Pyrolysis characteristics and kinetics of low rank coals by distributed activation energy model

International Nuclear Information System (INIS)

Song, Huijuan; Liu, Guangrui; Wu, Jinhu

2016-01-01

Highlights: • Types of carbon in coal structure were investigated by curve-fitted "1"3C NMR spectra. • The work related pyrolysis characteristics and kinetics with coal structure. • Pyrolysis kinetics of low rank coals were studied by DAEM with Miura integral method. • DAEM could supply accurate extrapolations under relatively higher heating rates. - Abstract: The work was conducted to investigate pyrolysis characteristics and kinetics of low rank coals relating with coal structure by thermogravimetric analysis (TGA), the distributed activation energy model (DAEM) and solid-state "1"3C Nuclear Magnetic Resonance (NMR). Four low rank coals selected from different mines in China were studied in the paper. TGA was carried out with a non-isothermal temperature program in N_2 at the heating rate of 5, 10, 20 and 30 °C/min to estimate pyrolysis processes of coal samples. The results showed that corresponding characteristic temperatures and the maximum mass loss rates increased as heating rate increased. Pyrolysis kinetics parameters were investigated by the DAEM using Miura integral method. The DAEM was accurate verified by the good fit between the experimental and calculated curves of conversion degree x at the selected heating rates and relatively higher heating rates. The average activation energy was 331 kJ/mol (coal NM), 298 kJ/mol (coal NX), 302 kJ/mol (coal HLJ) and 196 kJ/mol (coal SD), respectively. The curve-fitting analysis of "1"3C NMR spectra was performed to characterize chemical structures of low rank coals. The results showed that various types of carbon functional groups with different relative contents existed in coal structure. The work indicated that pyrolysis characteristics and kinetics of low rank coals were closely associated with their chemical structures.

Co-pyrolysis characteristics and kinetics of coal and plastic blends

International Nuclear Information System (INIS)

Zhou Limin; Luo Taian; Huang Qunwu

2009-01-01

Co-pyrolysis behaviors of different plastics (high density polyethylene, low density polyethylene and polypropylene), low volatile coal (LVC) and their mixtures were investigated by TGA. Experiments were conducted under N 2 atmosphere at heating rate of 20 deg. C/min from room temperature to 750 deg. C. The results showed that the thermal degradation temperature range of plastic was 438-521 deg. C, while that of coal (LVC) was 174-710 deg. C. Plastics showed similar pyrolysis characteristics due to similar chemical bonds in their molecular structures. The overlapping degradation temperature interval between coal and plastic provide an opportunity for free radicals from coal pyrolysis to participate in the reactions of plastic decomposition. The difference of weight loss percent (ΔW) between experimental and theoretical ones, calculated as an algebraic sum of those from each separated component, ΔW is 2.0-2.7% at the pyrolysis temperature higher than 530 deg. C, which indicates that the synergistic effect during pyrolysis occurs mainly in the high temperature region. The kinetic studies were performed according to Coats and Redfern method for first-order reaction. It was found that for plastics (HDPE, LDPE and PP), the pyrolysis process can be described by one first-order reaction. However, for LVC and LVC/plastic blends, this process can be described by three and four consecutive first-order reactions, respectively. The estimated kinetic parameters viz., activation energies and pre-exponential factors for coal, plastic and their blends, were found to be in the range of 35.7-572.8 kJ/mol and 27-1.7 x 10 38 min -1 , respectively

Characterisation of model compounds and a synthetic coal by TG/MS/FTIR to represent the pyrolysis behaviour of coal

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Pevida, C.; Rubiera, F.; Garcia, R.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2004-06-01

Coal pyrolysis is the initial, accompanying reaction of a number of coal conversion processes such as hydrogenation, combustion and gasification. However, because of the inherent complexity of coal composition, it is difficult to describe coal pyrolysis clearly. Single model compounds have been used before in order to provide additional insight into the complex processes that occur in the pyrolysis of coal. Yet the picture obtained is a simplified one and certain important aspects such as coal structure, interactions between different surface groups and cross-links are omitted. The approach used in this work involves the preparation of a synthetic coal, SC, with a known structure by curing a mixture of single, well-defined model compounds. By means of chemical characterisation, the SC was shown to contain the macroscopic features of a high volatile coal (proximate and ultimate analyses). FTIR characterisation revealed the presence of functional groups similar to those of coal in the structure of the SC. Temperature-programmed pyrolysis tests were performed in a thermobalance linked to a mass spectrometer and a Fourier transform infrared analyser (TG/MS/FTIR). The thermal behaviour of the synthetic coal (i.e., rate of mass loss and the evolution profiles of gaseous compounds during pyrolysis tests) is very similar to that of the high volatile bituminous coal which was used as a reference material. The great advantage of using SC lies in the fact that its composition and structure can be accurately determined and employed in subsequent applications in basic and mechanistic studies.

Coal pyrolysis. VII. Economic viability of pyrolysis. Pirolisis del carbon. VII. Viabilidad economica de la pirolisis

Energy Technology Data Exchange (ETDEWEB)

Molinar, R.; Adanez, J.; Miranda, J.L.; Ibarra, J.V. (Instituto de Carboquimica, Zaragoza (Spain))

1989-04-01

Analyses the most important economic parameters of the main pyrolysis processes. Considers the markets available for semi-coke and tars. Concludes that no single technology or process has clear advantages over the others because all depends on the type of coal being used and the purpose for which the end product is to be used. Refers to studies carried out in Canada and the USA on the same subject and reports their findings. Concludes optimistically that coal pyrolysis shows promise of being economically viable in the future because although initially, costs reflect the high financial outlay necessary to begin operations, after a certain period, these costs fall and the end product can be sold at a lower price. A further point in favour of pyrolysis is that coal prices are likely to rise more slowly than oil prices. 5 refs., 8 tabs.

Thermal behavior and kinetics of bio-ferment residue/coal blends during co-pyrolysis

International Nuclear Information System (INIS)

Du, Yuying; Jiang, Xuguang; Lv, Guojun; Ma, Xiaojun; Jin, Yuqi; Wang, Fei; Chi, Yong; Yan, Jianhua

2014-01-01

Highlights: • The Activation energy for the blends is lower than that of BR and coal when BR < 50%. • The BR/coal blends start to decompose at approximately 45 °C releasing ammonia. • The yield of gaseous products increases with increasing BR blending ratio. • NH 3 , alkanes and CO 2 increase with increasing BR blending ratio. • Interactions most likely occur between the BR and the coal during co-pyrolysis. - Abstract: In this work, the thermal behavior and kinetics of bio-ferment residue (BR) and coal blends during co-pyrolysis were investigated using TG-FTIR and kinetic analysis. The co-pyrolysis of BR and coal occurred in three major stages. The BR/coal blends lost most of their weight during the devolatilization stage. The kinetics of the BR/coal blends in this stage implied that the activation energy was lower than that of BR and coal below a certain BR blending ratio. The BR/coal blends started to decompose at approximately 45 °C, releasing ammonia followed by alkanes, carbon dioxide, methane and carbon monoxide. The total yield of gaseous products (primarily ammonia, alkanes and carbon dioxide) increased with increasing BR blending ratio. Moreover, interactions most likely occurred between the BR and the coal during co-pyrolysis

Thermal behaviour during the pyrolysis of low rank perhydrous coals

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Rubiera, F.; Pis, J.J.; Cuesta, M.J.; Suarez-Ruiz, I. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain); Iglesias, M.J. [Area de Quimica Organica, Universidad de Almeria, Carretera de Sacramento, 04120 Almeria (Spain); Jimenez, A. [Area de Cristalografia y Mineralogia, Departamento de Geologia, Campus de Llamaquique, 33005 Oviedo (Spain)

2003-08-01

Perhydrous coals are characterised by high H/C atomic ratios and so their chemical structure is substantially modified with respect to that of conventional coals. As a result, perhydrous coals show different physico-chemical properties to common coals (i.e. higher volatile matter content, enhancement of oil/tar potential, relatively lower porosity and higher fluidity during carbonisation). However, there is little information about thermal behaviour during the pyrolysis of this type of coal. In this work, six perhydrous coals (H/C ratio between 0.83 and 1.07) were pyrolysed and analysed by simultaneous thermogravimetry/mass spectrometry. The results of this work have revealed the influence of high H/C values on the thermal behaviour of the coals studied. During pyrolysis the perhydrous coals exhibit very well defined, symmetrical peaks in the mass loss rate profiles, while normal coals usually show a broader peak. The shape of such curves suggests that in perhydrous coals fragmentation processes prevailed over condensation reactions. The high hydrogen content of perhydrous coals may stabilise the free radicals formed during heat treatment, increasing the production of light components.

Novel technique for coal pyrolysis and hydrogenation product analysis

Energy Technology Data Exchange (ETDEWEB)

Pfefferle, L.D.

1992-01-01

This report covers the last quarter of the last year of the three-year grant period. In the final project year, we concentrated on the pyrolysis and oxidative pyrolysis of large hydrocarbons and mixtures of large and small hydrocarbons in order to develop the VUV-MS technique for compounds more representative of those in coal pyrolysis applications. Special focus was directed at the pyrolysis and oxidative pyrolysis of benzene and benzene acetylene mixtures. The acetylene/benzene mixtures were used to gain a better understanding of the mechanisms of molecular growth in such systems specifically to look at the kinetics of aryl-aryl reactions as opposed to small molecule addition to phenyl radicals. Sarofim and coworkers at MIT have recently demonstrated the importance of these reactions in coal processing environments. In the past, the growth mechanism for the formation of midsized PAH has been postulated to involve primarily successive acetylene additions to phenyl-type radicals, our work confmns this as an important mechanism especially for smaller PAH but also investigates conditions where biaryl formation can play an important role in higher hydrocarbon formation.

Fluidized bed selective pyrolysis of coal

Science.gov (United States)

Shang, Jer Y.; Cha, Chang Y.; Merriam, Norman W.

1992-01-01

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

Cleavage and crosslinking of polymeric coal structures during pyrolysis. Final report

Energy Technology Data Exchange (ETDEWEB)

McMillen, D.F.; Malhotra, R.

1992-02-01

The ultimate objective of this project was to develop a better understanding of volatiles production to help optimize the yield and character of condensable coproducts during coal pyrolysis or mild gasification. The specific objectives were to (1) Develop pyrolysis procedures that minimize secondary reactions; and (2) Develop coal pretreatments that current knowledge suggests will prorate bond scission or prevent retrograde reactions. Our approach was to study the pyrolysis of coals and tar-loaded coals by using several techniques that span a range of heating rates and pressures. Slow-heating pyrolyses were performed at low pressures in the inlet of a field ionization mass spectrometer and at atmospheric pressures in a thermogravimetric analyzer. Moderately rapid-heating pyrolyses were performed in a vacuum TGA apparatus and in sealed silica ampules heated in a molten-salt bath. The fastest heating rates were achieved with laser pyrolysis at about 30,000 X/s. The high tar yield seen in this work where the entire volume of the coal particle becomes hot and fluid at very nearly the same time, taken together with the evident non-vapor transport of the tar under these conditions, emphasizes the importance of better understanding the development of fluidity during coal heating. This specifically includes the profound effects--long-recognized but poorly understood that mild oxidation has in suppressing coal fluidity. It also includes the more recently recognized fact that heating in the presence of an inert gas produced substantially greater fluidity than does heating in the presence of combustion gases, even if the conditions are very fuel rich and all the oxygen itself has already been consumed when the coal particles are encountered.

Dependence of Pyrolysis Rate of Coal on Temperature

Directory of Open Access Journals (Sweden)

Slyusarskiy Konstantin V.

2015-01-01

Full Text Available Pyrolysis process of coal has been researched to define kinetic constants which can be used for design and optimization of different processes of fuel transformation. The article considers anthracite powders and bituminous coal of Krasnogorsky mine with the use of non-isothermal thermogravimetric analysis with mass spectrometry. Spectroscanning microscopy and laser diffraction for definition of sizes and forms of particles distribution has been done. Other parameters – carbon content, ash and volatiles, density and moisture have been defined by standard methods. Energy of activation and pre-exponent with the use of models of Freedman, Starink and distributed activation energy model (DAEM, and also relative deviation of design data from experimental ones have been designed. The results of the analysis have shown the important influence of volatiles content and coal transformation degree on maximum reaction rate. Energy activation values received with the help of DAEM model are higher than with Freedman and Starink models. Process of pyrolysis of bituminous coal has a big rate in comparison with anthracite, and is better described by the above-mentioned models.

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.

Novel technique for coal pyrolysis and hydrogenation product analysis

Energy Technology Data Exchange (ETDEWEB)

Pfefferle, L.D.; Boyle, J.

1993-03-15

A microjet reactor coupled to a VUV photoionization time-of-flight mass spectrometer has been used to obtain species measurements during high temperature pyrolysis and oxidation of a wide range of hydrocarbon compounds ranging from allene and acetylene to cyclohexane, benzene and toluene. Initial work focused on calibration of the technique, optimization of ion collection and detection and characterization of limitations. Using the optimized technique with 118 nm photoionization, intermediate species profiles were obtained for analysis of the hydrocarbon pyrolysis and oxidation mechanisms. The soft'' ionization, yielding predominantly molecular ions, allowed the study of reaction pathways in these high temperature systems where both sampling and detection challenges are severe. Work has focused on the pyrolysis and oxidative pyrolysis of aliphatic and aromatic hydrocarbon mixtures representative of coal pyrolysis and hydropyrolysis products. The detailed mass spectra obtained during pyrolysis and oxidation of hydrocarbon mixtures is especially important because of the complex nature of the product mixture even at short residence times and low primary reactant conversions. The combustion community has advanced detailed modeling of pyrolysis and oxidation to the C4 hydrocarbon level but in general above that size uncertainties in rate constant and thermodynamic data do not allow us to a priori predict products from mixed hydrocarbon pyrolyses using a detailed chemistry model. For pyrolysis of mixtures of coal-derived liquid fractions with a large range of compound structures and molecular weights in the hundreds of amu the modeling challenge is severe. Lumped models are possible from stable product data.

Dynamic model of coal/organic wastes pyrolysis

Czech Academy of Sciences Publication Activity Database

Kříž, Vlastimil

-, č. 16 (2007), s. 39-60 ISSN 1214-9691 R&D Projects: GA ČR(CZ) GA105/07/1407 Institutional research plan: CEZ:AV0Z30460519 Keywords : pyrolysis * coal * rubber Subject RIV: CI - Industrial Chemistry, Chemical Engineering

Influence of metal additives on pyrolysis behavior of bituminous coal by TG-FTIR analysis

Energy Technology Data Exchange (ETDEWEB)

Su, Wenjuan; Fang, Mengxiang; Cen, Jianmeng; Li, Chao; Luo, Zhongyang; Cen, Kefa [Zhejiang Univ., Hangzhou (China). State Key Lab. of Clean Energy Utilization

2013-07-01

To study the catalytic effects of alkali, alkaline earth and transition metal additives on coal pyrolysis behavior, bituminous coal loaded NaCl, KCl, CaCl{sub 2}, MgCl{sub 2}, FeCl{sub 3} and NiCl{sub 2} was respectively investigated using Thermogravimetry and Fourier Transform Infrared Spectroscopy (TG-FTIR). Results indicated that the maximum mass loss rate decreased under the metal additives in the primary pyrolysis stage. The total mass loss of pyrolysis was reduced in metals catalyzed pyrolysis except for Na loaded sample. Kinetic analysis was taken for all samples adopting the method of Coats-Redfern. Activation energy of raw coal in the primary pyrolysis stage was 92.15vkJ.mol{sup -1}, which was lowered to 44.59-73.42 kJ.mol{sup -1} under metal additives. The orders of catalytic effect for this bituminous coal were Mg > Fe > Ca > Ni > K > Na according to their activation energies. Several investigated volatiles including CH{sub 4}, CO{sub 2}, CO, toluene, phenol and formic acid were identified from FTIR spectra. The yields of CH{sub 4}, CO{sub 2}, toluene, phenol and formic acid were decreased, but the evolution of CO was increased. The presence of metals in the coal samples have been involved in a repeated bond-forming and bond-breaking process, which greatly hindered the release of tars during pyrolysis as the tar precursors were connected to coal/char matrix and were thermally cracked, becoming a part of char.

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.

Online study on the co-pyrolysis of coal and corn with vacuum ultraviolet photoionization mass spectrometry.

Science.gov (United States)

Weng, Jun-Jie; Liu, Yue-Xi; Zhu, Ya-Nan; Pan, Yang; Tian, Zhen-Yu

2017-11-01

With the aim to support the experimental tests in a circulating fluidized bed pilot plant, the pyrolysis processes of coal, corn, and coal-corn blend have been studied with an online pyrolysis photoionization time-of-flight mass spectrometry (Py-PI-TOFMS). The mass spectra at different temperatures (300-800°C) as well as time-evolved profiles of selected species were measured. The pyrolysis products such as alkanes, alkenes, phenols, aromatics, as well as nitrogen- and sulfur-containing species were detected. As temperature rises, the relative ion intensities of high molecular weight products tend to decrease, while those of aromatics increase significantly. During the co-pyrolysis, coal can promote the reaction temperature of cellulose in corn. Time-evolved profiles demonstrate that coal can affect pyrolysis rate of cellulose, hemicellulose, and lignin of corn in blend. This work shows that Py-PI-TOFMS is a powerful approach to permit a better understanding of the mechanisms underlying the co-pyrolysis of coal and biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Slow and pressurized co-pyrolysis of coal and agricultural residues

International Nuclear Information System (INIS)

Aboyade, Akinwale O.; Carrier, Marion; Meyer, Edson L.; Knoetze, Hansie; Görgens, Johann F.

2013-01-01

Highlights: ► Evaluation of co-pyrolysis of coal and biomass in pressurized packed bed reactor. ► Relative influence of coal–biomass mix ratio, temperature and pressure also investigated. ► Results show significant synergy or chemical interactions in the vapor phase. ► Synergistic interactions did not influence distribution of lumped solid liquid and gas products. - Abstract: The distribution of products from the slow heating rate pyrolysis of coal, corn residues (cobs and stover), sugarcane bagasse and their blends were investigated by slow pressurized pyrolysis in a packed bed reactor. A factorial experimental design was implemented to establish the relative significance of coal–biomass mix ratio, temperature and pressure on product distribution. Results showed that the yield and composition of tar and other volatile products were mostly influenced by mix ratio, while temperature and pressure had a low to negligible significance under the range of conditions investigated. Analysis of the composition of condensates and gas products obtained showed that there was significant synergy or chemical interactions in the vapor phase during co-pyrolysis of coal and biomass. However, the interactions did not significantly affect the relative distribution of the lumped solid, liquid and gas products obtained from the blends, beyond what would be expected assuming additive behavior from the contributing fuels.

Research on pyrolysis characteristics and kinetics of super fine and conventional pulverized coal

International Nuclear Information System (INIS)

Zhang Chaoqun; Jiang Xiumin; Wei Lihong; Wang Hui

2007-01-01

Based on isothermal thermogravimetric analysis (TGA) and kinetic equations, the optimization toolbox of MATLAB was applied to study the effects of particle size and heating rate on the pyrolysis characteristics and kinetics and to obtain the mechanism function and kinetic parameters of Yuanbaoshan coal at four different particle sizes and heating rates. The pyrolysis characteristics of the samples were analyzed using thermogravimetric (TG) curves and differential thermogravimetric (DTG) curves. The results show that the coal pyrolysis process is strongly affected by heating rate and particle size. As the heating rate increases, the temperature of volatile matter initiation increases, the total volatile matter evolved decreases and the DTG peak shifts toward higher temperature. As the particle size decreases, the temperature of volatile matter initiation of the coal sample decreases and the maximum rate of mass loss increases. In the pyrolysis of coal, the activation energies of the samples were found to increase with growing particle size and decreasing heating rate for both of the devolatilization temperature stages. In the lower temperature stage, the coal samples show a great difference in mechanism function at different particle sizes and heating rates

Influence of reaction parameters on brown coal-polyolefinic plastic co-pyrolysis behavior

Energy Technology Data Exchange (ETDEWEB)

Sharypov, V.I.; Beregovtsova, N.G.; Kuznetsov, B.N. [Institute of Chemistry and Chemical Technology SB RAS, K.Marx Str. 42, 660049 Krasnoyarsk (Russian Federation); Cebolla, V.L. [Instituto de Carboquimica, CSIC, Miguel Luesma, 4, 50015 Zaragoza (Spain); Collura, S.; Finqueneisel, G.; Zimny, T.; Weber, J.V. [Laboratoire de Chimie et Applications, Universite de Metz, rue V.Demange, 57500 Saint-Avold (France)

2007-03-15

Co-processing of polyolefinic polymers with Kansk-Achinsk (Russia) brown coal was investigated by thermogravimetry (TG) and autoclave pyrolysis under argon and hydrogen pressure in catalytic conditions (or not). Gas chromatography-mass spectrometry (GC-MS) and high performance thin layer chromatography (HPTLC) were used to analyze the distillate products. Some synergistic effects indicate chemical interaction between the products of thermal decomposition of coal and plastic. In co-pyrolysis under H{sub 2} a significant increasing of coal conversion degree as a function of polymer amount in feedstock was found. Simultaneously the coal promoted formation of distillate products from polymers. Some alkyl aromatic and O-containing substances were detected in co-pyrolysis fraction boiling in the range 180-350 C, indicating interactions between coal and plastic. Iron containing ore materials, modified by mechanochemical treatment, demonstrated a catalytic activity in hydropyrolysis process. In catalytic conditions, increases of the mixtures conversion degree by 9-13 wt.%, of distillate fraction yields by 1.2-1.6 times and a decrease of olefins and polycyclic components were observed. (author)

Dynamic measurement of coal thermal properties and elemental composition of volatile matter during coal pyrolysis

Directory of Open Access Journals (Sweden)

Rohan Stanger

2014-01-01

Full Text Available A new technique that allows dynamic measurement of thermal properties, expansion and the elemental chemistry of the volatile matter being evolved as coal is pyrolysed is described. The thermal and other properties are measured dynamically as a function of temperature of the coal without the need for equilibration at temperature. In particular, the technique allows for continuous elemental characterisation of tars as they are evolved during pyrolysis and afterwards as a function of boiling point. The technique is demonstrated by measuring the properties of maceral concentrates from a coal. The variation in heats of reaction, thermal conductivity and expansion as a function of maceral composition is described. Combined with the elemental analysis, the results aid in the interpretation of the chemical processes contributing to the physical and thermal behaviour of the coal during pyrolysis. Potential applications in cokemaking studies are discussed.

Flash pyrolysis of coal-solvent slurry prepared from the oxidized coal and the coal dissolved in solvent; Ichibu yokaishita sanka kaishitsutan slurry no jinsoku netsubunkai

Energy Technology Data Exchange (ETDEWEB)

Maki, T.; Mae, K.; Okutsu, H.; Miura, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1996-10-28

In order to develop a high-efficiency coal pyrolysis method, flash pyrolysis was experimented on slurry prepared by using liquid-phase oxidation reformed coal and a methanol-based solvent mixture. Australian Morwell coal was used for the experiment. The oxidized coal, into which carboxyl groups have been introduced, has the condensation structure relaxed largely, and becomes highly fluid slurry by means of the solvent. Char production can be suppressed by making the oxidation-pretreated coal into slurry, resulting in drastically improved pyrolytic conversion. The slurry was divided into dissolved solution, dried substance, extracted residue, and residual slurry, which were pyrolized independently. The dissolved solution showed very high conversion. Improvement in the conversion is contributed by separating the dissolved substances (coal macromolecules) at molecular levels, coagulating the molecules, suppressing cross-link formation, and reducing molecular weight of the dissolved substances. Oxidized coal can be dissolved to 80% or higher by using several kinds of mixed solvents. As a result of the dissolution, a possibility was suggested on pyrolysis which is easy in handling and high in conversion. 7 refs., 6 figs., 2 tabs.

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

Decomposition of pyrite and the interaction of pyrite with coal organic matrix in pyrolysis and hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

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

2000-10-01

The thermal behaviour of pure pyrite was studied under nitrogen and hydrogen atmospheres in a pressurized thermal balance. The transfer of pyrite in coal during pyrolysis and hydropyrolysis was investigated in a fixed-bed reactor. The results suggest that the indigenous hydro-carbon with hydrogen donor ability in coal can promote the reduction of pyrite in pyrolysis. At low temperatures, organic sulfur removal is almost the same in pyrolysis and hydropyrolysis of two coals. It is likely that indigenous hydrogen in coal is the dominant factor in organic sulfur elimination in the low-temperature stage. An increase of organic sulfur in pyrolysis of Hongmiao coal indicates that the lack of the indigenous hydrogen may be the key factor determining the transformation of pyritic sulfur into organic sulfur. Oxygen affects the conversion of pyrite into organic sulfur through the competitive consumption of hydrogen. 12 refs., 5 figs., 1 tab.

Experimental study of Coal Pyrolysis 2.: Experimental characterisation of volatile matter

International Nuclear Information System (INIS)

Hugony, F.; Migliavacca, G.

2008-01-01

In this paper considerations about experiments conducted through T G-Ftir are reported, in order to study the gas composition coming from coal pyrolysis. In particular qualitative and semi-qualitative evaluation of hydrocarbon evolution rate, as CH4, C2H4 and C3H6 are reported. It has been observed a strict relation between the evolution rate of the listed compounds, the coal rank and their elementary composition. The reported data constitute a good support to the validation of the predictive models of coal devolatilization. To complete the study two papers will be published in the next months: one containing experimental data from pyrolysis process in a fixed bed reactor and another one concerning the NMR analysis of the produced char. [it

Co-pyrolysis of waste tire/coal mixtures for smokeless fuel, maltenes and hydrogen-rich gas production

International Nuclear Information System (INIS)

Bičáková, Olga; Straka, Pavel

2016-01-01

Highlights: • Co-pyrolysis of waste tires/coal mixtures yields mainly smokeless fuel (55–74 wt%). • Alternatively, the smokeless fuel can serve as carbonaceous sorbent. • The obtained tar contained maltenes (80–85 wt%) and asphaltenes (6–8 wt%). • Tar from co-pyrolysis can serve as heating oil or a source of maltenes for repairing of asphalt surfaces. • The hydrogen-rich gas was obtained (61–65 vol% H_2, 24–25 vol% CH_4, 1.4–2 vol% CO_2). - Abstract: The processing of waste tires with two different types of bituminous coal was studied through the slow co-pyrolysis of 1 kg of waste tire/coal mixtures with 15, 30 and 60 wt% waste tires on a laboratory scale. The waste tire/coal mixtures were pyrolysed using a quartz reactor in a stationary bed. The mixtures were heated at a rate 5 °C/min up to the final temperature of 900 °C with a soaking time of 30 min at the required temperature. The mass balance of the process and the properties of the coke and tar obtained were evaluated, further, the influence of the admixture in the charge on the amount and composition of the obtained coke and tar was determined. It was found that the smokeless fuel/carbonaceous sorbent and a high yield of tar for further use can be obtained through the slow co-pyrolysis. The obtained tars contained mostly maltenes (80–85 wt%). FTIR analysis showed that the maltenes from the co-pyrolysis of coal/waste tires exhibited significantly lower aromaticity as compared with that from coal alone. The gas obtained from pyrolysis or co-pyrolysis of waste tire/coal mixtures contained a high amount of hydrogen (above 60 vol%) and methane (above 20 vol%).

Change in electric and dielectric properties of some Australian coals during the processes of pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Zubkova, V.; Prezhdo, V. [Institute of Chemistry, Jan Kochanowski University, 5 Checinska Street, 25-020 Kielce (Poland)

2006-03-01

The investigation of change in electric and dielectric properties of Australian coals was carried out during their pyrolysis. The relation between the increase of the tangent of dielectric losses and electrical resistivity in the pre-plastic state of pyrolysis was established. It was shown that at the pre-plastic stage of pyrolysis, when the organic coal mass is in the glassy state, the decrease in value of electrical resistivity is caused by the increase in rotational movement of segments of macromolecules as evidenced by the increase in tg{delta} parameter. The character of change in curves r=f(T{sup o}) and tg{delta}=f(T{sup o}C) in the pre-plastic state of the process of coal pyrolysis predetermines the values of parameters of coke durability. (author)

Effect of Ni-Co Ternary Molten Salt Catalysts on Coal Catalytic Pyrolysis Process

Science.gov (United States)

Cui, Xin; Qi, Cong; Li, Liang; Li, Yimin; Li, Song

2017-08-01

In order to facilitate efficient and clean utilization of coal, a series of Ni-Co ternary molten salt crystals are explored and the catalytic pyrolysis mechanism of Datong coal is investigated. The reaction mechanisms of coal are achieved by thermal gravimetric analyzer (TGA), and a reactive kinetic model is constructed. The microcosmic structure and macerals are observed by scanning electron microscope (SEM). The catalytic effects of ternary molten salt crystals at different stages of pyrolysis are analyzed. The experimental results show that Ni-Co ternary molten salt catalysts have the capability to bring down activation energy required by pyrolytic reactions at its initial phase. Also, the catalysts exert a preferable catalytic action on macromolecular structure decomposition and free radical polycondensation reactions. Furthermore, the high-temperature condensation polymerization is driven to decompose further with a faster reaction rate by the additions of Ni-Co ternary molten salt crystal catalysts. According to pyrolysis kinetic research, the addition of catalysts can effectively decrease the activation energy needed in each phase of pyrolysis reaction.

Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; MacPhee, J.A.; Vancea, L.; Ciavaglia, L.A.; Nandi, B.N.

1983-04-01

Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500 C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by N.M.R. and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars. (19 refs.)

Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; Ciavaglia, L.A.; MacPhee, J.A.; Nandi, B.N.; Vancea, L.

1983-04-01

Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500/sup 0/C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by n.m.r., and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars.

Removal of pollutants from poor quality coals by pyrolysis

Directory of Open Access Journals (Sweden)

Natas Panagiotis

2006-01-01

Full Text Available Combustion of poor quality coals and wastes is used today worldwide for energy production. However, this entails significant environmental risks due to the presence of polluting compounds in them, i. e. S, N, Hg, and Cl. In the complex environment of combustion these substances are forming conventional (i. e. SOx, NOx and toxic (PCDD/Fs pollutants, while, the highly toxic Hg is volatilized in the gas phase mainly as elemental mercury. Aiming to meet the recently adopted strict environmental standards, and the need of affordable in cost clean power production, a preventive fuels pre-treatment technique, based on low temperature carbonization, has been tested. Clean coals were produced from two poor quality Greek coals (Ptolemais and Megalopolis and an Australian coal sample, in a lab-scale fixed bed reactor under helium atmosphere and ambient pressure. The effect of carbonization temperature (200-900 °C and residence time (5-120 minutes on the properties of the chars, obtained after pyrolysis, was investigated. Special attention was paid to the removal of pollutants such as S, N, Hg, and Cl. To account for possible mineral matter effects, mainly on sulphur removal, tests were also performed with demineralized coal. Reactivity variation of produced clean coals was evaluated by performing non-isothermal combustion tests in a TA Q600 thermo gravimetric analyzer. Results showed that the low temperature carbonization technique might contribute to clean coal production by effectively removing the major part of the existing polluting compounds contained in coal. Therefore, depending on coal type, nitrogen, mercury, and chlorine abatement continuously increases with temperature, while sulphur removal seems to reach a plateau above 500-600 °C. More-over, the prolongation of carbonization time above 20 minutes does not affect the elemental conversion of the pollutants and carbonization at 500-600 °C for ~20 minutes may be considered sufficient for clean

Analysis of small molecular phase in coal involved in pyrolysis and solvent extraction by PGC

Energy Technology Data Exchange (ETDEWEB)

Jie Feng; Wen-Ying Li; Ke-Chang Xie [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology

2004-06-01

The small molecular phase, which strongly affects coal's reactivity, is the main part of the structure unit in coal. At present, its composition and structure features have not been clearly understood. In this paper, a flash pyrolysis technique with on-line GC (PGC) was used to investigate the properties of the small molecular phase from six kinds of rank coal in China. Experiments were divided into two parts: one is PGC of parent coal; another is PGC of coal extracts from NMP + CS{sub 2} (75:1) solvent extraction at 373 K. Results show that the small molecular phase mainly consists of C12-C16 compounds that could be integrally released when the heating rate was greater than 10 K/ms and the final pyrolysis temperature was 1373 K; other compounds may be the products of decomposition and polymerization from this small molecular phase during pyrolysis. 13 refs., 7 figs., 1 tab.

Nitrogen conversion during rapid pyrolysis of coal and petroleum coke in a high-frequency furnace

International Nuclear Information System (INIS)

Yuan, Shuai; Zhou, Zhi-jie; Li, Jun; Wang, Fu-chen

2012-01-01

Highlights: ► Use a high-frequency furnace to study N-conversion during rapid pyrolysis of coal. ► Scarcely reported N-conversion during rapid pyrolysis of petroleum coke was studied. ► Both of NH 3 and HCN can be formed directly from coal during rapid pyrolysis. ► NH 3 –N yields are higher than HCN–N yields in most conditions. ► NH 3 –N yields of petroleum coke increase with temperature and no HCN detected. -- Abstract: Rapid pyrolysis of three typical Chinese coals, lignite from Inner Mongolia, bituminous from Shenfu coalfield, and anthracite from Guizhou, as well as a petroleum coke were carried out in a drop-style high-frequency furnace. The reactor was induction coil heated and had a very small high-temperature zone, which could restrain secondary conversions of nitrogen products. The effects of temperature and coal rank on conversions of fuel-N to primary nitrogen products (char-N, HCN–N, NH 3 –N and (tar + N 2 )–N) have been investigated. The results showed that, the increasing temperature reduced the yields of char-N and promoted the conversion of fuel-N to N 2 . Char-N yields increased, while volatile-N yields decreased as the coal rank increased. In most of the conditions, NH 3 –N yields were higher than HCN–N yields during rapid pyrolysis of coal. In the case of petroleum coke, NH 3 –N yields increased gradually with the increasing temperature, but no HCN was detected. We argue that NH 3 –N can be formed directly through the primary pyrolysis without secondary reactions. Although volatile-N yields of lignite were higher than those of bituminous, yields of (HCN + NH 3 )–N in volatile-N of lignite were lower than those of bituminous. While the (HCN + NH 3 )–N yields of anthracite were the lowest of the three coals. Both of the (HCN + NH 3 )–N yields and (HCN + NH 3 )–N proportions in volatile-N of petroleum coke were lower than the three coals.

Novel technique for coal pyrolysis and hydrogenation production analysis

Energy Technology Data Exchange (ETDEWEB)

Pfefferle, L.D.

1990-01-01

The overall objective of this study is to establish vacuum ultraviolet photoionization-MS and VUV pulsed EI-MS as useful tools for a simpler and more accurate direct mass spectrometric measurement of a broad range of hydrocarbon compounds in complex mixtures for ultimate application to the study of the kinetics of coal hydrogenation and pyrolysis processes. The VUV-MS technique allows ionization of a broad range of species with minimal fragmentation. Many compounds of interest can be detected with the 118 nm wavelength, but additional compound selectivity is achievable by tuning the wavelength of the photo-ionization source in the VUV. Resonant four wave mixing techniques in Hg vapor will allow near continuous tuning from about 126 to 106 nm. This technique would facilitate the scientific investigation of coal upgrading processes such as pyrolysis and hydrogenation by allowing accurate direct analysis of both stable and intermediate reaction products.

Novel technique for coal pyrolysis and hydrogenation product analysis. Final technical report

Energy Technology Data Exchange (ETDEWEB)

Pfefferle, L.D.; Boyle, J.

