet, P.; Fillatre, A.; Schill, R.; Micaud, G.

    1977-01-01

    Two nuclear grades of coal tar pitch coke graphites have been developed and tested under neutron irradiation. The neutron irradiation induced dimensional changes between 400 and 1400 0 C, at fluences up to 1,2.10 22 n.cm -2 PHI.FG show a behavior comparable to anisotropic petroleum coke graphites. Less than 10% variation in thermal expansion, maximum decrease by a factor four in thermal conductivity, and large increase of the Young modulus have been observed

  20. Product Knowledge Modelling and Management

    DEFF Research Database (Denmark)

    Zhang, Y.; MacCallum, K. J.; Duffy, Alex

    1996-01-01

    function-oriented design. Both Specific Product Knowledge and Product Domain Knowledge are modelled at two levels, a meta-model and an information-level.Following that, a computer-based scheme to manage the proposed product lknowledge models within a dynamically changing environment is presented.......The term, Product Knowledge is used to refer to two related but distinct concepts; the knowledge of a specific product (Specific Product Knowledge) and the knowledge of a product domain (Product Domain Knowledge). Modelling and managing Product Knowlege is an essential part of carrying out design.......A scheme is presented in this paper to model, i.e. classify, structure and formalise the product knowledge for the purpose of supporting function-oriented design. The product design specification and four types of required attributes of a specific product have been identified to form the Specific Product...

  1. CFD-Modeling of the Multistage Gasifier Capacity of 30 KW

    Science.gov (United States)

    Levin, A. A.; Kozlov, A. N.; Svishchev, D. A.; Donskoy, I. G.

    2017-11-01

    Single-stage fuel gasification processes have been developed and widely studied in Russia and abroad throughout the 20th century. They are fundamental to the creation and design of modern gas generator equipment. Many studies have shown that single-stage gasification process, have already reached the limit of perfection, which was a significant improvement in their performance becomes impossible and unprofitable. The most fully meet modern technical requirements of multistage gasification technology. In the first step of the process, is organized allothermic biomass pyrolysis using heat of exhaust gas and generating power plant. At this stage, the yield of volatile products (gas and tar) of fuel. In the second step, the layer of fuel is, the tar is decomposed by the action of hot air and steam, steam-gas mixture is formed further reacts with the charcoal in the third process stage. The paper presents a model developed by the authors of the multi-stage gasifier for wood chips. The model is made with the use of CFD-modeling software package (COMSOL Multiphisics). To describe the kinetics of wood pyrolysis and gasification of charcoal studies were carried out using a set of simultaneous thermal analysis. For this complex developed original methods of interpretation of measurements, including methods of technical analysis of fuels and determine the parameters of the detailed kinetics and mechanism of pyrolysis.

  2. Hydrogen production by biomass steam gasification in fluidized bed reactor with Co catalyst

    International Nuclear Information System (INIS)

    Kazuhiko Tasaka; Atsushi Tsutsumi; Takeshi Furusawa

    2006-01-01

    The catalytic performances of Co/MgO catalysts were investigated in steam gasification of cellulose and steam reforming of tar derived from cellulose gasification. For steam reforming of cellulose tar in a secondary fixed bed reactor, 12 wt.% Co/MgO catalyst attained more than 80% of tar reduction. The amount of produced H 2 and CO 2 increased with the presence of catalyst, and kept same level during 2 hr at 873 K. It is indicated that steam reforming of cellulose tar proceeds sufficiently over Co/MgO catalyst. For steam gasification of cellulose in a fluidized bed reactor, it was found that tar reduction increases with Co loading amount and 36 wt.% Co/MgO catalyst showed 84% of tar reduction. The amounts of produced gas kept for 2 hr indicating that 36 wt.% Co/MgO catalyst is stable during the reaction. It was concluded that these Co catalysts are promising systems for the steam gasification of cellulose and steam reforming of cellulose tar. (authors)

  3. Evaluation of natural attenuation processes in the groundwater of a tar oil contaminated site: development of a monitoring network

    International Nuclear Information System (INIS)

    Borke, P.; Husers, N.; Werner, P.; Leibenath, C.

    2005-01-01

    Tar oil is a complex mixture of mainly aromatic hydrocarbons. It is found in the subsurface of manufactured gas plants (MGP), coking plants or wood preserving facilities. The transportation into the soil and groundwater stands for a severe contamination. This is due to the physico-chemical properties of the DNAPL (dense non aqueous phase liquid) and its mobility in the soil and aquifer system. Additionally most of the contaminants show a low biological degradability and solubility under in situ conditions. Therefore it is known as a long term source of contamination. Nevertheless, natural attenuation (NA) processes are detectable at tar oil contaminated sites. In the thematic network two of the German funding priority KORA (http://www.natural-attenuation.de) these processes are matter of investigation. Four typical contaminated sites were chosen to evaluate under which circumstances monitored natural attenuation (MNA) is applicable. Furthermore enhanced natural attenuation questions are examined. The design of monitoring networks at tar oil contaminated sites plays a significant role in gaining field evidence for natural attenuation as well as documenting the efficiency of the attenuation processes and evaluating the matching of performance goals. Well designed monitoring networks include the placement of monitoring wells in 3D so that 3D flow path, mass balances and an estimation of mass flux can be monitored. As an example the history of the monitoring network of a wood preserving facility is shown. Starting from a risk assessment network to a network for MNA is presented. In this case for example especially the determination of the groundwater flow direction in time and space is connected to the number of observation wells and their location. Moreover in the beginning the observation wells were located according to the assumed centerline of the plume. Because of the variability of the groundwater flow direction and the need to determine mass flux a control plane

  4. Algunos aspectos ecológicos de “tarántulas” (Araneae: Theraphosidae en dos tipos de bosques en San Juan Bautista, Loreto, Perú

    Directory of Open Access Journals (Sweden)

    Pablo Reátegui Suárez

    2014-12-01

    Full Text Available Los resultados muestran la presencia de tarántulas del área de concesión de la empresa Perufish Aquarium EIRL, quebrada Yanayacu, río Itaya, Loreto. Reportándose un total de 5 especies de la familia Theraphosidae. Las 5 especies estuvieron en los bosques de colinas bajas moderadamente disectadas y 3 de estas en el bosque de colinas bajas ligeramente disectadas. Las especies más abundantes fueron Megaphobema velvetosoma con 64.3% y Cyriocosmus sellatus con 35%. El tamaño promedio de la abertura de las madrigueras varió en relación al tamaño de las especies, la más grande correspondió a Megaphobema velvetosoma con un promedio de 66,6 mm, y la más pequeña a Acanthoscurria ferina con un promedio de 21 mm. La temperatura del interior de las madrigueras varió de 25,2°C a 25,7°C y la humedad relativa de 88% a 88,7%. Las madrigueras se encontraron en el suelo con una capa de hojarasca que varió de 2,7 a 4,9 cm. Las especies de tarántulas se distribuyeron formando grupos en las zonas evaluadas. Las muestras de tarántulas se encuentran depositadas en la Universidad Nacional de la Amazonia Peruana y en la empresa Perufish Aquarium EIRL.

  5. Analytical filtration model for nonlinear viscoplastic oil in the theory of oil production stimulation and heating of oil reservoir in a dual-well system

    Science.gov (United States)

    Ivanovich Astafev, Vladimir; Igorevich Gubanov, Sergey; Alexandrovna Olkhovskaya, Valeria; Mikhailovna Sylantyeva, Anastasia; Mikhailovich Zinovyev, Alexey

    2018-02-01

    Production of high-viscosity oil and design of field development systems for such oil is one of the most promising directions in the development of world oil industry. The ability of high-viscosity oil to show in filtration process properties typical for non-Newtonian systems is proven by experimental studies. Nonlinear relationship between the pressure gradient and the rate of oil flow is due to interaction of high-molecular substances, in particular, asphaltenes and tars that form a plastic structure in it. The authors of this article have used the analytical model of stationary influx of nonlinear viscoplastic oil to the well bottom in order to provide rationale for the intensifying impact on a reservoir. They also have analyzed the method of periodic heating of productive reservoir by means of dual-wells. The high-temperature source is placed at the bottom of the vertical well, very close to the reservoir; at the same time the side well, located outside the zone of expected rock damage, is used for production. Suggested method of systemic treatment of reservoirs with dual wells can be useful for small fields of high-viscosity oil. The effect is based on the opportunity to control the structural and mechanical properties of high-viscosity oil and to increase depletion of reserves.