1993-03-15

A microjet reactor coupled to a VUV photoionization time-of-flight mass spectrometer has been used to obtain species measurements during high temperature pyrolysis and oxidation of a wide range of hydrocarbon compounds ranging from allene and acetylene to cyclohexane, benzene and toluene. Initial work focused on calibration of the technique, optimization of ion collection and detection and characterization of limitations. Using the optimized technique with 118 nm photoionization, intermediate species profiles were obtained for analysis of the hydrocarbon pyrolysis and oxidation mechanisms. The ``soft`` ionization, yielding predominantly molecular ions, allowed the study of reaction pathways in these high temperature systems where both sampling and detection challenges are severe. Work has focused on the pyrolysis and oxidative pyrolysis of aliphatic and aromatic hydrocarbon mixtures representative of coal pyrolysis and hydropyrolysis products. The detailed mass spectra obtained during pyrolysis and oxidation of hydrocarbon mixtures is especially important because of the complex nature of the product mixture even at short residence times and low primary reactant conversions. The combustion community has advanced detailed modeling of pyrolysis and oxidation to the C4 hydrocarbon level but in general above that size uncertainties in rate constant and thermodynamic data do not allow us to a priori predict products from mixed hydrocarbon pyrolyses using a detailed chemistry model. For pyrolysis of mixtures of coal-derived liquid fractions with a large range of compound structures and molecular weights in the hundreds of amu the modeling challenge is severe. Lumped models are possible from stable product data.

Formation of radicals in coal pyrolysis examined by electron spin resonance

Directory of Open Access Journals (Sweden)

Tong Chang

2017-09-01

Full Text Available Electron spin resonance (ESR spectroscopy is used to study materials with unpaired electrons, such as organic radicals and metal complexes. This method can also be used to follow radical reactions during pyrolysis of carbonaceous materials. However, the temperature dependence of ESR measurement should be considered. To enable reasonable comparisons, results measured at different temperatures must be converted. In this study, we investigated the behavior of free radicals in the process of coal pyrolysis using in situ and ex situ ESR. The ESR data were collected at both pyrolysis and room temperatures, and apparent differences were analyzed. The differences were diminished when our data were converted to the same measurement temperature level based on the Boltzmann distribution law. Furthermore, we investigated the effects of process conditions on the behavior of free radicals in the solid phase of coal. We found that temperature is the most important factor determining the formation and behavior of free radicals in the solid phase, followed by the residence time. Relatively active radicals were quenched by hydrogen-donor solvents to some degree, while stable radicals remained.

Novel technique for coal pyrolysis and hydrogenation product analysis. Quarterly report, June 1, 1992

Energy Technology Data Exchange (ETDEWEB)

Pfefferle, L.D.

1992-12-31

This report covers the last quarter of the last year of the three-year grant period. In the final project year, we concentrated on the pyrolysis and oxidative pyrolysis of large hydrocarbons and mixtures of large and small hydrocarbons in order to develop the VUV-MS technique for compounds more representative of those in coal pyrolysis applications. Special focus was directed at the pyrolysis and oxidative pyrolysis of benzene and benzene acetylene mixtures. The acetylene/benzene mixtures were used to gain a better understanding of the mechanisms of molecular growth in such systems specifically to look at the kinetics of aryl-aryl reactions as opposed to small molecule addition to phenyl radicals. Sarofim and coworkers at MIT have recently demonstrated the importance of these reactions in coal processing environments. In the past, the growth mechanism for the formation of midsized PAH has been postulated to involve primarily successive acetylene additions to phenyl-type radicals, our work confmns this as an important mechanism especially for smaller PAH but also investigates conditions where biaryl formation can play an important role in higher hydrocarbon formation.

Application of House of Quality in evaluation of low rank coal pyrolysis polygeneration technologies

International Nuclear Information System (INIS)

Yang, Qingchun; Yang, Siyu; Qian, Yu; Kraslawski, Andrzej

2015-01-01

Highlights: • House of Quality method was used for assessment of coal pyrolysis polygeneration technologies. • Low rank coal pyrolysis polygeneration processes based on solid heat carrier, moving bed and fluidized bed were evaluated. • Technical and environmental criteria for the assessment of technologies were used. • Low rank coal pyrolysis polygeneration process based on a fluidized bed is the best option. - Abstract: Increasing interest in low rank coal pyrolysis (LRCP) polygeneration has resulted in the development of a number of different technologies and approaches. Evaluation of LRCP processes should include not only conventional efficiency, economic and environmental assessments, but also take into consideration sustainability aspects. As a result of the many complex variables involved, selection of the most suitable LRCP technology becomes a challenging task. This paper applies a House of Quality method in comprehensive evaluation of LRCP. A multi-level evaluation model addressing 19 customer needs and analyzing 10 technical characteristics is developed. Using the evaluation model, the paper evaluates three LRCP technologies, which are based on solid heat carrier, moving bed and fluidized bed concepts, respectively. The results show that the three most important customer needs are level of technical maturity, wastewater emissions, and internal rate of return. The three most important technical characteristics are production costs, investment costs and waste emissions. On the basis of the conducted analysis, it is concluded that the LRCP process utilizing a fluidized bed approach is the optimal alternative studied

Kinetic Study of Coal and Biomass Co-Pyrolysis Using Thermogravimetry

Energy Technology Data Exchange (ETDEWEB)

Wang, Ping [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hedges, Sheila W. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Chaudharib, Kiran [West Virginia Univ., Morgantown, WV (United States). Department of Chemical Engineering; Turtonb, Richard [West Virginia Univ., Morgantown, WV (United States). Department of Chemical Engineering

2013-10-29

The objectives of this study are to investigate thermal behavior of coal and biomass blends in inert gas environment at low heating rates and to develop a simplified kinetic model using model fitting techniques based on TGA experimental data. Differences in thermal behavior and reactivity in co-pyrolysis of Powder River Basin (PRB) sub-bituminous coal and pelletized southern yellow pine wood sawdust blends at low heating rates are observed. Coal/wood blends have higher reactivity compared to coal alone in the lower temperature due to the high volatile matter content of wood. As heating rates increase, weight loss rates increase. The experiment data obtained from TGA has a better fit with proposed two step first order reactions model compared single first order reaction model.

Mutagenicity and genotoxicity of coal fly ash water leachate.

Science.gov (United States)

Chakraborty, Rajarshi; Mukherjee, Anita

2009-03-01

Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals-sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significant (Ppercentage (%), tail length (mum), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

Effect of ultrafine iron and mineral matter on conversion of nitrogen and carbon during pyrolysis and gasification of coal

Energy Technology Data Exchange (ETDEWEB)

Ohtsuka, Y.; Furimsky, E. [Tohoku University, Sendai (Japan). Inst. for Chemical Reaction Science

1995-01-01

A subbituminous coal was used to determine the distribution of N{sub 2}, NH{sub 3}, and HCN during slow rate heating pyrolysis in He and gasification in 10% CO{sub 2} + He balance. During pyrolysis, the N{sub 2} was the major product followed by NH{sub 3} and HCN. During gasification, the N{sub 2} yields were significantly enhanced and those of NH{sub 3} and HCN decreased. Partial demineralization of coal resulted in a decrease in carbon and nitrogen conversion. This effect was also evident by comparing the nitrogen and carbon conversions of chars prepared at 500{degree}C from the fresh and demineralized coals. The addition of ultrafine Fe to coal increased conversion of carbon and nitrogen to N{sub 2} during gasification but had little effect during pyrolysis. Thus, during the former more than 80% of the coal nitrogen was released as N{sub 2}. Also, in the presence of Fe the temperature of N{sub 2} release was decreased by about 100{degree}C both during pyrolysis and gasification. During gasification of chars prepared at 1000{degree}C, the conversion of the coal nitrogen to N{sub 2} was much lower than that of carbon. 16 refs., 9 figs., 3 tabs.

Coal pyrolysis under synthesis gas, hydrogen and nitrogen

Energy Technology Data Exchange (ETDEWEB)

Ariunaa, A.; Li Bao-Qing; Li Wen; Purevsuren, B. (and others) [Chinese Academy of Sciences, Taiyuan (China)

2007-02-15

Chinese Xundian, Mongolian Shiveeovoo lignites and Khoot oil shale are pyrolyzed under synthesis gas (SG) at temperature range from 400 to 800{sup o}C for lignite and from 300 to 600{sup o}C for oil shale with heating rate of 10{sup o}C/min in a fixed bed reactor. The results were compared with those obtained by pyrolysis under hydrogen and nitrogen. The results showed that unlike pyrolysis at high pressure, there are only slight different in the yields of char and tar among pyrolyses under various gases at room pressure for lignite, while higher liquid yield with lower yields of char and gas was obtained in pyrolysis of oil shale under SG and H{sub 2} than under N{sub 2}. It is found that the pyrite S can be easily removed to partially convert to organic S under various gaseous atmosphere and the total sulfur removal for oil shale is much less than lignite, which might be related to its high ash content. The higher total sulfur removal and less organic S content in the presence of SG in comparison with those under N{sub 2} and even under H{sub 2} in pyrolysis of Xundian lignite might result from the action of CO in SG. However, CO does not show its function in pyrolysis of Khoot oil shale, which might also be related to the high ash content. The results reported show the possibility of using synthesis gas instead of pure hydrogen as the reactive gas for coal hydropyrolysis. 11 refs., 4 figs., 6 tabs.

Synergistic effect on co-pyrolysis of capsicum stalks and coal | Niu ...

African Journals Online (AJOL)

With the depletion of fossil fuel and the concern about environmental issues, the utilization of biomass resources has attracted increasing worldwide interest. The pyrolysis behavior of capsicum stalks and Baoji coal mixtures was investigated by TG-DSC. Results show that the thermal degradation temperature range of ...

Pyrolysis gas chromatographic atomic emission detection for sediments, coals and other petrochemical precursors

Energy Technology Data Exchange (ETDEWEB)

Seeley, J.A.; Zeng, Y.D.; Uden, P.C.; Eglinton, T.I.; Ericson, I. (Massachusetts University, Amherst, MA (USA). Dept. of Chemistry)

1992-09-01

On-line flash pyrolysis coupled to a capillary gas chromatograph for the characterization of marine sediments, coals and other heterogeneous solid samples is described. A helium microwave-induced plasma is used for chromatographic detection by atomic emission spectrometry. Simultaneous multi-element detection is achieved with a photodiode array detector. The optical path of the gas chromatographic atomic emission detector is purged with helium, allowing simultaneous, sensitive detection of atomic emission from sulfur 181 nm, phosphorous 186 nm, arsenic 189 nm, selenium 196 nm and carbon 193 nm. Several sediment and coal samples have been analysed for their carbon, nitrogen, sulfur, oxygen, phosphorous, arsenic and selenium content. Qualitative information indicating the occurrence and distribution of these elements in the samples can be used to gauge the relative stage of diagenetic evolution of the samples and provide information on their depositional environment. In some instances the chromatographic behaviour of the compounds produced upon pyrolysis is improved through on-line alkylation. This on-line derivatization is achieved by adding liquid reagents to the pyrolysis probe or by adding liquid reagents to the pyrolysis probe or by adding solid reagents either to the solid sample or by packing the reagent in the injection port of the chromatograph.

Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

Science.gov (United States)

Chen, Luguang; Bhattacharya, Sankar

2013-02-05

Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

In Situ Catalytic Pyrolysis of Low-Rank Coal for the Conversion of Heavy Oils into Light Oils

Directory of Open Access Journals (Sweden)

Muhammad Nadeem Amin

2017-01-01

Full Text Available Lighter tars are largely useful in chemical industries but their quantity is quite little. Catalytic cracking is applied to improve the yield of light tars during pyrolysis. Consequently, in situ upgrading technique through a MoS2 catalyst has been explored in this research work. MoS2 catalyst is useful for the conversion of high energy cost into low energy cost. The variations in coal pyrolysis tar without and with catalyst were determined. Meanwhile, the obtained tar was analyzed using simulated distillation gas chromatograph and Elemental Analyzer. Consequently, the catalyst reduced the pitch contents and increased the fraction of light tar from 50 to 60 wt.% in coal pyrolysis tar. MoS2 catalyst increased the liquid yield from 18 to 33 (wt.%, db and decreased gas yield from 27 to 12 (wt.%, db compared to coal without catalyst. Moreover, it increased H content and hydrogen-to-carbon ratio by 7.9 and 3.3%, respectively, and reduced the contents of nitrogen, sulphur, and oxygen elements by 8.1%, 15.2%, and 23.9%, respectively, in their produced tars compared to coal without catalyst.

Desulphurisation of coal pyrolysis and magnetic separation. Desulfuracion de carbones mediante pirolisis y separacion magnetica

Energy Technology Data Exchange (ETDEWEB)

Ruiz, J.C.; Ayala, N.; Ibarra, J.V.; Moliner, R.; Miranda, J.L.; Vazquez, A. (CENIM, Madrid (Spain))

1991-07-01

The desulphurisation of coal intended for use inthermal power stations is a priority issue in the national strategy for the reduction of acid rain. This article studies the feasibility of eliminating pyritic sulphur from coal by physical methods using high intensity pyrolysis and magnetic separation. 6 refs., 9 figs., 4 tabs.

The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample

Energy Technology Data Exchange (ETDEWEB)

Mody, D.; Li, C.Z.

1999-07-01

A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.

Pyrolysis and liquefaction of acetone and mixed acetone/ tetralin swelled Mukah Balingian Malaysian sub-bituminous coal-The effect on coal conversion and oil yield

International Nuclear Information System (INIS)

Mohd Pauzi Abdullah; Mohd Azlan Mohd Ishak; Khudzir Ismail

2008-01-01

The effect of swelling on Mukah Balingian (MB) Malaysian sub-bituminous coal macrostructure was observed by pyrolysing the swelled coal via thermogravimetry under nitrogen at ambient pressure. The DTG curves of the pyrolyzed swelled coal samples show the presence of evolution peaks at temperature ranging from 235 - 295 degree Celsius that are due to releasing of light molecular weight hydrocarbons. These peaks, however, were not present in the untreated coal, indicating some changes in the coal macrostructure has occurred in the swelled coal samples. The global pyrolysis kinetics for coal that follows the first-order decomposition reaction was used to evaluate the activation energy of the pyrolyzed untreated and swelled coal samples. The results thus far have shown that the activation energy for the acetone and mixed acetone/ tetralin-swelled coal samples exhibit lower values than untreated coal, indicating less energy is required during the pyrolysis process due to the weakening of the coal-coal macromolecular interaction network. Moreover, liquefaction on the swelled coal samples that was carried out at temperatures ranging from 360 to 450 degree Celsius at 4 MPa of nitrogen pressure showed the enhancement of the coal conversion and oil yield at temperature of 420 degree Celsius, with retrogressive reaction started to dominate at higher temperature as indicated by decreased and increased in oil yield and high molecular weight pre-asphaltene, respectively. These observations suggest that the solvent swelling pre-treatment using acetone and mixed acetone/ tetralin can improve the coal conversion and oil yields at less severe liquefaction condition. (author)

Characteristics of Malaysian coals with their pyrolysis and gasification behaviour

International Nuclear Information System (INIS)

Nor Fadzilah Othman; Mohd Hariffin Bosrooh; Kamsani Abdul Majid

2010-01-01

This study was conducted since comprehensive study on the gasification behaviour of Malaysian coals is still lacking. Coals were characterised using heating value determination, proximate analysis, ultimate analysis and ash analysis. Pyrolysis process was investigated using thermogravimetric analyser. While, atmospheric bubbling fluidized bed gasifier was used to investigate the gasification behaviour. Three Malaysian coals, Merit Pila, Mukah Balingian, Silantek; and Australian coal, Hunter Valley coals were used in this study. Thermal degradation of four coal samples were performed, which involved weight loss profile and derivative thermogravimetric (DTG) curves. The kinetic parameters, such as maximum reactivity value, R max , Activation Energy, E a and Arrhenius constant, ln R o for each coal were determined using Arrhenius Equation. Merit Pila coal shows the highest maximum reactivity among other Malaysian coals. E a is the highest for Merit Pila coal (166.81kJmol -1 ) followed with Mukah Balingian (101.15 kJmol -1 ), Hunter Valley (96.45 kJmol -1 ) and Silantek (75.23 kJmol -1 ) coals. This finding indicates direct correlation of lower rank coal with higher E a . Merit Pila coal was studied in detail using atmospheric bubbling fluidized bed gasifier. Different variables such as equivalence ratio (ER) and gasifying agents were used. The highest H 2 proportion (38.3 mol.%) in the producer gas was reached at 715 degree Celsius and ER=0.277 where the maximization of LHV pg (5.56 MJ/Nm 3 ) was also detected. ER and addition of steam had shown significant contributions to the producer gas compositions and LHV pg . (author)

Electric plants to gas, influence of both Mineral Matter and Air Oxidation in coal pyrolysis

International Nuclear Information System (INIS)

Mondragon, F.; Jaramillo, A.; Quintero, G.

1995-01-01

In this work some coal samples from different Colombia's deposits are analyzed. In first stage, material matter is removed from coal by acid treatment with HF/HCl, and aerial oxidation of coal is made with air in oven to 150 Centigrade degree temperature. In second stage, pyrolysis is carried out in two different techniques: 1. Thermogravimetric Analysis (TGA) and 2. Programmed Temperature Pyrolysis (PTP) in a pyrolyzer equipped with a quadrupole mass spectrometer. In both techniques, the coal samples are heated in different rates to 650 Centigrade degree. During PTP trials the evolution of CH4, H2S, hydrocarbons (m/z=42), CO2, benzene and toluene are monitored. Studied coal samples showed: 1). A gas conversion range between 48.8% to 21.8%; 2). A decrease in the gas conversion between 2% to 4%, when oxidation it is applied; 3). The temperature at the one which is presented the maximum evolution of CH4 is similar for all coal samples; 4). The maximum evolution of H2S depends on mineral matter composition, occurs between 480 to 550 Centigrade degrees and is presented due to pyrite decomposition. 5). The evolution of CO2 occurs between 100 to 650 Centigrade degree, its production is generated in different stage of the mentioned temperature range, and in some coal samples is presented due to inorganic origin

Molecular analysis of sulphur-rich brown coals by flash pyrolysis-gas chromatography-mass spectrometry: The type III-S kerogen

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Las Heras, F.X.C. de; Leeuw, J.W. de

1992-01-01

The molecular composition of five brown coals from three different basins (Maestrazgo, Mequinenza and Rubielos) in Spain was investigated by flash pyrolysis-gas chromatography and flash pyrolysis-gas chromatography-mass spectrometry. In these techniques, the macromolecular material is thermally

Experimental studies on the group ignition of a cloud of coal particles: Volume 2, Pyrolysis and ignition modeling

Energy Technology Data Exchange (ETDEWEB)

Annamalai, K.; Ryan, W.

1992-01-01

The primary objectives of this work are to formulate a model to simulate transient coal pyrolysis, ignition, and combustion of a cloud of coal particles and to compare results of the program with those reported in the literature elsewhere.

Thermal-maturity limit for primary thermogenic-gas generation from humic coals as determined by hydrous pyrolysis

Science.gov (United States)

Lewan, Michael; Kotarba, M.J.

2014-01-01

Hydrous-pyrolysis experiments at 360°C (680°F) for 72 h were conducted on 53 humic coals representing ranks from lignite through anthracite to determine the upper maturity limit for hydrocarbon-gas generation from their kerogen and associated bitumen (i.e., primary gas generation). These experimental conditions are below those needed for oil cracking to ensure that generated gas was not derived from the decomposition of expelled oil generated from some of the coals (i.e., secondary gas generation). Experimental results showed that generation of hydrocarbon gas ends before a vitrinite reflectance of 2.0%. This reflectance is equivalent to Rock-Eval maximum-yield temperature and hydrogen indices (HIs) of 555°C (1031°F) and 35 mg/g total organic carbon (TOC), respectively. At these maturity levels, essentially no soluble bitumen is present in the coals before or after hydrous pyrolysis. The equivalent kerogen atomic H/C ratio is 0.50 at the primary gas-generation limit and indicates that no alkyl moieties are remaining to source hydrocarbon gases. The convergence of atomic H/C ratios of type-II and -I kerogen to this same value at a reflectance of indicates that the primary gas-generation limits for humic coal and type-III kerogen also apply to oil-prone kerogen. Although gas generation from source rocks does not exceed vitrinite reflectance values greater than , trapped hydrocarbon gases can remain stable at higher reflectance values. Distinguishing trapped gas from generated gas in hydrous-pyrolysis experiments is readily determined by of the hydrocarbon gases when a -depleted water is used in the experiments. Water serves as a source of hydrogen in hydrous pyrolysis and, as a result, the use of -depleted water is reflected in the generated gases but not pre-existing trapped gases.

Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part IV. Catalytic effects of NaCl and ion-exchangeable Na in coal on char reactivity

Energy Technology Data Exchange (ETDEWEB)

Dimple Mody Quyn; Hongwei Wu; Jun-ichiro Hayashi; Chun-Zhu Li, [Monash University, Monash, Vic. (Australia). CRC for Clean Power from Lignite, Department of Chemical Engineering

2003-03-01

The purpose of this study is to investigate the catalytic effects of Na as NaCl or as sodium carboxylates ( COONa) in Victorian brown coal on the char reactivity. A Na-exchanged coal and a set of NaCl-loaded coal samples prepared from a Loy Yang brown coal were pyrolysed in a fluidised-bed/fixed-bed reactor and in a thermogravimetric analyser (TGA). The reactivities of the chars were measured in air at 400{sup o}C using the TGA. The experimental data indicate that the Na in coal as NaCl and as sodium carboxylates ( COONa) had very different catalytic effects on the char reactivity. It is the chemical form and dispersion of Na in char, not in coal, that govern the catalytic effects of Na. For the Na-form (Na-exchanged) coal, the char reactivity increased with increasing pyrolysis temperature from 500 to 700{sup o}C and then decreased with pyrolysis temperature from 700 to 900{sup o}C. The increase in reactivity with pyrolysis temperature (500 700{sup o}C) is mainly due to the changes in the relative distribution of Na in the char matrix and on the pore surface. For the NaCl-loaded coals, when Cl was released during pyrolysis or gasification, the Na originally present in coal as NaCl showed good catalytic effects for the char gasification. Otherwise, Cl would combine with Na in the char to form NaCl during gasification, preventing Na from becoming an active catalyst. Controlling the pyrolysis conditions to favour the release of Cl can be a promising way to transform NaCl in coal into an active catalyst for char gasification. 38 refs., 5 figs.

Effect of blending ratio to the liquid product on co-pyrolysis of low rank coal and oil palm empty fruit bunch

Directory of Open Access Journals (Sweden)

Zullaikah Siti

2018-01-01

Full Text Available The utilization of Indonesia low rank coal should be maximized, since the source of Indonesia law rank coals were abundant. Pyrolysis of this coal can produce liquid product which can be utilized as fuel and chemical feedstocks. The yield of liquid product is still low due to lower of comparison H/C. Since coal is non-renewable source, an effort of coal saving and to mitigate the production of greenhouse gases, biomass such as oil palm empty fruit bunch (EFB would added as co-feeding. EFB could act as hydrogen donor in co-pyrolysis to increase liquid product. Co-pyrolysis of Indonesia low rank coal and EFB were studied in a drop tube reactor under the certain temperature (t= 500 °C and time (t= 1 h used N2 as purge gas. The effect of blending ratios of coal/EFB (100/0, 75/25, 50/50, 25/75 and 0/100%, w/w % on the yield and composition of liquid product were studied systematically. The results showed that the higher blending ratio, the yield of liquid product and gas obtained increased, while the char decreased. The highest yield of liquid product (28,62 % was obtained used blending ratio of coal/EFB = 25/75, w/w%. Tar composition obtained in this ratio is phenol, polycyclic aromatic hydrocarbons, alkanes, acids, esters.

Differentiation of pre-existing trapped methane from thermogenic methane in an igneous-intruded coal by hydrous pyrolysis

Science.gov (United States)

Dias, Robert F.; Lewan, Michael D.; Birdwell, Justin E.; Kotarba, Maciej J.

2014-01-01

So as to better understand how the gas generation potential of coal changes with increasing rank, same-seam samples of bituminous coal from the Illinois Basin that were naturally matured to varying degrees by the intrusion of an igneous dike were subjected to hydrous pyrolysis (HP) conditions of 360 °C for 72 h. The accumulated methane in the reactor headspace was analyzed for δ13C and δ2H, and mol percent composition. Maximum methane production (9.7 mg/g TOC) occurred in the most immature samples (0.5 %Ro), waning to minimal methane values at 2.44 %Ro (0.67 mg/g TOC), and rebounding to 3.6 mg/g TOC methane in the most mature sample (6.76 %Ro). Methane from coal with the highest initial thermal maturity (6.76 %Ro) shows no isotopic dependence on the reactor water and has a microbial δ13C value of −61‰. However, methane from coal of minimal initial thermal maturity (0.5 %Ro) shows hydrogen isotopic dependence on the reaction water and has a δ13C value of −37‰. The gas released from coals under hydrous pyrolysis conditions represents a quantifiable mixture of ancient (270 Ma) methane (likely microbial) that was generated in situ and trapped within the rock during the rapid heating by the dike, and modern (laboratory) thermogenic methane that was generated from the indigenous organic matter due to thermal maturation induced by hydrous pyrolysis conditions. These findings provide an analytical framework for better assessment of natural gas sources and for differentiating generated gas from pre-existing trapped gas in coals of various ranks.

Pyrolysis of coal, biomass and their blends: performance assessment by thermogravimetric analysis.

Science.gov (United States)

Ferrara, Francesca; Orsini, Alessandro; Plaisant, Alberto; Pettinau, Alberto

2014-11-01

With the aim to support the experimental tests in a gasification pilot plant, the thermal decomposition of coal, biomass and their mixtures has been carried out through a thermogravimetric analysis (TGA) and a simplified kinetic analysis. The TGA of pure fuels indicates the low reactivity of South African coal and the relatively high reactivity of Sardinian Sulcis coal during pyrolysis. Among the tested fuels, biomass (stone pine wood chips) is the most reactive one. These results fully confirm those obtained during the experimental tests in the gasification pilot plant. As for the fuel blends, the analysis shows that the synergic effects between the considered coals and biomass are negligible when they are co-pyrolyzed. The results of the analysis confirm that TGA could be very useful to generally predict the gasification performance and to optimize the experimental campaigns in pilot-scale gasification plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterization of products from pyrolysis of coal with the addition of polyethylene terephthalate

Czech Academy of Sciences Publication Activity Database

Havelcová, Martina; Bičáková, Olga; Sýkorová, Ivana; Weishauptová, Zuzana; Melegy, A.

2016-01-01

Roč. 154, DEC 15 (2016), 123-131 ISSN 0378-3820 R&D Projects: GA ČR(CZ) GA13-18482S Grant - others:OPPK(XE) CZ.2.16/3.1.00/21538 Program:OPPK Institutional support: RVO:67985891 Keywords : pyrolysis * sub-bituminous coal * polyethylene terephthalate * coke Subject RIV: DD - Geochemistry Impact factor: 3.752, year: 2016

Coal pyrolysis in a continuous fluidized bed - process development studies

Energy Technology Data Exchange (ETDEWEB)

Ramakrishnan, N N; Akmal, M A.K.; Vaidyeswaran, R

1981-10-01

The paper deals with the development of a process development unit (PDU) for the fluid bed pyrolysis of non-caking slack coal obtained from Singareni and Talcher coalfields. Preheated air is used as the fluidizing medium. It is necessary to avoid its maldistribution by a suitable design of the gas distributor. In this regard perforated conical distributors appear to play an important role. In the low temperature carbonization of coal an operation around 500 C gives optimum yields of char and tar of desirable quality. Carbonization reactions are generally completed within about 20 min of the feed entry into the fluidized bed and the char attains an equilibrium volatile matter content. Since air is used as the fluidizing medium carbonization gas is diluted with nitrogen and non-combustibles. The heating value of the gas is low. (5 refs.)

Mutagenicity of complex mixtures

International Nuclear Information System (INIS)

Pelroy, R.A.

1985-01-01

The effect of coal-derived complex chemical mixtures on the mutagenicity of 6-aminochrysene (6-AC) was determined with Salmonella typhimurium TA98. Previous results suggested that the mutagenic potency of 6-AC for TA98 in the standard microsomal activation (Ames) assay increased if it was presented to the cells mixed with high-boiling coal liquids (CL) from the solvent refined coal (SRC) process. In this year's work, the apparent mutational synergism of CL and 6-AC was independently verified in a fluctuation bioassay which allowed quantitation of mutational frequencies and cell viability. The results of this assay system were similar to those in the Ames assay. Moreover, the fluctation assay revealed that mutagenesis and cellular toxicity induced by 6-AC were both strongly enhanced if 6-AC was presented to the cells mixed in a high-boiling CL. 4 figures

MINIMIZING NET CO2 EMISSIONS BY OXIDATIVE CO-PYROLYSIS OF COAL / BIOMASS BLENDS

Energy Technology Data Exchange (ETDEWEB)

Todd Lang; Robert Hurt

2001-12-23

This study presents a set of thermodynamic calculations on the optimal mode of solid fuel utilization considering a wide range of fuel types and processing technologies. The technologies include stand-alone combustion, biomass/coal cofiring, oxidative pyrolysis, and straight carbonization with no energy recovery but with elemental carbon storage. The results show that the thermodynamically optimal way to process solid fuels depends strongly on the specific fuels and technologies available, the local demand for heat or for electricity, and the local baseline energy-production method. Burning renewable fuels reduces anthropogenic CO{sub 2} emissions as widely recognized. In certain cases, however, other processing methods are equally or more effective, including the simple carbonization or oxidative pyrolysis of biomass fuels.

Using the Salmonella assay to delineate the dispersion routes of mutagenic compounds from coal wastes in contaminated soil.

Science.gov (United States)

da Silva Júnior, Flavio Manoel Rodrigues; Vargas, Vera Maria Ferrão

2009-03-17

The mutagenicity of acidic and organic extracts of surface soil under the influence of a coal-fired power plant was evaluated by Salmonella/microsome assay using strains TA97a, TA98 and TA100 in the absence and presence of exogenous metabolic systems (S9 mix). Additionally, strains YG1041 and YG1042 (sensitive to nitroderivatives) were used for the organic extracts. In general, the responses were higher in the organic extracts in the presence of S9 mix. The comparison between strains TA98 and TA100 and their derived strains YG1041 and YG1042, respectively, allowed the detection of the presence of nitro-aromatic compounds in some sampling areas, which was confirmed by chemical analysis. The interpretation of the set of mutagenesis data suggests that there are two important mutagenic compound dispersion routes in the area of study: frameshift mutagens were dispersed predominantly by runoff and leaching, while base-pair substitution mutagens were dispersed mainly by the atmosphere. This mutagenic damage might be attributed to the effects of several substances detected in the area, such as aliphatic hydrocarbons and the metals aluminum, cadmium, lead and iron.

Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Ruediger, H; Greul, U; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1997-12-31

Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Ruediger, H.; Greul, U.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1996-12-31

Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

Use of pyrolysis gas from coal as reburn fuel. Final report; Einsatz von kohlestaemmigem Pyrolysegas als Reduktionsbrennstoff. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Greul, U.; Magel, C.; Moersch, O.; Ruediger, H.; Storm, C.; Schnell, U.; Spliethoff, H.; Hein, K.R.G.

1996-12-31

The research project`s aim was to reduce nitrogen emissions from pulverized-coal furnaces by fuel staging with pyrolysis gas from coal. The test fuels were 6 German and Australian coals. The aim achieved has been the statement that the described method is an adequate means to attain to and remain below emission values of 200 mg/m{sup 3}. The method of fuel staging using coal-original gases was investigated with tests focussing the most important process parameters such as coal type, devolatilization ratio, temperature, residence time, and stoichiometry. The relevant features determined with an entrained flow reactor and with a fluidized-bed reactor were the impact of devolatilization temperatures on carbonized residue and pyrolysis products, the distribution of fuel nitrogen, and the quality of gas and tar, including the respective effects on NO{sub x} formation and reduction in staged combustion. The validation of the mathematical model was done with the experimentally obtained data. The criteria considered fundamental for achieving the NO{sub x} reduction level are temperature, air ratio, and residence time in the reduction zone of the furnace. The pyrolysis tests manifested the strong influence of the coal type and the devolatilization conditions on the composition of the gases and the attainable NO{sub x} reduction. The tars in the pyrolysis gases, with their nitrogen compounds, improve the reducing effect of available nitrogen oxides. By using pyrolysis gases from coal as reburning fuel, NO{sub x} emissions of less than 200 mg/m{sup 3} can be obtained at air ratios around 0.95. (orig./SR) [Deutsch] Das Forschungsprojekt verfolgte das Ziel mit 6 deutschen und australischen Kohlen die Stickoxidemissionen aus Kohlestaubfeuerungen durch Brennstoffstufung mit Pyrolysegas als Reduktionsbrennstoff zu verringern. Das erreichte Ziel war der Nachweis, dass mit dem beschriebenen Verfahren NO{sub x}-Emissionswerte von 200 mg/m{sup 3} erreicht und unterschritten werden

Decomposition of pyrite and the interaction of pyrite with coal organic matrix in pyrolysis and hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

Chen, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

1999-07-01

The thermal decomposition and reduction behaviour of pure pyrite crystals were studied under nitrogen and hydrogen atmospheres. Decomposition of pyrite in coal during pyrolysis and hydropyrolysis, and the behaviour of organic sulphur, are discussed. Temperature and pressure effects are considered. 7 refs., 6 figs., 1 tab.

Desulfurization of coal by pyrolysis and hydropyrolysis with addition of KOH/NaOH

Energy Technology Data Exchange (ETDEWEB)

Quanrun Liu; Haoquan Hu; Shengwei Zhu; Qiang Zhou; Wenying Li; Xianyong Wei; Kechang Xie [Dalian University of Technology, Dalian (China). Institute of Coal Chemical Engineering

2005-08-01

In this paper, a two-step desulfurization process for high-sulfur coal was investigated. Two Chinese coals with the addition of 10 wt % potassium hydroxide or sodium hydroxide were pyrolyzed under an atmosphere of nitrogen or hydrogen in a fixed-bed reactor at 600{sup o}C, and then the obtained chars were washed with hot water. The results indicated that, without the addition of an alkali component, the sulfur removal of these two coals by pyrolysis and hydropyrolysis is {approximately}40%-50% and the sulfur content of chars is reduced only slightly, in comparison with the original coals; with the addition of 10 wt % potassium hydroxide or sodium hydroxide into the original coals and the chars being washed with hot water, the sulfur removal is {approximately}70%-80% and the sulfur content in chars is reduced dramatically. The combustion behavior of chars was also investigated, using thermogravimetric analysis. The results showed that those chars that had an added alkali component and were subjected to water-washing were more reactive and can be burned more easily than those without added alkali, which was also confirmed by a kinetics analysis of char combustion. 21 refs., 3 figs., 6 tabs.

Bacterial and human cell mutagenicity study of some C[sub 18]H[sub 10] cyclopenta-fused polycyclic aromatic hydrocarbons associated with fossil fuels combustion

Energy Technology Data Exchange (ETDEWEB)

Lafleur, A.L.; Longwell, J.P.; Marr, J.A.; Monchamp, P.A.; Thilly, W.G. (Massachusetts Institute of Technology, Cambridge (United States)); Mulder, P.P.Y.; Boere, B.B.; Cornelisse, J.; Lugtenburg, J. (Univ. of Leiden (Netherlands))

1993-06-01

A number of isomeric C[sub 18]H[sub 10] polycyclic aromatic hydrocarbons (PAHs), thought to be primarily cyclopenta-fused PAHs, are produced during the combustion and pyrolysis of fossil fuels. To determine the importance of their contributions to the total mutagenic activity of combustion and pyrolysis samples in which they are found, we characterized reference quantities of four C[sub 18]H[sub 10] CP-PAHs: benzol [ghi] fluoranthene (BF), cyclopenta [cd] pyrene (CPP), cyclopent [hi] acephenanthrylene (CPAP), and cyclopent [hi] acaenthrylene (CPAA). Synthesis of CPAA and CPAP is described. The availability of reference samples of these isomers also proved to be an essential aid in the identification of the C[sub 18]H[sub 10] species often found in combustion and pyrolysis samples. Chemical analysis of selected combustion and pyrolysis samples showed that CPP was generally the most abundant C[sub 18]H[sub 10] isomer, followed by CPAP and BF. CPAA was detected only in pyrolysis products from pure PAHs. We tested the four C[sub 18]H[sub 10] PAHs for mutagenicity in a forward mutation assay using S. typhimurium. CPP, BF, and CPAA were roughly twice as mutagenic as benzo[a]pyrene (BaP), whereas CPAP was only slightly active. These PAHs were also tested for mutagenic activity in human cells. In this assay, CPP and CPAA were strongly mutagenic but less active than BaP, whereas CPAP and BF were inactive at the dose levels tested. Also, the bacterial and human cell mutagenicity of CPAA and CPAP were compared with the mutagenicity of their monocyclopenta-fused analogs, aceanthrylene and acephenanthrylene. Although the mutagenicities of CPAP and acephenanthrylene are similar, the mutagenic activity of CPAA is an order of magnitude greater than that of aceanthrylene.

Laser induced pyrolysis techniques

International Nuclear Information System (INIS)

Vanderborgh, N.E.

1976-01-01

The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

Experimental study of Coal Pyrolysis 1.: Review of the experimental information from the literature

International Nuclear Information System (INIS)

Hugony, F.; Migliavacca, G.

2007-01-01

A brief analysis of some of the main experimental works published in the past decades about coal pyrolysis is here reported. In particular the results of some series of experiments are cited and reported in details, coming from the activity of some important international research teams; they supply a survey wide and complete enough of the different operating and experimental conditions proposed in this field. With the aim of giving a comparison benchmark for the original experimental data published in the companion paper of this series and in order to grant a good support to the validation of the predictive models of coal devolatilization [it

Quantitative analysis of sulfur forms of coal and the pyrolysis behavior of sulfur compounds; Sekitanchu no io kagobutsu no keitaibetsu gan`yuryo no teiryo to sono netsubunkai kyodo

Energy Technology Data Exchange (ETDEWEB)

Mae, K.; Miura, K.; Shimada, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

1996-10-28

As part of the studies on coal utilization basics, considerations were given on quantification of sulfur forms of coal and the pyrolysis behavior of sulfur compounds. With the temperature raising oxidation method, a thermo-balance was connected directly to a mass analyzer, and the coal temperature was raised at a rate of 5{degree}C per minute and gasified. Peak division was performed on SO2 and COS production to derive sulfur forms of coal. Using the slow-speed pyrolysis method, production rates of H2S, COS, SO2 and mercaptans were measured at a temperature raising rate of 20{degree}C per minute. Sulfur content in char was also measured. With the quick pyrolysis method, a Curie point pyrolyzer was connected directly to a gas chromatograph, by which secondary reaction is suppressed, and initial pyrolytic behavior can be tracked. All kinds of coals produce a considerable amount of SO2 in the slow-speed pyrolysis, but very little in the quick pyrolysis. Instead, H2S and mercaptans are produced. Sulfur compound producing mechanisms vary depending on the temperature raising rates. By using a parallel primary reaction model, analysis was made on reactions of H2S production based on different activation energies, such as those generated from pyrite decomposition and organic sulfur decomposition. The analytic result agreed also with that from the temperature raising oxidation method. 4 refs., 6 figs., 1 tab.

Pyrolysis of coal in the presence of nitric oxide

Energy Technology Data Exchange (ETDEWEB)

Berkowitz, N; Dammeyer, W

1956-01-01

Examination of tars obtained by low-temperature carbonization of a subbituminous coal in the presence of NO suggests that NO will both retard thermal decomposition and inhibit secondary polymerization in the tar phase. But both reactions are subject to the condition that NO is present at the start of incipient pyrolysis (they do not occur if NO is admitted to the retorts at a point above the decomposition temperature of the coal), and their extent depends sharply upon the concentration of NO. At comparatively low partial pressure of NO, the dominant reaction is retardation of decomposition; significant modification of the tar, leading to a greater proportion of low-boiling material, is confined to high-partial pressure of NO. Conclusions, after analyzing tar yields and infrared spectra of tar fractions, are that the inhibition of secondary polymerization in the tar phase involves the transient attachment of NO to primary tar molecules, and that the inhibitory effect of NO is essentially temporary. Tars modified by NO do not appear to be more stable than normal tars in the presence of light, and their composition, as determined by infrared spectroscopy, is not perceptibly different.

Preparation of combustible material from high sulphur coal by means of pyrolysis: magnetic separation; Obtencion de combustibles limpios a partir de carbones con altos contenidos en azure mediante procesos de pirolisis: separacion magnetica

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-11-01

Basic studies on coal desulphurization by pyrolysis have been carried out with a series of low rank coals with high total sulphur contents and differences in the distribution of sulphur forms. The evolved sulphur compounds were studied by sulphide selective electrode H{sub 2}S and Fourier transform infrared (FTIR) spectroscopy. The mechanisms affecting the sulphur removal during pyrolysis have been studied by scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) and photoelectronic spectroscopy (XPS). A sample coal of 11 Tm, representative of the Teruel basins was processed at pilot scale in a rotary kiln (coal HR). A series of pyrolysis runs simulating the experimental conditions of the rotary kiln were also carried out in laboratory scale. The magnetic behaviour of the chars from the rotary kiln and from the lab-scale pyrolysis was tested. The efficiency of the desulphurization, including pyrolysis and magnetic separation, was calculated. Chars from rotary kiln were tested by thermogravimetric analysis, air reactivity and carbon efficiency combustion in fluidized bed.

Transformation of sulfur during pyrolysis and hydropyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Chen, H.; Li, B.; Yang, J.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

1998-05-01

It is reported that the transformation of sulfur during pyrolysis (Py) under nitrogen and hydropyrolysis (HyPy) of Chinese Yanzhou high sulfur bituminous coal and Hongmiao lignite was studied in a fixed-bed reactor. The volatile sulfur-containing products were determined by gas chromatography with flame photometric detection. The sulfur in initial coal and char (mainly aliphatic and thiophenic sulfur forms) was quantitatively analyzed using X-ray photoelectron spectroscopy (XPS). The desulfurization yield was calculated by elemental analysis. The main volatile sulfur-containing gas was H{sub 2}S in both Py and HyPy. Both the elemental analysis and XPS results indicated that more sulfur was removed in HyPy than in Py under nitrogen. Thiophenic sulfur can be partially hydrogenated and removed in HyPy. Pyrite can be reduced to a ferrous sulfide completely even as low as 400{degree}C in HyPy while in Py the reduction reaction continues up to 650{degree}C. Mineral matter can not only fix H{sub 2}S produced in Py and HyPy to form higher sulfur content chars but also catalyses the desulfurization reactions to form lower sulfur content tars in HyPy. 24 refs., 8 figs., 4 tabs.

Co-pyrolysis of waste tire/coal mixtures for smokeless fuel, maltenes and hydrogen-rich gas production

Czech Academy of Sciences Publication Activity Database

Bičáková, Olga; Straka, Pavel

2016-01-01

Roč. 116, MAY 15 (2016), s. 203-213 ISSN 0196-8904 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21538 Program:OPPK Institutional support: RVO:67985891 Keywords : waste tires * coal * co-pyrolysis * smokeless fuel * tar * hydrogen -rich gas Subject RIV: DM - Solid Waste and Recycling Impact factor: 5.589, year: 2016 http://www.sciencedirect.com/science/article/pii/S0196890416300991

Experimental studies on the group ignition of a cloud of coal particles: Volume 2, Pyrolysis and ignition modeling. Final report, August 15, 1988--October 15, 1991

Energy Technology Data Exchange (ETDEWEB)

Annamalai, K.; Ryan, W.

1992-01-01

The primary objectives of this work are to formulate a model to simulate transient coal pyrolysis, ignition, and combustion of a cloud of coal particles and to compare results of the program with those reported in the literature elsewhere.

Thermal characteristics and surface morphology of char during co-pyrolysis of low-rank coal blended with microalgal biomass: Effects of Nannochloropsis and Chlorella.

Science.gov (United States)

Wu, Zhiqiang; Yang, Wangcai; Yang, Bolun

2018-02-01

In this work, the influence of Nannochloropsis and Chlorella on the thermal behavior and surface morphology of char during the co-pyrolysis process were explored. Thermogravimetric and iso-conversional methods were applied to analyzing the pyrolytic and kinetic characteristics for different mass ratios of microalgae and low-rank coal (0, 3:1, 1:1, 1:3 and 1). Fractal theory was used to quantitatively determine the effect of microalgae on the morphological texture of co-pyrolysis char. The result indicated that both the Nannochloropsis and Chlorella promoted the release of volatile from low-rank coal. Different synergistic effects on the thermal parameters and yield of volatile were observed, which could be attributed to the different compositions in the Nannochloropsis and Chlorella and operating condition. The distribution of activation energies shows nonadditive characteristics. Fractal dimensions of the co-pyrolysis char were higher than the individual char, indicating the promotion of disordered degree due to the addition of microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

New method for reduction of burning sulfur of coal

International Nuclear Information System (INIS)

Lyutskanov, L.; Dushanov, D.

1998-01-01

The coal pyrolysis is key phase in the the pyrolysis-combustion cycle as it provides char for combustor. The behaviour of sulfur compounds during coal pyrolysis depends on factors as rank of coal, quantity of sulfur and sulfur forms distribution in the coal, quantity and kind of mineral matter and the process conditions. The mineral content of coal may inhibit or catalyze the formation of volatile sulfur compounds. The pyrolysis itself is a mean of removing inorganic and organic sulfur but anyway a portion of it remains in the char while the other moves into the tar and gas. The aim of this study was to determine an optimal reduction of burning sulfur at the coal pyrolysis by varying parametric conditions. The pyrolysis of different kinds of coal has been studied. The samples with size particles o C at atmospheric pressure and with a heating rate of 6-50 o C min -1 . They were treated with exhaust gas and nitrogen at an addition of steam and air. The char obtained remains up to 10 min at the final temperature. The char samples cool without a contact with air. Two methods of desulfurization-pyrolysis were studied - using 9-vertical tubular reactor and 9-horizontal turning reactor. The results obtained show that at all samples there is a decrease of burning sulfur with maximal removal efficiency 83%. For example at a pyrolysis of Maritsa Iztok lignite coal the burning sulfur is only 16% in comparison with the control sample. The remained is 90% sulfate, 10% organic and pyrite traces when a mixture 'exhaust gas-water stream-air' was used. The method of desulfurization by pyrolysis could be applied at different kinds of coal and different conditions. Char obtained as a clean product can be used for generating electric power. This innovation is in a stage of patenting

Pyrolysis of superfine pulverized coal. Part 4. Evolution of functionalities in chars

International Nuclear Information System (INIS)

Liu, Jiaxun; Ma, Yang; Luo, Lei; Ma, Junfang; Zhang, Hai; Jiang, Xiumin

2017-01-01

Highlights: • A combination of XPS and NMR is adopted for analyzing char chemical structures during superfine pulverized coal pyrolysis. • The chemisorbed NO can be transformed into pyridine N with the favor of adjacent oxygenated groups in chars. • Particle size has significant influence on oxygen-containing configurations in chars. - Abstract: The properties of the coal-derived char play crucial roles in coal conversion reactions and the formation of air pollutants. The nascent char is highly reactive due to the existence of numerous free radicals, active sites, and organic functional groups on its surface. Here, we showed that a combination of nuclear magnetic resonance spectroscopy (NMR) and X-ray photoelectron spectroscopy (XPS) techniques is an effective and precise way to characterize the occurrence, distribution, and evolution of organic functionalities in coal chars. Using these methods, we explored detailed information about chemical features of superfine pulverized coal chars in different atmospheres, and we also discussed the influence of particle size on the evolutionary behavior of functionalities. Results indicate that, in both N_2 and CO_2 atmospheres, the content of C−O species increases with the reduction in char particle sizes. This increment facilitates the heterogeneous reduction of NOx on char surfaces. The chemisorbed NO is susceptible to being incorporated into chars, and being transformed into pyridine-type nitrogen with the favor of adjacent oxygen-containing groups. Moreover, the significant increment in oxygen-containing groups with the reduction of particle size is further confirmed through "1"3C NMR analysis. It was shown that there is an excellent correlation between estimates derived from XPS and NMR for oxygen configuration. The findings from this work provide some new insights into NOx reduction mechanisms and shed light on the practical application of superfine pulverized coal in the future.

New approach to the characterization of pyrolysis coal products by gas chromatography mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Cappiello, A.; Mangani, F.; Bruner, F.; Bonfanti, L. [University of Urbino, Urbino (Italy)

1996-06-07

A method for the characterization of coal thermal behaviour, based on gas chromatographic-mass spectrometric analysis of the pyrolysate, is presented. Twelve different coal samples representative of the entire coal rank, were selected. The pyrolysis products, obtained at 800{degree}C, were first collected and then analysed in two GC-MS systems. The sampling apparatus consisted of three different traps in order to separate the products into three fractions on the basis of their volatility. The GC-MS analysis was also arranged according to this criterion. A packed column, coupled to a double-focusing magnetic mass spectrometer, was used for the volatile fractions of the pyrolysate and a capillary column, coupled to a quadruple analyser, was employed for the analysis of the condensed fraction. Sampling and analysis procedures were carried out separately, thus allowing careful optimization of the strategy for the characterization of the pyrolysate. The condensate was analysed in the selected-ion monitoring mode for the determination of different classes of compounds. Some evaluations and comparisons, extrapolated from the results obtained, are presented.

Relations between flash pyrolysis reactivity and oil/gas products from coals of different rank; Sekitankado no kotonaru shushu no sekitan no flash pyrolysis hannosei to gas oyobi eki seiseibutsu no kankei

Energy Technology Data Exchange (ETDEWEB)

Nonaka, T.; Kishino, M.; Sakanishi, K.; Korai, Y.; Mochida, I. [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study

1996-10-28

Curie point flash pyrolysis (FP) reactivity was studied experimentally using three kinds of coals with different coal ranks such as Yallourn brown coal, Tanitoharum sub-bituminous coal and Wandoan sub-bituminous coal. Experiment was performed using a curie point pyrolyzer in carrier gas of 20ml/min in gas flow rate at 450, 590 and 740{degree}C for 5sec. The experimental results were as follows. Each gas component obviously increased at 450-590{degree}C, however, C4-C6 gases drastically decreased at 590-740{degree}C accompanying reduction of the whole gas quantity. All of each polar component remarkably increased at 450-590{degree}C. Yallourn brown coal with high Owt%, in particular, contained a large amount of alkyl-hydroxybenzene group. The amount of cresol of all of three coal specimens also increased at 740{degree}C. It was thus suggested that this is coal constituent molecules derived from cutting of methylene-ether bridged bond by higher-temperature FP. 8 refs., 5 figs., 3 tabs.

Metabolic aspects of pyrolysis mutagens in food

International Nuclear Information System (INIS)

Sato, S.; Negishi, C.; Umemoto, A.; Sugimura, T.

1986-01-01

The first step in metabolic activation of mutagenic and carcinogenic heterocyclic amines has been elucidated to be N-hydroxylation by cytochrome P-448. N-Hydroxyamino compounds are further activated to form N-O-acyl derivatives that readily react with DNA. The adducts between the metabolites of Trp-P-2 and Glu-P-1 and DNA were shown to have a C 8 -guanylamino structure. In the case of Glu-P-1, modification of guanine in GC clusters occurred preferentially. Glutathione transferases and myeloperoxidase were shown to inactivate some heterocyclic amines or their active metabolites. Hemin and fatty acids bind to and inactivate them. Fibers and other factors from vegetables also work to inactivate heterocyclic amines. Nitrite at low pH also degraded some heterocyclic amines, but those with an imidazole moiety were resistant. Glu-P-1 induced intestinal tumors in a high incidence when fed orally to rats. When 14 C-Glu-P-1 was administered by gavage into rats about 50% and 35% were excreted into feces and urine, respectively, within 24 hr. When the bile was collected, around 60% of radioactivity was excreted into it within 24 hr. In the bile, N-acetyl-Glu-P-1 was identified as one of the metabolites of Glu-P-1. It showed a mutagenic activity of about one fourth that of Glu-P-1 with S9 mix. Some radioactivity was also detected in the blood. At 24 hr after administration, most of the radioactivity was found to be bound to erythrocyte β-globins and serum proteins including albumin

Thermal relaxation of bituminous coal to improve donation ability of hydrogen radicals in flash pyrolysis; Sekitan kozo kanwa ni yoru suiso radical kyoyo noryoku no kojo wo mezashita netsubunkai mae shori

Energy Technology Data Exchange (ETDEWEB)

Mori, T.; Isoda, T.; Kusakabe, K.; Morooka, S. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hayashi, J. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

1996-10-28

In terms of coal conversion reaction, the behavior of bituminous coal heated beyond a glass transition point was examined on the basis of pyrolyzed products, and the effect of an increase in proton mobility on promotion of coal decomposition was evaluated. In experiment, after Illinois bituminous coal specimen was heated up to a specific temperature in N2 or He gas flow at a rate of 5K/min, the specimen was directly transferred to a pyrolyzer for instantaneous pyrolysis. As the experimental result, the glass transition temperature of the Illinois coal specimen was calculated to be 589K from a differential scanning calorimetry (DSC) profile. From the pyrolysis result of the Illinois coal specimen heated up to 623K, the char yield decreased by 3kg as compared with that of the original coal, while the tar yield increased by 4kg up to 27kg per 100kg of the original coal. This tar increase was larger than that of cooled coal. These results suggested that the donation of hydrogen radicals to coal fragments is improved with an increase in proton mobility. 4 refs., 4 figs., 1 tab.

Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system

Energy Technology Data Exchange (ETDEWEB)

1992-01-13

The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

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 ...

Chemical and Pyrolytic Thermogravimetric Characterization of Nigerian Bituminous Coals

Directory of Open Access Journals (Sweden)

Nyakuma Bemgba Bevan

2016-12-01

Full Text Available The discovery of new coal deposits in Nigeria presents solutions for nation’s energy crises and prospects for socioeconomic growth and sustainable development. Furthermore, the quest for sustainable energy to limit global warming, climate change, and environmental degradation has necessitated the exploration of alternatives using cleaner technologies such as coal pyrolysis. However, a lack of comprehensive data on physico-chemical and thermal properties of Nigerian coals has greatly limited their utilization. Therefore, the physico-chemical properties, rank (classification, and thermal decomposition profiles of two Nigerian bituminous coals – Afuze (AFZ and Shankodi-Jangwa (SKJ – were examined in this study. The results indicate that the coals contain high proportions of C, H, N, S, O and a sufficiently high heating value (HHV for energy conversion. The coal classification revealed that the Afuze (AFZ coal possesses a higher rank, maturity, and coal properties compared to the Shankodi-Jangwa (SKJ coal. A thermal analysis demonstrated that coal pyrolysis in both cases occurred in three stages; drying (30-200 °C, devolatilization (200-600 °C, and char decomposition (600-1000 °C. The results also indicated that pyrolysis at 1000 °C is not sufficient for complete pyrolysis. In general, the thermochemical and pyrolytic fuel properties indicate that the coal from both places can potentially be utilized for future clean energy applications.

Kinetics of coal pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Seery, D.J.; Freihaut, J.D.; Proscia, W.M. (United Technologies Research Center, East Hartford, CT (USA)); Howard, J.B.; Peters, W.; Hsu, J.; Hajaligol, M.; Sarofim, A. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Jenkins, R.; Mallin, J.; Espindola-Merin, B. (Pennsylvania State Univ., University Park, PA (USA)); Essenhigh, R.; Misra, M.K. (Ohio State Univ., Columbus, OH (USA))

1989-07-01

This report contains results of a coordinated, multi-laboratory investigation of coal devolatilization. Data is reported pertaining to the devolatilization for bituminous coals over three orders of magnitude in apparent heating rate (100 to 100,000 + {degree}C/sec), over two orders of magnitude in particle size (20 to 700 microns), final particle temperatures from 400 to 1600{degree}C, heat transfer modes ranging from convection to radiative, ambient pressure ranging from near vacuum to one atmosphere pressure. The heat transfer characteristics of the reactors are reported in detail. It is assumed the experimental results are to form the basis of a devolatilization data base. Empirical rate expressions are developed for each phase of devolatilization which, when coupled to an awareness of the heat transfer rate potential of a particular devolatilization reactor, indicate the kinetics emphasized by a particular system reactor plus coal sample. The analysis indicates the particular phase of devolatilization that will be emphasized by a particular reactor type and, thereby, the kinetic expressions appropriate to that devolatilization system. Engineering rate expressions are developed from the empirical rate expressions in the context of a fundamental understanding of coal devolatilization developed in the course of the investigation. 164 refs., 223 figs., 44 tabs.

Inclined fluidized bed system for drying fine coal

Science.gov (United States)

Cha, Chang Y.; Merriam, Norman W.; Boysen, John E.

1992-02-11

Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

Influence of impregnation by inorganic substances on the yield of pyrolysis products

Energy Technology Data Exchange (ETDEWEB)

Shevkoplyas, V N; Saranchuk, V I [AN Ukrainskoj SSR, Donetsk (Ukraine). Inst. Fiziko-Organicheskoj Khimii i Uglekhimii

1998-09-01

In papers was shown that fossil coals impregnation by aqueous solution of inorganic substances with a subsequent pyrolysis leads to the rise of the rate and depth of its organic mass destruction into liquid and gaseous products. This is, apperently, conditioned by changes in coals structure already on the stage of treatment. But, there are few papers that study an activating effect of inorganic reactants upon natural coals structure and their behaviour at pyrolysis. One of the methods which allows to judge structural transformation in coals at their impregnation by inorganic substances is an X-ray analysis. (orig.)

Pyrolysis process and apparatus

Science.gov (United States)

Lee, Chang-Kuei

1983-01-01

This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

Combustion reactivity of chars from copyrolysis of coal with coke-oven gas

Energy Technology Data Exchange (ETDEWEB)

Liao Hongqiang; Sun Chenggong; Li Baoqing [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

1997-12-31

The combustion reactivity of char from pyrolysis of Xianfeng lignite with coke-oven gas (COG) is related to the pyrolysis pressure and heating rate. Decreasing pressure and increasing heating rate enhance the char yields and combustion reactivity. The combustion reactivities of char from coal pyrolysis with COG nearly reach to that of char from hydropyrolysis, but lower than those of char from coal pyrolysis under N{sub 2}. (orig.)

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.

Literature survey of properties of synfuels derived from coal

Science.gov (United States)

Reynolds, T. W.; Niedzwiecki, R. W.; Clark, J. S.

1980-02-01

A literature survey of the properties of synfuels for ground-based gas turbine applications is presented. Four major concepts for converting coal into liquid fuels are described: solvent extraction, catalytic liquefaction, pyrolysis, and indirect liquefaction. Data on full range syncrudes, various distillate cuts, and upgraded products are presented for fuels derived from various processes, including H-coal, synthoil, solvent-refined coal, donor solvent, zinc chloride hydrocracking, co-steam, and flash pyrolysis. Some typical ranges of data for coal-derived low Btu gases are also presented.

Literature survey of properties of synfuels derived from coal

Science.gov (United States)

Reynolds, T. W.; Niedzwiecki, R. W.; Clark, J. S.

1980-01-01

A literature survey of the properties of synfuels for ground-based gas turbine applications is presented. Four major concepts for converting coal into liquid fuels are described: solvent extraction, catalytic liquefaction, pyrolysis, and indirect liquefaction. Data on full range syncrudes, various distillate cuts, and upgraded products are presented for fuels derived from various processes, including H-coal, synthoil, solvent-refined coal, donor solvent, zinc chloride hydrocracking, co-steam, and flash pyrolysis. Some typical ranges of data for coal-derived low Btu gases are also presented.

Pyrolitics Oils in Coal Flotation

OpenAIRE

Čáblík, V.; Išek, J.; Herková, M.; Halas, J.; Čáblíková, L.; Vaculíková, L. (Lenka)

2014-01-01

The aim of this article was the research of new flotation reagents, which were formed through pyrolysis of different types of waste. Potential new flotation reagents are liquid organic phase pyrolysis of tires, plastic and wooden materials. Another goal is to achieve the coal flotation ash content quality below 10%. The results imply that it is possible to produce flotation collectors from various types of waste, which may be applicabe in black coal flotation. Producing and application of a s...

Experiments and stochastic simulations of lignite coal during pyrolysis and gasification

International Nuclear Information System (INIS)

Ahmed, I.I.; Gupta, A.K.

2013-01-01

Highlights: ► Lignite pyrolysis and gasification has been conducted in a semi batch reactor. ► The objective is to understand mechanism of syngas evolution during pyrolysis. ► Stochastic simulations of lignite pyrolysis were conducted using Gillespie algorithm. ► First order, single step mechanism failed to fit cumulative yield of hydrogen. ► Evolution of hydrogen via pyrolysis of gaseous hydrocarbon following bridges scission. -- Abstract: Lignite pyrolysis and gasification has been conducted in a semi batch reactor at reactor temperatures of 800–950 °C in 50 °C intervals. CO 2 has been used as the gasifying agent for gasification experiments. The objective of this investigation is to understand the mechanism of syngas evolution during pyrolysis and to unravel the effect of CO 2 on pyrolysis mechanism. Stochastic simulations of lignite pyrolysis have been conducted using Gillespie algorithm. Two reaction mechanisms have been used in the simulations; first order, single step mechanism and the FLASHCHAIN mechanism. The first order single step mechanism was successful in fitting cumulative yield of CO 2 , CO, CH 4 and other hydrocarbons (C n H m ). The first order, single step failed to fit the cumulative yield of hydrogen, which suggests a more complex mechanism for hydrogen evolution. Evolution of CO 2 , CO, CH 4 , C n H m and H 2 flow rates has been monitored. The only effect of CO 2 on pyrolysis mechanism is promotion of reverse water gas shift reaction for the experiments described here. Methane evolution extended for slightly longer time than other hydrocarbons and hydrogen evolution extended for a slightly longer time than methane. This indicated the evolution of hydrogen via further pyrolysis of aliphatic hydrocarbon. It is also suggested that this step occurs in series after aliphatic hydrocarbons evolution by bridges scission.

Mutagenicity of Tween 80-solvated mild gasification products in the Ames salmonella microsomal assay system. [Quarterly report, October--December 1991

Energy Technology Data Exchange (ETDEWEB)

1992-01-13

The results of the Tween 80-solvated Ames testing of six mild gasification samples indicate significant mutagenic activity only in the composite materials (MG-119 and MG-120), previously suspected from the DMSO-solvated assays, which had shown some variable but ultimately insignificant mutagenic responses. The activity of these samples from the Tween 80-solvated assays was quite low when compared to either the positive controls or the SRC-II HD coal-liquefaction reference material. The class of mutagenic activity expressed by these samples solvated in Tween 80 was that of an indirect-acting, frameshift mutagen(s) since significant activity was found only on tester strain TA98 in the presence of the metabolic activation fraction (S9). Because DMSO and other solvents have been shown to affect the mutagenic activity of certain pure chemicals, the possibility of solvent/mutagen interactions in complex mixtures such as coal-derived liquids exists. Thus, the testing of the genotoxic activity of undefined, chemically complex compounds may require the use of at least two solvent systems to reduce the possibility of artifactual findings. 10 refs., 4 tabs.

Bioassays for risk assessment of coal conversion products

Energy Technology Data Exchange (ETDEWEB)

Schacht, S.; Sinder, C.; Pfeifer, F.; Klein, J. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany)

1999-07-01

Traditional as well as biotechnological processing coal leads to complex mixtures of products. Besides chemical and physical characterization, which provides the information for product application, there is a need for bioassays to monitor properties that are probably toxic, mutagenic or cancerogenic. Investigations carried out focused on the selection, adaptation and validation of bioassays for the sensitive estimation of toxic effects. Organisms like bacteria, Daphnia magna and Scenedesmus subspicatus, representing different complexities in the biosphere, were selected as test systems for ecotoxicological and mutagenicity studies. The results obtained indicate that bioassays are, in principle, suitable tools for characterization and evaluation of coal-derived substances and bioconversion products. Using coal products, coal-relevant model compounds and bioconversion products, data for risk assessment are presented. (orig.)

Rapid pyrolysis of Serbian soft brown coals

Directory of Open Access Journals (Sweden)

Jankes Goran

2009-01-01

Full Text Available Soft brown coals of the open coal fields of Kolubara and Kostolac are the main domestic energy sources of Serbia. This paper presents the results of investigations on rapid devolatilization of these two coals which have covered kinetics of devolatilization (based on total volatile yield, forms of sulphur and petrographic analysis of coal and char. Experiments of devolatilization were performed in inert gas (N2 at atmospheric pressure and in batch-type hot-wire screen reactor. The mass-loss values of both coals at selected final reaction temperatures (300-900°C and retention times (3-28 s were obtained. Anthony and Howard's kinetic model was applied over two temperature ranges (300-500 and 700-900°C. The types of sulphur as monosulphide, sulphate, pyritic, and organic sulphur were determined for chars and original coals. Strong transformation of pyrite was evident even at low temperatures (300°C. Devolatilization of all types of sulphur has started over 600 and at 900°C the content of sulphur in char remained only 66% of total sulphur in original coal. Microscopic investigations were carried out on samples prepared for reflected light measurements. The petrographic analysis included: the ratio of unchanged and changed coal, maceral types, the share of cenosferes, isotropic mixed carbonized grains, mixed grains, small fragments, clay, and pyrite. The change of the structure of devolatilized coal was also observed.

Analysis of the effects of biomass on the co-pyrolysis of coal using TGA method

International Nuclear Information System (INIS)

Yaman, S.; Haykiri-Acma, H.

2009-01-01

Turkey is a developing country with a population of 7.15 million and its economy is the 16th biggest in the world and 7th biggest in Europe (after Germany, United Kingdom, France, Italy, Spain, and Russia) with a Gross Domestic Product (GDP) of about 700 billion dollar. Low quality lignitic coals are the most significant primary energy resources of Turkey. Consequently, production of lignite in 2007 is 72 million tons, representing about 7.5% of lignite consumption of the world. However, undesirable characteristics of these lignites such as low calorific value, high ash, and high sulfur are some of serious drawbacks in the usage of them in conventional burning systems, regarding problematic deposit formations and polluting emissions. Therefore, alternative processes for these lignites such as pyrolysis and gasification to produce fuel gases and chemical are preferable. In this study, co-pyrolysis characteristics of Afsin-Elbistan lignite with biomass species such as hazelnut shells, sunflower seed shells, and hybrid poplar were investigated by Non-isothermal Thermogravimetry (TGA) technique. Structural differences in the physical and chemical properties of the samples were studied applying some methods such as X-Ray Diffractometry and Scanning Electron Microscopy. This study showed that addition of such biomass materials into lignite and then co-pyrolysis of these mixtures led to conversion levels that are seriously higher than the conversion level of the lignite alone under the same pyrolytic conditions. It is concluded that there are evident differences between the thermal reactivities of the lignite and the biomass materials, and the increase in the thermal reactivity when biomass was introduced may be explained by synergistic interactions between the constituents of lignite and biomass. (author)

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)

Pyrolysis at low-temperature of Mequinenza coal

Energy Technology Data Exchange (ETDEWEB)

Chorower, C

1940-01-01

In the low-temperature distillation of Mequinenza coal 13 to 14.5% of tar was obtained in the carbonizing unit and 10.7 to 12.0% in the rotary drum with or without steam. The yield of semicoke was 65 to 70.5%; the gas production was 91 to 109 liter per kilogram. The tar was distilled with and without steam, the fractions were freed from phenol and paraffin and purified by treatment with H/sub 2/SO/sub 4/. The coal tested was in many respects more like mineral coal than soft coal (thus, the liquid tar was of higher specific gravity, was free from resins and lower in paraffin and higher in phenol than in the case of soft coal). The pitch content of the tar was very slight, the yield of viscous oils was high. By distillation with steam 32% of benzine was obtained. Of the high S content established in the coking 8.5% was present in the benzine, 6.3% in the motor oil and 5.6% in the lubricating oil from the tar.

Effects of fractal pore on coal devolatilization

Energy Technology Data Exchange (ETDEWEB)

Chen, Yongli; He, Rong [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Wang, Xiaoliang; Cao, Liyong [Dongfang Electric Corporation, Chengdu (China). Centre New Energy Inst.

2013-07-01

Coal devolatilization is numerically investigated by drop tube furnace and a coal pyrolysis model (Fragmentation and Diffusion Model). The fractal characteristics of coal and char pores are investigated. Gas diffusion and secondary reactions in fractal pores are considered in the numerical simulations of coal devolatilization, and the results show that the fractal dimension is increased firstly and then decreased later with increased coal conversions during devolatilization. The mechanisms of effects of fractal pores on coal devolatilization are analyzed.

Preparation of Fe-intercalated Graphite Based on Coal Tailings, Dimensional Structure

Directory of Open Access Journals (Sweden)

Irfan Gustian

2015-12-01

Full Text Available Intercalated graphite from coal tailings have been modified through the intercalation of iron. Coal tailings which is a byproduct of the destruction process and flakes washing results from mining coal. Intercalation of iron goal is to improve the physical properties of graphite and modifying sizes of crystal lattice structure with thermal method. Modification process begins with the carbonization of coal tailings at 500ºC and activated with phosphoric acid. Activation process has done by pyrolysis at 700ºC. The results of pyrolysis was soaked in mineral oil for 24 hours, then pyrolysis again with variations in temperature 800°C and 900ºC for 1 hour and subsequent intercalation iron at 1% and 2%. Material before activated, after activated, and the results of pyrolysis still indicates order nano: 29, 25 and 36 nm respectively. X-ray diffraction characterization results indicate that change in the structure, the sizes crystal lattice structure of the material The greater the concentration of iron was added, the resulting peak at 2θ = 33 and 35 also will be more sharply. The results of SEM showed different morphologies from each treatment.

Pyrolysis and Gasification

DEFF Research Database (Denmark)

Astrup, Thomas; Bilitewski, B.

2011-01-01

a waste management perspective, pyrolysis and gasification are of relatively little importance as an overall management option. Today, gasification is primarily used on specific waste fractions as opposed to mixed household wastes. The main commercial activity so far has been in Japan, with only limited....... Today gasification is used within a range of applications, the most important of which are conversion of coal into syngas for use as chemical feedstock or energy production; but also gasification of biomass and waste is gaining significant interest as emerging technologies for sustainable energy. From...... success in Europe and North America (Klein et al., 2004). However, pyrolysis and gasification of waste are generally expected to become more widely used in the future. A main reason for this is that public perceptions of waste incineration in some countries is a major obstacle for installing new...

Thermal processing of Khoot coal and characterization of obtained solid and liquid products

Directory of Open Access Journals (Sweden)

S Batbileg

2014-12-01

Full Text Available On 21st January 2015, the abstract of this paper was replaced with the correct abstract.The coal of Khoot deposit have been investigated and determined the technical characteristics, elemental and petrographical maceral compositions. On the basis of proximate, ultimate, petrographic and IR analysis results have been confirmed that the Khoot coal is a sub-bituminous coal. The hard residue after pyrolysis have been activated by heated water steam and determined the iodine and methylene blue adsorption of initial coal and activated carbon samples from pyrolysis hard residue. The porosity structure of initial coal, activated carbon of pyrolysis hard residue and hard residue after thermolysis (thermal dissolution have been determined by SEM analysis. The liquid tar product of thermolysis of Khoot coal was investigated by FTIR, 13C and 1H NMR spectrometric analysis. The results of thermolysis of Khoot coal in tetralin with constant mass ratio between coal and tetralin (1:1.8 at 450°C show that 60.8% of liquid product can be obtained after thermolysis of the coal organic mass.DOI: http://doi.dx.org/10.5564/mjc.v15i0.326 Mongolian Journal of Chemistry 15 (41, 2014, p66-72

Investigation on characterization of Ereen coal deposit

OpenAIRE

S. Jargalmaa; B. Purevsuren; Ya. Davaajav; B. Avid; B. Bat-Ulzii; B. Ochirhuyag

2016-01-01

The Ereen coal deposit is located 360 km west from Ulaanbaatar and 95 km from Bulgan town. The coal reserve of this deposit is approximately 345.2 million tons. The Ereen coal is used directly for the Erdenet power plant for producing of electricity and heat. The utilization of this coal for gas and liquid product using gasification and pyrolysis is now being considered. The proximate and ultimate analysis show that the Ereen coal is low rank D mark hard coal, which corresponds to subbitumino...