  6. A model for optimizing the production of pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Nevena Gospodinova

    2017-05-01

    Full Text Available The problem associated with the optimal production planning is especially relevant in modern industrial enterprises. The most commonly used optimality criteria in this context are: maximizing the total profit; minimizing the cost per unit of production; maximizing the capacity utilization; minimizing the total production costs. This article aims to explore the possibility for optimizing the production of pharmaceutical products through the construction of a mathematical model that can be viewed in two ways – as a single-product model and a multi-product model. As an optimality criterion it is set the minimization of the cost per unit of production for a given planning period. The author proposes an analytical method for solving the nonlinear optimization problem. An optimal production plan of Tylosin tartrate is found using the single-product model.

  7. Product Platform Modeling

    DEFF Research Database (Denmark)

    Pedersen, Rasmus

    for customisation of products. In many companies these changes in the business environment have created a controversy between the need for a wide variety of products offered to the marketplace and a desire to reduce variation within the company in order to increase efficiency. Many companies use the concept...... other. These groups can be varied and combined to form different product variants without increasing the internal variety in the company. Based on the Theory of Domains, the concept of encapsulation in the organ domain is introduced, and organs are formulated as platform elements. Included......This PhD thesis has the title Product Platform Modelling. The thesis is about product platforms and visual product platform modelling. Product platforms have gained an increasing attention in industry and academia in the past decade. The reasons are many, yet the increasing globalisation...

  8. Simulation of ground-water flow in the St. Peter aquifer in an area contaminated by coal-tar derivatives, St. Louis Park, Minnesota. Water Resources Investigation

    International Nuclear Information System (INIS)

    Lorenz, D.L.; Stark, J.R.

    1990-01-01

    A model constructed to simulate ground-water flow in part of the Prairie du Chien-Jordan and St. Peter aquifers, St. Louis Park, Minnesota, was used to test hypotheses about the movement of ground water contaminated with coal-tar derivatives and to simulate alternatives for reducing the downgradient movement of contamination in the St. Peter aquifer. The model, constructed for a previous study, was applied to simulate the effects of current ground-water withdrawals on the potentiometric surface of the St. Peter aquifer. Model simulations predict that the multiaquifer wells have the potential to limit downgradient migration of contaminants in the St. Peter aquifer caused by cones of depression created around the multiaquifer wells. Differences in vertical leakage to the St. Peter aquifer may exist in areas of bedrock valleys. Model simulations indicate that these differences are not likely to affect significantly the general patterns of ground-water flow

  9. International Organization of Standardization (ISO) and Cambridge Filter Test (CFT) Smoking Regimen Data Comparisons in Tobacco Product Marketing Applications.

    Science.gov (United States)

    Chae, Changyu; Walters, Matthew J; Holman, Matthew R

    2017-07-01

    We investigated the differences in TNCO (tar, nicotine, and carbon monoxide) smoke yields generated under the International Organization of Standardization (ISO) and Federal Trade Commission (FTC) Cambridge Filter Test (CFT) smoking regimens. Twenty-nine commercial cigarette products from the US marketplace were acquired in 2015 and tested by measuring the TNCO smoke yields generated under these 2 nonintense smoking regimens. Data obtained demonstrated a linear relationship between the TNCO yields produced under the 2 smoking regimens (R 2 > 0.99). TNCO yields produced by each product were higher under the CFT smoking regimen than the ISO smoking regimen. We found that tar, nicotine, and carbon monoxide yields were consistently 10% to 13% higher under the CFT smoking regimen than under the ISO smoking regimen. This strong correlation indicates that the 2 smoking regimens can be used to apply a correlation correction to CFT TNCO data and allow its comparison to ISO TNCO data in tobacco product marketing applications.

  10. Determination of coal tar and creosote constituents in the aquatic environment

    International Nuclear Information System (INIS)

    Hale, R.C.; Aneiro, K.M.

    1997-01-01

    Creosote and its parent material, coal tar, are complex mixtures. Assessment of their fate and concentrations in the environment needs to consider a wide variety of both compounds and matrices. Analyses are typically complicated, consisting of sample extraction, purification and chromatography-based final characterization steps. Several new techniques have been introduced to reduce or simplify the number of steps, solvent and time required. Recently developed extraction methods include supercritical fluid, accelerated solvent, microwave and solid-phase microextraction. On-line purification and coupling of extraction and chromatography have also emerged. HPLC and GC remain the major tools for performing the final separations. Application of mass spectrometry has increased as more reliable, versatile and less expensive units have become available, such as the ion trap and mass selective detectors. Fluorescence and diode array UV, in concert with HPLC, and C-, S- and N-selective gas chromatographic detectors are also being applied

  11. CRC-cards for Product Modelling

    DEFF Research Database (Denmark)

    Hvam, Lars; Riis, Jesper; Hansen, Benjamin Loer

    2003-01-01

    , transportation, service and decommissioning. A main challenge when building product models is to collect and document the product related data, information and knowledge in a structured way. CRC cards are index cards (or computerized versions of these) which are used to record proposed classes, the behavior......This paper describes the CRC (class, responsibility, collaboration) modelling process for building product models. A product model is normally represented in an IT system which contains data, information and knowledge on industrial products and their life cycle properties e.g. manufacturing...... of the classes, their responsibilities, and their relationship to other classes (collaboration). CRC modelling gives an effective, low-tech method for domain-experts, programmers and users to work closely together to identify, structure, understand and document a product model. CRC cards were originally...

  12. ZnO template strategy for the synthesis of 3D interconnected graphene nanocapsules from coal tar pitch as supercapacitor electrode materials

    Science.gov (United States)

    He, Xiaojun; Li, Xiaojing; Ma, Hao; Han, Jiufeng; Zhang, Hao; Yu, Chang; Xiao, Nan; Qiu, Jieshan

    2017-02-01

    3D interconnected graphene nanocapsules (GNCs) were prepared from diverse aromatic hydrocarbons by a nano-ZnO-template strategy coupled with in-situ KOH activation technique. The as-made graphene networks feature thin carbonaceous shells with well-balanced micropores and mesopores. Such 3D porous networks provide freeways for good electron conduction, short pores for ion fast transport, and abundant micropores for ion adsorption. As the electrodes in supercapacitors, the unique 3D GNCs show a high capacitance of 277 F g-1 at 0.05 A g-1, a good rate performance of 194 F g-1 at 20 A g-1, and an excellent cycle stability with over 97.4% capacitance retention after 15000 cycles in 6 M KOH electrolyte. This synthesis strategy paves a universal way for mass production of 3D graphene materials from diverse aromatic hydrocarbon sources including coal tar pitch and petroleum pitch for high performance supercapacitors as well as support and sorbent.

  13. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    International Nuclear Information System (INIS)

    Kienzler, Aude; Mahler, Barbara J.; Van Metre, Peter C.; Schweigert, Nathalie; Devaux, Alain; Bony, Sylvie

    2015-01-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. - Highlights: • Co-exposure to runoff from coal-tar-sealcoated pavement and UVA caused DNA damage. • Significant genotoxicity occurred with a 1:100 dilution of runoff. • Runoff collected up to 36 d following coal-tar-sealcoat application was genotoxic. • Exposure to runoff from sealed pavement impaired an important DNA repair pathway. • Repair capacity was impaired with a 1:10 dilution of runoff (1:100 not

  14. Exposure to runoff from coal-tar-sealed pavement induces genotoxicity and impairment of DNA repair capacity in the RTL-W1 fish liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Kienzler, Aude, E-mail: aude.kienzler@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Mahler, Barbara J., E-mail: bjmahler@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Van Metre, Peter C., E-mail: pcvanmet@usgs.gov [U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754 (United States); Schweigert, Nathalie [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Devaux, Alain, E-mail: alain.devaux@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France); Bony, Sylvie, E-mail: bony@entpe.fr [Université de Lyon, UMR LEHNA 5023, USC INRA, ENTPE, rue Maurice Audin, Vaulx-en-Velin F-69518 (France)

    2015-07-01

    Coal-tar-based (CTB) sealcoat, frequently applied to parking lots and driveways in North America, contains elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and related compounds. The RTL-W1 fish liver cell line was used to investigate two endpoints (genotoxicity and DNA-repair-capacity impairment) associated with exposure to runoff from asphalt pavement with CTB sealcoat or with an asphalt-based sealcoat hypothesized to contain about 7% CTB sealcoat (AS-blend). Genotoxic potential was assessed by the Formamido pyrimidine glycosylase (Fpg)-modified comet assay for 1:10 and 1:100 dilutions of runoff samples collected from 5 h to 36 d following sealcoat application. DNA-repair capacity was assessed by the base excision repair comet assay for 1:10 dilution of samples collected 26 h and 36 d following application. Both assays were run with and without co-exposure to ultraviolet-A radiation (UVA). With co-exposure to UVA, genotoxic effects were significant for both dilutions of CTB runoff for three of four sample times, and for some samples of AS-blend runoff. Base excision repair was significantly impaired for CTB runoff both with and without UVA exposure, and for AS-blend runoff only in the absence of UVA. This study is the first to investigate the effects of exposure to the complex mixture of chemicals in coal tar on DNA repair capacity. The results indicate that co-exposure to runoff from CT-sealcoated pavement and UVA as much as a month after sealcoat application has the potential to cause genotoxicity and impair DNA repair capacity. - Highlights: • Co-exposure to runoff from coal-tar-sealcoated pavement and UVA caused DNA damage. • Significant genotoxicity occurred with a 1:100 dilution of runoff. • Runoff collected up to 36 d following coal-tar-sealcoat application was genotoxic. • Exposure to runoff from sealed pavement impaired an important DNA repair pathway. • Repair capacity was impaired with a 1:10 dilution of runoff (1:100 not

  15. Product and Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian T.; Gani, Rafiqul

    . These approaches are put into the context of life cycle modelling, where multiscale and multiform modelling is increasingly prevalent in the 21st century. The book commences with a discussion of modern product and process modelling theory and practice followed by a series of case studies drawn from a variety......This book covers the area of product and process modelling via a case study approach. It addresses a wide range of modelling applications with emphasis on modelling methodology and the subsequent in-depth analysis of mathematical models to gain insight via structural aspects of the models...... to biotechnology applications, food, polymer and human health application areas. The book highlights to important nature of modern product and process modelling in the decision making processes across the life cycle. As such it provides an important resource for students, researchers and industrial practitioners....

  16. Production of hydrocarbons of value

    Energy Technology Data Exchange (ETDEWEB)

    1931-06-16

    A process is described for the production of hydrocarbons of great value by treating with heat and pressure carbonaceous materials such as coals, tars, mineral oils, and products of distillation and transformation of these materials, also for the refining with heat and pressure of mixed liquid hydrocarbons by means of hydrogen gas, preferably in the presence of catalysts, consisting in using as the hydrogenating gas that obtained by gasification of combustible solids after partial or complete cleaning at atmospheric or elevated pressures, by means of solid adsorbents, chemical agents or catalysts, or mixtures of these agents, the hydrocarbons being characterized by strong unsaturation, and the presence of oxygen, sulfur compounds, and oxides of nitrogen.

  17. Alignment of Product Models and Product State Models - Integration of the Product Lifecycle Phases

    DEFF Research Database (Denmark)

    Larsen, Michael Holm; Kirkby, Lars Phillip; Vesterager, Johan

    1999-01-01

    The purpose of this paper is to discuss the integration of the Product Model (PM) and the Product State Model (PCM). Focus is on information exchange from the PSM to the PM within the manufacturing of a single ship. The paper distinguishes between information and knowledge integration. The paper ...... provides some overall strategies for integrating PM and PSM. The context of this discussion is a development project at Odense Steel Shipyard....

  18. Sydney Tar Ponds: Some problems in quantifying toxic waste

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

    2002-07-01

    Information on the type and amount of hazardous and toxic waste is required to develop a meaningful strategy and estimate a realistic cost for clean up of the Sydney Tar Pond site which is located on Cape Breton, in the province of Nova Scotia, Canada. The site covers the area of the decommissioned Sysco (Sydney Steel Corporation) plant. The materials of concern include BTEX (benzene, toluene, ethylbenzene, and xylenes), PAH (polycyclic aromatic hydrocarbons), PCB (polychlorinated biphenyl), and particulates laden with toxic metals, such as arsenic, lead, and others. The originally nontoxic materials such as soil, blast furnace slag, and vegetation, as well as surface and ground waters, which were subsequently contaminated, must also be included if they fail tests prescribed by environmental regulations. An extensive sampling program must be undertaken to obtain data for an accurate estimate of the waste to be cleaned and disposed of. Apparently, 700,000 tons of toxic waste which is believed to be present on the site, may represent only a fraction of the actual amount. The clean-up of the site is only part of the solution. Toxic waste has to be disposed of in accordance with environmental regulations.

  19. Sydney tar ponds: some problems in quantifying toxic waste.

    Science.gov (United States)

    Furimsky, Edward

    2002-12-01

    Information on the type and amount of hazardous and toxic waste is required to develop a meaningful strategy and estimate a realistic cost for clean up of the Sydney Tar Pond site which is located on Cape Breton, in the province of Nova Scotia, Canada. The site covers the area of the decommissioned Sysco (Sydney Steel Corporation) plant. The materials of concern include BTEX (benzene, toluene, ethylbenzene, and xylenes), PAH (polycyclic aromatic hydrocarbons), PCB (polychlorinated biphenyl), and particulates laden with toxic metals, such as arsenic, lead, and others. The originally nontoxic materials such as soil, blast furnace slag, and vegetation, as well as surface and ground waters, which were subsequently contaminated, must also be included if they fail tests prescribed by environmental regulations. An extensive sampling program must be undertaken to obtain data for an accurate estimate of the waste to be cleaned and disposed of. Apparently, 700,000 tons of toxic waste, which is believed to be present on the site, may represent only a fraction of the actual amount. The clean-up of the site is only part of the solution. Toxic waste has to be disposed of in accordance with environmental regulations.

  20. Method of removing paraffin from mineral oils, shale oils, tar oils, and their fractions or residues

    Energy Technology Data Exchange (ETDEWEB)

    Palmquist, F T.E.

    1949-09-08

    A method is described for removing paraffin from mineral oils, shale oils, tar oils, and their fractions or residues by centrifuging in the presence of oil-dissolving and paraffin-precipitating solvents, by which the precipitated paraffin is made to pass through an indifferent auxiliary liquid, in which a removal of oil takes place, characterized in that as auxiliary liquid is used a liquid or mixture of liquids whose surface tension against the oil solution is sufficiently low for the paraffin to pass the layer of auxiliary liquid in the form of separate crystals.

  1. Proactive Modeling of Market, Product and Production Architectures

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik; Hansen, Christian Lindschou; Hvam, Lars

    2011-01-01

    This paper presents an operational model that allows description of market, products and production architectures. The main feature of this model is the ability to describe both structural and functional aspect of architectures. The structural aspect is an answer to the question: What constitutes...... the architecture, e.g. standard designs, design units and interfaces? The functional aspect is an answer to the question: What is the behaviour or the architecture, what is it able to do, i.e. which products at which performance levels can be derived from the architecture? Among the most important benefits...... of this model is the explicit ability to describe what the architecture is prepared for, and what it is not prepared for - concerning development of future derivative products. The model has been applied in a large scale global product development project. Among the most important benefits is contribution to...

  2. Policy and health implications of using the U.S. Food and Drug Administration product design approach in reducing tobacco product risk.

    Science.gov (United States)

    Givel, Michael

    2008-06-01

    Purported risk or harm reduction through product design change of cigarettes has occurred in three phases in the U.S. The first phase from the 1940s to the early 1960s included a gradual rise in filtered cigarettes. The second phase, which began in the early 1960s in response to the landmark 1964 U.S. Surgeon General's report that linked smoking with lung cancer and other diseases, included the introduction of purportedly low tar and nicotine cigarettes. Subsequent research found that both filters and low tar and nicotine cigarettes were ineffective approaches to reducing health risks associated with smoking. Despite this, these product design changes were used in tobacco industry marketing campaigns to allay consumer health concerns and stabilize tobacco markets and sales. Since 2004, a new risk or harm reduction phase has occurred with the backing by Philip Morris as well as major U.S. health groups of U.S. Food and Drug Administration legislation that would require disclosure of tobacco ingredients, ban misleading health claims, prohibit or reduce harmful ingredients, and require prior approval of tobacco design, performance changes, and modified risk tobacco products. However, current scientific literature indicates that there is no scientific consensus and little evidence on what tobacco ingredients are linked to particular morbidities and mortalities and at what levels. This will allow the tobacco industry to implicitly or explicitly claim their products are "safer." Instead, health advocates should advocate for scientifically proven policy measures such as smoke free public places or higher tobacco taxes that control and reduce tobacco markets and consumption.