Aromatic inputs derived from Candiota Coal: quick hydro pyrolysis results; Insumos aromaticos a partir do carvao de Candiota: resultados da hidropirolise rapida

Energy Technology Data Exchange (ETDEWEB)

Cencig, M O; Gomes, J R; Luengo, C A [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

1985-12-31

A coal hydro pyrolysis process has been built and operated at the Laboratory for Alternative Fuels, University of Campinas, Brazil, to obtain desired liquid and gaseous chemical and valuable liquid fuels. A bench, down flow reactor, processes up to 3 kg per hour of powdered coal in hydrogen atmosphere at high pressures (up to 50 atm). Reactor temperatures reach 800 deg C. Residual solids are quenched from the gaseous mainstream. Immediately afterwards, appropriate condensers remove the liquid products. On line gas chromatography is used for monitoring output gas composition after the reaction chamber. Condensed oils had a heating value of 8000 kCal per minute. Results of systematic testing during the last two years are presented. Hardware developments and future applications to biomass materials are also discussed. (author). 13 refs., 2 figs., 1 tab

Clean coal technologies in Japan: technological innovation in the coal industry

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-12-15

This brochure reviews the history clean coal technologies (CCT) in Japan and systematically describes the present state of CCT insofar. The brochure contains three parts. Part 1. CCT classifications; Part 2. CCT overview; and Part 3. Future outlook for CCT. The main section is part 2 which includes 1) technologies for coal resources development; 2) coal-fired power generation technologies - combustion technologies and gasification technologies; 3) iron making and general industry technologies; 4) multi-purpose coal utilization technologies - liquefaction technologies, pyrolysis technologies, powdering, fluidization, and co-utilisation technologies, and de-ashing and reforming technologies; 5) Environmental protection technologies - CO{sub 2} recovery technologies; flue gas treatment and gas cleaning technologies, and technologies to effectively use coal has; 6) basic technologies for advanced coal utilization; and 7) co-production systems.

Health effects of soy-biodiesel emissions: mutagenicity-emission factors.

Science.gov (United States)

Mutlu, Esra; Warren, Sarah H; Matthews, Peggy P; King, Charly; Walsh, Leon; Kligerman, Andrew D; Schmid, Judith E; Janek, Daniel; Kooter, Ingeborg M; Linak, William P; Gilmour, M Ian; DeMarini, David M

2015-01-01

Soy biodiesel is the predominant biodiesel fuel used in the USA, but only a few, frequently conflicting studies have examined the potential health effects of its emissions. We combusted petroleum diesel (B0) and fuels with increasing percentages of soy methyl esters (B20, B50 and B100) and determined the mutagenicity-emission factors expressed as revertants/megajoule of thermal energy consumed (rev/MJ(th)). We combusted each fuel in replicate in a small (4.3-kW) diesel engine without emission controls at a constant load, extracted organics from the particles with dichloromethane, determined the percentage of extractable organic material (EOM), and evaluated these extracts for mutagenicity in 16 strains/S9 combinations of Salmonella. Mutagenic potencies of the EOM did not differ significantly between replicate experiments for B0 and B100 but did for B20 and B50. B0 had the highest rev/MJ(th), and those of B20 and B100 were 50% and ∼85% lower, respectively, in strains that detect mutagenicity due to polycyclic aromatic hydrocarbons (PAHs), nitroarenes, aromatic amines or oxidative mutagens. For all strains, the rev/MJ(th) decreased with increasing biodiesel in the fuel. The emission factor for the 16 EPA Priority PAHs correlated strongly (r(2 )= 0.69) with the mutagenicity-emission factor in strain TA100 + S9, which detects PAHs. Under a constant load, soy-biodiesel emissions were 50-85% less mutagenic than those of petroleum diesel. Without additional emission controls, petroleum and biodiesel fuels had mutagenicity-emission factors between those of large utility-scale combustors (e.g. natural gas, coal, or oil) and inefficient open-burning (e.g. residential wood fireplaces).

Relationships between data from Rock-Eval pyrolysis and proximate, ultimate, petrographic, and physical analyses of 142 diverse U.S. coal samples

Science.gov (United States)

Bostick, N.H.; Daws, T.A.

1994-01-01

Basic research on coal and oil shale led to automated pyrolysis analysis of petroleum source rocks; most widely used is the Rock-Eval equipment. In order to interpret Rock-Eval analyses in relation to traditional coal data, we analyzed 142 commercial coals with diverse rank, age, maceral and sulfur contents, for most regions of the United States. We compared the Rock-Eval data with traditional industrial coal data, including volatile matter, calorific value, hydrogen and oxygen content, free swelling index, and vitrinite reflectance. We found: (1) there is a close relationship between Tmax and vitrinite reflectance in the ranges 420-590??C Tmax and 0.4-3%Romax of most coals. (2) A close relationship between Tmax and volatile matter (%VM) extends through the entire sample range, including low-rank samples with 35-70% VM, a range where %VM is not considered to be a useful rank parameter. (3) TOC of medium- and high-rank coals is seriously under-measured by Rock-Eval; TOC of low-rank coals (less than 0.8%Romax) is close to "dry basis" carbon from ultimate analysis. (4) The direct relationships between oxygen index (OI) and %O and between hydrogen index (HI) and %H are clear, though only broadly defined. However, there is virtually no band of concentrated data points on the HI versus OI pseudo-Van Krevelen diagram comparable to the "development line" on the H/C versus O/C diagram. (5) There are systematic relationships between Rock-Eval and industrial coal parameters such as calorific value and FSI, but much standardization would be needed before Rock-Eval could find a place in the coal industry. Tests with blends of coal and quartz sand and with various loads of coal alone showed that the amount of organic matter in the Rock-Eval load greatly influences results. Total load in the crucible, if largely inert, plays a small role, however. Increasing absolute or relative coal content causes under-evaluation of Rock-Eval TOC and over-rating of hydrogen. Blends of several

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.

Influence of Pyrolysis Temperature and Type of Ligno-Cellulose and Cellulose Biomass on Yield, Specific Surface Area and Mechanical Resistance of Active Coal

OpenAIRE

Pohořelý, Michael

2012-01-01

In the Czech Republic, there are many contaminated agricultural soils due to anthropogenic activity and geogenic origin. The contaminated biomass of plants grown on the contaminated soils needs to be appropriately disposed of to prevent the re-releace of heavy metals into the environment. One way of processing contaminated biomass is pyrolysis, where the heavy metals are concentrated in biochar (active coal). This can be applied to soil where it improves the physical properties. The aim of ...

Investigation on pyrolysis of some organic raw materials

Directory of Open Access Journals (Sweden)

Purevsuren B

2017-02-01

Full Text Available We have been working on pyrolysis of some organic raw materials including different rank coals, oil shale, wood waste, animal bone, cedar shell, polypropylene waste, milk casein and characterization of obtained hard residue, tar and pyrolytic water and gas after pyrolysis. The technical characteristics of these organic raw materials have been determined and the thermal stability characteristics such as thermal stability indices (T5% and T25% determined by using thermogravimetric analysis. The pyrolysis experiments were performed at different heating temperatures and the yields of hard residue, tar, pyrolysis water and gaseous products were determined and discussed. The main technical characteristics of hard residue of organic raw materials after pyrolysis have been determined and the adsorption ability of pyrolysis hard residue and its activated carbon of organic raw materials also determined. The pyrolysis tars of organic raw materials were distilled in air condition and determined the yields of obtained light, middle and heavy fractions and bitumen like residue with different boiling temperature. This is the first time to investigate the curing ability of pyrolysis tars of organic raw materials for epoxy resin and the results of these experiments showed that only tar of milk casein has the highest (95.0%, tar of animal bone has certain (18.70% and tars of all other organic raw materials have no curing ability for epoxy resin.

Desulfurization and denitrogenation in copyrolysis of coal with hydrogen-rich gases

Energy Technology Data Exchange (ETDEWEB)

Liao, H.; Li, B.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

1999-06-01

Desulfurization and denitrogenation were systematically investigated by analyzing the chars and tars from copyrolysis of Yanzhou high sulfur bituminous coal with coke-oven gas (COG), synthesis gas (SG) and hydrogen. The results indicated that under the conditions of 3MPa, up to 650{degree}C with a heating rate of 10{degree}C/min, the desulfurization of coal pyrolysis with COG, SG and hydrogen were almost equal (about 80%, w%, ad), the order of denitrogenation were: hydrogen (41%) {gt} SG(35%) {gt} COG(30%). The distributions of sulfur in char, oil and gas was very similar under the three reactive gases, i.e., about 205 in char, 105 in tar and 70% (diff.) in gas, respectively. Compared with hydropyrolysis at the same hydrogen partial pressure, the desulfurization of coal pyrolysis with coke oven gas was increased by about 4.5%, while the denitrogenation was decreased by about 3.5%. There is an important desulfurization advantage for hydropyrolysis using COG and SG instead of pure hydrogen. Compared with the copyrolysis of coal with COG, Yanzhou coal pyrolysis under SG can achieve the same level of desufurization but higher denitrogenation. 11 refs., 3 figs., 4 tabs.

Urine mutagenicity of steel workers exposed to coke oven emissions

Energy Technology Data Exchange (ETDEWEB)

De Meo, M.P.; Dumenil, G.; Botta, A.H.; Laget, M.; Zabaloueff, V.; Mathias, A.

1987-03-01

Urine mutagenicity of 19 individuals was investigated at a steel mill. All the subjects worked on the coal processing unit. Urine samples were collected at the end of a working day. Urine samples of two exposed workers were collected at the end of two periods of rest and two periods of working. Mutagens were extracted on XAD-2 resin and tested by the Salmonella microsomal assay and the SOS spot test. Mutagenic potencies of exposed smokers and exposed non-smokers were 8.62 +/- 6.56 and 1.1 +/- 0.48 revertants/mg creatinine respectively with Salmonella typhimurium strain TA98 + S9. Both values were significantly higher than those of unexposed smokers and non-smokers (5.07 +/- 3.33 and 0.47 +/- 0.72 revertants/mg creatinine respectively). The urinary mutagenic potency of the two exposed individuals increased at the end of periods of working (15.97 +/- 2.57 revertants/mg creatinine) and decreased at the end of periods of rest (12.31 +/- 2.45 revertants/mg creatinine). Urinary mutagens were detected with S. typhimurium strain TA100 + S9 to a lesser extent. No direct-acting mutagens were detected by the SOS spot test. Atmospheric benzo(a)pyrene (BaP) were also measured by h.p.l.c. on the coke battery. BaP concentrations ranged between 0.01 and 0.6 microgram/m3 air at the different working sites. Biological monitoring with short-term tests is discussed.

Variations in the stable isotope ratios of specific aromatic and aliphatic hydrocarbons from coal conversion processes

Energy Technology Data Exchange (ETDEWEB)

McRae, C.; Snape, C.E.; Fallick, A.E. [University of Strathclyde, Glasgow (United Kingdom). Dept. of Pure and Applied Chemistry

1998-07-01

To establish the scope for applying gas chromatography-isotope ratio mass spectrometry ({sup {delta}-13}C GC-IRMS) to molecular recognition problems in coal utilisation, {sup 13}C/{sup 12}C isotope ratios were determined for n-alkanes and polycyclic aromatic hydrocarbons (PAHs) as a function of coal rank and process conditions. Six coals ranging from a lignite to a low volatile bituminous coal were subjected to chloroform extraction, fixed-bed pyrolysis under hydrogen pressure (hydropyrolysis) and fluidised-bed (flash) pyrolysis. No significant variations in the stable isotope ratios of n-alkanes were evident as a function of either rank or conversion regime. In contrast, the isotope ratios of PAHs show large variations with those for hydropyrolysis (-23 to -25 parts per thousand) being similar to the bulk values of the initial coals and being isotopically heavier (less negative) than their fluidised-bed pyrolysis counterparts by 2-3 parts per thousand. However, the PAHs from fluidised-bed pyrolysis, which resemble closely those obtained from high temperature coal carbonization, are still heavier (by 2-3 parts per thousand) than those from diesel particulates and coal gasification and combustion residues. This provides a firm basis for the source apportionment of airborne PAHs in the proximity of coking plants, particularly with no major variations in the PAH isotope ratios being found as a function of rank.

Prospects for coal science in the 21st century

Energy Technology Data Exchange (ETDEWEB)

Bao Qing Li; Zhen Yu Liu (eds.)

1999-07-01

391 papers are presented under the following session headings: physical, chemical and petrographic characterisation; structure and chemical reactivity; combustion and gasification; pyrolysis and carbonization; liquefaction and hydropyrolysis; chemicals and materials from coal; coal preparation and beneficiation; and environmental aspects.

Co-pyrolysis behaviour and kinetic of two typical solid wastes in China and characterisation of activated carbon prepared from pyrolytic char.

Science.gov (United States)

Ma, Yuhui; Niu, Ruxuan; Wang, Xiaona; Wang, Qunhui; Wang, Xiaoqiang; Sun, Xiaohong

2014-11-01

This is the first study on the co-pyrolysis of spent substrate of Pleurotus ostreatus and coal tar pitch, and the activated carbon prepared from the pyrolytic char. Thermogravimetry (TG) analysis was carried out taking spent substrate, coal tar pitch and spent substrate-coal tar pitch mixture. The activation energies of pyrolysis reactions were obtained via the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods. The kinetic models were determined by the master-plots method. The activated carbons were characterised by N2-adsorption, Fourier transform infrared spectroscopy and X-ray diffraction. Experimental results demonstrated a synergistic effect happened during co-pyrolysis, which was characterised by a decreased maximum decomposition rate and an enhanced char yield. The average activation energies of the pyrolysis reactions of spent substrate, coal tar pitch and the mixture were 115.94, 72.92 and 94.38 kJ mol(-1) for the Flynn-Wall-Ozawa method, and 112.17, 65.62 and 89.91 kJ mol(-1) for the Kissinger-Akahira-Sunose method. The reaction model functions were f(α) = (1-α)(3.42), (1-α)(1.72) and (1-α)(3.07) for spent substrate, coal tar pitch and the mixture, respectively. The mixture char-derived activated carbon had a Brunauer-Emmett-Teller surface area up to 1337 m(2) g(-1) and a total pore volume of 0.680 cm(3) g(-1). Mixing spent substrate with coal tar pitch led to the creation of more micropores and a higher surface area compared with the single spent substrate and coal tar pitch char. Also, the mixture char-derived activated carbon had a higher proportion of aromatic stacking. This study provides a reference for the utilisation of spent substrate and coal tar pitch via co-pyrolysis, and their pyrolytic char as a promising precursor of activated carbon. © The Author(s) 2014.

Formation of N2 in the fixed-bed pyrolysis of low rank coals and the mechanisms; Koteisho netsubunkai ni okeru teitankatan kara no N2 no sisei

Energy Technology Data Exchange (ETDEWEB)

Wu, Z.; Otsuka, Y. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

1996-10-28

In order to establish coal NOx preventive measures, discussions were given on formation of N2 in the fixed-bed pyrolysis of low rank coals and the mechanisms thereof. Chinese ZN coal and German RB coal were used for the discussions. Both coals do not produce N2 at 600{degree}C, and the main product is volatile nitrogen. Conversion into N2 does not depend on heating rates, but increases linearly with increasing temperature, and reaches 65% to 70% at 1200{degree}C. In contrast, char nitrogen decreases linearly with the temperature. More specifically, these phenomena suggest that the char nitrogen or its precursor is the major supply source of N2. When mineral substances are removed by using hydrochloric acid, their catalytic action is lost, and conversion into N2 decreases remarkably. Iron existing in ion-exchanged condition in low-rank coal is reduced and finely diffused into metallic iron particles. The particles react with heterocyclic nitrogen compounds and turn into iron nitride. A solid phase reaction mechanism may be conceived, in which N2 is produced due to decomposition of the iron nitride. 5 refs., 4 figs., 1 tab.

Catalytic technology in the energy/environment field. Utilization of catalyst in coal pyrolysis and gasification processes; Energy kankyo bun`ya ni okeru shokubai gijutsu. Sekitan no netsubunkai oyobi gas ka ni okeru shokubai no riyo

Energy Technology Data Exchange (ETDEWEB)

Otsuka, Y. [Tohoku University, Institute for Chemical Reaction Science (Japan)

1998-05-20

This review article focuses on the utilization of several catalysts during coal pyrolysis and gasification. In situ or off line catalytic upgrading of volatile matters during pyrolysis of low rank coals is carried out in pressurized H2 with different reactors to produce BTX (benzene, toluene and xylene). When NiSO4 and Ni(OH)2 are used in the hydropyrolysis of Australian brown coal using an entrained bed reactor with two separated reaction zones, BTX yield reaches 18-23%. MS-13X zeolite and USY zeolite mixed with Al2O3 are effective for producing BTX with powder-particle fluidized bed and two-stage reactors, respectively. Catalytic gasification is described from a standpoint of direct production of SNG(CH4) from coal and steam. When K2CO3 and Ni are compared for this purpose, Ni catalyst is more suitable at low temperatures of 500-600degC, where CH4 formation is thermodynamically favorable. Fe and Ca catalysts can successfully be prepared from inexpensive raw materials and are rather active for steam gasification at {>=}700degC. The use of upgrading and gasification catalysts is discussed in terms of preparation, performance, life and recovery. 27 refs., 6 figs., 2 tabs.

Sumpor u ugljenu (Sulphur in Coal

Directory of Open Access Journals (Sweden)

Rađenović, A.

2004-12-01

Full Text Available The presence of sulphur in coal possesses important environmetal problems in its usage. The sulphur dioxide (S02 emissions produced during coal combustion account for a significant proportion of the total global output of anthropogenic SO2. The extent of sulphur separation depends on several variables such as the form of sulphur in coal, intimacy of contact between minerals and the products of devolatilization. The total sulphur in coal varies in the range of 0.2 - 11 wt %, although in most cases it is beetwen 1 and 3 wt %. Sulphur occurs in a variety of both inorganic and organic forms. Inorganic sulphur is found mainly as iron pyrite, marcasite, pyrrhotite, sphalerite, galena, chalcopirite and as sulphates (rarely exceeds w = 0,1 %. Organic sulphur is found in aromatic rings and aliphatic functionalities usually as mercaptans, aliphatic and aryl sulfides, disulfides and thiophenes. Organic and pyritic sulphur quantities depend on coal rank. Higher rank coals tend to have a high proportion of labile sulphur. All the organic sulphur is bivalent and it is spread throughout the organic coal matrix. Sulphur occurs in all the macerals and most minerals. Vitrinite contains the major part of organic sulphur and metals. Elemental sulphur is produced during coal weathering. The depolymerization methods as pyrolysis and hydrogenation are very drastic methods wich change the structure of the coal and the sulphur groups. In the case of pyrolysis, high levels of desulphurization, in chars and additional production of liquid hydrocarbon can be achieved. Thiophenes and sulphides were the major sulphur components of tars from coal pyrolysis. Hyrdogen sulphide and the lower mercaptans and sulphides were found in the volatile matters. Hydrogen sulphide and thiophenes are practically the only sulphur products of coal hydrogenation. H2S is produced in char hydrodesulphurization. A number of options are available for reducing sulphur emissions including the

Co-pyrolysis of lignite and sugar beet pulp

International Nuclear Information System (INIS)

Yilgin, M.; Deveci Duranay, N.; Pehlivan, D.

2010-01-01

Today, worldwide studies have been undertaken on the biomass usage and co-conversion of biomass and coal to seek out alternative fuels for supplying energy in an environmental friendly way. The objective of this work is to study co-pyrolysis of lignite and sugar beet pulp in 50/50 (wt./wt.) ratio of blend pellets, to elucidate their thermal behaviour under pyrolysis conditions and to assess major decomposition products in terms of their yields. A special chamber, which has enabled very fast heating rates, was used in the pyrolysis experiments carried at 600 deg. C. The results were interpreted in the light of liquid, solid and gaseous yields, resulting from thermal decomposition, and kinetics of thermogravimetric analysis. Proximate volatile matter and ash contents of the blends were different compared to those found by using individual values. Sugar beet pulp decomposed faster within a relatively narrow temperature range than lignite and underwent a significant shrinkage during pyrolysis. It was found that the chars left behind after the flash pyrolysis of these pellets at 600 deg. C have substantial amounts of volatile matter that would evolve upon further heating.

Biomass Pyrolysis in DNS of Turbulent Particle-Laden Flow

NARCIS (Netherlands)

Russo, E; Fröhlich, Jochen; Kuerten, Johannes G.M.; Geurts, Bernardus J.; Armenio, Vincenzo

2015-01-01

Biomass is important for co-firing in coal power plants thereby reducing CO2 emissions. Modeling the combustion of biomass involves various physical and chemical processes, which take place successively and even simultaneously [1, 2]. An important step in biomass combustion is pyrolysis, in which

Prospects for coal science in the 21st century

Energy Technology Data Exchange (ETDEWEB)

Bao Qing Li; Zhen Yu Liu [eds.

1999-07-01

391 papers are presented under the following session headings: physical, chemical and petrographic characterization; structure and chemical reactivity; combustion and gasification; pyrolysis and carbonization; liquefaction and hydropyrolysis; chemicals and materials from coal; coal preparation and beneficiation; and environmental aspects. Papers have been abstracted separately.

Comprehensive Report to Congress Clean Coal Technology Program: Clean power from integrated coal/ore reduction

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-01

This report describes a clean coal program in which an iron making technology is paired with combined cycle power generation to produce 3300 tons per day of hot metal and 195 MWe of electricity. The COREX technology consists of a metal-pyrolyzer connected to a reduction shaft, in which the reducing gas comes directly from coal pyrolysis. The offgas is utilized to fuel a combined cycle power plant.

Kinetics of copyrolysis of coal with polyamide 6

Czech Academy of Sciences Publication Activity Database

Straka, Pavel; Náhunková, Jana; Brožová, Zuzana

2004-01-01

Roč. 71, č. 1 (2004), s. 213-221 ISSN 0165-2370. [Pyrolysis 2002, 15th International Symposium on Analytical and Applied Pyrolysis. Leoben, 17.09.2002-20.09.2002] R&D Projects: GA AV ČR IBS3046004 Institutional research plan: CEZ:AV0Z3046908 Keywords : coal * kinetics * polyamide 6 Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.352, year: 2004

Hydrocracking mechanisms in molten zinc chloride. Isotope scrambling and pyrolysis studies

International Nuclear Information System (INIS)

Larsen, J.W.; Earnest, S.

1979-01-01

Bruceton coal was hydrocracked in molten zinc chloride using H 2 -D 2 mixtures. No H-D was observed. The pyrolysis of Bruceton coal and a lignite in molten zinc chloride and an inert salt was carried out and the tetrahydrofuran and pyridine extractability of the products determined. In the absence of H 2 , zinc chloride is not an effective cracking catalyst. It is tentatively concluded that the catalytically active species is formed from zinc chloride and something in the coal and H 2 . The interactions between zinc chloride and the lignite appear to be significantly different than the interactions between zinc chloride and the bituminous coal. (Auth.)

Thermal Behavior of Coal Used in Rotary Kiln and Its Combustion Intensification

Directory of Open Access Journals (Sweden)

Qiang Zhong

2018-04-01

Full Text Available Pyrolysis and combustion behaviors of three coals (A, B, and C coals were investigated and their combustion kinetics were calculated by the Freeman–Carroll method to obtain quantitative insight into their combustion behaviors. Moreover, the effects of coal size, air flow, oxygen content, and heating rate on coal combustion behaviors were analyzed. Results showed that the three coals have a similar trend of pyrolysis that occurs at about 670 K and this process continuously proceeds along with their combustion. Combustion characteristics and kinetic parameters can be applied to analyze coal combustion behaviors. Three coals having combustion characteristics of suitable ignition temperature (745–761 K, DTGmax (14.20–15.72%/min, and burnout time (7.45–8.10 min were analyzed in a rotary kiln. Combustion kinetic parameters provide quantitative insights into coal combustion behavior. The suitable particle size for coal combustion in a kiln is that the content of less than 74 μm is 60% to 80%. Low activation energy and reaction order make coal, especially C coal, have a simple combustion mechanism, great reactivity, be easily ignited, and a low peak temperature in the combustion state. Oxygen-enrichment and high heating rates enhance coal combustion, increasing combustion intensity and peak value, thus shortening burnout time.

The effect of catalysts blending on coal pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Pinto, F.; Gulyurtlu, I.; Lobo, L.S.; Cabrita, I. [INETI, Lisbon (Portugal)

1999-05-01

The effect of several catalysts on coal hydropyrolysis efficiency was studied, having selected catalysts with different characteristics and behaviours. For the experimental conditions used Fe{sub 2}O{sub 3} and ICI 41-6 showed selectivity towards lighter fractions, whilst ZnCl{sub 2} led to the highest coal conversion and to the greatest preasphaltenes yields. These results suggested the use of mixtures of catalysts. The heavier molecules of asphaltenes produced as a result of ZnCl{sub 2} action, could then be converted into lighter fractions by the action of a selective catalyst. Coal hydropyrolysis tests were undertaken using ZnCl{sub 2} mixed with Fe{sub 2}O{sub 3} or ICI 41-6. These mixtures of catalysts led to increased conversions and higher product yields. The best results were obtained in the presence of ZnCl{sub 2} mixed with Fe{sub 2}O{sub 3}. In an attempt to interpret these results, coal structure before and after swelling pre-treatment was also studied using SEM. 17 refs., 11 figs., 1 tab.

A study of the evolution of nitrogen compounds during coal devolatilisation

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Rubiera, F.; Moreno, A.H.; Pevida, C.; Pis, J.J. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Dept. of Energy and Environment

2001-07-01

Emissions of nitrogen oxides during combustion are a major environmental problem. The chemically bound nitrogen in fuel accounts for up to 80% of total NOx emissions. In this respect, fundamental studies are needed to clarify the mechanisms and to identify the different species that are precursors in the formation of the NOx. In this work, two methodologies were employed. Simultaneous thermogravimetric-mass spectrometric (TG-MS) analysis was used to study the pyrolysis behaviour of three coals of varying rank. The release of different nitrogen compounds was followed by means of temperature-programmed pyrolysis experiments. The influence of coal rank on the evolution of volatile compounds was also considered. In addition, a series of coal chars with different burn-off degrees were obtained in a bench scale fluidised bed reactor, using the same parent coal. The evolution of gaseous compounds arising from the thermal treatment of the partially burned chars was studied in the TG-MS system. It was found that the different chemical structure of the chars exerted some influence on the evolution of the gaseous compounds during the devolatilisation process. Finally, the evolution of the volatile compounds was also studied in the bench scale fluidised bed reactor. Special attention was given to the formation of N{sub 2}O during the pyrolysis of the coals used. 27 refs., 8 figs., 3 tabs.

Fundamental studies of coal liquefaction

Energy Technology Data Exchange (ETDEWEB)

1995-01-01

The authors have examined the pyrolysis of Argonne samples of Wyodak and Illinois No. 6 coal in argon, undecane, Tetralin, and water. The effects of the pyrolysis on individual particles of coal were monitored visually in a cell with diamond windows capable of operation to temperature and pressures in excess of 500{degrees}C and 3000 psi. The changes in the particles from ambient to 460{degrees}C were recorded in real time on video tape, and images were then taken from the tape record and analyzed. The study showed that in argon both coals developed tars at 350{degrees}-370{degrees}C. The tars then quickly evaporated, leaving core particles remarkably similar in size and shape to the initial particles. These observations suggest that coal does not melt nor become fully liquid when heated. Nor does the softened coal undergo crosslinking to generate coke. Rather the simple loss of volatiles leaves behind the core residue as coke. Contrary to the common view, there appears to be no link between the bond-breaking processes yielding tar and the interaction of the coal with H-donors leading to liquefaction. Water as a medium was surprising in its effect. Both coals began to shrink at 300{degrees}-350{degrees}C, with the effect appearing to be more of an erosion rather than a uniform loss of substance as seen in Tetralin. The Wyodak continued to shrink to 460{degrees}C to about half its initial size. With the Illinois No. 6 coal, however, the process reversed at around 420{degrees}C, and the particles appeared to grow with the evolution of a tar, continuing to 460{degrees}C. The authors submit that this final observation is evidence for hydrothermal synthesis of hydrocarbons at these conditions.

Process for converting coal into liquid fuel and metallurgical coke

Science.gov (United States)

Wolfe, Richard A.; Im, Chang J.; Wright, Robert E.

1994-01-01

A method of recovering coal liquids and producing metallurgical coke utilizes low ash, low sulfur coal as a parent for a coal char formed by pyrolysis with a volatile content of less than 8%. The char is briquetted and heated in an inert gas over a prescribed heat history to yield a high strength briquette with less than 2% volatile content.

Thermal analysis and kinetics of coal during oxy-fuel combustion

Science.gov (United States)

Kosowska-Golachowska, Monika

2017-08-01

The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

Reactivities of acid and/or tetralin pretreated Wandoan coal for a Curie point flash pyrolysis; Sanzen shori, tetralin yobaimae shori Wandoan tan no kyusoku netsubunkai

Energy Technology Data Exchange (ETDEWEB)

Kishino, M.; Sakanishi, K.; Korai, Y.; Mochida, I. [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study

1996-10-28

Discussions were given on effects of acid pretreatment and tetralin swelling in Wandoan coal on a Curie point flash pyrolysis (which used a Curie point pyrolyzer). Residue yield loss effects were obtained at 3.9% in hydrochloric acid pretreatment, and 6.2% in acetic acid pretreatment. The effects of tetralin swelling pretreatment were compared in the similar manner in terms of the residue yield loss. The effects were 4.0% in untreated coal, 2.0% in the hydrochloric acid pretreatment, and 0.6% in the acetic acid pretreatment. It is thought that components that can be activated by acetic acid have already been activated, but the remaining components would not be activated by tetralin. Average microporosity (area) in the remaining particle as a whole shows very little difference both in acetic acid pretreated coal and untreated coal. However, with the acetic acid pretreatment, pores smaller than 4{mu}m{sup 2} disappeared, and pores as large as 205 to 411{mu}m{sup 2} increased largely. This phenomenon was observed as an increase in foaming degree under microscopic observation, even if the average microporosity remains equal. Thermoplasticity of the coal increased, and so did volatilization reactivity as a result of the acetic acid pretreatment, resulting in appearance of a large number of large pores. 6 refs., 2 figs., 2 tabs.

Use of stable sulphur isotopes to monitor directly the behaviour of sulphur in coal during thermal desulphurization

Science.gov (United States)

Liu, Chao-Li; Hackley, Keith C.; Coleman, D.D.

1987-01-01

A method has been developed using stable sulphur isotope analyses to monitor the behaviour of sulphur forms in a coal during thermal desulphurization. In this method, the natural stable isotopic composition of the pyritic and organic sulphur in coal is used as a tracer to follow their mobility during the desulphurization process. This tracer method is based on the fact that the isotopic compositions of pyritic and organic sulphur are significantly different in some coals. Isotopic results of pyrolysis experiments at temperatures ranging from 350 to 750 ??C indicate that the sulphur released with the volatiles is predominantly organic sulphur. The pyritic sulphur is evolved in significant quantities only when pyrolysis temperatures exceed 500 ??C. The presence of pyrite seems to have no effect on the amount of organic sulphur evolved during pyrolysis. The chemical and isotopic mass balances achieved from three different samples of the Herrin (No. 6) coal of the Illinois Basin demonstrate that this stable isotope tracer method is quantitative. The main disadvantage of this tracing technique is that not all coals contain isotopically distinct organic and pyritic sulphur. ?? 1987.

Chromatographic methods and techniques used in studies of coals, their progenitors and coal-derived materials

Energy Technology Data Exchange (ETDEWEB)

Zubkova, Valentina [Jan Kochanowski University of Humanities and Sciences, Institute of Chemistry, Kielce (Poland)

2011-03-15

The use of chromatography in studies of coals, their progenitors and coal-related products was reviewed. The specificity of the coal structure was discussed. The use of extraction in preparing study samples was discussed paying special attention to the occurrence of undesirable phenomena such as aggregation of coal derivate molecules, resulting from the formation of their dimers and trimers, and degradation of polar solvents at temperatures above 350 C. The following ways of fractionating samples of coal materials were considered: thermal, solvent, column with the use of preparative size exclusive chromatography and preparative thin layer chromatography as well as membrane separation. The use of chromatography coupled with experimental techniques such as mass spectrometry, infrared spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and pyrolysis was analysed. (orig.)

Evaluation of pyrolysis curves for volatile elements in aqueous standards and carbon-containing matrices in electrothermal vaporization inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Silva, A.F. [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Julianalaan 136, 2628 BL Delft (Netherlands); Universidade Federal de Santa Catarina, Departamento de Quimica, 88040-900 Florianopolis, SC (Brazil); Welz, B. [Universidade Federal de Santa Catarina, Departamento de Quimica, 88040-900 Florianopolis, SC (Brazil); Loos-Vollebregt, M.T.C. de [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Julianalaan 136, 2628 BL Delft (Netherlands)], E-mail: m.t.c.deloos-vollebregt@tudelft.nl

2008-07-15

Pyrolysis curves in electrothermal atomic absorption spectrometry (ET AAS) and electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) have been compared for As, Se and Pb in lobster hepatopancreas certified reference material using Pd/Mg as the modifier. The ET AAS pyrolysis curves confirm that the analytes are not lost from the graphite furnace up to a pyrolysis temperature of 800 deg. C. Nevertheless, a downward slope of the pyrolysis curve was observed for these elements in the biological material using ETV-ICP-MS. This could be related to a gain of sensitivity at low pyrolysis temperatures due to the matrix, which can act as carrier and/or promote changes in the plasma ionization equilibrium. Experiments with the addition of ascorbic acid to the aqueous standards confirmed that the higher intensities obtained in ETV-ICP-MS are related to the presence of organic compounds in the slurry. Pyrolysis curves for As, Se and Pb in coal and coal fly ash were also investigated using the same Pd/Mg modifier. Carbon intensities were measured in all samples using different pyrolysis temperatures. It was observed that pyrolysis curves for the three analytes in all slurry samples were similar to the corresponding graphs that show the carbon intensity for the same slurries for pyrolysis temperatures from 200 deg. C up to 1000 deg. C.

Cheap carbon sorbents produced from lignite by catalytic pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, B.N.; Schchipko, M.L. [Inst. of Chemistry of Natural Organic Materials, Akademgorodok, Krasnoyarsk (Russian Federation)

1995-12-01

Some data are presented describing the new technology of carbon sorbent production from powdered lignite in the installation with fluidized bed of catalyst. It was shown the different types of char products with extended pore structure and high sorption ability can be produced from cheap and accessible lignite of Kansk-Achinsk coal pit in pilot installation with fluidized bed of Al-Cu-Cr oxide catalyst or catalytically active slag materials. In comparison with the conventional technologies of pyrolysis the catalytic pyrolysis allows to increase by 3-5 times the process productivity and to decrease significantly the formation of harmful compounds. The latter is accomplished by complete oxidation of gaseous pyrolysis products in the presence of catalysts and by avoiding the formation of pyrolysis tars - the source of cancerogenic compounds. The technology of cheap powdered sorbent production from lignites makes possible to obtain from lignite during the time of pyrolysis only a few seconds char products with porosity up to 0.6 cm{sup 3} /g, and specific surface area more than 400 m{sup 3} /g. Some methods of powdered chars molding into carbon materials with the different shape were proved for producing of firmness sorbents. Cheap carbon sorbents obtained by thermocatalytic pyrolysis can be successfully used in purification of different industrial pollutants as one-time sorbent or as adsorbents of long-term application with periodic regeneration.