  3. Product models for the Construction industry

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    1996-01-01

    Different types of product models for the building sector was elaborated and grouped. Some discussion on the different models was given. The "definition" of Product models was given.......Different types of product models for the building sector was elaborated and grouped. Some discussion on the different models was given. The "definition" of Product models was given....

  4. Aquatic toxicity of petroleum products and dispersant agents determined under the U.S. EPA Oil Spill Research Program

    Science.gov (United States)

    The U.S. EPA Office of Research and Development has developed baseline data on the ecotoxicity of selected petroleum products and several chemical dispersants as part of its oil spills research program. Two diluted bitumens (dilbits) from the Alberta Tar Sands were tested for acu...

  5. A case study on effects of oil spills and tar-ball pollution on beaches of Goa (India).

    Science.gov (United States)

    Rekadwad, Bhagwan N; Khobragade, Chandrahasya N

    2015-11-15

    This paper reports the impact of oil spills and tar-ball pollution on the coastal ecosystem of Goa. The factors responsible for degrading the marine ecosystem of the Goan coastline are analyzed. Uncontrolled activities were found to degrade the marine and coastal biodiversity, in turn polluting all beaches. This had a direct impact on the Goan economy through a decline in tourism. The government must adopt the necessary control measures to restore Goan beaches and the surrounding coastal areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Net energy yield from production of conventional oil

    International Nuclear Information System (INIS)

    Dale, Michael; Krumdieck, Susan; Bodger, Pat

    2011-01-01

    Historic profitability of bringing oil to market was profound, but most easy oil has been developed. Higher cost resources, such as tar sands and deep off-shore, are considered the best prospects for the future. Economic modelling is currently used to explore future price scenarios commensurate with delivering fuel to market. Energy policy requires modelling scenarios capturing the complexity of resource and extraction aspects as well as the economic profitability of different resources. Energy-return-on-investment (EROI) expresses the profitability of bringing energy products to the market. Net energy yield (NEY) is related to the EROI. NEY is the amount of energy less expenditures necessary to deliver a fuel to the market. This paper proposes a pattern for EROI of oil production, based on historic oil development trends. Methodology and data for EROI is not agreed upon. The proposed EROI function is explored in relation to the available data and used to attenuate the International Energy Agency (IEA) world oil production scenarios to understand the implications of future declining EROI on net energy yield. The results suggest that strategies for management and mitigation of deleterious effects of a peak in oil production are more urgent than might be suggested by analyses focussing only on gross production. - Highlights: → Brief introduction to methodological issues concerning net energy analysis. → Description of EROI function over the whole production cycle of an energy resource. → Calibration of this function to EROI data from historic oil production. → Application to determine the net energy yield from current global oil production. → Calculation of net energy yield from IEA projections of future oil production.

  7. A procedure for Building Product Models

    DEFF Research Database (Denmark)

    Hvam, Lars

    1999-01-01

    , easily adaptable concepts and methods from data modeling (object oriented analysis) and domain modeling (product modeling). The concepts are general and can be used for modeling all types of specifications in the different phases in the product life cycle. The modeling techniques presented have been......The application of product modeling in manufacturing companies raises the important question of how to model product knowledge in a comprehensible and efficient way. An important challenge is to qualify engineers to model and specify IT-systems (product models) to support their specification...... activities. A basic assumption is that engineers have to take the responsability for building product models to be used in their domain. To do that they must be able to carry out the modeling task on their own without any need for support from computer science experts. This paper presents a set of simple...

  8. Molecular dynamics and MM/GBSA-integrated protocol probing the correlation between biological activities and binding free energies of HIV-1 TAR RNA inhibitors.

    Science.gov (United States)

    Peddi, Saikiran Reddy; Sivan, Sree Kanth; Manga, Vijjulatha

    2018-02-01

    The interaction of HIV-1 transactivator protein Tat with its cognate transactivation response (TAR) RNA has emerged as a promising target for developing antiviral compounds and treating HIV infection, since it is a crucial step for efficient transcription and replication. In the present study, molecular dynamics (MD) simulations and MM/GBSA calculations have been performed on a series of neamine derivatives in order to estimate appropriate MD simulation time for acceptable correlation between ΔG bind and experimental pIC 50 values. Initially, all inhibitors were docked into the active site of HIV-1 TAR RNA. Later to explore various conformations and examine the docking results, MD simulations were carried out. Finally, binding free energies were calculated using MM/GBSA method and were correlated with experimental pIC 50 values at different time scales (0-1 to 0-10 ns). From this study, it is clear that in case of neamine derivatives as simulation time increased the correlation between binding free energy and experimental pIC 50 values increased correspondingly. Therefore, the binding energies which can be interpreted at longer simulation times can be used to predict the bioactivity of new neamine derivatives. Moreover, in this work, we have identified some plausible critical nucleotide interactions with neamine derivatives that are responsible for potent inhibitory activity. Furthermore, we also provide some insights into a new class of oxadiazole-based back bone cyclic peptides designed by incorporating the structural features of neamine derivatives. On the whole, this approach can provide a valuable guidance for designing new potent inhibitors and modify the existing compounds targeting HIV-1 TAR RNA.

  9. Innovation Production Models

    Directory of Open Access Journals (Sweden)

    Tamam N. Guseinova

    2016-01-01

    Full Text Available The article is dedicated to the study of the models of production of innovations at enterprise and state levels. The shift towards a new technology wave induces a change in systems of division of labour as well as establishment of new forms of cooperation that are reflected both in theory and practice of innovation policy and management. Within the scope of the research question we have studied different generation of innovation process, starting with simple linear models - "technology push" and "market pull" - and ending with a complex integrated model of open innovations. There are two organizational models of innovation production at the enterprise level: start-ups in the early stages of their development and ambidextrous organizations. The former are prone to linear models of innovation process, while the latter create innovation within more sophisticated inclusive processes. Companies that effectuate reciprocal ambidexterity stand out from all the rest, since together with start-ups, research and development centres, elements of innovation infrastructure and other economic agents operating in the same value chain they constitute the core of most advanced forms of national innovation systems, namely Triple Helix and Quadruple Helix systems. National innovation systems - models of innovation production at the state level - evolve into systems with a more profound division of labour that enable "line production" of innovations. These tendencies are closely related to the advent and development of the concept of serial entrepreneurship that transforms entrepreneurship into a new type of profession. International experience proves this concept to be efficient in various parts of the world. Nevertheless, the use of above mentioned models and concepts in national innovation system should be justified by socioeconomic conditions of economic regions, since they determine the efficiency of implementation of certain innovation processes and

  10. Topical tazarotene vs. coal tar in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

    2010-07-15

    The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

  11. European oil product supply modelling

    International Nuclear Information System (INIS)

    Saint-Antonin, V.

    1998-01-01

    Over the last few years, trends in European oil product consumption (in terms of level as structure and quality) has important implications of the refining industry. In this context, the purpose of this thesis consists in building a mathematical programming model applied to the European refineries in order to determine oil product supply prices, European refining industry investments and oil product exchanges of the European Union. The first part presents the reason for our choice for a long-term aggregate multi-refineries linear programming model, based on European refineries characteristics and the objectives of our model. Its dual properties are studied in detail and we focus particularly on the European exchange modelling. In the second part, an analysis of the European refining trends leads us to identify parameters and variables of the model that are essential to the aggregate representation of the European oil product supply. The third part is devoted to the use of this model, regarding two scenarios of increasingly stringent specifications for gasoline and diesel oil. Our interest for these products is due to their important share of the European oil product consumption and the not insignificant responsibility of the transport sector for atmospheric pollution. Finally, in order to have the use of an overall picture of the European refining industry, we build a regression model summarizing, though a few equations, the main relations between the major endogenous and exogenous variables o the LP model. Based on pseudo-data, this kind of model provides a simple and robust representation of the oil product supply. But a more specialized analysis of the refining industry operations, turning on a technical assessment of processing units, is reliant on the use of an optimization model such as the model we have built. (author)

  12. Leafcutter bee nests and pupae from the Rancho La Brea Tar Pits of southern California: Implications for understanding the paleoenvironment of the Late Pleistocene

    Science.gov (United States)

    The Rancho La Brea Tar Pits is the world’s richest and most important Late Pleistocene fossil locality and best renowned for numerous fossil mammals and birds excavated over the past century. Less researched are insects, even though these specimens frequently serve as the most valuable paleoenvironm...

  13. A procedure for building product models

    DEFF Research Database (Denmark)

    Hvam, Lars; Riis, Jesper; Malis, Martin

    2001-01-01

    This article presents a procedure for building product models to support the specification processes dealing with sales, design of product variants and production preparation. The procedure includes, as the first phase, an analysis and redesign of the business processes, which are to be supported...... with product models. The next phase includes an analysis of the product assortment, and the set up of a so-called product master. Finally the product model is designed and implemented using object oriented modelling. The procedure is developed in order to ensure that the product models constructed are fit...... for the business processes they support, and properly structured and documented, in order to facilitate that the systems can be maintained continually and further developed. The research has been carried out at the Centre for Industrialisation of Engineering, Department of Manufacturing Engineering, Technical...

  14. Effects of mineral matter on products and sulfur distributions in hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

    1999-05-01

    The effects of the mineral matter on the product yield and sulfur distribution in hydropyrolysis and pyrolysis of Chinese Hongmiao lignite were investigated using a fixed-bed reactor. The volatile sulfur-containing gases (H{sub 2}S, COS, CH{sub 3}SH) were also analyzed as a function of pyrolysis temperature. Coal samples were treated with HCl/HF or HCl/HF and CrCl{sub 2} solution to eliminate minerals and pyrite respectively. In hydropyrolysis, demineralized Hongmiao lignite showed lower yields of tar and water than the raw coal. Demineralization cannot only minimize the fixation effect of basic mineral matter on sulfur-containing gases, but also increase the sulfur distribution of the tar. Further, from the evolution profiles of sulfur-containing gases, it is possible to elucidate the contribution of minerals, pyrite and organic sulfur to the sulfur evolution. Pyrite may not be the only source of COS formation. 32 refs., 14 figs., 3 tabs.

  15. Development and start up of a co-injection system of coal tar/natural gas in blast furnace no. 4; Desarrollo y puesta en operacion de un sistema de co-inyeccion de alquitran/gas natural en el alto horno no. 4

    Energy Technology Data Exchange (ETDEWEB)

    Falcon Rodriguez, Manuel I; Mata Esparza, Hector Rolando; Arevalo Ballesteros, Gerardo [Altos Hornos de Mexico S. A., Coahuila (Mexico)

    1994-12-31

    The crisis has attracted the world`s attention on the need for energy conservation and the development in a greater extent the utilization of carbon base fuels and other energy sources (nuclear energy). Being a blast furnace, not only an energy consumer but also an energy producer, the greatest contribution to the pig iron cost is the energy needed to melt and reduce to metallic state the iron ores, this energy is mainly derived from coke. The dependence on coal via the coking plant to produce first fusion iron is incremented day after day as a result of the high levels of production. Altos Hornos de Mexico (AHMSA), contemplated within its strategic plan, the reduction in the production of its coking plants derived from the natural aging of its furnaces, consequently the shortage of coke for productions higher than 2.6 MMT of pig iron is pending. The injection of fuels into a blast furnace through its nozzles is a technology used for the diminishing the coke consumption of coke, its use implies a change in the philosophy of the blast furnace operation, and is currently employed in most of the blast furnaces of the world. AHMSA taking advantage of coal tar production (approx. 130 tons/day) in its coking plants decided the design and put into operation a co-injection system of coal tar and natural gas. The activities tending to carry out this project were initiated on April 1993, performing all of them with its own resources, completing them on July 18, 1993, day on which the injection of coal tar/natural gas in blast furnace No. 4 in a stable form. To date (October 1993), the coal tar injection has been increased up to 36 kg/ton of pig iron. During the injection periods, the presence of operational, mechanical and instrumentation problems have not been an obstacle for the evolution on the injection, fulfilling its function of substituting coke in a replacing relationship of 1:1, i.e. 1 kg of coal tar per each kg of coke, without affecting the product quality

  16. Development and start up of a co-injection system of coal tar/natural gas in blast furnace no. 4; Desarrollo y puesta en operacion de un sistema de co-inyeccion de alquitran/gas natural en el alto horno no. 4

    Energy Technology Data Exchange (ETDEWEB)

    Falcon Rodriguez, Manuel I.; Mata Esparza, Hector Rolando; Arevalo Ballesteros, Gerardo [Altos Hornos de Mexico S. A., Coahuila (Mexico)

    1993-12-31

    The crisis has attracted the world`s attention on the need for energy conservation and the development in a greater extent the utilization of carbon base fuels and other energy sources (nuclear energy). Being a blast furnace, not only an energy consumer but also an energy producer, the greatest contribution to the pig iron cost is the energy needed to melt and reduce to metallic state the iron ores, this energy is mainly derived from coke. The dependence on coal via the coking plant to produce first fusion iron is incremented day after day as a result of the high levels of production. Altos Hornos de Mexico (AHMSA), contemplated within its strategic plan, the reduction in the production of its coking plants derived from the natural aging of its furnaces, consequently the shortage of coke for productions higher than 2.6 MMT of pig iron is pending. The injection of fuels into a blast furnace through its nozzles is a technology used for the diminishing the coke consumption of coke, its use implies a change in the philosophy of the blast furnace operation, and is currently employed in most of the blast furnaces of the world. AHMSA taking advantage of coal tar production (approx. 130 tons/day) in its coking plants decided the design and put into operation a co-injection system of coal tar and natural gas. The activities tending to carry out this project were initiated on April 1993, performing all of them with its own resources, completing them on July 18, 1993, day on which the injection of coal tar/natural gas in blast furnace No. 4 in a stable form. To date (October 1993), the coal tar injection has been increased up to 36 kg/ton of pig iron. During the injection periods, the presence of operational, mechanical and instrumentation problems have not been an obstacle for the evolution on the injection, fulfilling its function of substituting coke in a replacing relationship of 1:1, i.e. 1 kg of coal tar per each kg of coke, without affecting the product quality

  17. Cloning of the Repertoire of Individual Plasmodium falciparum var Genes Using Transformation Associated Recombination (TAR)

    Science.gov (United States)

    Schmid, Christoph D.; Bühlmann, Tobias; Louis, Edward J.; Beck, Hans-Peter

    2011-01-01

    One of the major virulence factors of the malaria causing parasite is the Plasmodium falciparum encoded erythrocyte membrane protein 1 (PfEMP1). It is translocated to It the membrane of infected erythrocytes and expressed from approximately 60 var genes in a mutually exclusive manner. Switching of var genes allows the parasite to alter functional and antigenic properties of infected erythrocytes, to escape the immune defense and to establish chronic infections. We have developed an efficient method for isolating VAR genes from telomeric and other genome locations by adapting transformation-associated recombination (TAR) cloning, which can then be analyzed and sequenced. For this purpose, three plasmids each containing a homologous sequence representing the upstream regions of the group A, B, and C var genes and a sequence homologous to the conserved acidic terminal segment (ATS) of var genes were generated. Co-transfection with P. falciparum strain ITG2F6 genomic DNA in yeast cells yielded 200 TAR clones. The relative frequencies of clones from each group were not biased. Clones were screened by PCR, as well as Southern blotting, which revealed clones missed by PCR due to sequence mismatches with the primers. Selected clones were transformed into E. coli and further analyzed by RFLP and end sequencing. Physical analysis of 36 clones revealed 27 distinct types potentially representing 50% of the var gene repertoire. Three clones were selected for sequencing and assembled into single var gene containing contigs. This study demonstrates that it is possible to rapidly obtain the repertoire of var genes from P. falciparum within a single set of cloning experiments. This technique can be applied to individual isolates which will provide a detailed picture of the diversity of var genes in the field. This is a powerful tool to overcome the obstacles with cloning and assembly of multi-gene families by simultaneously cloning each member. PMID:21408186

  18. Modeling Novo Nordisk Production Systems

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1997-01-01

    This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'.......This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'....

  19. Summary of research and information needs for the management of selected onshore energy minerals: oil shale, tar sands, arctic oil and gas, and uranium. Final report 1982-83

    Energy Technology Data Exchange (ETDEWEB)

    1983-11-01

    The report assesses research needs for the management, regulation, reclamation, and conservation of oil shale, tar sands, arctic oil and gas, and uranium deposits currently under federal jurisdiction and concludes that additional research is required to achieve the goals of good management, including conservation, protection of life and property, and minimization of environmental degradation. The report recommends (1) establishment of a standing advisory scientific and engineering committee on onshore minerals management research to influence future research directions and implementation; (2) development of a comprehensive library and data center for research results; and (3) encouragement of the operation of demonstration-scale production facilities where they are lacking. More detailed summaries of current knowledge and perceived research needs are to be found in the four interim reports of the committee.