Effects of mineral matters on evolution of sulfur-containing gases in pyrolysis and hydropyrolysis

Energy Technology Data Exchange (ETDEWEB)

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

1998-07-01

The evolution of sulfur-containing gases were investigated using two Chinese coals with their de-ash and de-pyrite forms in pyrolysis and hydropyrolysis. Mineral matter can not only return H{sub 2}S produced in pyrolysis and hydropyrolysis, but also catalyse hydrodesulfurization and reduce COS formation. Secondary reactions markedly influence COS formation. Mineral matter can reduce CH{sub 3}SH formation, and pyrite shows positive effects on CH{sub 3}SH formation. 7 refs., 6 figs., 1 tab.

Co-pyrolysis of coal with hydrogen-rich gases. 1. Coal pyrolysis under coke-oven gas and synthesis gas

Energy Technology Data Exchange (ETDEWEB)

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

1998-06-01

To improve the economics of the hydropyrolysis process, it has been suggested that cheaper hydrogen-rich gases (such as coke oven gas, synthesis gas) could be used instead of pure hydrogen. Pyrolysis of Chinese Xianfeng lignite was carried out with coke oven gas (COG) and synthesis gas (SG) as reactive gases at 0.1-5 MPa and at a final temperature up to 650{degree}C with a heating rate of 5-25{degree}C min{sup -1} in a 10 g fixed-bed reactor. The results indicate that it is possible to use COG and SG instead of pure hydrogen in hydropyrolysis, but that the experimental conditions must be adjusted to optimize the yields of the valuable chemicals. 14 refs., 3 figs., 6 tabs.

Pyrolisator Coal to be Cokes (Coal Cokes Casting Metal Industry Standard

Directory of Open Access Journals (Sweden)

Sukamto

2016-01-01

Full Text Available Pyrolisis of coal is partial combustion to reduce total moisture, volatile matter and sulfur contens and increase the calorific value of coal. The results of pyrolysis of coal is coke. At the laboratory level studies, pyrolisis done in batch using different calorie, namely 5800, 6000, 6300 kcal/kg and a time of 15-60 minutes and the temperature 400-800°C. Maximum results obtained total moisture (0.44%, fixed carbon (89%, volatile matter (2.4%, sulfur content (undetected and ash (7.2%. Then applied to the scale miniplant with continuous processes using multitube pyrolisator which are designed to operate in the temperature range 400-800°C and a flow rate of 240-730 kg/h, obtained coal cokes that meets industry quality standards, namely TM (0.42%, FC (90.40%, VM (2.16%, S (not detected, Ash (6.8% incalori 6300 kcal/h, a flow rate of 240 kg / h and temperatures between 600-700°C

Pyrolysis of chromium rich tanning industrial wastes and utilization of carbonized wastes in metallurgical process.

Science.gov (United States)

Tôrres Filho, Artur; Lange, Liséte Celina; de Melo, Gilberto Caldeira Bandeira; Praes, Gustavo Eduardo

2016-02-01

Pyrolysis is the thermal degradation of organic material in oxygen-free or very lean oxygen atmosphere. This study evaluates the use of pyrolysis for conversion of leather wastes from chromium tanning processes into Carbonized Leather Residues (CLR), and the utilization of CLR in metallurgical processes through the production of iron ore pellets. CLR was used to replace mineral coal in proportions of 10% and 25% on fixed carbon basis content in the mixtures for pellets preparation. Experimental conversions were performed on a pilot scale pyrolysis plant and a pelletizing reactor of the "pot grate" type. The results demonstrated the technical feasibility of using the charcoal product from animal origin as an energy source, with recovery of up to 76.47% of chromium contained in CLR in the final produced of iron ore pellets. Pellets with 25% replacement of fixed carbon in the coal showed an enhanced compressive strength, with an average value of 344kgfpellet(-1), compared to 300kgfpellet(-1) for standard produced pellets. Copyright © 2015. Published by Elsevier Ltd.

Thermal effects from the release of selenium from a coal combustion during high-temperature processing: a review.

Science.gov (United States)

Hu, Jianjun; Sun, Qiang; He, Huan

2018-04-11

The release of selenium (Se) during coal combustion can have serious impacts on the ecological environment and human health. Therefore, it is very important to study the factors that concern the release of Se from coal combustion. In this paper, the characteristics of the release of Se from coal combustion, pyrolysis, and gasification of different coal species under different conditions are studied. The results show that the amount of released Se increases at higher combustion temperatures. There are obvious increases in the amount of released Se especially in the temperature range of 300 to 800 °C. In addition, more Se is released from the coal gasification than coal combustion process, but more Se is released from coal combustion than pyrolysis. The type of coal, rate of heating, type of mineral ions, and combustion atmosphere have different effects on the released percentage of Se. Therefore, having a good understanding of the factors that surround the release of Se during coal combustion, and then establishing the combustion conditions can reduce the impacts of this toxic element to humans and the environment.

Proceedings of the 11th international conference on coal science

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The theme of the conference was 'Exploring the horizons of coal'. The proceedings include 370 papers dealing with coal petrography, physical structure and properties, advanced characterization, oxidation and weathering, coal preparation and beneficiation, liquefaction and pyrolysis reactivity and products, combustion and combustion modeling, NOx, SO{sub x} and particulate emissions and controls, gasification fundamentals and processing, coal in iron making processes, chemistry of S, N, and Cl, mineral matter, trace elements and HAPS, chemicals, carbons and carbon products, coal combustion byproducts and ash chemistry, and greenhouse gases and sequestration. Although 'proceedings' are published, the conference was cancelled.

Thermovolumetric investigations of steam gasification of coals and their chars

Directory of Open Access Journals (Sweden)

Porada Stanisław

2017-01-01

Full Text Available The process of steam gasification of three coals of various rank and three chars obtained from these coals by the ex-situ method at 900 °C was compared. In the coal gasification process, the pyrolysis stage plays a very important part, which is connected with its direct impact on the kinetics of gasification of the resulting char. What is more, taking into consideration the impact of pyrolysis conditions on char properties, it should be anticipated that the gasification kinetics of coal and char, formed from it by the ex situ method, will be different. In order to examine and compare the process of gasification of coals and chars, an isothermal thermovolumetric method, designed by the authors, was applied. For all the examined samples the measurements were performed at three temperatures, i.e. 850, 900, and 950 °C, and at the pressure of 0.1 MPa. An evaluation of the impact of raw material on the steam gasification of the examined samples was made. The carbon conversion degree and the kinetic parameters of CO and H2 formation reaction were calculated. It was observed that the course of gasification is different for coals and chars obtained from them and it can be concluded that coals are more reactive than chars. Values of kinetic parameters of carbon monoxide and hydrogen formation calculated for coals and corresponding chars are also different. Due to the observed differences the process of gasification of coals and of chars with steam should not be equated.

Groundwater and underground coal gasification in Alberta

International Nuclear Information System (INIS)

Haluszka, A.; MacMillan, G.; Maev, S.

2010-01-01

Underground coal gasification has potential in Alberta. This presentation provided background information on underground coal gasification and discussed groundwater and the Laurus Energy demonstration project. A multi-disciplined approach to project assessment was described with particular reference to geologic and hydrogeologic setting; geologic mapping; and a hydrogeologic numerical model. Underground coal gasification involves the conversion of coal into synthesis gas or syngas. It can be applied to mined coal at the surface or applied to non-mined coal seams using injection and production wells. Underground coal gasification can effect groundwater as the rate of water influx into the coal seams influences the quality and composition of the syngas. Byproducts created include heat as well as water with dissolved concentrations of ammonia, phenols, salts, polyaromatic hydrocarbons, and liquid organic products from the pyrolysis of coal. A process overview of underground coal gasification was also illustrated. It was concluded that underground coal gasification has the potential in Alberta and risks to groundwater could be minimized by a properly designed project. refs., figs.

Effects of alkali and alkaline earth metals on nitrogen release during temperature programmed pyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Ohtsuka, Y.; Wu, Z.; Furimsky, E. [Tohoku University, Sendai (Japan). Inst. for Chemical Reaction Science

1997-11-01

The paper reports that the formation of HCN, NH{sub 3} and N{sub 2} during fixed-bed pyrolysis at 10 K min{sup -1} has been studied using coal samples after partial demineralization followed by addition of metal hydroxides from aqueous systems. Without additives, NH{sub 3} is the predominant product at {le} 700{degree}C, showing the two peaks in the formation rate profile, whereas N{sub 2} is the only product at {ge} 800{degree}C. The presence of NaOH, KOH and Ca(OH){sub 2} promotes considerable NH{sub 3} formation between 450 and 600{degree}C, but in contrast suppresses HCN formation in this region. The Ca shows the largest effect on both the promotion and suppression. It is likely that the NH{sub 3} increased by Ca addition arises partly from HCN, but mainly from secondary reactions of tar-N. These hydroxides affect N{sub 2} formation in quite different manners: the Na decreases the rate between 700 and 950{degree}C, and the K changes it less significantly than the Na, but the Ca remarkably increases the rate in a low temperature region of 550-700{degree}C. These different features are discussed in terms of solid-phase reactions of alkali metal carbonates with char-N and secondary decomposition reactions of tar-N on CaO particles. As a result, total conversion of coal-N to HCN, NH{sub 3} and N{sub 2} up to 1000{degree}C increases in the sequence of Na {lt} none {lt} K {lt} Ca. 40 refs., 10 figs., 2 tabs.

Flash pyrolysis, a process for utilizing contaminated wood; Flash-Pyrolyse - eine Moeglichkeit der stofflichen Verwertung von kontaminiertem Holz

Energy Technology Data Exchange (ETDEWEB)

Meier, D; Wehlte, S; Faix, O [Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzchemie und Chemische Technologie des Holzes

1997-12-31

Flash pyrolysis of wood treated with common pesticides poses no technical probelms. Product yields, with a maximum oil yield at 475 C, are similar to those of untreated wood. Most of the heavy metals are retained by the coal while a small part aheres to the coal layer of the sand bed. The resulting pyrolysis oil contains neither chromium nor copper. (orig) [Deutsch] Die Flash-Pyrolyse der mit den gaengigsten Schutzmitteln behandelten Hoelzer bereitet verfahrenstechnisch keine Probleme. Auch die Produktausbeuten, mit einem oelmaximum bei 475 C, aehneln denen von naturbelassenem Holz. Der groesste Teil der Schwermetalle wurde an die Kohle gebunden, ein geringer Teil blieb auf der Kohleschicht des Sandes haften. Im Hauptprodukt Pyrolyseoel konnten weder Chrom noch Kupfer nachgewiesen werden. (orig)

Flash pyrolysis, a process for utilizing contaminated wood; Flash-Pyrolyse - eine Moeglichkeit der stofflichen Verwertung von kontaminiertem Holz

Energy Technology Data Exchange (ETDEWEB)

Meier, D.; Wehlte, S.; Faix, O. [Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzchemie und Chemische Technologie des Holzes

1996-12-31

Flash pyrolysis of wood treated with common pesticides poses no technical probelms. Product yields, with a maximum oil yield at 475 C, are similar to those of untreated wood. Most of the heavy metals are retained by the coal while a small part aheres to the coal layer of the sand bed. The resulting pyrolysis oil contains neither chromium nor copper. (orig) [Deutsch] Die Flash-Pyrolyse der mit den gaengigsten Schutzmitteln behandelten Hoelzer bereitet verfahrenstechnisch keine Probleme. Auch die Produktausbeuten, mit einem oelmaximum bei 475 C, aehneln denen von naturbelassenem Holz. Der groesste Teil der Schwermetalle wurde an die Kohle gebunden, ein geringer Teil blieb auf der Kohleschicht des Sandes haften. Im Hauptprodukt Pyrolyseoel konnten weder Chrom noch Kupfer nachgewiesen werden. (orig)

Investigation on characterization of Ereen coal deposit

Directory of Open Access Journals (Sweden)

S. Jargalmaa

2016-03-01

Full Text Available The Ereen coal deposit is located 360 km west from Ulaanbaatar and 95 km from Bulgan town. The coal reserve of this deposit is approximately 345.2 million tons. The Ereen coal is used directly for the Erdenet power plant for producing of electricity and heat. The utilization of this coal for gas and liquid product using gasification and pyrolysis is now being considered. The proximate and ultimate analysis show that the Ereen coal is low rank D mark hard coal, which corresponds to subbituminous coal. The SEM images of initial coal sample have compact solid pieces. The SEM image of carbonized and activated carbon samples are hard material with high developed macro porosity structure. The SEM images of hard residue after thermal dissolution in autoclave characterizes hard pieces with micro porous structure in comparison with activated carbon sample. The results of the thermal dissolution of Ereen coal in tetralin with constant weight ratio between coal and tetralin (1:1.8 at the 450ºC show that 38% of liquid product can be obtained by thermal decomposition of the COM (coal organic matter.Mongolian Journal of Chemistry 16 (42, 2015, 18-21

Copyrolysis of Biomass and Coal: A Review of Effects of Copyrolysis Parameters, Product Properties, and Synergistic Mechanisms

Science.gov (United States)

2016-01-01

Concerns in the last few decades regarding the environmental and socioeconomic impacts of the dependence on fossil fuels have resulted in calls for more renewable and alternative energy sources. This has led to recent interest in copyrolysis of biomass and coal. Numerous reviews have been found related to individual pyrolysis of coal and biomass. This review deals mainly with the copyrolysis of coal and biomass and then compares their results with those obtained using coal and biomass pyrolysis in detail. It is controversial whether there are synergistic or additive behaviours when coal and biomass are blended during copyrolysis. In this review, the effects of reaction parameters such as feedstock types, blending ratio, heating rate, temperature, and reactor types on the occurrence of synergy are discussed. Also, the main properties of the copyrolytic products are pointed out. Some possible synergistic mechanisms are also suggested. Additionally, several outlooks based on studies in the literature are also presented in this paper. PMID:27722171

The Charfuel coal refining process

International Nuclear Information System (INIS)

Meyer, L.G.

1991-01-01

The patented Charfuel coal refining process employs fluidized hydrocracking to produce char and liquid products from virtually all types of volatile-containing coals, including low rank coal and lignite. It is not gasification or liquefaction which require the addition of expensive oxygen or hydrogen or the use of extreme heat or pressure. It is not the German pyrolysis process that merely 'cooks' the coal, producing coke and tar-like liquids. Rather, the Charfuel coal refining process involves thermal hydrocracking which results in the rearrangement of hydrogen within the coal molecule to produce a slate of co-products. In the Charfuel process, pulverized coal is rapidly heated in a reducing atmosphere in the presence of internally generated process hydrogen. This hydrogen rearrangement allows refinement of various ranks of coals to produce a pipeline transportable, slurry-type, environmentally clean boiler fuel and a slate of value-added traditional fuel and chemical feedstock co-products. Using coal and oxygen as the only feedstocks, the Charfuel hydrocracking technology economically removes much of the fuel nitrogen, sulfur, and potential air toxics (such as chlorine, mercury, beryllium, etc.) from the coal, resulting in a high heating value, clean burning fuel which can increase power plant efficiency while reducing operating costs. The paper describes the process, its thermal efficiency, its use in power plants, its pipeline transport, co-products, environmental and energy benefits, and economics

Use of image analysis on the prediction of coal burnout performance in a drop tube furnace

Energy Technology Data Exchange (ETDEWEB)

R. Barranco; M. Cloke; E. Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, SChEME

2003-07-01

An experimental investigation in a drop-tube furnace (DTF) into the combustion burnout performance of some South American coals was carried out. The coal samples, mainly from Colombia, were crushed and screened into three size fractions: 53-75 {mu}m, 106-125 {mu}m, and 150-180 {mu}m. These samples were characterised by standard tests along with a specially developed image analysis technique (grey-scale histogram). Pyrolysis of these samples was performed at a temperature of 1300{sup o}C, in a 1% of oxygen in nitrogen atmosphere for 200 ms. The chars obtained were then re-fired in the same apparatus, at the same temperature, at various residence times, in an atmosphere containing 5% of oxygen in nitrogen. The changes in the characteristics of the chars produced were assessed using a number of different techniques including intrinsic reactivity test and automatic char analysis. Despite the fact that all the coals used in this study were vitrinite-rich, variations in char morphology were evident. This demonstrated that it was impossible to assign any one char type to a single maceral group. It was apparent that vitrinite generates a wide range of char types depending upon the rank of the parent coal and on the maceral associations within the coal. In addition, a reactivity parameter, derived from the grey-scale histogram obtained by image analysis of the coal, was found to be important in the prediction of coal combustion behaviour. Some properties of the re-fired chars were compared with morphology and intrinsic reactivity data of the pyrolysed chars. The results showed that the poor burnout of one of the coals was clearly due to the formation of some particular chars during pyrolysis. This confirms the usefulness of high temperature pyrolysis chars as a predictor of burnout performance. 18 refs., 8 figs., 2 tabs.

Thermogravimetric-mass spectrometric study on the evolution of nitrogen compounds during coal devolatilisation

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Rubiera, F.; Pevida, C.; Pis, J.J. [Department of Energy and Environment, Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2002-10-01

Emissions of nitrogen oxides during coal combustion are a major environmental problem. The chemically bound nitrogen in fuel accounts for up to 80% of total NO{sub x} emissions. In this respect, fundamental studies are needed to clarify the mechanisms and to identify the different species that are precursors in the formation of the NO{sub x}. Mass spectrometry (MS) has been used for decades as a successful technique in evolved gas analysis. However, MS is normally used to identify typical volatile compounds formed during coal pyrolysis (i.e. H{sub 2}, CH{sub 4}, CO, CO{sub 2} and H{sub 2}O) but very few works on the detection by MS of nitrogen compounds during coal devolatilisation can be found. In this work, the possibility of detecting different nitrogen compounds by means of thermogravimetric-MS during the temperature-programmed pyrolysis of coal was evaluated. Interferences in the N-compounds MS signals were determined. The use of model compounds provided additional information on the MS response factors of the volatile compounds produced.

Decarbonisation of fossil energy via methane pyrolysis

Energy Technology Data Exchange (ETDEWEB)

Kreysa, G.; Agar, D.W.; Schultz, I. [Technische Univ. Dortmund (Germany)

2010-12-30

Despite the rising consumption of energy over the last few decades, the proven reserves of fossil fuels have steadily increased. Additionally, there are potentially tremendous reserves of methane hydrates available, which remain to be exploited. The use of fossil energy sources is thus increasingly being dictated less by supply than by the environmental concerns raised by climate change. In the context of the decarbonisation of the global energy system that this has stimulated, new means must be explored for using methane as energy source. Noncatalytic thermal pyrolysis of methane is proposed here as a promising concept for utilising methane with low to zero carbon dioxide emissions. Following cracking, only the energy content of the hydrogen is used, while the carbon can be stored safely and retrievably in disused coal mines. The thermodynamics and different process engineering concepts for the technical realisation of such a carbon moratorium technology are discussed. The possible contribution of methane pyrolysis to carbon negative geoengineering is also addressed. (orig.)

Intermediate pyrolysis of agro-industrial biomasses in bench-scale pyrolyser: Product yields and its characterization.

Science.gov (United States)

Tinwala, Farha; Mohanty, Pravakar; Parmar, Snehal; Patel, Anant; Pant, Kamal K

2015-01-01

Pyrolysis of woody biomass, agro-residues and seed was carried out at 500 ± 10 °C in a fixed bed pyrolyser. Bio-oil yield was found varying from 20.5% to 47.5%, whereas the biochar and pyrolysis gas ranged from 27.5% to 40% and 24.5% to 40.5%, respectively. Pyrolysis gas was measured for flame temperature along with CO, CO2, H2, CH4 and other gases composition. HHV of biochar (29.4 MJ/kg) and pyrolitic gas (8.6 MJ/kg) of woody biomass was higher analogous to sub-bituminous coal and steam gasification based producer gas respectively, whereas HHV of bio-oil obtained from seed (25.6 MJ/kg) was significantly more than husks, shells and straws. TGA-DTG studies showed the husks as potential source for the pyrolysis. Bio-oils as a major by-product of intermediate pyrolysis have several applications like substitute of furnace oil, extraction of fine chemicals, whereas biochar as a soil amendment for enhancing soil fertility and gases for thermal application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Induced mutations in chickpea (Cicer arietinum L.) I. comparative mutagenic effectiveness and efficiency of physical & chemical mutagens

International Nuclear Information System (INIS)

Kharkwal, M.C.

1998-01-01

Mutagenic effectiveness usually means the rate of mutation as related to dose. Mutagenic efficiency refers to the mutation rate in relation to damage. Studies on comparative mutagenic effectiveness and efficiency of two physical (gamma rays and fast neutrons) and two chemical mutagens (NMU and EMS) on two desi (G 130 & H 214), one kabuli (C 104) and one green seeded (L 345) chickpea (Cicer arietinum L.) have been reported. The treatments included three doses each of gamma rays (400, 500 and 600 Gy) and fast neutrons (5, 10 and 15 Gy) and two concentrations with two different durations of two chemical mutagens, NMU 0.01% 20h and 0.02% 8h) and EMS (0.1% 20h and 0.2% 8h). Results indicated that chemical mutagens, particularly NMU are not only more effective but also efficient than physical mutagens in inducing mutations in chickpea. Mutagenic effectiveness and efficiency showed differential behaviour depending upon mutagen and varietal type. Chemical mutagens were more efficient than physical in inducing cholorophyll as well as viable and total number of mutations. Among the mutagens NMU was the most potent, while in the physical, gamma rays were more effective. Out of four mutagens, NMU was the most effective and efficient in inducing a high frequency and wide spectrum of chlorophyll mutations in the M2 followed by fast neutrons. While gamma rays showed least effectiveness, EMS was least efficient mutagens. Major differences in the mutagenic response of the four cultivars were observed. The varieties of desi type were more resistant towards mutagenic treatment than kabuli and green seeded type

Rapid estimation of the organic sulphur content of kerogens, coals and asphaltenes by pyrolysis-gas chromatography

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Eglinton, T.I.; Kohnen, M.E.L.; Leeuw, J.W. de

1990-01-01

A pyrolysis-gas Chromatographic (py-g.c.) method for estimation of the Sorg/C ratio in kerogens and other forms of sedimentary macromolecular organic matter is described. The method is based upon flash pyrolysis at 610 °C for 10s and areal integration of the FID peaks attributed to

Analysis of coals and biomass pyrolysis using the distributed activation energy model.

Science.gov (United States)

Li, Zhengqi; Liu, Chunlong; Chen, Zhichao; Qian, Juan; Zhao, Wei; Zhu, Qunyi

2009-01-01

The thermal decomposition of coals and biomass was studied using thermogravimetric analysis with the distributed activation energy model. The integral method resulted in Datong bituminous coal conversions of 3-73% at activation energies of 100-486 kJ/mol. The corresponding frequency factors were e(19.5)-e(59.0)s(-1). Jindongnan lean coal conversions were 8-52% at activation energies of 100-462 kJ/mol. Their corresponding frequency factors were e(13.0)-e(55.8)s(-1). The conversion of corn-stalk skins were 1-84% at activation energies of 62-169 kJ/mol with frequency factors of e(10.8)-e(26.5)s(-1). Datong bituminous coal, Jindongnan lean coal and corn-stalk skins had approximate Gaussian distribution functions with linear ln k(0) to E relationships.

Briquetting and coking behavior of Bobov-Dol coal

Energy Technology Data Exchange (ETDEWEB)

Naundorf, W.

1987-01-01

Hard Bulgarian glance brown coal (23.2% ash content, 16% coal moisture 2.39% sulfur) was studied for its general suitability for partial black coal coke substitution in coking plants and for the possibility of producing pyrolysis briquets for coking purposes. Laboratory briquetting variants include coal briquetting without binders, with sulfite lye as binder, briquetting after partial demineralization by wet classification, briquetting of different screening fractions (0 to 4 mm), briquetting as a mixture with type 35 caking black coal as well as mixed with type 34 less caking black coal under addition of black coal tar, pitch or bitumen. Coking of the briquets produced was carried at with and without charge compacting. Graphs and tables provide briquetting and coking results. It is concluded that high strength coke can be produced from this brown coal, but it can only be used commercially as heating coke due to its high ash and sulfur content. Briquetting and coking of partially demineralized brown coal in a mixture with black coal and binders resulted in suitable metallurgical coke. Maximum percentage of brown coal in the briquetting mixture was 30%. 4 refs.

Determination of Kinetic Parameters of Coal Pyrolysis to Simulate the Process of Underground Coal Gasification (UCG

Directory of Open Access Journals (Sweden)

Beata Urych

2014-01-01

Originality/value: The devolatilization of a homogenous lump of coal is a complex issue. Currently, the CFD technique (Computational Fluid Dynamics is commonly used for the multi-dimensional and multiphase phenomena modelling. The mathematical models, describing the kinetics of the decomposition of coal, proposed in the article can, therefore, be an integral part of models based on numerical fluid mechanics.

Chemical carcinogenic and mutagenic agents in the workplace, Poland, 2008–2010

Directory of Open Access Journals (Sweden)

Katarzyna Konieczko

2013-04-01

Full Text Available Background: The aim of this paper is to present a concise but comprehensive information on the occurrence of carcinogenic or mutagenic agents in Polish enterprises and the number of workers exposed to those agents reported to the central register by employers. Objectives and responsibilities of the register, as well as the range and methods of data gathering are discussed. Material and Methods: Data concerning carcinogenic or mutagenic chemical substances and technological processes reported to central register in 2008-2010 were analyzed. Results: In 2008-2010 more than 300 carcinogenic or mutagenic chemical substances were reported to the register. Approximately 2500 plants reported above 150 000 per-person-exposures annually. Among all technological processes regarded as occupational carcinogens, hardwood dusts exposure (about 660 companies; 11 000-13 000 exposed workers each year and exposure to polycyclic aromatic hydrocarbons (PAHs present in coal products (117-125 plantsl 3000 exposed per year were reported. Conclusions: The most widespread carcinogenic/mutagenic substances were: benzene, chromium(VI compounds: potassium dichromate and chromate, chromium(VI trioxide and other chromium compounds, ethylene oxide, asbestos, benzo[a]pyrene and gasoline. The highest number of men was exposed to particular PAHs and benzene , and the majority of women was exposed to benzene, potassium dichromate and chromate, acrylamide, ethylene oxide and gasoline. The lack of clear-cut definitione of occupational exposure to carcinogen creates a problem faced by employers in defining the accurate number of exposed workers. Med Pr 2013;64(2:181–192

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

Energy Technology Data Exchange (ETDEWEB)

Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

2005-08-01

Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

Kinetic study of coals gasification into carbon dioxide atmosphere

Directory of Open Access Journals (Sweden)

Korotkikh A.G.

2015-01-01

Full Text Available The solid fuel gasification process was investigated to define chemical reactions rate and activation energy for a gas-generator designing and regime optimizing. An experimental procedure includes coal char samples of Kuznetskiy and Kansko-Achinskiy deposits consequent argon pyrolysis into argon and oxidating into carbon dioxide with different temperatures. The thermogravimetric analysis data of coal char gasification into carbon dioxide was obtained in the temperature range 900–1200 ºC. The mass loss and gasification time dependencies from temperature were defined to calculate chemical reaction frequency factor and activation energy. Two coal char gasification physico-mathematical models were proposed and recommendations for them were formed.

The formation of impurities in fluidized-bed gasification of biomass, peat and coal; Epaepuhtauksien muodostuminen leijukerroskaasutuksessa

Energy Technology Data Exchange (ETDEWEB)

Kurkela, E.; Laatikainen-Luntama, J.; Kurkela, M.; Leppaelahti, J.; Koljonen, T.; Oesch, P. [VTT Energy, Espoo (Finland); Alen, R. [Jyvaeskylae Univ. (Finland)

1996-12-01

The objective of this three-year-long project was to study the effects of different process parameters and bed materials on the formation of impurities in pressurized fluidized-bed gasification. The main emphasis of the project was focused on the formation of tars and nitrogen compounds in wood, peat and coal gasification. The aims of the research were to find out such operating conditions, where the formation of problematic high-molecular-weight tars can be minimised and to create a better understanding on the fate of fuel nitrogen in fluidized-bed gasifiers. Main part of the research was carried out in a bench-scale pressurised fluidized-bed reactor (ID 30 mm), where the effects of pressure, temperature, gas atmosphere and bed material were studied with different feedstocks. Most of the test series were carried out using the same feedstocks as earlier used in the PDU-scale fluidized-bed gasification tests of VTT (pine wood, pine bark, wheat straw, two peats, Rhenish brown coal, Polish and Illinois No.6 bituminous coals). The effects of operating parameters on the product yields (gas components, tars, char) were first studied under inert nitrogen atmosphere. The conversion of fuel nitrogen into ammonia and HCN were also determined for the different feedstocks over the different operating conditions. These studies showed that ammonia is the main fixed nitrogen compound of fluidized-bed pyrolysis with all the feedstocks studied. The conversions of fuel nitrogen into ammonia and HCN was highest with the high volatile fuels and lowest with the two hard coals. Gas atmosphere had a dramatic effect on the conversion of fuel nitrogen; much higher ammonia yields were determined in real gasification gas atmosphere than in inert pyrolysis carried out in N{sub 2} or Argon atmosphere. In addition to the pressurised fluidized-bed pyrolysis tests, laboratory scale pyrolysis research was carried out in order to compare the pyrolysis behaviour of the different feedstocks

Investigation on characterization and liquefaction of coals from Tavan tolgoi deposit

Directory of Open Access Journals (Sweden)

B Purevsuren

2014-10-01

Full Text Available On the basis of proximate, ultimate, petrographic and IR analysis results have been confirmed that the Tavan tolgoi coal is a high-rank G mark stone coal. The results of X-ray fluorescence analysis of coal ash show that the Tavan tolgoi coal is a subbituminous coal. The ash of Tavan tolgoi coal has an acidic character. The results of pyrolysis of Tavan tolgoi coal at different heating temperatures show that a maximum yield - 5.0% of liquid product can be obtained at 700°C. The results of thermal dissolution of Tavan tolgoi coal in tetralin with constant mass ratio between coal and tetralin (1:1.8 at 450°C show that 50.0% of liquid product can be obtained after thermal decomposition of the COM (coal organic matter. DOI: http://dx.doi.org/10.5564/mjc.v14i0.191 Mongolian Journal of Chemistry 14 (40, 2013, p12-19

Coal trends and prospects in Malaysia. Malaysia no sekitan doko to mitoshi

Energy Technology Data Exchange (ETDEWEB)

Husin, T. (Tenaga Nasional Berhad (Malaysia))

1993-03-01

This paper describes problems in coal development and coal processing techniques used in Malaysia. Malaysia has a national organization placing importance on maximizing natural gas source development, but no such an organization is available for coal. Necessity exists in developing transportation infrastructures that can transport coal at a competitive price from coal mines to users inside and outside the country. Majority of the Merit Pila coal is produced in mines with relatively thin coal beds, which raise production cost higher. Coal resources are mostly of low calorific power. Since the coal resource development is a new economic activity, it requires training of people in related areas, and frameworks of legislative regulation. Important in coal development is to select technologies that can meet environmental requirements and stand with competitions in the world coal markets. New coal processing technologies available for discussion in coal refining processes include relaxed gasification or pyrolysis, coal liquefaction, coal-water mixture to mix coal powder and water with additives, coal pretreatment techniques, coal cleaning techniques, and fluidized bed combustion. 1 fig., 1 tab.

Mutagenicity and co-mutagenicity of static magnetic field in SOD-deficient Escherichia coli

International Nuclear Information System (INIS)

Yoshie, Sachiko; Ikehata, Masateru; Hayakawa, Toshio; Hirota, Noriyuki; Takemura, Taro; Minowa, Takashi; Hanagata, Nobutaka

2008-01-01

The effects of strong static magnetic fields (SMFs) on mutagenesis related to reactive oxygen species were investigated. To estimate mutagenicity of SMFs, superoxide dismutase (SOD)-deficient Escherichia coli QC774 and its parental strain GC4468 were employed. Tester strains were exposed to 5, 10 and 13 T SMFs for 24 hr at 37 C degrees in LB medium. After exposure, mutation frequency on thymine synthesis genes was determined for evaluation of mutagenicity of SMFs exposure. In the result, no statistically significant difference in mutation frequency on thymine synthesis genes was observed between SMF-exposed cells and unexposed cells in all of magnetic flux densities. Furthermore, SMFs up to 13 T did not affect mutagenicity of plumbagine under its presence of 25 μM, respectively. It suggests that SMF did not have either mutagenicity or co-mutagenicity in SOD-deficient and its parental E. coli strains under the condition in this study. (author)

Long-range transport of mutagens and other air pollutants from mainland East Asia to western Japan.

Science.gov (United States)

Coulibaly, Souleymane; Minami, Hiroki; Abe, Maho; Hasei, Tomohiro; Oro, Tadashi; Funasaka, Kunihiro; Asakawa, Daichi; Watanabe, Masanari; Honda, Naoko; Wakabayashi, Keiji; Watanabe, Tetsushi

2015-01-01

Asian dust events, transport of dust particles from arid and semi-arid areas in China and Mongolia to the east by prevailing westerlies, are often observed in Japan in spring. In recent decades, consumption of fossil fuels has markedly increased in mainland East Asia with rapid economic growth, and severe air pollution has occurred. A part of air pollutants including mutagens, such as polycyclic aromatic hydrocarbons (PAHs), generated in mainland East Asia are thought to be transported to Japan by the prevailing westerlies, like Asian dust, and winter monsoon. The objective of this study was to clarify the long-range transport of mutagens and other air pollutants in East Asia. Thus, we collected total suspended particles (TSP) at a rural town in western Japan, namely, Yurihama in Tottori Prefecture, for 1 year (June 2012-May 2013), and investigated their chemical constituents and mutagenicity. Many TSP collected from January to March showed high mutagenicity toward Salmonella typhimurium YG1024 with and without S9 mix, and high levels of lead (Pb) and sulfate ions (SO4 (2-)), which are indicators of transboundary air pollutions from mainland East Asia, were detected in those TSP. A large amount of iron, which is an indicator of sand, was found in highly mutagenic TSP collected in March, but not in TSP collected in January and February. High levels of PAHs were detected in highly mutagenic TSP collected from January to March. The ratios of the concentration of fluoranthene to those of fluoranthene and pyrene suggested that the main source of PAHs in TSP collected in winter and spring was coal and biomass combustion. Backward trajectories of air masses on days when high levels of mutagenicity were found indicated that these air masses had traveled from eastern or northern China to Yurihama. These results suggest that high levels of mutagens were transported from mainland East Asia to western Japan, and this transportation accompanied Asian dust in March, but not in

Mutagenicity of cooked foods. Kuumennuskaesiteltyjen elintarvikkeiden mutageenisuus

Energy Technology Data Exchange (ETDEWEB)

Tikkanen, L. (Valtion teknillinen tutkimuskeskus, Espoo (Finland). Elintarvikelaboratorio)

1989-09-01

In this study the mutagenic activity in different kinds of ordinary Finnish foods was determined using mainly the Ames Salmonella bacterial assay. The purpose of this study was also to acquire the technical capability to study cooked food mutagens and to get basic informavtion about the mutagenic activity of foods under different cooking conditions. The samples tested were different kinds of ready-to-eat foods. Products were industrially heat-processed by frying and roasting, sterilization, smoking, deep-frying, spray-drying and UHT-treatment. According to the results, the majority of the fried and roasted food samples containing meat or fish were clearly or strongly mutagenic. Some of the products processed by sterilization and deep-frying were marginally mutagenic. The effect of the frying temperature on the mutagenicity in the Ames test was studied with minced meat. The mutagenic activity of the fried meat clearly correlated with the frying temperature. There were conspicuous differences in mutagenic activity between different fried and roasted products. Charcoal-grilled fish and the surface layers of the grilled meat and chicken were strongly mutagenic. Meat and fish hamburgers were in most cases only slightly mutagenic. The mutagenic activity was stronger in the surface layers of the products than in the inside. Also reheating by frying increased the mutagenicity of meat patties clearly. Differences in mutagenic activity between equivalent products of different manufacturers were evident in many cases. Variation of the mutagenicity was most conspicuous in the grilled products. This variation indicates that the industrial processing of food has a marked effect on the mutagenic activity of the final product, which thus might be reduced by modifying the process. The solvent extraction method used in this study was more effective than the Blue-Cotton method for the isolation of mutagenic compounds.