  20. Investigation of changes in {delta}{sup 13}C of PAHs during phytoremediation of coal tar-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Mick Cooper; Cheng-Gong Sun; Margaret Smith; Harry Duncan; Colin Snape [University of Nottingham, Nottingham (United Kingdom). School of Chemical Environmental and Mining Engineering

    2007-07-01

    It has been shown that phytoremediation of polyaromatic hydrocarbon (PAH) contaminated land is a useful, low cost, low maintenance method of cleaning up land at former gas and coking works. However, PAH degradation in the soil and sediment is slow, but PAHs may be degraded through properly stimulated soil micro-organisms. Here we describe a laboratory trial, employing the clover Trifolium pretense (L.)(TP), which was grown in samples of soil contaminated by fresh coal tar, and in soil heavily contaminated by PAHs, obtained from a former coking works. As the latter substrate was 'naturally' contaminated, it contained both pure PAHs and their derivatives, and was thus considered fully 'weathered', and contained recalcitrant PAH species. Conventional analytical techniques (for example, GC-MS) generally provide little information on the source of pollutants such as PAHs. Previous work has established, however, that significant differences existed in the {sup 13}C/{sup 12}C isotopic ratios between PAHs from various sources. Source apportionment of PAH contamination by stable isotope analysis is a powerful technique, but one which assumes that isotopic fractionation is not a significant factor in aged or bioaltered matrices. Phytoremediation trials described here have been utilised in order to determine whether or not any such fractionation of {sup 13}C occurs during the process. Although PAH distributions can be markedly altered by biodegradation, it has been demonstrated that, for low temperature coal tar, the carbon stable isotopic values of the parent PAHs remain fairly constant. 22 refs., 2 figs., 5 tabs.

  1. Product Family Modelling for Manufacturing Planning

    DEFF Research Database (Denmark)

    Jørgensen, Kaj Asbjørn; Petersen, Thomas Ditlev; Nielsen, Kjeld

    2011-01-01

    To enable product configuration of a product family, it is important to develop a model of the selected product family. From such a model, an often performed practice is to make a product configurator from which customers can specify individual products from the family. To get further utilisation...

  2. Volatilisation of aromatic hydrocarbons from soil: part II, fluxes from coal tar contaminated soils residing below the soil surface

    International Nuclear Information System (INIS)

    Lindhardt, B.; Christensen, T.H.

    1996-01-01

    The non-steady-state fluxes of aromatic hydrocarbons from coal tar contaminated soil, placed below a 5 cm deep layer of uncontaminated soil, were measured in the laboratory over a period of 53 days. The contaminated soil originated from a former gasworks site and contained concentrations of 11 selected aromatic hydrocarbons between 50 to 840 μg/cm 3 . Where the microbial activity was inhibited, the fluxes stabilized on a semi-steady-state level for the monocyclic aromatic hydrocarbons, naphthalene and 1-methylnaphthalene after a period of 10-20 days. Fluxes of acenaphthene and fluorene were only measurable in an experiment that utilized a cover soil with a low organic content. The fluxes were predicted by a numerical model assuming that the compounds acted independently of each other and that local equilibrium between the air, water, and sorbed phases existed. The model overestimated the fluxes for all the detected aromatic hydrocarbons by a factor of 1.3 to 12. When the cover soil was adapted to degrade naphthalene, the fluxes of naphthalene and 1-methylnaphthalene approached the detection limit after 5 to 8 days. Thereafter the fluxes of these two compounds were less than predicted by the model employing half-life values of 0.5 and 1 day for naphthalene and 1-methylnaphthalene respectively. 10 refs., 6 figs., 7 tabs

  3. Modelling production system architectures in the early phases of product development

    DEFF Research Database (Denmark)

    Guðlaugsson, Tómas Vignir; Ravn, Poul Martin; Mortensen, Niels Henrik

    2016-01-01

    are needed and appropriate to enable determination of obtainable product quality. In order to meet this challenge, it is suggested that a visual modelling framework be adopted that clarifies which product and production features are known at a specific time of the project and which features will be worked...... on – leading to an improved basis for prioritizing activities in the project. Requirements for the contents of the framework are presented, and literature on production and system models is reviewed. The production system architecture modelling framework is founded on methods and approaches in literature......This article suggests a framework for modelling a production system architecture in the early phases of product development.The challenge in these phases is that the products to be produced are not completely defined and yet decisions need to be made early in the process on what investments...

  4. Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

    Directory of Open Access Journals (Sweden)

    Fajri Vidian

    2016-01-01

    Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.

  5. Microstructural characteristics of toluene and quinoline-insolubles from coal-tar pitch and their cokes

    Energy Technology Data Exchange (ETDEWEB)

    Panaitescu, C. [University POLITEHNICA Bucharest, Faculty of Industrial Chemistry, Fuel Laboratory, Polizu St. 1, Sector 1, 011061, Bucharest (Romania); Predeanu, G. [Metallurgical Research Institute, Department of Raw Materials, Mehadia St. 39, Sector 6, 060543 Bucharest (Romania)

    2007-08-01

    The structural composition of coal-tar pitch used in the preparation of the special binder-pitch, was determined with special emphasis on the optical properties of the {beta}-resins, as typical components necessary to obtain electrodes of best quality through the pyrogenetic processes of baking and graphitization. In addition to raw toluene- and quinoline-insolubles (TI, QI), the corresponding cokes were analysed to evaluate, by structural composition and microtexture, the behaviour of pitch fractions during carbonization. The results suggest the dependence of the texture development on the type of toluene- and quinoline-insolubles and {beta}-resins during processing conditions, which influence the mesophase formation. An original and important result of the carbopetrographical study is represented by the identification and evaluation of {beta}-resins in the coke texture. (author)

  6. The production of hydrogen-rich gas by wet sludge pyrolysis using waste heat from blast-furnace slag

    International Nuclear Information System (INIS)

    Luo, Siyi; Feng, Yu

    2016-01-01

    Blast furnace (BF) slag, a byproduct of steelmaking industry, contains a large amount of sensible heat and is composed of some metal oxides, which exhibits preferable catalytic performance in improving tar cracking and C_nH_m reforming. This paper presents a heat recovery system from the heat of BF slag, which generates hydrogen-rich gas via the endothermic reactions of sludge pyrolysis. The effects of various parameters including the slag temperature, the mass ratio of slag to sludge (B/S), particle size and feed moisture on product yields and gas characteristics were evaluated separately. It was found that the pyrolysis products distribution was significantly influenced by the BF slag temperature. The differences resulting from varying B/S practically disappear as higher temperature heat carrier is approached. The optimum feed moisture was in favour of sludge pyrolysis by getting char and tar participate in gasification reactions, improving gas yield and quality. BF slag as catalyst can greatly increase H_2 and CO contents of gas by improving tar degradation and reforming of biogas (CO_2 and CH_4). Decreasing the slag particles size was helpful to sludge primary pyrolysis to produce more light gases, less char and condensate, while its effects on gas compositions was not evident. - Highlights: • The sensible heat of molten slag was recovered and converted into combustible gas. • A novel rotary pyrolysis reactor using BF slag as heat carrier was presented. • The moisture in sludge was used as the gasification medium and hydrogen source.

  7. Productivity Problems and Remedies for Cereals Farming in Sivas

    Directory of Open Access Journals (Sweden)

    Sancar Bulut

    2016-07-01

    Full Text Available Yörede, tarımsal işletmelerde sermaye ve teknik bilginin yetersiz oluşu, tarımla uğraşan nüfusun yaşlı ve eğitim düzeyinin düşüklüğü, yeterince teknik eleman olmayışına bağlı olarak tarımsal kuruluşların tarımsal yayım faaliyetleri konusunda yetersiz kalması ve zaman zaman iklim koşullarında yaşanan olumsuzluklar tahıl üretimi ve verimliliğini ekonomik olarak olumsuz etkilemektedir. Ayrıca, ilde monokültür tahıl tarım alanlarında yüksek oranda nadas uygulanması, sertifikalı tohumluk kullanımının yetersiz olması, toprak işleme ve tohum yatağı hazırlığındaki yanlışlıklar, kışlık ekimlerin geciktirilmesi ya da yüksek oranda yazlık ekim yapılması (özellikle arpada, yüksek maliyet nedeniyle kimyasal gübre kullanımındaki yetersizlikler, tahıllar konusunda bilimsel araştırma eksikliği ve yabancı ot mücadelesinin zamanında yapılmaması tahıl verimlerini pratikte uygulanan yada uygulanamayan sebeplerden dolayı önemli ölçüde sınırlamaktadır. Sivas’ta tahıl tarımında yüksek verim elde etmek için gerek ekonomik ve gerekse teorik bu eksiklikler mutlaka giderilmelidir.