Characterization of Canadian coals by nuclear magnetic resonance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.; Ripmeester, J.

1983-06-01

Apparent aromaticities of a series of Canadian coals of different rank were estimated by solid state nuclear magnetic resonance spectroscopy. The aromaticities varied from 0.57 for a lignite up to 0.86 for a semi-anthracite coal. The aromaticities correlated well with fixed carbon and oxygen content of the coals as well as with the mean reflectance of the coals. Correlations were also established between aromaticities and the H/C and H/SUB/a/SUB/r/SUB/u/C/SUB/a/SUB/r ratios of the coals. Uncertainties in calculation of the hypothetical H/SUB/a/SUB/r/SUB/u/C/SUB/a/SUB/r ratios, from experimental data were pointed out. Structural parameters of the chars derived from the coals by pyrolysis at 535 C were, also, estimated. The H/C and H/SUB/a/SUB/r/SUB/u/C/SUB/a/SUB/r ratios of the chars were markedly lower than those of coals. This was complemented by higher apparent aromaticities of the chars compared with the coals. (21 refs.)

Comparison of FeS, FeS + S and solid superacid catalytic properties for coal hydro-liquefaction

Energy Technology Data Exchange (ETDEWEB)

Zhicai Wang; Hengfu Shui; Dexiang Zhang; Jinsheng Gao [East China University of Science and Technology, Shanghai (China). College of Resource and Environment Engineering

2007-03-15

Catalyst plays an important role in direct coal liquefaction. This paper focuses on the catalytic behavior of a novel SO{sub 4}{sup 2-}/ZrO{sub 2} superacid catalyst in coal hydro-liquefaction. A series of hydro-liquefaction experiments were conducted under mild conditions - 400{sup o}C, 30 min and H{sub 2} initial pressure 4 MPa in a batch autoclave with a volume of 100 ml. The catalytic property of SO{sub 4}{sup 2-}/ZrO{sub 2} was compared with FeS and FeS + S by Shenhua coal. The liquefaction products catalyzed by different catalysts were analyzed by FTIR spectrum, {sup 1}H NMR spectrum and element analysis. In addition, the SO{sub 4}{sup 2-}/ZrO{sub 2} solid superacid was characterized. The results indicated that the SO{sub 4}{sup 2-}/ZrO{sub 2} solid superacid shows outstanding catalytic property for direct liquefaction of coal and gives the highest coal conversion and gas + oil yield compared to other two catalysts. The THF conversion and the extraction yield of CS{sub 2}/NMP mixed solvent of liquefied coal catalyzed with SO{sub 4}{sup 2-}/ZrO{sub 2} are 76.3%, daf and 81.2%, daf respectively, and the yield of gas + oil is 62.5%, daf under the condition used in this study. The pyrolysis of coal macromolecular clusters can be promoted by catalysts such as FeS, FeS + S and SO{sub 4}{sup 2-}/ZrO{sub 2}. There may be only the pyrolysis of volatile matter and the relaxation of the structure of coal macromolecular clusters in non-catalytic liquefaction at 400{sup o}C. Added sulfur in FeS can improve the catalytic activity of hydrogenation. SO{sub 4}{sup 2-}/ZrO{sub 2} is a notable catalyst in the study of coal direct liquefaction because it shows excellent catalytic activities for the pyrolysis and the hydrogenation. In addition, it has been found that the C-O bond is the most stable group in coal liquefaction reaction except for the covalent bond between carbon and carbon. 34 refs., 6 figs., 6 tabs.

Microwave pyrolysis for conversion of materials to energy : A review

International Nuclear Information System (INIS)

Mokhtar, M.; Omar, R.; MOhammad Salleh, M.A.; Idris, A.

2009-01-01

Full text: The disposal of wastes in Malaysia is becoming a serious problem in many industrialized and public sectors. This is due to the high production of waste such as municipal solid waste, sludge from waste water treatment plants, agricultural waste and other used non-biodegradable products such as plastics and tyres. These wastes although are reused as compost, fuel, recycled and so on, there are still abundant left. These leftovers pose problems such as heavy metal leaching, leachates, green house gas emissions and mosquito breeding grounds. The disposal cost of these wastes sometimes can be costly at up to RM 2,200/ ton such as petroleum sludge by Kualiti Alam. Several methods have been used to convert these residues to energy via thermal treatment such as combustion, incineration and gasification. However, pyrolysis becomes one of the popular methods as the alternative to the wastes disposal recently. Not only energy (as gas) is produced, by-products such as chemical feedstock and solid absorbent can be produced. The use of microwave for pyrolysis, although relatively new for waste treatment, has several advantages compared to conventional heating. This includes easy control of the heating process, time saving, higher heating efficiency, etc. Tyre microwave pyrolysis plant in UK is known as the earliest plant using microwave technology to breakdown polymer in used tyres. Since 1990s, there are many patents for microwave pyrolysis. The processes are based on microwave pyrolysis of waste include coffee hulls, wood, coal, sewage sludge, hospital waste, plastic wastes, corn cobs and rice straw. The most important factors influencing the yield of product during the pyrolysis is temperature in range from 500 to 1000 degree Celsius according to product preference. High temperature favors gas products; whereas lower temperature favors liquid products. Comparatively, microwave pyrolysis produced gas with higher hydrogen and carbon monoxide (syngas) content compared

Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

Energy Technology Data Exchange (ETDEWEB)

Hooftman, R.N.

1983-08-01

The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of these that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

Energy Technology Data Exchange (ETDEWEB)

Hooftman, R.N.

1983-08-01

The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of those that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

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)

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.

Multiple-heteroatom-containing sulfur compounds in a high sulfur coal

International Nuclear Information System (INIS)

Winans, R.E.; Neill, P.H.

1990-01-01

Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry yielding information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system and the products characterized by high resolution mass spectrometry (HRMS). A significant number of products were observed which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracts and liquefaction products

Actual development of the conversion of energy sources of minor value in so-called bio coal. A comparison of pyrolysis process with the HTC process; Aktuelle Entwicklung bei der Konversion von minderwertigen Energietraegern in die so genannte Biokohle. Ein Vergleich von Pyrolyse- und HTC-Verfahren

Energy Technology Data Exchange (ETDEWEB)

Neudeck, Diana; Roedger, Jan-Markus [HAWK Hochschule fuer angewandte Wissenschaft und Kunst, Goettingen (Germany); Loewen, Achim

2012-07-01

The conversion of biomass with low quality into biochar through pyrolysis or hydro-thermal carbonization is suitable to substitute lignite and hard coal as a fuel and thereby improve the carbon footprint of a firing plant: Additionally there is the possibility to apply biochar to fields. Carbon compounds, stabilized by the carbonization process, could simultaneously increase crop yields and sequester carbon for mid- and long term. This paper compares the two processes pyrolysis and hydrothermal carbonization regarding input-material, process-parameters, product-properties and possible applications for each product. The aim is to give an overview which process with given parameters leads to which final product and application. (orig.)

Organic sulphur in macromolecular sedimentary organic matter. II. Analysis of distributions of sulphur-containing pyrolysis products using multivariate techniques

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Eglinton, T.I.; Pool, W.; Leeuw, J.W. de; Eijkel, G.; Boon, J.J.

1992-01-01

This study describes the analysis of sulphur-containing products from Curie-point pyrolysis (Py) of eighty-five samples (kerogens, bitumen, and petroleum asphaltenes and coals) using gas chromatography (GC) in combination with sulphur-selective detection. Peak areas of approximately forty individual

Biomass flash pyrolysis for energy and chemical inputs production; Pirolise ultra-rapida de biomassas para obtencao de insumos quimicos e energeticos

Energy Technology Data Exchange (ETDEWEB)

Luengo, Carlos A; Cencig, Mario O [Universidade Estadual de Campinas, SP (Brazil). Inst. de Fisica

1988-12-31

In this work, flash pyrolysis, a modern processing technique applied to biomass and municipal wastes, is critically reviewed. Similarities and differences with the process of carbonization are indicated in relation to main processing parameters. At the University of Campinas, Brazil (UNICAMP), flash pyrolysis development and applications to high ash coals usually founds in the southern Brazil. Presently, research is being extended to include types of biomass relevant to local conditions. (author) 28 refs., 3 figs., 1 tab.

Synergistic Effect of Co-utilization of Coal and Biomass Char: An Overview

Science.gov (United States)

Paiman, M. E. S.; Hamzah, N. S.; Idris, S. S.; Rahman, N. A.; Ismail, K.

2018-05-01

Global concerns on impact of greenhouse gases emission, mostly released from coal-fired power plant, and the depletion of fossil fuel particularly coal, has led the production of electricity from alternatives resources such as co-utilization technologies. Previous studies proved that the co-utilization of coal and biomass/biomass chars has significantly reduced the emission of greenhouse gases either during the pyrolysis, combustion or gasification process in laboratories, pilots as well as in the industrial scales. Interestingly, most of the studies reported the presence of synergistic effect during the co-utilization processes particularly between coal and biomass char while some are not. Biomass chars were found to have porous and highly disorder carbon structure and belong to the class of most reactive carbon material, resulting to be more reactive than those hard coal and lignite. Up to date, microwave assisted pyrolysis is one of the best and latest techniques employed to produce better quality of biomass chars and it is also reduce the processing cost. Lot of works has been done regarding on the existence of synergistic effects during its co-utilization. However, the knowledge is limited to thermal and product characteristics so far. Even so, the specific reasons behind its existence are yet to understand well. Therefore, in this paper, the emphasis will be given on the synergistic effects on emission characteristics of co-utilization of coal and biomass chars so that it can be apply in energy-based industries to help in reduction of the greenhouse gases emission.

Engineering Graphene Films from Coal

Science.gov (United States)

Vijapur, Santosh H.

Graphene is a unique material with remarkable properties suitable for a wide array of applications. Chemical vapor deposition (CVD) is a simple technique for synthesis of large area and high quality graphene films on various metal substrates. Among the metal substrates, copper has been shown to be an excellent support for the growth of graphene films. Traditionally, hydrocarbon gases are used for the graphene synthesis via CVD. Unconventional solid carbon sources such as various polymers and food waste have also shown great potential for synthesis of graphene films. Coal is one such carbon enriched and abundantly available unconventional source. Utilization of coal as a carbon source to synthesize large area, transparent, and high quality few-layer graphene films via CVD has been demonstrated in the present work. Hydrocarbon gases are released as products of coal pyrolysis at temperatures ≥400 °C. This study hypothesized that, these hydrocarbon gases act as precursors for the synthesis of graphene films on the copper substrate. Hence, atmospheric pressure CVD and low temperature of 400 °C were utilized initially for the production of graphene films. These conditions were suitable for the formation of amorphous carbon (a-C) films but not crystalline graphene films that were the objective of this work. The synthesized a-C films on the copper substrate were shown to be uniform and transparent with large surface area. The thickness and surface roughness of the a-C films were determined to have typical values of 5 nm and 0.55 nm, respectively. The a-C film has >95 % optical transmittance and sheet resistivity of 0.6 MO sq-1. These values are comparable to other carbon thin films synthesized at higher temperatures. Further, the a-C films were transferred onto any type of substrate such as silicon wafer and titanium foil, and can be utilized for diverse applications. However, crystalline graphene films were not produced by implementing atmospheric pressure CVD and low

Research on novel coal conversion technology for energy and environment in 21st century

Energy Technology Data Exchange (ETDEWEB)

T. Takarada [Gunma University (Japan)

2003-07-01

In the 21st century, more efficient coal conversion technology will be needed. In this paper, novel gasification, pyrolysis and desulfurization processes using active catalysts are introduced. In particular, the application of ion-exchanged metals in brown coal to coal conversion technology is featured in this study. Other topics discussed include: Catalysis of mineral matter in coal; Catalytic effectiveness of Ni and K{sub 2}CO{sub 3} for various coals; Direct production of methane from steam gasification; Preparation of active catalysts from NaCl and KCl using brown coal; Gasification of high rank coal by mixing K-exchanged brown coal; Recovery of sulfur via catalytic SO{sub 2} gasification of coal char; Research on novel coal conversion technology BTX production by hydropyrolysis of coal in PPFB using catalyst; High BTU gas production by low-temperature catalytic hydropyrolysis of coal; and Ca-exchanged brown coal as SO{sub 2} and H{sub 2}S sorbents. 12 refs., 17 figs.

Coal combustion aerothermochemistry research. Final report

Energy Technology Data Exchange (ETDEWEB)

Witte, A.B.; Gat, N.; Denison, M.R.; Cohen, L.M.

1980-12-15

On the basis of extensive aerothermochemistry analyses, laboratory investigations, and combustor tests, significant headway has been made toward improving the understanding of combustion phenomena and scaling of high swirl pulverized coal combustors. A special attempt has been made to address the gap between scientific data available on combustion and hardware design and scaling needs. Both experimental and theoretical investigations were conducted to improve the predictive capability of combustor scaling laws. The scaling laws derived apply to volume and wall burning of pulverized coal in a slagging high-swirl combustor. They incorporate the findings of this investigation as follows: laser pyrolysis of coal at 10/sup 6/ K/sec and 2500K; effect of coal particle shape on aerodynamic drag and combustion; effect of swirl on heat transfer; coal burnout and slag capture for 20 MW/sub T/ combustor tests for fine and coarse coals; burning particle trajectories and slag capture; particle size and aerodynamic size; volatilization extent and burnout fraction; and preheat level. As a result of this work, the following has been gained: an increased understanding of basic burning mechanisms in high-swirl combustors and an improved model for predicting combustor performance which is intended to impact hardware design and scaling in the near term.

Monitor of ash content of coal with X-ray source

International Nuclear Information System (INIS)

Wawrzonek, L.

1983-01-01

The coal ash monitor is used on-line to measure the ash content of raw, washed and blended coals. The instrument consists of a presentation unit and electronic unit. In the presentation unit a compact layer of coal is formed and there is also a radiation measuring system. A plutonium 238 source is used and the backscattered X-rays are detected by a proportional counter. The count rate is processed in the electronic unit and displayed as the ash percentage in the coal. A wide range of Polish coals was analysed. The monitor was tested in a power plant over the period of one year. The ash content in the coal analysed was in the range 5 to 50%. The gauge readings were compared with the pyrolysis results. An accuracy of 3.2% (95% confidence limit) was reached. These results were not corrected for the free moisture content which varied in the range 5 to 15 %. (author)

Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach

Energy Technology Data Exchange (ETDEWEB)

Fletcher, Thomas; Pugmire, Ronald

2015-01-01

Three pristine Utah Green River oil shale samples were obtained and used for analysis by the combined research groups at the University of Utah and Brigham Young University. Oil shale samples were first demineralized and the separated kerogen and extracted bitumen samples were then studied by a host of techniques including high resolution liquid-state carbon-13 NMR, solid-state magic angle sample spinning 13C NMR, GC/MS, FTIR, and pyrolysis. Bitumen was extracted from the shale using methanol/dichloromethane and analyzed using high resolution 13C NMR liquid state spectroscopy, showing carbon aromaticities of 7 to 11%. The three parent shales and the demineralized kerogens were each analyzed with solid-state 13C NMR spectroscopy. Carbon aromaticity of the kerogen was 23-24%, with 10-12 aromatic carbons per cluster. Crushed samples of Green River oil shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000°C. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). The demineralized kerogen was pyrolyzed at 10 K/min in nitrogen at atmospheric pressure at temperatures up to 525°C, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, GC/MS, and FTIR. Details of the kerogen pyrolysis have been modeled by a modified version of the chemical percolation devolatilization (CPD) model that has been widely used to model coal combustion/pyrolysis. This refined CPD model has been successful in predicting the char, tar, and gas yields of the three shale samples during pyrolysis. This set of experiments and associated modeling represents the most sophisticated and complete analysis available for a given set of oil shale samples.

Research on Improving Low Rank Coal Caking Ability by Moderate Hydrogenation

Science.gov (United States)

Huang, Peng

2017-12-01

The hydrogenation test of low metamorphic coal was carried out by using a continuous hydrogen reactor at the temperature of (350-400)°C and the initial hydrogen pressure of 3 ~ 6Mpa. The purpose of the experiment was to increase the caking property, and the heating time was controlled from 30 to 50min. The test results show that the mild hydrogenation test, no adhesion of low metamorphic coal can be transformed into a product having adhesion, oxygen elements in coal have good removal, the calorific value of the product has been improved significantly and coal particles during pyrolysis, swelling, catalyst, hydrogenation, structural changes and the combined effects of particles a new component formed between financial and is a major cause of coal caking enhancement and lithofacies change, coal blending test showed that the product can be used effectively in the coking industry.

NO Reduction over Biomass and Coal Char during Simultaneous Combustion

DEFF Research Database (Denmark)

Zhao, Ke; Glarborg, Peter; Jensen, Anker Degn

2013-01-01

This paper reports an experimental study of NO reduction over chars of straw, bark, bituminous coal, and lignite. The experiments were performed in a fixed bed reactor in the temperature range 850–1150 °C. The chars were generated by in situ pyrolysis at the reaction temperature to minimize further...

Nitrogen evolution during rapid hydropyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Xu, W.-C.; Kumagai, M. [Institute of Research and Innovation, Kashiwa (Japan)

2002-12-01

The behavior of nitrogen evolution during rapid hydropyrolysis of coal has been investigated at temperatures ranging from 923 to 1123 K and hydrogen pressure up to 5 MPa using a continuous free fall pyrolyzer. Three coals have been tested in this study. The dominant nitrogen gaseous species is ammonia, together with a little amount of HCN because most of HCN is converted to NH{sub 3} through secondary reactions. The results show that the evolution of nitrogen in coal is caused mainly by devolatilization at temperatures below 973 K, while the evolution of volatile nitrogen in char is accelerated with increasing temperature and hydrogen pressure. The mineral matter in coal act as catalysts to promote the evolution of volatile nitrogen in char to N{sub 2} apparently at high temperatures of 1123 K, as found during pyrolysis of coal by Ohtsuka et al. A pseudo-first-order kinetic model was applied to the evolution of nitrogen in coal during rapid hydropyrolysis. The model shows the activation energy for the nitrogen evolution from coal is 36.6 58.6 kJ/mol while the rate of the nitrogen evolution depends on hydrogen pressure in the order of 0.16 0.24. 41 refs., 11 figs., 3 tabs.

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.

Investigations on potential co-mutagenic effects of formaldehyde

Energy Technology Data Exchange (ETDEWEB)

Speit, Günter, E-mail: guenter.speit@uni-ulm.de; Linsenmeyer, Regina; Duong, Giang; Bausinger, Julia

2014-02-15

Highlights: • A549 cells were exposed to formaldehyde in combination with various mutagens. • Formaldehyde did not affect the induction and removal of DNA damage (comet assay). • Formaldehyde did not affect the induction of micronuclei by the mutagens tested. • The expression of the O{sup 6}-methylguanine-DNA methyltransferase was not affected. - Abstract: The genotoxicity and mutagenicity of formaldehyde (FA) has been well-characterized during the last years. Besides its known direct DNA-damaging and mutagenic activity in sufficiently exposed cells, FA at low concentrations might also enhance the mutagenic and carcinogenic effects of other environmental mutagens by interfering with the repair of DNA lesions induced by these mutagens. To further assess potential co-mutagenic effects of FA, we exposed A549 human lung cells to FA in combination with various mutagens and measured the induction and removal of DNA damage by the comet assay and the production of chromosomal mutations by the cytokinesis-block micronucleus assay (CBMN assay). The mutagens tested were ionizing radiation (IR), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), N-nitroso-N-methylurea (methyl nitrosourea; MNU) and methyl methanesulfonate (MMS). FA (10–75 μM) did not enhance the genotoxic and mutagenic activity of these mutagens under the test conditions applied. FA alone and in combination with MNU or MMS did not affect the expression (mRNA level) of the gene of the O{sup 6}-methylguanine-DNA methyltransferase (MGMT) in A549 cells. The results of these experiments do not support the assumption that low FA concentrations might interfere with the repair of DNA damage induced by other mutagens.

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

International Nuclear Information System (INIS)

Chun, Ung Kyung

1997-01-01

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

Energy Technology Data Exchange (ETDEWEB)

Chun, Ung Kyung [Korea Electric Power Research Insititute, Taejon (Korea, Republic of)

1997-12-31

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs.

Method selection for mercury removal from hard coal

Directory of Open Access Journals (Sweden)

Dziok Tadeusz

2017-01-01

Full Text Available Mercury is commonly found in coal and the coal utilization processes constitute one of the main sources of mercury emission to the environment. This issue is particularly important for Poland, because the Polish energy production sector is based on brown and hard coal. The forecasts show that this trend in energy production will continue in the coming years. At the time of the emission limits introduction, methods of reducing the mercury emission will have to be implemented in Poland. Mercury emission can be reduced as a result of using coal with a relatively low mercury content. In the case of the absence of such coals, the methods of mercury removal from coal can be implemented. The currently used and developing methods include the coal cleaning process (both the coal washing and the dry deshaling as well as the thermal pretreatment of coal (mild pyrolysis. The effectiveness of these methods various for different coals, which is caused by the diversity of coal origin, various characteristics of coal and, especially, by the various modes of mercury occurrence in coal. It should be mentioned that the coal cleaning process allows for the removal of mercury occurring in mineral matter, mainly in pyrite. The thermal pretreatment of coal allows for the removal of mercury occurring in organic matter as well as in the inorganic constituents characterized by a low temperature of mercury release. In this paper, the guidelines for the selection of mercury removal method from hard coal were presented. The guidelines were developed taking into consideration: the effectiveness of mercury removal from coal in the process of coal cleaning and thermal pretreatment, the synergy effect resulting from the combination of these processes, the direction of coal utilization as well as the influence of these processes on coal properties.

formation and behaviour of coal free radicals in relation to ...

African Journals Online (AJOL)

DJFLEX

61, 1249 – 1253. Xu L., Yang J and liu Z., 2004. Behaviour of organic sulfur model compounds in pyrolysis under coal like environment. Fuel Processing Technology 85 (8 - 10),. 1013 - 1024. Yokono T. Iyama S. Sanada Y. Shimokawa S and Yamada E., 1986. High temperature and high pressure 1H nmr and esr studies on.

Effect of process distillation on mutagenicity and cell-transformation activity of solvent-refined, coal-derived liquids

Energy Technology Data Exchange (ETDEWEB)

Pelroy, R.A.; Frazier, M.E.; Later, D.W.; Wright, C.W.; Wilson, B.W.

1985-05-01

Blended SRC-II process streams, representing a full boiling range distillate material, were fractionally distilled into non-overlapping 50 F cuts with bp between 300 and 850 C and another set with bp ranging between 138 and 1055 F. Distillate cuts were assayed for mutagenic activity using the histidine reversion assay with Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, as well as for mammalian-cell transformation (mct) activity in the Syrian hamster embryo test, and DNA damage in the prophage induction assay (pia). Samples were also separated into chemical class fractions by alumina column chromatography and analysed by high resolution gas chromatography. In the met and microbial mutagenicity assays, significant activity was found almost exclusively in cuts with bp> above 700 F, with the highest activity in the mct assay observed for cuts above 800 F. All of the cuts showed increased levels of DNA damage as expressed by lambda pia in Escherichia coli 8177. However, the greatest activity was associated with cuts with bp in the 800 F+ range. Chemical analysis of the 50 F cuts showed a variety of polycyclic aromatic hydrocarbons (PAH) and amino-PAH compounds to be present in the cuts with bp> above 700 F and essentially absent from cuts with bp< 700 F. The sample set of non-overlapping (50 F) cuts were reblended according to the proportions of each cut found in the original blend material. These reblended composites were then assayed to compare their activity with that predicted from the activities of the component cuts. The results indicated the microbial mutagenicity response was essentially additive. Met activities were non-additive, indicating a compositional effect on the expression of transforming agents in the complex mixture. 18 references.

Extent of pyrolysis impacts on fast pyrolysis biochar properties.

Science.gov (United States)

Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

2012-01-01

A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Low-rank coal study: national needs for resource development. Volume 3. Technology evaluation

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

Technologies applicable to the development and use of low-rank coals are analyzed in order to identify specific needs for research, development, and demonstration (RD and D). Major sections of the report address the following technologies: extraction; transportation; preparation, handling and storage; conventional combustion and environmental control technology; gasification; liquefaction; and pyrolysis. Each of these sections contains an introduction and summary of the key issues with regard to subbituminous coal and lignite; description of all relevant technology, both existing and under development; a description of related environmental control technology; an evaluation of the effects of low-rank coal properties on the technology; and summaries of current commercial status of the technology and/or current RD and D projects relevant to low-rank coals.

Cooperative research in coal liquefaction. Final report, May 1, 1992--April 30, 1993

Energy Technology Data Exchange (ETDEWEB)

Huffman, G.P. [ed.

1996-03-01

Research on sulfate and metal (Mo, Sn) promoted Fe{sub 2}O{sub 3} catalysts in the current year focused on optimization of conditions. Parameters varied included temperature, solvent, solvent-to-coal ratio, and the effect of presulfiding versus in situ sulfiding. Oil yields were found to increase approximately proportionately with both temperature and solvent-to-coal ratio. The donor solvent, tetralin, proved to give better total conversion and oil yields than either 1-methylnaphthalene or Wilsonville recycle oil. A significant enhancement of both total liquefaction yields and oil yields from lignites and subbituminous coals has been achieved by incorporating iron into the coal matrix by cation exchange. A study has been conducted on the synthesis of iron, molybdenum, and tungsten catalysts using a laser pyrolysis technique.

Mutagenicity of vinyl chloride after metabolic activation

Energy Technology Data Exchange (ETDEWEB)

Rannug, U; Johansson, A; Ramel, C; Wachtmeister, C A

1974-01-01

Vinyl chloride has recently been shown to cause a malignant liver tumor disease in man after occupational exposure in PVC plants. This actualizes the problem of whether such hazards could be avoided or at least diminished in the future by a screening for mutagenicity of chemicals used in industries. The basis for such a screening procedure is the close correlation between carcinogenic and mutagenic effects of chemicals. Experiments with Salmonella bacteria showed that the carcinogenic hazard of vinyl chloride could have been traced by means of mutagenicity tests. The data indicate that vinyl chloride is not mutagenic per se but becomes mutagenic after a metabolic activation in the liver. 24 references, 1 figure, 4 tables.

Chemistry of mutagens and carcinogens in broiled food.

Science.gov (United States)

Nishimura, S

1986-01-01

From a chemical point of view, the following subjects are important areas in studies on mutagens and carcinogens in broiled foods. In addition to heterocyclic amines which need microsomal activation, the structural elucidation of more labile direct-acting mutagens is necessary. It is known that there are still various unknown minor mutagens in broiled foods. Although the structural characterization of such compounds is more difficult, it is important since they might be hazardous in spite of their low mutagenicity. A more feasible and easier method for quantitative analysis of mutagens, in addition to HPLC and GC/MS methods presently employed, must be developed. The mechanism of formation of mutagens by broiling of food should be studied. An effective chemical method to prevent formation of mutagens or to destroy them, once formed, should be developed. PMID:3757944

Human somatic, germinal and heritable mutagenicity

International Nuclear Information System (INIS)

Mendelsohn, M.L.

1987-05-01

This report deals with the general process of variant formation rather than with the consequences of a specific variant being present. It focusses on mutational mechanisms, mutagens, and the method for detecting de novo mutants and estimating mutation rate. It is to human genetics much like disease causation and prevention medicine are to medicine as a whole. The word ''mutagenicity'' is used in the title and throughout the text to connote the causation of all classes of genetic damage. Mutagenicity and the corresponding words mutation, mutagen and mutagenesis can have multiple meaning, sometimes relating to gene mutation, sometimes to heritable mutation, and somtimes to all types of genetic damage. 38 refs., 1 tab

Low severity conversion of activated coal

Energy Technology Data Exchange (ETDEWEB)

Hirschon, A.S.; Ross, D.S.

1990-01-01

The results suggest that coal contains regions with structural components significantly reactive under the hydrothermal environment. Although the specific mechanism for this process remains to be developed, this activity is reminiscent of findings in studies of accelerated maturation of oil shale, where hydrothermal treatment (hydrous pyrolysis) leads to the production of petroleum hydrocarbons. In line with what has been seen in the oil shale work, the pretreatment-generated hydrocarbons and phenols appear to represent a further or more complete maturation of some fraction of the organic material within the coal. These observations could have an impact in two areas. The first is in the area of coal structure, where immature, reactive regions have not been included in the structures considered at present. The second area of interest is the more practical one of conversions to coal liquids and pyrolytic tars. It seems clear that the hydrothermal pretreatment changes the coal in some manner that favorably affects the product quality substantially and, as in the CO/water liquefaction case, favorably affects the yields. The conversions of coals of lower rank, i.e., less mature coals, could particularly benefit in terms of both product quality and product quantity. The second portion of this project also shows important benefits to coal conversion technology. It deals with synthesizing catalysts designed to cleave the weak links in the coal structure and then linking these catalysts with the pretreatment methods in Task 2. The results show that highly dispersed catalysts can effectively be used to increase the yields of soluble material. An important aspect of highly dispersed catalysts are that they can effectively catalyze coal conversion even in poor liquefaction solvents, thus making them very attractive in processes such as coprocessing where inexpensive liquefaction media such as resids are used.

A study of coal-solid waste blend reactivity

Directory of Open Access Journals (Sweden)

Nayibe Guerrero

2008-05-01

Full Text Available The Flynn-Wall-Ozawa method was used for analysing coal-solid waste blend reactivity in an oxidising atmosphere. The presence of biomass strongly affected coal combustion kinetics when the blend contained more than 30% of it. Activation energy values (evaluated by different blends were 28.7495 kJ/mol for 0% biomass, 31.3915 kJ/mol for 30% biomass, 39.0365 kJ/mol for 50% biomass, 102.431 kJ/mol for 70% biomass and 107.8075 kJ/mol for 100% biomass; these values were close to those reported in the literature. First-order kinetics correlated the data ve-ry well for the 100% coal sample and the blend having 30% biomass and 70% coal. Eighth-order kinetics were more suitable for correlating the experimental data for the 70% biomass-30% coal blend and the 100% biomass sample. Combustion was done without previous pyrolysis of the blends; however segregation of phenomena could be appre-ciated. This seems to indicate that combustion and devolatilisation are independent processes which should be taken into account when building equipment using these kinds of blend.

Two-Nozzle Flame Spray Pyrolysis (FSP) Synthesis of CoMo/Al2O3 Hydrotreating Catalysts

DEFF Research Database (Denmark)

Høj, Martin; Pham, David K.; Brorson, Michael

2013-01-01

and the hydrodenitrogenation activity improved from 70 to 90 % relative activity. This suggests that better promotion of the active molybdenum sulfide phase was achieved when using two-nozzle FSP synthesis, probably due to less formation of the undesired phase CoAl2O4, which makes Co unavailable for promotion.......Two-nozzle frame spray analysis (FSP) synthesis of CoMo/Al2O3 where Co and Al are sprayed in separate flames was applied to minimize the formation of CoAl2O4 observed in one-nozzle flame spray pyrolysis (FSP) synthesis and the materials were characterized by N2-adsorption (BET), X-ray diffraction...... (XRD), UV–vis diffuse reflectance spectroscopy, Raman spectroscopy, transmission electron microscopy, and catalytic performances in hydrotreating. By varying the flame mixing distances (81–175 mm) the amount of CoAl2O4 could be minimized. As evidenced by UV–vis spectroscopy, CoAl2O4 was detected only...

Study of anti mutagenic and mutagenic effect of different chemicals on clinically isolated strains of pseudomonas aeruginosa

International Nuclear Information System (INIS)

Qureshi, A.M.; Durrani, F.; Janjua, M.

1994-01-01

This project was undertaken to study the effect of twelve different compounds to test their anti mutagenic and mutagenic activity against clinically isolated strains of Pseudomonas aeruginosa. The effect of these compounds was estimated by counting the number of rifampicin resistant colonies growing in a particular time in a compound. The results were interpreted by plotting graphs between 10g N/NO (Rif R Colonies/ ml) and time to estimate the forward mutation rat. The results revealed that acridine, Basic fuchsin, Caffeine, cycloheximide, Ethidium bromide and Histidine probably have an anti mutagenic effect, while Cysteine, folic acid, Ethyl methane, suplphonate, Manganous Chloride and N-nitrosodietylamine acted as mutagen. Ecoli was used as control through out the study. (author)

Petrographic Changes in Compaction Thermal Treatment of Recent Plant Materials, Peat and Coals; Shokubutsu, deitan oyobi sekitan no atsumitsu kanetsu shoributsu no kenbikyo kansatsu

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, Yoshikazu. [National Institute of Materials and Chemical Research, Ibaraki (Japan); Okada, Kiyofumi. [Coal Energy Centre, Saitama (Japan); Suzuki, Yuichiro. [Geological Survey of Japan (Japan)

1999-03-20

Recent plant materials, peat and coals were compressed and thermally treated at various temperatures (200-400degreeC ) for 25 hours. The compaction pyrolysis products were observed with a microscope in both reflected and fluorescent lights, and their vitrinite reflectance (R{sub o}) were also measured. The R{sub o} values of the original samples varied from 0.1 of peat to 0.7 of Miike bituminous coal. After the thermal treatment at 300, 350 and 400degreeC, the R{sub o} values increased to 0.7-1.0, 1.2-1.4 and 1.7-2.1, respectively, in spite of the kind of the original material. The compaction pyrolysis products abtained from plant materials at 200degreeC showed sprcific textures which are often observed in natural low rank coals. Those textures became homogeneous with the increasing temperatures of the thermal treatment. Petrographic characteristice of the xylems of Morwell coal and red pine changed similarly during the thermal treatment. Because peat and humus soil sontained a large amount of mineral matter, they provided the pyrolysis products with different textures from other materials. The fluorercent material of leaf (metasequoia) after the thermal treatment at 200degreeC was considered as cutinite, and it stated to melt around 250degreeC and disappeared around 300degreeC , whereas thet of Miike bituminous coal did not melt and disappear even around 300degreeC. There still remain quite a few coal macerals of which origin and formation are unclear, and the artificial maturation followed by the microsopic investigation is one of effective approaches to elucidate them. (author)

Modelling of biomass pyrolysis

International Nuclear Information System (INIS)

Kazakova, Nadezhda; Petkov, Venko; Mihailov, Emil

2015-01-01

Pyrolysis is an essential preliminary step in a gasifier. The first step in modelling the pyrolysis process of biomass is creating a model for the chemical processes taking place. This model should describe the used fuel, the reactions taking place and the products created in the process. The numerous different polymers present in the organic fraction of the fuel are generally divided in three main groups. So, the multistep kinetic model of biomass pyrolysis is based on conventional multistep devolatilization models of the three main biomass components - cellulose, hemicelluloses, and lignin. Numerical simulations have been conducted in order to estimate the influence of the heating rate and the temperature of pyrolysis on the content of the virgin biomass, active biomass, liquid, solid and gaseous phases at any moment. Keywords: kinetic models, pyrolysis, biomass pyrolysis.