  8. Toxicological and chemical characterization of the process stream materials and gas combustion products of an experimental low-btu coal gasifier.

    Science.gov (United States)

    Benson, J M; Hanson, R L; Royer, R E; Clark, C R; Henderson, R F

    1984-04-01

    The process gas stream of an experimental pressurized McDowell-Wellman stirred-bed low-Btu coal gasifier, and combustion products of the clean gas were characterized as to their mutagenic properties and chemical composition. Samples of aerosol droplets condensed from the gas were obtained at selected positions along the process stream using a condenser train. Mutagenicity was assessed using the Ames Salmonella mammalian microsome mutagenicity assay (TA98, with and without rat liver S9). All materials required metabolic activation to be mutagenic. Droplets condensed from gas had a specific mutagenicity of 6.7 revertants/microgram (50,000 revertants/liter of raw gas). Methylnaphthalene, phenanthrene, chrysene, and nitrogen-containing compounds were positively identified in a highly mutagenic fraction of raw gas condensate. While gas cleanup by the humidifier-tar trap system and Venturi scrubber led to only a small reduction in specific mutagenicity of the cooled process stream material (4.1 revertants/microgram), a significant overall reduction in mutagenicity was achieved (to 2200 revertants/liter) due to a substantial reduction in the concentration of material in the gas. By the end of gas cleanup, gas condensates had no detectable mutagenic activity. Condensates of combustion product gas, which contained several polycyclic aromatic compounds, had a specific mutagenicity of 1.1 revertants/microgram (4.0 revertants/liter). Results indicate that the process stream material is potentially toxic and that care should be taken to limit exposure of workers to the condensed tars during gasifier maintenance and repair and to the aerosolized tars emitted in fugitive emissions. Health risks to the general population resulting from exposure to gas combustion products are expected to be minimal.

  9. Taste-aversion-prone (TAP) rats and taste-aversion-resistant (TAR) rats differ in ethanol self-administration, but not in ethanol clearance or general consumption.

    Science.gov (United States)

    Orr, T Edward; Whitford-Stoddard, Jennifer L; Elkins, Ralph L

    2004-05-01

    Taste-aversion (TA)-prone (TAP) rats and TA-resistant (TAR) rats have been developed by means of bidirectional selective breeding on the basis of their behavioral responses to a TA conditioning paradigm. The TA conditioning involved the pairing of an emetic-class agent (cyclophosphamide) with a novel saccharin solution as the conditioned stimulus. Despite the absence of ethanol in the selective breeding process, these rat lines differ widely in ethanol self-administration. In the current study, blood alcohol concentrations (BACs) were determined after 9 days of limited (2 h per day) access to a simultaneous, two-bottle choice of a 10% ethanol in water solution [volume/volume (vol./vol.)] or plain water. The BACs correlated highly with ethanol intake among TAR rats, but an insufficient number of TAP rats yielded measurable BACs to make the same comparison within this rat line. The same rats were subsequently exposed to 24-h access of a two-bottle choice (10% ethanol or plain water) for 8 days. Ethanol consumption during the 24-h access period correlated highly with that seen during limited access. Subsequent TA conditioning with these rats yielded line-typical differences in saccharin preferences. In a separate group of rats, ethanol clearance was determined by measuring BACs at 1, 4, and 7 h after injection of a 2.5-g/kg dose of ethanol. Ethanol clearance was not different between the two lines. Furthermore, the lines did not differ with respect to food and water consumption. Therefore, the TAP rat-TAR rat differences in ethanol consumption cannot be attributed to line differences in ethanol metabolism or in general consummatory behavior. The findings support our contention that the line differences in ethanol consumption are mediated by differences in TA-related mechanisms. The findings are discussed with respect to genetically based differences in the subjective experience of ethanol.

  10. A Production Model for Deteriorating Inventory Items with Production Disruptions

    OpenAIRE

    Yong He; Ju He

    2010-01-01

    Disruption management has recently become an active area of research. In this study, an extension is made to consider the fact that some products may deteriorate during storage. A production-inventory model for deteriorating items with production disruptions is developed. Then the optimal production and inventory plans are provided, so that the manufacturer can reduce the loss caused by disruptions. Finally, a numerical example is used to illustrate the model.

  11. An integrated production, inventory and preventive maintenance model for a multi-product production system

    International Nuclear Information System (INIS)

    Liu, Xuejuan; Wang, Wenbin; Peng, Rui

    2015-01-01

    This paper considers a production system that can produce multiple products alternately. Products go through the system in a sequence and a complete run of all products forms a production cycle. An integrated production, inventory and preventive maintenance model is constructed, which is characterized by the delay-time concept. Two different situations are studied based on whether the unqualified products and downtime caused by the failures of the system, set-up and preventive maintenance can be ignored or not. Three cases are considered for each situation, depending on the position of the preventive maintenance epochs: the first case, where preventive maintenance is carried out at the end of each production cycle; the second case, where preventive maintenance is carried out at each set-up time of the products; and the third case, where preventive maintenance is carried out at some set-up times only, since it may not always be optimal to carry out preventive maintenance at the end of the production cycle or at each set-up time. The modeling objectives are to find the optimal number of production cycles per year and the optimal position of preventive maintenance that will maximize the expected profit per unit time. Numerical examples, using real data, are presented to illustrate the model. - Highlights: • We propose an integrated economic production quantity and preventive maintenance model. • The situation that multiple products are produced on the same system alternately is studied. • Two situations are studied based on whether the downtime and the product quality can be ignored or not. • We use enumeration method and analytical method to select the optimal preventive maintenance policy, respectively. • We use the delay-time concept to model the preventive maintenance policy

  12. Comparison of Soxhlet and Shake Extraction of Polycyclic Aromatic Hydrocarbons from Coal Tar Polluted Soils Sampled in the Field

    DEFF Research Database (Denmark)

    Lindhardt, Bo; Holst, Helle; Christensen, Thomas Højlund

    1994-01-01

    This study compares three extraction methods for PAHs in coal tar polluted soil: 3-times repeated shaking of the soil with dichloromethane-methanol (1:1), Soxhlet extraction with dichloromethane, and Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol....... The extraction efficiencies were determined for ten selected PAHs in triplicate samples of six soils sampled at former gasworks sites. The samples covered a wide range of PAH concentrations, from 0.6 to 397 mg/kg soil. Soxhlet extraction with dichloromethane followed by Soxhlet extraction with methanol...

  13. Annotated Bibliography to Accompany Anderson, Pollay, & Ling, "Taking Ad-Vantage of Lax Advertising Regulations: Reassuring and Distracting Health-Concerned Smokers" (Social Science & Medicine, 2006)

    OpenAIRE

    Anderson, Stacey J Ph.D.

    2006-01-01

    We explored the evolution from cigarette product attributes to psychosocial needs in advertising campaigns for low-tar cigarettes. Analysis of previously secret tobacco industry documents and print advertising images indicated that low-tar brands targeted smokers who were concerned about their health with advertising images intended to distract them from the health hazards of smoking. Advertising first emphasized product characteristics (filtration, low tar) that implied health benefits. O...

  14. Taking ad-Vantage of lax advertising regulation in the USA and Canada: Reassuring and distracting health-concerned smokers

    OpenAIRE

    Anderson, Stacey J; Pollay, Richard W; Ling, Pamela M

    2006-01-01

    We explored the evolution from cigarette product attributes to psychosocial needs in advertising campaigns for low-tar cigarettes. Analysis of previously secret tobacco industry documents and print advertising images indicated that low-tar brands targeted smokers who were concerned about their health with advertising images intended to distract them from the health hazards of smoking. Advertising first emphasized product characteristics (filtration, low tar) that implied health benefits. Over...

  15. Framework for product knowledge and product related knowledge which supports product modelling for mass customization

    DEFF Research Database (Denmark)

    Riis, Jesper; Hansen, Benjamin Loer; Hvam, Lars

    2003-01-01

    on experience from product modelling projects in several companies. Among them for example companies manufacturing electronic switchboards, spray dryer systems and air conditioning equipment. The framework is divided into three views: the product knowledge view, the life phase system view and the transformation...... and personalization. The framework for product knowledge and product related knowledge is based on the following theories: axiomatic design, technical systems, theory of domains, theory of structuring, theory of properties and the framework for the content of product and product related models. The framework is built......The article presents a framework for product knowledge and product related knowledge which can be used to support the product modelling process which is needed for developing IT systems. These IT systems are important tools for many companies when they aim at achieving mass customization...