Investigation on the transient enthalpy of coal combustion

Energy Technology Data Exchange (ETDEWEB)

Fu, Pei-fang; Wang, Na; Yu, Bo; Zhang, Bin; Liu, Yang; Zhou, Huai-chun [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

2013-07-01

The transient enthalpy ({Delta}h) of coal/char combustion of the three different coals (including anthracite, bituminous, and lignite) during the process of combustion is determined as a function of burn-off degree by using thermo-gravimetric-differential scanning calorimeter (TG-DSC) simultaneous thermal analyzer, and The error of determining calorific values of coals/chars is less 5% compared the results of TG-DSC with that of an automatic isoperibol calorimeter. It is found that In the initial stage, all the {Delta}h of coals are greater than that of the char pyrolysized from parent coal for many of volatiles contained more a great deal of heat per unit mass oxidized at low temperature, it also imply that coal is more easily ignited than char corresponded; And in the middle stage, all the {Delta}h of coals is lower than that of the char pyrolysized, so the pyrolysized char oxidation can supply much more of thermo-energy per unit mass. {Delta}h are almost a constant when the burn-off degree is equal to between 0.35/0.15 and 0.95/0.85 for ZCY bituminous coal/char and JWY anthracite/char, between 0.35/0.35 and 0.75/0.9 for SLH lignite/char; In the later stage, the {Delta}h of the coal/char decreased with the burn-off degree, it imply that the activity of the coal/char decreases. Therefore, coal pyrolysis changes not only the structure of char, but also the property of release heat; the transient enthalpy of coal/char combustion has been in change with the burn-out degree.

Non-slag co-gasification of biomass and coal in entrained-bed furnace

Science.gov (United States)

Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

2018-02-01

Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a

Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

Energy Technology Data Exchange (ETDEWEB)

Dmochowska, Barbara [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Piosik, Jacek; Woziwodzka, Anna [Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Kladki 24, 80-822 Gdansk (Poland); Sikora, Karol; Wisniewski, Andrzej [Department of Carbohydrate Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Wegrzyn, Grzegorz, E-mail: wegrzyn@biotech.univ.gda.pl [Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk (Poland)

2011-10-15

Highlights: {yields} A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. {yields} The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. {yields} The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. {yields} We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

Mutagenicity of quaternary ammonium salts containing carbohydrate moieties

International Nuclear Information System (INIS)

Dmochowska, Barbara; Piosik, Jacek; Woziwodzka, Anna; Sikora, Karol; Wisniewski, Andrzej; Wegrzyn, Grzegorz

2011-01-01

Highlights: → A series of quaternary ammonium salts containing carbohydrate moieties, with configuration D-galacto, D-gluco and D-manno, was synthesized and characterized. → The quaternary ammonium salts containing carbohydrate moieties revealed potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. → The N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. → We suggest that quaternary ammonium salts may be more hazardous than previously supposed. - Abstract: Quaternary ammonium salts are widely used in industrial, agricultural, healthcare and domestic applications. They are believed to be safe compounds, with little or no health hazard to humans. However, in this report, we demonstrate that a series of newly synthesized quaternary ammonium salts containing carbohydrate moieties reveal potent mutagenic activities, as assessed by using the Vibrio harveyi bioluminescence mutagenicity test. D-Gluco- and D-galacto-derivatives were found to have a higher mutagenic potential than D-manno-derivatives. Among the former groups of compounds, the N-[2-(D-glycopyranosyloxy)ethyl]-N,N,N-trimethylaminium salts were of the highest activity in the mutagenicity assay. These results suggest that the safety of quaternary ammonium salts may be lower than previously supposed, indicating a need for testing such compounds for their mutagenicity.

Past, present, and future of mutagens in cooked foods.

Science.gov (United States)

Sugimura, T

1986-08-01

Mutation assay with Salmonella typhimurium enabled us to detect various types of mutagens in cooked foods. A series of mutagenic heterocyclic amines has been isolated and identified in broiled fish and meat and in pyrolyzates of amino acids and proteins. Feeding experiments showed these mutagens to be carcinogenic in mice and rats. The mechanism of formation and pathway of metabolic activation of these heterocyclic amines have been elucidated. Their contents in various cooked foods have been determined. The presence of mutagenic nitropyrenes (some of which were confirmed as carcinogens) in grilled chicken was also established. Roasted coffee beans also yield mutagens such as methylglyoxal. The formation of mutagen precursors, including beta-carboline derivatives and tyramine which become mutagens with nitrite treatment, was found during food processing. Oncogene activation in animal tumors induced by some of these food mutagens/carcinogens has been confirmed. The role of mutagens/carcinogens in cooked foods in human cancer development has not yet been exactly evaluated. In order to do this, more information on their carcinogenic potency, human intake, metabolism in the human body, and the effects of combined administration with other initiators, promoters and other modifying factors in food is required.

The behavior of catalysts in hydrogasification of sub-bituminous coal in pressured fluidized bed

International Nuclear Information System (INIS)

Yan, Shuai; Bi, Jicheng; Qu, Xuan

2017-01-01

Highlights: •CCHG in a pressured fluidized bed achieved 77.3 wt.% of CH 4 yield in 30 min. •Co-Ca and Ni-Ca triggered catalytic coal pyrolysis and char hydrogasification. •The reason for better catalytic performance of 5%Co-1%Ca was elucidated. •Sintered catalyst blocked the reactive sites and suppressed coal conversion. •Co-Ca made the catalyzed coal char rich in mesopore structures and reactive sites. -- Abstract: The catalytic hydrogasification of the sub-bituminous coal was carried out in a lab-scale pressurized fluidized bed with the Co-Ca, Ni-Ca and Fe-Ca as catalysts at 850 °C and 3 MPa. The effect of different catalysts on the characteristics of gasification products was investigated, and the behavior of the catalysts was also explored by means of the X-ray diffraction (XRD), FT-Raman, Brunauer–Emmett–Teller (BET), etc. Experiment results showed that all the catalysts promoted the carbon conversion in the coal catalytic hydrogasification (CCHG), and the catalytic activity was in the order: 5%Co-1%Ca > 5%Ni-1%Ca > 5%Fe-1%Ca. Compared with the raw coal hydrogasification, the carbon conversion increased from 43.4 wt.% to 91.3 wt.%, and the CH 4 yield increased from 23.7 wt.% to 77.3 wt.% within 30 min after adding the 5%Co-1%Ca catalyst into the coal. Co-Ca and Ni-Ca possessed catalytic effect on both processes of pyrolysis of coal and hydrogasification of coal char in CCHG, by which the graphitization of the coal was suppressed and methane formation rate was significantly accelerated. Fe/Co/Ni-Ca could penetrate into the interior of coal during CCHG, making the catalytic production of CH 4 conduct in the pore structures. The activity difference of the catalysts was owing to the different ability of rupturing the amorphous C−C bonds in coal structure. The incomplete carbon conversion of the 5%Co-1%Ca loaded coal was due to the agglomeration of the catalyst and the blockage of the reactive sites by the sintered catalyst. This work will provide

FAST PYROLYSIS PROCESS OF ORANGE SOLID WASTE. FACTORS INFLUENCE IN THE PROCESS

Directory of Open Access Journals (Sweden)

Leonardo Aguiar Trujillo

2015-04-01

Full Text Available The orange processing industry generates high volumes of solid residue. This residue has been used in animal feeding and biochemical processes. A possible energy use of the waste can be thermochemical fast pyrolysis process. The objective was to determine the influence of the heating rate and temperature in the process of rapid pyrolysis of orange solid residue. In the process a design, 2k full factorial experiment was used, evaluating the influence of the independent variables and its interactions on the answers, using a 95 % significance level. We found that temperature is the most significant influence on the responses parameter having significant influence on the yields to: gas, coal, tar and the calorific value of the gas and the heating rate does not influence the answers. Finally, the interaction affects the gas yield. The results obtained in this study are: Rgas (19 – 38 %, Rchar (25 – 42 %, Ralq (6 – 12 %, PCIgas entre (140 – 1050 kJ/m3N.

Kinetics of coal combustion: Part 3, Mechanisms and kinetics of char combustion

Energy Technology Data Exchange (ETDEWEB)

Gavalas, G. R.; Flagan, R. C. [California Inst. of Tech., Pasadena, CA (USA)

1988-09-01

This report summarizes a three-year research program aimed at developing this level of understanding of char combustion through a combination of detailed analysis of chars as produced during devolatilization and as they evolve during oxidation, and theoretical studies of the porous microstructures and of pore diffusion and reaction within the coal particles. A small number of coals have been studied in detail, namely a HVA bituminous (PSOC 1451), a sub-bituminous (PSOC 1488), and a lignite (PSOC 1443). Chars have been generated from size-classified samples of these coals by pyrolysis in an inert atmosphere in a drop tube furnace. The chars were then characterized both chemically and physically. Subsequent oxidation studies were performed on these chars. 42 refs., 54 figs., 4 tabs.

Mutagenic azide metabolite is azidoalanine

International Nuclear Information System (INIS)

Owais, W.M.; Rosichan, J.L.; Ronald, R.C.; Kleinhofs, A.; Nilan, R.A.

1981-01-01

Sodium axide produces high mutation rates in a number of species. Azide mutagenicity is mediated through a metabolite in barley and bacteria. Many studies showed that azide affects the L-cysteine biosynthesis pathway. Cell-free extracts of Salmonella typhimurium convert azide and O-acetylserine to the mutagenic metabolite. O-acetylserine sulfhydrylase was identified as the enzyme responsible for the metabolite biosynthesis. To confirm the conclusion that the azide metabolite is formed through the β-substitution pathway of L-cysteine, we radioactively labeled the azide metabolite using 14 C-labeled precursors. Moreover, the mutagenic azide metabolite was purified and identified as azidoalanine based on mass spectroscopy and elemental analysis. 26 refs., 3 figs., 1 tab

Analysis of commercial bouillons for trace levels of mutagens.

Science.gov (United States)

Stavric, B; Matula, T I; Klassen, R; Downie, R H

1993-12-01

A new method, developed specifically for the extraction of heterocyclic aromatic amine (HAA) type mutagens from different food matrices, was applied to various forms of commercially available bouillons. This procedure is based on liquid-liquid extraction of the sample at different pH values. Recovery and reproducibility of the procedure was determined by processing spiked samples using a mutagenicity bioassay technique as an endpoint. The mutagenicity was tested in the Salmonella/microsome assay using strain TA98 with metabolic activation. 22 bouillon samples in liquid, cube or powder forms from seven manufacturers were extracted and tested for potential mutagenicity. The mutagenic activity of these samples varied and ranged from non-detectable to about 1200 induced revertants per gram of solid material, with a median value of approximately 250 revertants/g. The mutagenic response appeared to be dependent on the source rather than the type or form of the product tested. A negative response was obtained from only one chicken bouillon, and the highest positive response was obtained from a beef bouillon in cube form. It appears that the average beef sample, regardless of form, has a higher mutagenic potency than chicken or chicken and turkey samples. Overall, the intake of mutagens from commercial bouillons (obtained as cubes, concentrates or dry mixes) to prepare one serving (as bouillon, soup, casseroles, etc.) is considerably less than that reported in the literature for one serving of fried beef or pork. The extractability and mutagenic characteristics of these samples indicate the presence of HAA-type mutagens. Work is in progress to identify the mutagenic factors in bouillons.

Liquid fuels from Canadian coals

Energy Technology Data Exchange (ETDEWEB)

Taylor, G. W.

1979-06-15

In Canadian energy planning, the central issue of security of supply must be addressed by developing flexible energy systems that make the best possible use of available resources. For liquid fuel production, oil sands and heavy oil currently appear more attractive than coal or biomass as alternatives to conventional crude oil, but the magnitude of their economic advantage is uncertain. The existence of large resources of oil sands, heavy oils, natural gas and low-sulfur coals in Western Canada creates a unique opportunity for Canadians to optimize the yield from these resources and develop new technology. Many variations on the three basic liquefaction routes - hydroliquefaction, pyrolysis and synthesis - are under investigation around the world, and the technology is advancing rapidly. Each process has merit under certain circumstances. Surface-mineable subbituminous and lignite coals of Alberta and Saskatchewan appear to offer the best combination of favorable properties, deposit size and mining cost, but other deposits in Alberta, Nova Scotia and British Columbia should not be ruled out. The research effort in Canada is small by world standards, but it is unlikely that technology could be imported that is ideally suited to Canadian conditions. Importing technology is undesirable: innovation or process modification to suit Canadian coals and markets is preferred; coprocessing of coal liquids with bitumen or heavy oils would be a uniquely Canadian, exportable technology. The cost of synthetic crude from coal in Canada is uncertain, estimates ranging from $113 to $220/m/sup 3/ ($18 to $35/bbl). Existing economic evaluations vary widely depending on assumptions, and can be misleading. Product quality is an important consideration.

Mutagenicity potential of commercial broth cubes at varying concentrations

International Nuclear Information System (INIS)

De Torres, Nelson Velasquez; Talain, Augusto Nicolas.

1997-01-01

Today, there has been a growing concern on the mutagenicity potential of environmental chemical systems. These environmental chemicals such as pesticides, food additives, synthetic drugs, water and atmospheric pollutants are possible causes of mutagenic activity. Meat products and some meat flavorings, were also reported to exhibit mutagenic activity. And since these products are normal part of the daily human diet, there is a need for extensive studies regarding the possible mutagenic activity associated with these products. This study aimed to evaluate the mutagenicity potential of commercial broth cubes at varying concentration. The researchers sought to answer the following questions: 1. Do beef, pork and chicken broth cubes exhibit mutagenic activity? 2. Are there significant differences in the mutagenic activity among the three samples? 3. Are these significant differences in the mutagenic activity exhibited by each of the samples compared to that of Mitomycin-C (positive control)? 4. Which of the sample of each specific concentration exhibit the greatest mutagenic activity? Three specific concentrations of beef, pork and chicken broth cubes were prepared and their mutagenicity potential was evaluated by using the Micronucleus test. The formation of micro nucleated polychromatic and micro nucleated normo chromatic erythrocytes in bone marrow cells of mice treated with these samples were detected using a Carl-Zeiss photo microscope. The statistical tool used to test the validity of the null hypothesis was analysis of variance using randomized complete block design and independent T- test. (author)

Mutagenicity potential of commercial broth cubes at varying concentrations

Energy Technology Data Exchange (ETDEWEB)

De Torres, Nelson Velasquez; Talain, Augusto Nicolas

1998-12-31

Today, there has been a growing concern on the mutagenicity potential of environmental chemical systems. These environmental chemicals such as pesticides, food additives, synthetic drugs, water and atmospheric pollutants are possible causes of mutagenic activity. Meat products and some meat flavorings, were also reported to exhibit mutagenic activity. And since these products are normal part of the daily human diet, there is a need for extensive studies regarding the possible mutagenic activity associated with these products. This study aimed to evaluate the mutagenicity potential of commercial broth cubes at varying concentration. The researchers sought to answer the following questions: 1. Do beef, pork and chicken broth cubes exhibit mutagenic activity? 2. Are there significant differences in the mutagenic activity among the three samples? 3. Are these significant differences in the mutagenic activity exhibited by each of the samples compared to that of Mitomycin-C (positive control)? 4. Which of the sample of each specific concentration exhibit the greatest mutagenic activity? Three specific concentrations of beef, pork and chicken broth cubes were prepared and their mutagenicity potential was evaluated by using the Micronucleus test. The formation of micro nucleated polychromatic and micro nucleated normo chromatic erythrocytes in bone marrow cells of mice treated with these samples were detected using a Carl-Zeiss photo microscope. The statistical tool used to test the validity of the null hypothesis was analysis of variance using randomized complete block design and independent T- test. (author). 28 refs., 9 figs., 26 tabs.

Molecular and genetic mechanisms of environmental mutagens

International Nuclear Information System (INIS)

Kubitschek, H.E.; Derstine, P.L.; Griego, V.M.; Matsushita, T.; Peak, J.G.; Peak, M.J.; Reynolds, P.R.; Webb, R.B.; Williams-Hill, D.

1981-01-01

This program is primarily concerned with elucidation of the nature of DNA lesions produced by environmental and energy related mutagens, their mechanisms of action, and their repair. The main focus is on actions of chemical mutagens and electromagnetic radiations. Synergistic interactions between mutagens and the mutational processes that lead to synergism are being investigated. Mutagens are chosen for study on the basis of their potential for analysis of mutation (as genetic probes), for development of procedures for reducing mutational damage, for their potential importance to risk assessment, and for development of improved mutagen testing systems. Bacterial cells are used because of the rapidity and clarity of scientific results that can be obtained, the detailed genetic maps, and the many well-defined mutand strains available. The conventional tools of microbial and molecular genetics are used, along with intercomparison of genetically related strains. Advantage is taken of tcollective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

Mechanism of obtaining carbon monoxide and hydrogen during brown coal radiolysis. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Rustamov, V R; Kurbanov, M A; Dzantiev, B T; Kerimov, V K; Musaeva, P F

1982-05-01

This article analyzes effects of gamma radiation on the yield of products of coal gasification: hydrogen and carbon monoxide. Samples of brown coal from the Kansk-Achins basin were treated by gamma radiation with cobalt 60 radiation source. Analyses show that accumulation of hydrogen and carbon monoxide in brown coal under influence of gamma radiation is characterized by a constant rate. Yields of carbon monoxide and hydrogen amount to 0.16 molecule/100 electro volt and 0.21 molecule/electro volt respectively. Reducing radiation dose from 2.5 to 0.7 millirad/h reduces yields of hydrogen and carbon monoxide. Increasing temperature of vacuum brown coal pyrolysis from 200 to 600 C causes decrease of hydrogen yield. Hydrogen yield decrease during temperature increase is caused by a high content of aromatic nuclei in the samples used in the radiolysis. (5 refs.)

Interaction of organic solvent with a subbituminous coal below pyrolysis temperature

Energy Technology Data Exchange (ETDEWEB)

Lindsey, D.; Grens, E.A.

1978-06-01

The interactions of a subbituminous coal with certain binary organic solvent mixtures have been studied at 250/sup 0/C. Mixtures of pyridine, quinoline, piperidine, tetrahydroquinoline, and ethylenediamine with either toluene or tetralin were contacted with coal in a successive batch, stirred reactor, the extractions being carried to near completion. Two distinct behaviors of extraction yield as a function of composition have been identified. In the majority of the solvent mixtures the extraction yield increases linearly with increasing concentration of the more active solvent. When the active solvent is ethylenediamine, however, the extraction yield increases rapidly when small concentrations of ethylenediamine are used but then levels out close to its maximum value in a 50 to 50 mix. This behavior is an indication that, except in the case of ethylenediamine, the activity of solvent mixtures is a function of bulk solution properties.

Comparison of Australasian tertiary coals based on resolution- enhanced solid-state /sup 13/C NMR spectra

Energy Technology Data Exchange (ETDEWEB)

Newman, R H; Davenport, S J

1986-04-01

/sup 13/C solid-state nuclear magnetic resonance spectroscopy was used to characterize 32 low-rank coals from New Zealand and Australia. A combination of high magnetic field (4.7 T) and resolution enhancement was used to extract spectral details beyond those seen in published spectra of coals of similar rank. Signal heights were used to characterize organic functional distributions. The spectra showed close similarities between Australian brown coals and low-rank New Zealand subbituminous coals, particularly those mined in the North Island. The spectra of New Zealand lignites all showed stronger signals from cellulose, methoxyl groups and phenols. Almost all of the New Zealand coals showed a relatively strong signal from polymethylene chains, compared with the Australian brown coals. This led to a prediction of higher alkene yields from pyrolysis of the New Zealand coals. Variations in phenolic substitution patterns were attributed to variations in the relative proportions of tannins and lignins in the depositional environments.

Acute wood or coal exposure with carbon monoxide intoxication induces sister chromatid exchange

Energy Technology Data Exchange (ETDEWEB)

Ozturk, S.; Vatansever, S.; Cefle, K.; Palanduz, S.; Guler, K.; Erten, N.; Erk, O.; Karan, M.A.; Tascioglu, C. [University of Istanbul, Istanbul (Turkey). Istanbul Faculty of Medicine

2002-07-01

The object of this study was to investigate the genotoxic effect of acute overexposure to combustion products originating from coal or wood stoves in patients presenting with acute carbon monoxide intoxication. The authors analyzed the frequency of sister chromatid exchange and the carboxyhemoglobin concentration in 20 consecutive patients without a history of smoking or drug use who had been treated in the Emergency Care Unit of Istanbul Medical Faculty due to acute carbon monoxide intoxication. All of these cases were domestic accidents due to dysfunctioning coal or wood stoves. The results were compared with a control group of 20 nonsmoking, nondrug-using healthy individuals matched for age, sex, and absence of other chemical exposure. It was concluded that acute exposure to combustion products of wood or coal is genotoxic to DNA. Potential causes of genotoxicity include known mutagenic compounds present in coal or wood smoke and ash, oxygen radicals formed during combustion, as well as hypoxic and reperfusion injury mechanisms initiated by carbon monoxide intoxication.

Mutagenicity screening: General principles and minimal criteria. Report of a committee of the European Environmental Mutagen Society

NARCIS (Netherlands)

Kilbey, B.J.; Igali, S.; Lohman, P.H.M.

1978-01-01

A statement of general principles and minimal criteria for the screening of chemicals for potential mutagenicity in man that may be used as guidelines for regulatory agencies and industrial organisations. To make clear the potentialities and current limitations of short-term mutagenicity testing for

COAL/POLYMER COPROCESSING WITH EFFICIENT USE OF HYDROGEN

Energy Technology Data Exchange (ETDEWEB)

Dr. Linda J. Broadbelt; Matthew J. DeWitt; Hsi-Wu Wong

2000-09-30

The final project period was devoted to investigating the binary mixture pyrolysis of polypropylene and polystyrene. Their interactions were assessed in order to provide a baseline for experiments with multicomponent mixtures of polymers with coal. Pyrolysis of polypropylene, polystyrene and their binary mixture was investigated at temperatures of 350 C and 420 C with reaction times from 1 to 180 minutes. Two different loadings, 10 mg and 20 mg, were studied for neat polypropylene and polystyrene to assess the effect of total pressure on product yields and selectivities. For neat pyrolysis of polypropylene, total conversion was much higher at 420 C, and no significant effect of loading on the total conversion was observed. Four classes of products, alkanes, alkenes, dienes, and aromatic compounds, were observed, and their distribution was explained by a typical free radical mechanism. For neat polystyrene pyrolysis, conversion reached approximately 75% at 350 C, while at 420 C the conversion reached a maximum around 90% at 10 minutes and decreased at longer times because of condensation reactions. The selectivities to major products were slightly different for the two different loadings due to the effect of total reaction pressure on secondary reactions. For binary mixture pyrolysis, the overall conversion was higher than the average of the two neat cases. The conversion of polystyrene remained the same, but a significant enhancement in the polypropylene conversion was observed. This suggests that the less reactive polypropylene was initiated by polystyrene-derived radicals. These results are summarized in detail in an attached manuscript that is currently in preparation. The other results obtained during the lifetime of this grant are documented in the set of attached manuscripts.

Study on the hydrothermal treatment of Shenhua coal

Energy Technology Data Exchange (ETDEWEB)

Zhicai Wang; Hengfu Shui; Zhanning Pei; Jinsheng Gao [Anhui University of Technology, Ma' anshan (China). School of Chemistry and Chemical Engineering

2008-04-15

In this paper, the hydrothermal treatment of Shenhua coal was carried out under 0.1 MPa (initial pressure) nitrogen and different temperature. Effects of hydrothermal treatment on the structure and the hydro-liquefaction activity of Shenhua coal were investigated by the ultimate and proximate analyses, the FTIR measurements and TG analyses of hydrothermally treated coals, and the characterizations of extraction and swelling properties, and the batch hydro-liquefaction of treated coal were also carried out. The results indicate that hydrothermal treatment above 200{sup o}C can increase the hydrogen content of treated coal and decrease the yield of volatiles and the content of ash, especially a large amount of CO and CH{sub 4} are found in gas products obtained by the hydrothermal treatment above 250{sup o}C. Hydrothermal treatment disrupts the weak covalent bond such as ether, ester and side-chain substituent by hydrolysis and pyrolysis, and changes the distribution of H-bond in coal. The swelling ratio and the Soxhlet extraction yield of treated coal decrease with the increase of hydrothermal treatment temperature. The conversion of liquefaction and the yield of CS{sub 2}/NMP mixed solvent extraction at ambient temperature are enhanced by hydrothermal treatment at 300{sup o}C. Therefore hydrogen donation reactions and the rupture of non-covalent bond and weak covalent bonds present in the process of hydrothermal treatment resulting in the changes of structure and reactivity of Shenhua coal. The results show that the hydro-liquefaction activity of Shenhua coal can be improved by hydrothermal pretreatment between 250{sup o}C and 300{sup o}C. 15 refs., 5 figs., 4 tabs.

Distribution of volatile sulphur containing products during fixed bed pyrolysis and gasification of coals

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E.

1991-08-01

Various coals were used to study the evolution of H{sub 2}S COS, and SO{sub 2} in a fixed bed reactor. For all types of coal, most of H{sub 2}S and SO{sub 2} were released during the devolatilization stage. COS was formed only during the gasification stage in the presence of CO{sub 2}.

Modeling of biomass pyrolysis

International Nuclear Information System (INIS)

Samo, S.R.; Memon, A.S.; Akhund, M.A.

1995-01-01

The fuels used in industry and power sector for the last two decades have become expensive. As a result renewable energy source have been emerging increasingly important, of these, biomass appears to be the most applicable in the near future. The pyrolysis of biomass plays a key role amongst the three major and important process generally encountered in a gas producer, namely, pyrolysis, combustion and reduction of combustion products. Each biomass has its own pyrolysis characteristics and this important parameters must be known for the proper design and efficient operation of a gasification system. Thermogravimetric analysis has been widely used to study the devolatilization of solid fuels, such as biomass. It provides the weight loss history of a sample heated at a predetermined rate as a function of time and temperature. This paper presents the experimental results of modelling the weight loss curves of the main biomass components i.e. cellulose, hemicellulose and lignin. Thermogravimetric analysis of main components of biomass showed that pyrolysis is first order reaction. Furthermore pyrolysis of cellulose and hemicelluloe can be regarded as taking place in two stages, for while lignin pyrolysis is a single stage process. This paper also describes the Thermogravimetric Analysis (TGA) technique to predict the weight retained during pyrolysis at any temperature, for number of biomass species, such as cotton stalk, bagasse ad graoundnut shell. (author)

Pyrolysis characteristics of typical biomass thermoplastic composites

Directory of Open Access Journals (Sweden)

Hongzhen Cai

Full Text Available The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite. Keywords: Biomass thermoplastic composite, Calcium carbonate, Pyrolysis characteristic

Handbook of mutagenicity test procedures

International Nuclear Information System (INIS)

Kilbey, B.J.; Legatov, M.

1977-01-01

27 articles are presented on particular techniques of mutagen testing. Background information is given in materials, experimental design, pitfalls and difficults, to enable the reader to perform these tests with minimal additional help. Also included is the use of data from population records, the handling and safety aspects of mutagens and carcinogens and some of the basic statistical concepts to be borne in mind when mutation experiments are designed. (C.F.)

Modelling solid-convective flash pyrolysis of straw and wood in the Pyrolysis Centrifuge Reactor

DEFF Research Database (Denmark)

Bech, Niels; Larsen, Morten Boberg; Jensen, Peter Arendt

2009-01-01

in the Pyrolysis Centrifuge Reactor, a novel solid-convective flash pyrolysis reactor. The model relies on the original concept for ablative pyrolysis of particles being pyrolysed through the formation of an intermediate liquid compound which is further degraded to form liquid organics, char, and gas. To describe...

Low severity conversion of activated coal. Final report

Energy Technology Data Exchange (ETDEWEB)

Hirschon, A.S.; Ross, D.S.

1990-01-01

The results suggest that coal contains regions with structural components significantly reactive under the hydrothermal environment. Although the specific mechanism for this process remains to be developed, this activity is reminiscent of findings in studies of accelerated maturation of oil shale, where hydrothermal treatment (hydrous pyrolysis) leads to the production of petroleum hydrocarbons. In line with what has been seen in the oil shale work, the pretreatment-generated hydrocarbons and phenols appear to represent a further or more complete maturation of some fraction of the organic material within the coal. These observations could have an impact in two areas. The first is in the area of coal structure, where immature, reactive regions have not been included in the structures considered at present. The second area of interest is the more practical one of conversions to coal liquids and pyrolytic tars. It seems clear that the hydrothermal pretreatment changes the coal in some manner that favorably affects the product quality substantially and, as in the CO/water liquefaction case, favorably affects the yields. The conversions of coals of lower rank, i.e., less mature coals, could particularly benefit in terms of both product quality and product quantity. The second portion of this project also shows important benefits to coal conversion technology. It deals with synthesizing catalysts designed to cleave the weak links in the coal structure and then linking these catalysts with the pretreatment methods in Task 2. The results show that highly dispersed catalysts can effectively be used to increase the yields of soluble material. An important aspect of highly dispersed catalysts are that they can effectively catalyze coal conversion even in poor liquefaction solvents, thus making them very attractive in processes such as coprocessing where inexpensive liquefaction media such as resids are used.

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.

Pyrolysis characteristics of typical biomass thermoplastic composites

Science.gov (United States)

Cai, Hongzhen; Ba, Ziyu; Yang, Keyan; Zhang, Qingfa; Zhao, Kunpeng; Gu, Shiyan

The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA) has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite.

Hydrothermal pretreatment of coal

Energy Technology Data Exchange (ETDEWEB)

Ross, D.S.

1989-12-21

We have examined changes in Argonne Premium samples of Wyodak coal following 30 min treatment in liquid water at autogenous pressures at 150{degrees}, 250{degrees}, and 350{degrees}C. In most runs the coal was initially dried at 60{degrees}C/1 torr/20 hr. The changes were monitored by pyrolysis field ionization mass spectrometry (py-FIMS) operating at 2.5{degrees}C/min from ambient to 500{degrees}C. We recorded the volatility patterns of the coal tars evolved over that temperature range, and in all cases the tar yields were 25%--30% of the starting coal on mass basis. There was essentially no change after the 150{degrees}C treatment. Small increases in volatility were seen following the 250{degrees}C treatment, but major effects were seen in the 350{degrees} work. The tar quantity remained unchanged; however, the volatility increased so the temperature of half volatility for the as-received coal of 400{degrees}C was reduced to 340{degrees}C. Control runs with no water showed some thermal effect, but the net effect from the presence of liquid water was clearly evident. The composition was unchanged after the 150{degrees} and 250{degrees}C treatments, but the 350{degrees} treatment brought about a 30% loss of oxygen. The change corresponded to loss of the elements of water, although loss of OH'' seemed to fit the analysis data somewhat better. The water loss takes place both in the presence and in the absence of added water, but it is noteworthy that the loss in the hydrothermal runs occurs at p(H{sub 2}O) = 160 atm. We conclude that the process must involve the dehydration solely of chemically bound elements of water, the dehydration of catechol is a specific, likely candidate.

Analysis of solvent extracts from coal liquefaction in a flowing solvent reactor

Energy Technology Data Exchange (ETDEWEB)

Li, Wen-Ying; Feng, Jie; Xie, Ke-Chang [Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, No. 79 Yingze West Street, Taiyuan 030024 (China); Kandiyoti, R. [Department of Chemical Engineering and Chemical Technology, Imperial College, University of London, London SW7 2BY (United Kingdom)

2004-10-15

Point of Ayr coal has been extracted using three solvents, tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP) at two temperatures 350 and 450 C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. The three solvents differ in solvent power and the ability to donate hydrogen atoms to stabilise free radicals produced by pyrolysis of the coal. The extracts were prepared in a flowing solvent reactor to minimise secondary thermal degradation of the primary extracts. Analysis of the pentane-insoluble fractions of the extracts was achieved by size exclusion chromatography, UV-fluorescence spectroscopy in NMP solvent and probe mass. With increasing extraction temperature, the ratio of the amount having big molecular weight to that having small molecular weight in tetralin extracts was increased; the tetralin extract yield increased from 12.8% to 75.9%; in quinoline, increasing extraction temperature did not have an effect on the molecular weight of products but there was a big increase in extract yield. The extracts in NMP showed the enhanced solvent extraction power at both temperatures, with a shift in the ratio of larger molecules to smaller molecules with increasing extraction temperature and with the highest conversion of Point of Ayr coal among these three solvents at both temperatures. Solvent adducts were detected in the tetralin and quinoline extracts by probe mass spectrometry; solvent products were formed from NMP at both temperatures.

Understanding the fast pyrolysis of lignin.

Science.gov (United States)

Patwardhan, Pushkaraj R; Brown, Robert C; Shanks, Brent H

2011-11-18

In the present study, pyrolysis of corn stover lignin was investigated by using a micro-pyrolyzer coupled with a GC-MS/FID (FID=flame ionization detector). The system has pyrolysis-vapor residence times of 15-20 ms, thus providing a regime of minimal secondary reactions. The primary pyrolysis product distribution obtained from lignin is reported. Over 84 % mass balance and almost complete closure on carbon balance is achieved. In another set of experiments, the pyrolysis vapors emerging from the micro-pyrolyzer are condensed to obtain lignin-derived bio-oil. The chemical composition of the bio-oil is analyzed by using GC-MS and gel permeation chromatography techniques. The comparison between results of two sets of experiments indicates that monomeric compounds are the primary pyrolysis products of lignin, which recombine after primary pyrolysis to produce oligomeric compounds. Further, the effect of minerals (NaCl, KCl, MgCl(2), and CaCl(2)) and temperature on the primary pyrolysis product distribution is investigated. The study provides insights into the fundamental mechanisms of lignin pyrolysis and a basis for developing more descriptive models of biomass pyrolysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of hydrothermal treatment on some properties of Shenhua coal

Energy Technology Data Exchange (ETDEWEB)

Wang Zhi-cai; Shui Heng-fu; Zhang De-xiang; Gao Jin-sheng [East China University of Science and Technology, Shanghai (China). College of Resource and Environmental Engineering

2006-10-15

Effects of hydrothermal treatment on swelling, extraction and liquefaction behavior of Shenhua coal were studied through analyses of element content, ash content, volatile content and IR spectrum of treated coal. The results indicate that hydrogenation of coal is distinctly carried out in the process of hydrothermal pre-treatment and the hydrogen content of treated coal is more than that of raw coal. The contents of ash and volatile matters of treated coal are lower than those of raw coal. With the increase of treatment temperature the volatile content of the hydrothermal treated coal decreases and the ash content of treated coal increases. CO{sub 2} is main gas product and unvaries with the temperature changing, whereas CO and CH{sub 4} are formed when the temperature is above 250{sup o}C and increase with the temperature during hydrothermal treatment. Hydrothermal treatment is not in favor of coal swelling and the swelling ratio of treated coal decreases with the increase of treatment temperature. The swelling ratio of extraction residue by CS{sub 2}/NMP mixed solvent in NMP solvent is lower than that of the corresponding raw coal. The CS{sub 2}/NMP mixed solvent extraction yields of coal treated at appropriate temperature are higher than that of raw coal, but the extraction yields of treated coal obtained by n-hexane, toluene and THF successive Soxhelt extraction are lower. Hydrothermal treatment at 250-300{sup o}C can increase the conversion of treated coal in direct hydro-liquefaction. The gas + oil yield of treated coal is lower than that of raw coal and the preasphaltene yield of treated coal is much higher. IR spectra of treated coals show that the forms of non-covalent bonds are changed by hydrothermal treatment, and the hydrolysis of ester and ether bonds and the pyrolysis of aromatic side chains also maybe occur at high treatment temperature. 21 refs., 3 figs., 4 tabs.

Mutagenicity studies with the mouse spot test

Energy Technology Data Exchange (ETDEWEB)

Gocke, E.; Wild, D.; Eckhardt, K.; King, M.T.

1983-04-01

The mammalian spot test, which detects somatic gene mutations in mouse embryos, was investigated with selected chemicals to (a) further validate this test system ethylnitrosourea, ethyl methanesulfonate, 2-acetylaminofluorene and colchicine (ENU, EMS, 2AAF), and (b) evaluate the mutagenic potential, in a whole-mammal system, of environmental compounds that had been previously recognized as mutagens in other mammalian or submammalian test systems (1,2-dichloroethane, hydroquinone, nitrofurantoin, o-phenylenediamine, fried sausage extract). Of these substances, ENU, EMS and 2AAF were significantly mutagenic, 1,2-dichloroethane was probably weakly mutagenic. The ENU data were used to estimate the number of pigment precursor cells present at the time of treatment (day 9.25). We also describe in this report the use of a fluorescence microscope for classification of hairs from spots on the coat of C57BL/6JHan X T hybrids.