  16. Effect of separatrix magnetic geometry on divertor behavior in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Petrie, T.W., E-mail: petrie@fusion.gat.com [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Canik, J.M. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Lasnier, C.J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Leonard, A.W.; Mahdavi, M.A. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Watkins, J.G. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States); Fenstermacher, M.E. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Ferron, J.R.; Groebner, R.J. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Hill, D.N. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Hyatt, A.W. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Holcomb, C.T. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Luce, T.C. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Moyer, R.A. [University of California–San Diego, La Jolla, CA 92093-0417 (United States); Stangeby, P.C. [University of Toronto Institute of Aerospace Studies, Toronto (Canada)

    2013-07-15

    We report on recent experiments on DIII-D that examined the effects that variations in the parallel connection length in the scrape-off layer (SOL), L{sub ||}, and the radial location of the outer divertor target, R{sub TAR}, have on divertor plasma properties. Two-point modeling of the SOL plasma predicts that larger values of L{sub ||} and R{sub TAR} should lower temperature and raise density at the outer divertor target for fixed upstream separatrix density and temperature, i.e., n{sub TAR} ∝ [R{sub TAR}]{sup 2}[L{sub ||}]{sup 6/7} and T{sub TAR} ∝ [R{sub TAR}]{sup −2}[L{sub ||}]{sup −4/7}. The dependence of n{sub TAR} and T{sub TAR} on L{sub ||} was consistent with our data, but the dependence of n{sub TAR} and T{sub TAR} on R{sub TAR} was not. The surprising result that the divertor plasma parameters did not depend on R{sub TAR} in the predicted way may be due to convected heat flux, driven by escaping neutrals, in the more open configuration of the larger R{sub TAR} cases. Modeling results using the SOLPS code support this postulate.

  17. DNA-SIP identifies sulfate-reducing Clostridia as important toluene degraders in tar-oil-contaminated aquifer sediment

    Energy Technology Data Exchange (ETDEWEB)

    Winderl, C.; Penning, H.; von Netzer, F.; Meckenstock, R.U.; Lueders, T. [Helmholtz Zentrum Munchen, Neuherberg (Germany)

    2010-10-15

    Global groundwater resources are constantly challenged by a multitude of contaminants such as aromatic hydrocarbons. Especially in anaerobic habitats, a large diversity of unrecognized microbial populations may be responsible for their degradation. Still, our present understanding of the respective microbiota and their ecophysiology is almost exclusively based on a small number of cultured organisms, mostly within the Proteobacteria. Here, by DNA-based stable isotope probing (SIP), we directly identified the most active sulfate-reducing toluene degraders in a diverse sedimentary microbial community originating from a tar-oil-contaminated aquifer at a former coal gasification plant. On incubation of fresh sediments with {sup 13}C{sub 7}-toluene, the production of both sulfide and (CS{sub 2}){sup 13}CO{sub 2} was clearly coupled to the {sup 13}Clabeling of DNA of microbes related to Desulfosporosinus spp. within the Peptococcaceae (Clostridia). The screening of labeled DNA fractions also suggested a novel benzylsuccinate synthase alpha-subunit (bssA) sequence type previously only detected in the environment to be tentatively affiliated with these degraders. However, carbon flow from the contaminant into degrader DNA was only similar to 50%, pointing toward high ratios of heterotrophic CS{sub 2}-fixation during assimilation of acetyl-CoA originating from the contaminant by these degraders. These findings demonstrate that the importance of non-proteobacterial populations in anaerobic aromatics degradation, as well as their specific ecophysiology in the subsurface may still be largely ungrasped.

  18. Enriching step-based product information models to support product life-cycle activities

    Science.gov (United States)

    Sarigecili, Mehmet Ilteris

    The representation and management of product information in its life-cycle requires standardized data exchange protocols. Standard for Exchange of Product Model Data (STEP) is such a standard that has been used widely by the industries. Even though STEP-based product models are well defined and syntactically correct, populating product data according to these models is not easy because they are too big and disorganized. Data exchange specifications (DEXs) and templates provide re-organized information models required in data exchange of specific activities for various businesses. DEXs show us it would be possible to organize STEP-based product models in order to support different engineering activities at various stages of product life-cycle. In this study, STEP-based models are enriched and organized to support two engineering activities: materials information declaration and tolerance analysis. Due to new environmental regulations, the substance and materials information in products have to be screened closely by manufacturing industries. This requires a fast, unambiguous and complete product information exchange between the members of a supply chain. Tolerance analysis activity, on the other hand, is used to verify the functional requirements of an assembly considering the worst case (i.e., maximum and minimum) conditions for the part/assembly dimensions. Another issue with STEP-based product models is that the semantics of product data are represented implicitly. Hence, it is difficult to interpret the semantics of data for different product life-cycle phases for various application domains. OntoSTEP, developed at NIST, provides semantically enriched product models in OWL. In this thesis, we would like to present how to interpret the GD & T specifications in STEP for tolerance analysis by utilizing OntoSTEP.

  19. Pharmacokinetic/pharmacodynamic integration and modelling of florfenicol for the pig pneumonia pathogens Actinobacillus pleuropneumoniae and Pasteurella multocida.

    Directory of Open Access Journals (Sweden)

    Lucy Dorey

    Full Text Available Pharmacokinetic-pharmacodynamic (PK/PD integration and modelling were used to predict dosage schedules for florfenicol for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Pharmacokinetic data were pooled for two bioequivalent products, pioneer and generic formulations, administered intramuscularly to pigs at a dose rate of 15 mg/kg. Antibacterial potency was determined in vitro as minimum inhibitory concentration (MIC and Mutant Prevention Concentration in broth and pig serum, for six isolates of each organism. For both organisms and for both serum and broth MICs, average concentration:MIC ratios over 48 h were similar and exceeded 2.5:1 and times greater than MIC exceeded 35 h. From in vitro time-kill curves, PK/PD modelling established serum breakpoint values for the index AUC24h/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4log10 reductions in bacterial count; means were 25.7, 40.2 and 47.0 h, respectively, for P. multocida and 24.6, 43.8 and 58.6 h for A. pleuropneumoniae. Using these PK and PD data, together with literature MIC distributions, doses for each pathogen were predicted for: (1 bacteriostatic and bactericidal levels of kill; (2 for 50 and 90% target attainment rates (TAR; and (3 for single dosing and daily dosing at steady state. Monte Carlo simulations for 90% TAR predicted single doses to achieve bacteriostatic and bactericidal actions over 48 h of 14.4 and 22.2 mg/kg (P. multocida and 44.7 and 86.6 mg/kg (A. pleuropneumoniae. For daily doses at steady state, and 90% TAR bacteriostatic and bactericidal actions, dosages of 6.2 and 9.6 mg/kg (P. multocida and 18.2 and 35.2 mg/kg (A. pleuropneumoniae were required. PK/PD integration and modelling approaches to dose determination indicate the possibility of tailoring dose to a range of end-points.

  20. Catalytic upgrading of gas from biofuels and implementation of electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Simell, P.; Hepola, J.; Heiskanen, K. [VTT Energy, Espoo (Finland)

    1997-10-01

    Kinetic modelling of tar model compound (benzene) reaction with CO{sub 2} over dolomite (Kalkkimaa dolomite) catalyst has been carried out. This modelling has been based mainly on results obtained in earlier project. However, some additional tests have been made to complete the data. The data obtained was fitted to four different Langmuir-Hinshelwood type of kinetic rate equations in order to find the best suited model for the reaction. The model that best described the data assumed single site benzene adsorption and non-dissociative CO{sub 2} adsorption. Kinetical modelling work was continued by studies considering steam reforming of tar. Reaction rates were measured with large excess of water to benzene then with stoichiometric ratio of water to benzene and in simulated gasification gas. Conditions free of external (film) and internal (pore) diffusion effects were used. Reactor was operated both in differential and integral modes. Preliminary modelling was carried out and kinetical parameters for simple first order reaction model were calculated. During the first half of the year complementary experiments concerning earlier studies on sulfur poisoning of nickel catalysts were carried out. The experiments were performed in fixed bed tube reactors and in a TPH-reactor of VTT. In addition, several analytical methods for determining the nature of adsorbed sulfur on the catalyst surface was used. During the other part of the year two complementary report drafts concerning sulfur poisoning of nickel catalysts at hot gas cleaning conditions of gasification gas were prepared. (orig.)