Nonmutagenicity of betel leaf and its antimutagenic action against environmental mutagens.

Science.gov (United States)

Nagabhushan, M; Amonkar, A J; D'Souza, A V; Bhide, S V

1987-01-01

Betel leaf (Piper betel) water and acetone extract are nonmutagenic in S. typhimurium strains with and without S9 mix. Both the extracts suppress the mutagenicity of betel quid mutagens in a dose dependent manner. Moreover both the extracts of betel leaf reduce the mutagenicity of benzo(a)pyrene and dimethylbenzanthracene. Acetone extract is more potent than water extract in inhibiting mutagenicity of environmental mutagens.

Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

International Nuclear Information System (INIS)

Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

2017-01-01

Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

Refining fast pyrolysis of biomass

NARCIS (Netherlands)

Westerhof, Roel Johannes Maria

2011-01-01

Pyrolysis oil produced from biomass is a promising renewable alternative to crude oil. Such pyrolysis oil has transportation, storage, and processing benefits, none of which are offered by the bulky, inhomogeneous solid biomass from which it originates. However, pyrolysis oil has both a different

Pyrolysis oil as diesel fuel

Energy Technology Data Exchange (ETDEWEB)

Gros, S [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

1997-12-31

Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

Pyrolysis oil as diesel fuel

Energy Technology Data Exchange (ETDEWEB)

Gros, S. [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

1996-12-31

Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

Exploring evaluation to influence the quality of pulverized coal fly ash. Co-firing of biomass in a pulverized coal plant or mixing of biomass ashes with pulverized coal fly ash; Verkennende evaluatie kwaliteitsbeinvloeding poederkoolvliegas. Bijstoken van biomassa in een poederkoolcentrale of bijmenging van biomassa-assen met poederkoolvliegas

Energy Technology Data Exchange (ETDEWEB)

Van der Sloot, H.A.; Cnubben, P.A.J.P [ECN Schoon Fossiel, Petten (Netherlands)

2000-08-01

In this literature survey the consequences of co-firing of biomass and mixing of biomass ash with coal fly ash on the coal fly ash quality is evaluated. Biomass ash considered in this context is produced by gasification, pyrolysis or combustion in a fluidized bed. The irregular shape of biomass ash obtained from gasification, pyrolysis or combustion has a negative influence on the water demand in concrete applications of the coal fly ash resulting from mixing biomass ash and coal fly ash. In case of co-firing, high concentrations of elements capable of lowering the ash melting point (e.g., Ca and Mg) may lead to more ash agglomeration. This leads to a less favourable particle size distribution of the coal fly ash, which has a negative impact on the water demand in cement bound applications. Gasification, pyrolysis and combustion may lead to significant unburnt carbon levels (>10%). The unburnt carbon generally absorbs water and thus has a negative influence on the water demand in cement-bound applications. The contribution of biomass ash to the composition of coal fly ash will not be significantly different, whether the biomass is co-fired or whether the biomass ash is mixed off-line with coal fly ash. The limit values for Cl, SO4 and soluble salts can form a limitation for the use of coal fly ash containing biomass for cement-bound applications. As side effects of biomass co-firing, the level of constituents such as Na, K, Ca and Mg may lead to slagging and fouling of the boiler. In addition, a higher emission of flue gas contaminants As, Hg, F, Cl and Br may be anticipated in case more contaminated biomass streams are applied. This may also lead to a higher contamination level of gypsum produced from flue gas cleaning residues. Relatively clean biomass streams (clean wood, cacao shells, etc.) will hardly lead to critical levels of elements from a leaching point of view. More contaminated streams, such as sewage sludge, used and preserved wood, petcoke and RDF

Late Cretaceous coal overlying karstic bauxite deposits in the Parnassus-Ghiona Unit, Central Greece: Coal characteristics and depositional environment

Energy Technology Data Exchange (ETDEWEB)

Kalaitzidis, Stavros; Siavalas, George; Christanis, Kimon [Dept. of Geology, University of Patras, 26504 Rio-Patras (Greece); Skarpelis, Nikos [Dept. of Geology and Geoenvironment, University of Athens, 15784 Zografou (Greece); Araujo, Carla Viviane [Petrobras-Cenpes GEOQ/PDEXP, Rua Horacio Macedo n 950, Cidade Universitaria - Ilha do Fundao, 21941-915 Rio de Janeiro (Brazil)

2010-04-01

The Pera-Lakkos coal located on top of bauxite deposits in the Ghiona mining district (Central Greece), is the only known Mesozoic (Late Cretaceous) coal in the country. It was derived from herbaceous plants and algae growing in mildly brackish mires that formed behind a barrier system during a regression of the sea, on a karstified limestone partly filled in with bauxitic detritus. Petrological, mineralogical and geochemical data point to the predominance of reducing conditions and intense organic matter degradation in the palaeomires. O/C vs. H/C and OI vs. HI plots, based on elemental analysis and Rock-Eval data, characterize kerogen types I/II. This reflects the relatively high liptinite content of the coal. Besides kerogen composition, O/C vs. H/C plot for the Pera-Lakkos coals is in accordance with a catagenesis stage of maturation in contrast with vitrinite reflectance and T{sub max} from Rock-Eval pyrolysis, which indicate the onset of oil window maturation stage. Suppression of vitrinite reflectance should be considered and the high liptinite content corroborates this hypothesis. Despite some favourable aspects for petroleum generation presented by the Pera-Lakkos coal, its maximum thickness (up to 50 cm) points to a restricted potential for petroleum generation. Coal oxidation took place either during the late stage of peat formation, due to wave action accompanying the subsequent marine transgression, or epigenetically after the emergence of the whole sequence due to percolation of drainage waters. Both options are also supported by the REE shale-normalized profiles, which demonstrate an upwards depletion in the coal layer. Oxidation also affected pyrite included in the coal; this led to the formation of acidic (sulfate-rich) solutions, which percolated downwards resulting in bleaching of the upper part of the underlying bauxite. (author)

Impact of organic-mineral matter interactions on thermal reaction pathways for coal model compounds

Energy Technology Data Exchange (ETDEWEB)

Buchanan, A.C. III; Britt, P.F.; Struss, J.A. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

1995-07-01

Coal is a complex, heterogeneous solid that includes interdispersed mineral matter. However, knowledge of organic-mineral matter interactions is embryonic, and the impact of these interactions on coal pyrolysis and liquefaction is incomplete. Clay minerals, for example, are known to be effective catalysts for organic reactions. Furthermore, clays such as montmorillonite have been proposed to be key catalysts in the thermal alteration of lignin into vitrinite during the coalification process. Recent studies by Hatcher and coworkers on the evolution of coalified woods using microscopy and NMR have led them to propose selective, acid-catalyzed, solid state reaction chemistry to account for retained structural integrity in the wood. However, the chemical feasibility of such reactions in relevant solids is difficult to demonstrate. The authors have begun a model compound study to gain a better molecular level understanding of the effects in the solid state of organic-mineral matter interactions relevant to both coal formation and processing. To satisfy the need for model compounds that remain nonvolatile solids at temperatures ranging to 450 C, model compounds are employed that are chemically bound to the surface of a fumed silica (Si-O-C{sub aryl}linkage). The organic structures currently under investigation are phenethyl phenyl ether (C{sub 6}H{sub 5}CH{sub 2}CH{sub 2}OC{sub 6}H{sub 5}) derivatives, which serve as models for {beta}-alkyl aryl ether units that are present in lignin and lignitic coals. The solid-state chemistry of these materials at 200--450 C in the presence of interdispersed acid catalysts such as small particle size silica-aluminas and montmorillonite clay will be reported. Initial focus will be on defining the potential impact of these interactions on coal pyrolysis and liquefaction.

Proceedings of the papers of the 33rd Coal Science Conference (1996); Dai 33 kai sekitan kagaku kaigi happyo ronbunshu (1996)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-28

This is a proceedings of the papers made public in the 33rd (fiscal 1996) Coal Science Conference held by the Japan Institute of Energy. The number of the papers included is 82. The processes such as coal liquefaction, coal gasification and pyrolysis are largely influenced by reaction of the carbon compound in coal. However, coal, which is different in reaction characteristics depending on its producing area, is a comprehensive compound. Therefore, the trial has been made for clarifying the molecular structure and skeleton. In the sense, the following papers are taken notice of: Suzuki and others` Estimation for origin of coals by biomaker analysis; Sugimoto and others` Change of unit skeletons during the artificial coalification; Hirado and others` Study on the correlation between chemical and mineral composition of coal ashes; Okawa and others` Coal structure construction system with construction knowledge and partial energy evaluation; Kanbayashi and others` Analysis of the relationship between coal properties and liquefaction characteristics by using the coal database.

Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor

DEFF Research Database (Denmark)

Trinh, Ngoc Trung; Jensen, Peter Arendt; Sárossy, Zsuzsa

2013-01-01

Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained...... at temperatures of 500−550 °C, reactor gas residence time of 0.8 s, and feed rate of 5.6 g/min. Gas chromatography mass spectrometry and size-exclusion chromatography were used to characterize the Chemical properties of the lignin oils. Acetic acid, levoglucosan, guaiacol, syringols, and p-vinylguaiacol are found...... components and molecular mass distribution of the lignin oils. The obtained lignin oil has a very different components composition when compared to a beech wood oil....

Future developments and technological and economic assessment of methods for producing synthetic liquid fuel from coal

Energy Technology Data Exchange (ETDEWEB)

Shlikhter, E B; Khor' kov, A V; Zhorov, Yu M

1980-11-01

Promising methods for obtaining synthetic liquid fuel from coal are surveyed and described: thermal dissolution of coal by means of a hydrogen donor solution: hydrogenation; gasification with subsequent synthesis and pyrolysis. A technological and economic assessment of the above processes is given. Emphasis is placed on methods employing catalytic conversion of methanol into hydrocarbon fuels. On the basis of thermodynamic calculations of the process for obtaining high-calorific liquid fuel from methanol the possibility of obtaining diesel fractions as well as gasoline is demonstrated. (12 refs.) (In Russian)

Pyrolysis of Coconut Shell: An Experimental Investigation

Directory of Open Access Journals (Sweden)

E. Ganapathy Sundaram

2009-12-01

Full Text Available Fixed-bed slow pyrolysis experiments of coconut shell have been conducted to determine the effect of pyrolysis temperature, heating rate and particle size on the pyrolysis product yields. The effect of vapour residence time on the pyrolysis yield was also investigated by varying the reactor length. Pyrolysis experiments were performed at pyrolysis temperature between 400 and 600°C with a constant heating rate of 60°C/min and particle sizes of 1.18-1.80 mm. The optimum process conditions for maximizing the liquid yield from the coconut shell pyrolysis in a fixed bed reactor were also identified. The highest liquid yield was obtained at a pyrolysis temperature of 550 °C, particle size of 1.18-1.80 mm, with a heating rate of 60 °C/min in a 200 mm length reactor. The yield of obtained char, liquid and gas was 22-31 wt%, 38-44 wt% and 30-33 wt% respectively at different pyrolysis conditions. The results indicate that the effects of pyrolysis temperature and particle size on the pyrolysis yield are more significant than that of heating rate and residence time. The various characteristics of pyrolysis oil obtained under the optimum conditions for maximum liquid yield were identified on the basis of standard test methods.

Mutagenicity of heated sugar-casein systems: effect of the Maillard reaction.

Science.gov (United States)

Brands, C M; Alink, G M; van Boekel, M A; Jongen, W M

2000-06-01

The formation of mutagens after the heating of sugar-casein model systems at 120 degrees C was examined by the Ames test, using Salmonella typhimurium strain TA100. Several sugars (glucose, fructose, galactose, tagatose, lactose, and lactulose) were compared in their mutagenicities. Mutagenicity could be fully ascribed to Maillard reaction products and strongly varied with the kind of sugar. The differences in mutagenicity among the sugar-casein systems were caused by a difference in reaction rate and a difference in reaction mechanism. Sugars with a comparable reaction mechanism (glucose and galactose) showed a higher mutagenic activity corresponding with a higher Maillard reactivity. Disaccharides showed no mutagenic activity (lactose) or a lower mutagenic activity (lactulose) than their corresponding monosaccharides. Ketose sugars (fructose and tagatose) showed a remarkably higher mutagenicity compared with their aldose isomers (glucose and galactose), which was due to a difference in reaction mechanism.

Relation between the petrographic composition of coal and the morphology of pyrolysis char produced in fluidized bed

Energy Technology Data Exchange (ETDEWEB)

B. Valentim; M.J. Lemos de Sousa; P. Abelha; D. Boavida; I. Gulyurtlu [Centro de Geologia da Universidade do Porto, Porto (Portugal)

2004-06-01

Several previous studies have already established, for pulverized coal combustion conditions, global correlations between petrographic composition of the coal and those of char produced from the same coal. However, for fluidized bed combustion, there has not been much new work since the eighties. The results presented in this paper include the petrographic characterization of seven different coals from several origins and also of their respective chars produced at 700, 800, 900, and 1000{sup o}C in a laboratory fluidized bed reactor. The results show a marked predominance of tenuispheres as the trial temperatures increase. While vitrinite-rich coals essentially produced highly porous chars, the inertinite-rich coals produced large amounts of medium- and low-porous chars. Semi-anthracite vitrinite produced high-porous chars and thermal affected coal particles originated low-porous and angular char morphotypes. The analysis of the data obtained revealed that vitrinite + liptinite related well with the high-porous char (sum of cenospheres and tenuinetworks), classified as Group 1. The same trend, but with a weaker relation, was also observed between vitrinite and liptinite rich microlithotypes and Group 1. 32 refs., 17 refs., 3 tabs.

Cytological effects of some new mutagens on rice

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Jin Wei

2002-01-01

Air-dried seeds of five rice varieties were carried by recoverable satellite (RS) for space mutation and were irradiated by synchronous irradiation (soft X-rays), protons and nitrogen ions. The cytological effects were compared with that of γ-irradiation. The results indicated that all the mutagens were able to induce variation on chromosome structure in root tip cells. The space environment had a stimulating mitotic effect on root tip cells. Other mutagens had inhibiting mitotic actions. The rates of micronuclei induced by synchronous irradiation and other mutagens were higher than that by γ-rays; and the rates of chromosomal bridge were lower. Furthermore, the radiosensitivity of five varieties varied with different mutagens

Optimization of palm kernel shell torrefaction to produce energy densified bio-coal

International Nuclear Information System (INIS)

Asadullah, Mohammad; Adi, Ag Mohammad; Suhada, Nurul; Malek, Nur Hanina; Saringat, Muhammad Ilmam; Azdarpour, Amin

2014-01-01

Highlights: • Around 70% of bio-coal yield was achieved from PKS torrefaction at 300 °C. • The higher heating value of optimized bio-coal was 24.5 MJ/kg. • Around 94% of thermal yield was achieved with 70% mass yield. • The grindability of optimized bio-coal was comparable with coal. - Abstract: Biomass torrefaction is a thermal process, which is similar to a mild form of pyrolysis at temperatures ranging from 200 to 320 °C to produce energy densified solid fuel. The torrefied biomass is almost equivalent to coal and is termed as bio-coal. During torrefaction, highly volatile fraction of biomass including moisture and hemicellulose are released as vapors, providing energy enriched solid fuel, which is hydrophobic and brittle. In this study, bio-coal is produced from palm kernel shell (PKS) in a batch feeding reactor. The operating variables such as temperature, residence time and swiping gas flow rate are optimized. Around 73% yield of bio-coal with calorific value of 24.5 MJ/kg was achieved at optimum temperature 300 °C with residence time of 20 min and nitrogen gas flow rate of 300 mL/min. The thermal yield was calculated to be maximum of 94% for the bio-coal produced at 300 °C. The temperature and residence time of torrefaction are found to be the most sensitive parameters in terms of product yield, calorific value and thermal yield of bio-coal

The role of catalysts in the decomposition of phenoxy compounds in coal: A density functional theory study

Science.gov (United States)

Liu, Jiang-Tao; Wang, Ming-Fei; Gao, Zhi-Hua; Zuo, Zhi-Jun; Huang, Wei

2018-01-01

The pyrolysis mechanisms of anisole (C6H5OCH3), as a coal-based model compound, on CaO, ZnO and γ-Al2O3 catalysts were studied using density functional theory (DFT). In contrast to the products of pyrolysis (C6H6, H2 and CO), the products of catalytic pyrolysis on CaO, ZnO, and γ-Al2O3 are C6H5OH and C2H4; CO, C5H6 and C2H4; and C6H5OH and C2H4, respectively. Our results indicate that CaO, ZnO and γ-Al2O3 catalysts not only decrease the energy barrier of C6H5OCH3 decomposition but also alter the pyrolysis process and the products. It is also found that the pyrolysis gas H2 alters the products on CaO (C6H5OH and CH4), but it does not affect the products on ZnO and γ-Al2O3. In sum, these catalysts are beneficial for phenoxy compound decomposition.

Is Tobacco Smoke a Germ-Cell Mutagen?

Science.gov (United States)

Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

Kinetics assisted design of catalysts for coal liquefaction. Final report

Energy Technology Data Exchange (ETDEWEB)

Klein, M.T.; Foley, H.C.; Calkins, W.H.; Scouten, C.

1998-02-01

The thermal and catalytic reactions of 4-(1-naphthylmethyl)bibenzyl (NBBM), a resid and coal model compound, were examined. Catalytic reaction of NBBM was carried out at 400 C under hydrogen with a series of transition metal-based catalytic materials including Fe(CO){sub 4}PPh{sub 3}, Fe(CO){sub 3}(PPh{sub 3}){sub 2}, Fe(CO){sub 2}(PPh{sub 3}){sub 2}CS{sub 2}, Fe(CO){sub 5}, Mo(CO){sub 6}, Mn{sub 2}(CO){sub 10}, Fe{sub 2}O{sub 3} and MoS{sub 2}. Experimental findings and derived mechanistic insights were organized into molecular-level reaction models for NBBM pyrolysis and catalysis. Hydropyrolysis and catalysis reaction families occurring during NBBM hydropyrolysis at 420 C were summarized in the form of reaction matrices which, upon exhaustive application to the components of the reacting system, yielded the mechanistic reaction model. Each reaction family also had an associated linear free energy relationship (LFER) which provided an estimate of the rate constant k{sub i} given a structural property of species i or its reaction. Including the catalytic reaction matrices with those for the pyrolysis model provided a comprehensive NBBM catalytic reaction model and allowed regression of fundamental LFER parameters for the catalytic reaction families. The model also allowed specification of the property of an optimal catalyst. Iron, molybdenum and palladium were predicted to be most effective for model compound consumption. Due to the low costs associated with iron and its disposal, it is a good choice for coal liquefaction catalysis and the challenge remains to synthesize small particles able to access the full surface area of the coal macromolecule.

Mutagens from the cooking of food. III. Survey by Ames/Salmonella test of mutagen formation in secondary sources of cooked dietary protein

Energy Technology Data Exchange (ETDEWEB)

Bjeldanes, L F [Univ. of California, Berkeley; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-01-01

A survey of mutagen formation during the cooking of a variety of protein-rich foods that are minor sources of protein intake in the American diet is reported (see Bjeldanes, Morris, Felton et al. (1982) for survey of major protein foods). Milk, cheese, tofu and organ meats showed negligible mutagen formation except following high-temperature cooking for long periods of time. Even under the most extreme conditions, tofu, cheese and milk exhibited fewer than 500 Ames/Salmonella typhimurium revertants/100 g equivalents (wet weight of uncooked food), and organ meats only double that amount. Beans showed low mutagen formation after boiling followed by frying (with and without oil). Only boiling of beans followed by baking for 1 hr gave appreciable mutagenicity (3650 revertants/100 g equivalents). Seafood samples gave a variety of results: red snapper, salmon, trout, halibut and rock cod all gave more than 1000 revertants/100 g wet weight equivalents when pan-fried or griddle-fried for about 6 min/side. Baked or poached rock cod and deep-fried shrimp showed no significant mutagen formation. Broiled lamb chops showed mutagen formation similar to that in red meats tested in the preceding paper: 16,000 revertants/100 g equivalents. These findings show that as measured by bioassay in S. typhimurium, most of the food that are minor sources of protein in the American diet are also minor sources of cooking-induced mutagens.

Mutagens from the cooking of food. III. Survey by Ames/Salmonella test of mutagen formation in secondary sources of cooked dietary protein.

Science.gov (United States)

Bjeldanes, L F; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-08-01

A survey of mutagen formation during the cooking of a variety of protein-rich foods that are minor sources of protein intake in the American diet is reported (see Bjeldanes, Morris, Felton et al. (1982) for survey of major protein foods). Milk, cheese, tofu and organ meats showed negligible mutagen formation except following high-temperature cooking for long periods of time. Even under the most extreme conditions, tofu, cheese and milk exhibited fewer than 500 Ames/Salmonella typhimurium revertants/100 g equivalents (wet weight of uncooked food), and organ meats only double that amount. Beans showed low mutagen formation after boiling and boiling followed by frying (with and without oil). Only boiling of beans followed by baking for 1 hr gave appreciable mutagenicity (3650 revertants/100g equivalents). Seafood samples gave a variety of results: red snapper, salmon, trout, halibut and rock cod all gave more than 1000 revertants/100 g wet weight equivalents when pan-fried or griddle-fried for about 6 min/side. Baked or poached rock and deep-fried shrimp showed no significant mutagen formation. Broiled lamb chops showed mutagen formation similar to that in red meats tested in the preceding paper: 16,000 revertants/100 g equivalents. These findings show that as measured by bioassay in S. typhimurium, most of the foods that are minor sources of protein in the American diet are also minor sources of cooking-induced mutagens.

The lignin pyrolysis composition and pyrolysis products of palm kernel shell, wheat straw, and pine sawdust

International Nuclear Information System (INIS)

Chang, Guozhang; Huang, Yanqin; Xie, Jianjun; Yang, Huikai; Liu, Huacai; Yin, Xiuli; Wu, Chuangzhi

2016-01-01

Highlights: • The primarily pyrolysis composition of PKS lignin was p-hydroxyphenyl unit. • Higher phenol yield and lower gas energy yield were obtained from PKS pyrolysis. • PKS produced more bio-oil and biochar than WS and PS from pyrolysis at 650–850 °C. • PKS-char had poorer gasification reactivity due to higher ordering carbon degree. - Abstract: The lignin monomer composition of palm kernel shell (PKS) was characterized using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and the characteristics and distributions of products obtained from PKS pyrolysis were investigated using Py-GC/MS, GC, and a specially designed pyrolysis apparatus. The gasification reactivity of PKS biochar was also characterized using thermogravimetry (TG) and Raman spectroscopy. All the results were compared with those obtained from wheat straw (WS) and pine sawdust (PS). The results showed that PKS lignin is primarily composed of p-hydroxyphenyl structural units, while WS and PS lignins are mainly made up of guaiacyl units. Both the mass and energy yields of non-condensable gases from PKS pyrolysis were lower than those obtained from WS and PS pyrolysis at 650–850 °C, owing to the lower volatile content (75.21%) and lack of methoxy groups in PKS. Compared with WS and PS, higher bio-oil productivity was observed during PKS pyrolysis. Phenols were the main component of PKS bio-oil from pyrolysis at 500 °C, and the phenol content of PKS bio-oil (13.49%) was higher than in WS bio-oil (1.62%) and PS bio-oil (0.55%). A higher yield of biochar (on an ash-free basis) was also obtained from PKS pyrolysis. Because of its greater relative degree of ordered carbon, PKS biochar exhibited lower in situ reactivity during CO_2 or H_2O gasification than WS and PS biochars. A longer residence time and addition of steam were found to be beneficial during PKS biochar gasification.

MINIMIZATION OF CARBON LOSS IN COAL REBURNING

International Nuclear Information System (INIS)

Zamansky, Vladimir M.; Lissianski, Vitali V.

2001-01-01

This project develops Fuel-Flexible Reburning (FFR), which combines conventional reburning and Advanced Reburning (AR) technologies with an innovative method of delivering coal as the reburning fuel. The overall objective of this project is to develop engineering and scientific information and know-how needed to improve the cost of reburning via increased efficiency and minimized carbon in ash and move the FFR technology to the demonstration and commercialization stage. Specifically, the project entails: (1) optimizing FFR with injection of gasified and partially gasified fuels with respect to NO x and carbon in ash reduction; (2) characterizing flue gas emissions; (3) developing a process model to predict FFR performance; (4) completing an engineering and economic analysis of FFR as compared to conventional reburning and other commercial NO x control technologies, and (5) developing a full-scale FFR design methodology. The project started in August 2000 and will be conducted over a two-year period. The work includes a combination of analytical and experimental studies to identify optimum process configurations and develop a design methodology for full-scale applications. The first year of the program included pilot-scale tests to evaluate performances of two bituminous coals in basic reburning and modeling studies designed to identify parameters that affect the FFR performance and to evaluate efficiency of coal pyrolysis products as a reburning fuel. Tests were performed in a 300 kW Boiler Simulator Facility to characterize bituminous coals as reburning fuels. Tests showed that NO x reduction in basic coal reburning depends on process conditions, initial NO x and coal type. Up to 60% NO x reduction was achieved at optimized conditions. Modeling activities during first year concentrated on the development of coal reburning model and on the prediction of NO x reduction in reburning by coal gasification products. Modeling predicted that composition of coal

Effect of fuel origin on synergy during co-gasification of biomass and coal in CO2.

Science.gov (United States)

Zhang, Yan; Zheng, Yan; Yang, Mingjun; Song, Yongchen

2016-01-01

The effect of fuel origin on synergy in coal/biomass blends during co-gasification has been assessed using a congruent-mass thermogravimetry analysis (TGA) method. Results revealed that synergy occurs when ash residuals are formed, followed by an almost complete gasification of biomass. Potassium species in biomass ash play a catalytic role in promoting gasification reactivity of coal char, which is a direct consequence of synergy during co-gasification. The SEM-EDS spectra provided conclusive evidence that the transfer of potassium from biomass to the surface of coal char occurs during co-pyrolysis/gasification. Biomass ash rich in silica eliminated synergy in coal/biomass blends but not to the extent of inhibiting the reaction rate of the blended chars to make it slower than that of separated ones. The best result in terms of synergy was concluded to be the combination of low-ash coal and K-rich biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mutagenic DNA repair in enterobacteria

International Nuclear Information System (INIS)

Sedgwick, S.G.; Chao Ho; Woodgate, R.

1991-01-01

Sixteen species of enterobacteria have been screened for mutagenic DNA repair activity. In Escherichia coli, mutagenic DNA repair is encoded by the umuDC operon. Synthesis of UmuD and UmuC proteins is induced as part of the SOS response to DNA damage, and after induction, the UmuD protein undergoes an autocatalytic cleavage to produce the carboxy-terminal UmuD' fragment needed for induced mutagenesis. The presence of a similar system in other species was examined by using a combined approach of inducible-mutagenesis assays, cross-reactivity to E. coli UmuD and UmuD' antibodies to test for induction and cleavage of UmuD-like proteins, and hybridization with E. coli and Salmonella typhimurium u mu DNA probes to map umu-like genes. The results indicate a more widespread distribution of mutagenic DNA repair in other species than was previously thought. They also show that umu loci can be more complex in other species than in E. coli. Differences in UV-induced mutability of more than 200-fold were seen between different species of enteric bacteria and even between multiple natural isolates of E. coli, and yet some of the species which display a poorly mutable phenotype still have umu-like genes and proteins. It is suggested that umuDC genes can be curtailed in their mutagenic activities but that they may still participate in some other, unknown process which provides the continued stimulus for their retention

Radiation-thermal processes of conversion in the coals

International Nuclear Information System (INIS)

Mustafaev, I.I.

2002-01-01

Full text: The brief review, history, modern condition and bibliographic data on research of radiation-stimulated processes in coals are adduced in the report. Results of new researches of influence of gamma - radiation and accelerated electrons on pyrolysis, gasification, desulphurization, paramagnetism, adsorption and optical properties of coals in wide intervals of change of absorbed dose, dose rate, temperature, radiation type and other parameters of processes are stated. As object of researches Turkish (Yeni koy, Yatagan) and Russian (Siberia) coals were used. Specific peculiarities of influence of ionizing radiations on fossil fuels, bringing in change of their reactivity as result of destruction and polycondensation processes are considered. a)Pyrolysis: Under action of gamma-radiation and accelerated electrons the rate of thermal (t) pyrolysis grows and the ratio of radiation-thermal (rt) and thermal (t) processes: Wrt/ Wt depends on dose rate and temperature. By increase of dose rate the radiation effects grows, and at increase of temperature this effect is reduced. The influence of high rate heating of coals under pulls action of accelerated electrons on conversion degree and product composition has been established. The investigation regularities of formation liquid and gas products is resulted at radiation - thermal processing of mixtures of lignites with fuel oil. These experiments were conducted in flowing conditions in the interval of temperature T=350-500 degrees centigrade, power of the pulls accelerated electrons P=30-50 W, flow velocity of fuel oil 0,2-2 ml/minute. As a index of process were controlled conversion degree of coals, overall yield, contents and characteristic of liquid and gas products. The products of thermal treatment of these mixtures and also radiation-thermal treatment of separate components significantly less than radiation-thermal conversion of binary mixtures. It has been established that radiation effect has a positive

Mutagens from the cooking of food. II. Survey by Ames/Salmonella test of mutagen formation in the major protein-rich foods of the American diet

Energy Technology Data Exchange (ETDEWEB)

Bjeldanes, L.F. (Univ. of California, Berkeley); Morris, M.M.; Felton, J.S.; Healy, S.; Stuermer, D.; Berry, P.; Timourian, H.; Hatch, F.T.

1982-01-01

The formation of mutagens in the major cooked protein-rich foods in the US diet was studied in the Ames Salmonella typhimurium test. The nine protein-rich foods most commonly eaten in the USA--ground beef, beef steak, eggs, pork chops, fried chicken, pot-roasted beef, ham, roast beef and bacon--were examined for their mutagenicity towards S. typhimurium TA1538 after normal 'household' cooking (deep frying, griddle/pan frying, baking/roasting, broiling, stewing, braising or boiling at 100-475/sup 0/C). Well-done fried ground beef, beef steak, ham, pork chops and bacon showed significant mutagen formation. For chicken and beef steak high-temperature broiling produced the most mutagenicity, followed by baking/roasting and frying. Stewing, braising and deep frying produced little mutagen. Eggs andd egg products produced mutagens only after cooking at high temperatures (the yolk to a greater extent than the white). Commercially cooked hamburgers showed a wide range of mutagenic activity. We conclude that mutagen formation following cooking of protein-containing foods is a complex function of food type, cooking time and cooking temperature. It seems clear that all the major protein-rich foods if cooked to a well-done state on the griddle (eggs only at temperature above 225/sup 0/C) or by broiling will contain mutagens detectable by the Ames/Salmonella assay. This survey is a step towards determining whether any human health hazard results from cooking protein-rich foods. Further testing in both short- and long-term genotoxicity bioassays and carcinogenesis assays are needed before any human risk extrapolations can be made.

Mutagens from the cooking of food. II. Survey by Ames/Salmonella test of mutagen formation in the major protein-rich foods of the American diet.

Science.gov (United States)

Bjeldanes, L F; Morris, M M; Felton, J S; Healy, S; Stuermer, D; Berry, P; Timourian, H; Hatch, F T

1982-08-01

The formation of mutagens in the major cooked protein-rich foods in the US diet was studied in the Ames Salmonella typhimurium test. The nine protein-rich foods most commonly eaten in the USA--ground beef, beef steak, eggs, pork chops, fried chicken, pot-roasted beef, ham, roast beef and bacon--were examined for their mutagenicity towards S. typhimurium TA1538 after normal 'household' cooking (deep frying, griddle/pan frying, baking/roasting, broiling, stewing, braising or boiling of 100-475 degrees C). Well-done fried ground beef, beef steak, ham pork chops and bacon showed significant mutagen formation. For chicken and beef steak high-temperature broiling produced the most mutagenicity, followed by baking/roasting and frying. Stewing, braising and deep frying produced little mutagen. Eggs and egg products produced mutagens only after cooking at high temperatures (the yolk to a greater extent than the white). Commercially cooked hamburgers showed a wide range of mutagenic activity. We conclude that mutagen formation following cooking of protein-containing foods is a complex function of food type, cooking time and cooking temperature. It seems clear that all the major protein-rich foods if cooked to a well-done state on the griddle (eggs only at temperatures above 225 degrees C) or by broiling will contain mutagens detectable by the Ames/Salmonella assay. This survey is a step towards determining whether any human health hazard results from cooking protein-rich foods. Further testing in both short- and long-term genotoxicity bioassays and carcinogenesis assays are needed before any human risk extrapolations can be made.

Mutagens in urine of carbon electrode workers

Energy Technology Data Exchange (ETDEWEB)

Pasquini, R; Monarca, S; Sforzolini, G S; Conti, R; Fagioli, F

1982-01-01

Following previous work carried out in an Italian factory producing carbon electrodes and evaluating the occupational mutagenic-carcinogenic hazards, the authors studied the presence of mutagen metabolites in the urine of workers in the same factory who were exposed to petroleum coke and pitch and in the urine of a control group of unexposed workers. The urine samples were concentrated by absorption on XAD-2 columns and were tested using the Salmonella/microsome assay (strain TA98, TA100, TA1535, TA1538) with and without the addition of beta-glucuronidase and metabolizing system. The collection of urine samples was carried out twice, with an interval of 2 months; 'before working time', 'after working time', and also during Sunday. The results showed that urine samples collected 'before' occupational exposure (upon waking) or on Sunday revealed no mutagenic activity in either worker groups and that the urine samples collected after or during occupational exposure revealed high mutagenic activity in the exposed workers, with a statistically significant difference between the mean of the revertants/plate values for exposed and unexposed workers. On the basis of the previous and the present research, the authors suggest that application of the Salmonella/microsome test to work environments could offer useful and suitable tool for evaluating the health hazards due to mutagenic/carcinogenic substances from occupational exposure.

Prospects and technical and economic evaluation of methods for obtaining synthetic liquid from coal

Energy Technology Data Exchange (ETDEWEB)

Shlikhter, E B; Khor' kov, A V; Zhorov, Y M

1980-11-01

Rising oil prices and the exhaustion of cheap organic fuels point to the need for chemical processing of coal to obtain synthetic liquid fuels. Added importance for such development in the USSR is dictated by the remote location of many coal deposits, such as the Kansko-Achinsk basin. Methods for synthesizing described include thermal dissolution in a hydrogen donor solvent, hydrogenation, and gasification with subsequent synthesis and pyrolysis. The need for improved technology is stressed. Cost factors are related to the chemical process involved, rather than to losses in fuel quantities, and the methanol produced is readily transported by pipeline. It can be used for both gasoline and diesel fuels.

High pressure hydropyrolysis of coals by using a continuous free-fall reactor

Energy Technology Data Exchange (ETDEWEB)

W.-C. Xu; K. Matsuoka; H. Akiho; M. Kumagai; A. Tomita [Institute of Research and Innovation, Kashiwa (Japan)

2003-04-01

Rapid hydropyrolysis of coal was carried out at temperatures ranging from 923 to 1123 K and H{sub 2} pressures up to 7 MPa by using a continuous free-fall pyrolyzer. The effects of the reaction conditions on product yields were investigated. Carbon mass balance was fairly good. It was revealed that a large amount of methane was produced due to the hydrogenolysis of higher hydrocarbons and the hydrogasification of char. The influence of pyrolysis temperature was significant on both reactions while H{sub 2} pressure mainly affected the latter. A considerable amount of reactive carbon was formed during hydropyrolysis of coal. It was converted to methane at high temperatures and high H{sub 2} pressures, while the hydrogasification of reactive carbon takes place relatively slowly at low temperatures and low H{sub 2} pressures, resulting in a low overall carbon conversion. The coal conversions observed in the present study were much higher than those obtained with using reactors where the contact between coal particles and H{sub 2} is insufficient. 25 refs., 6 figs., 6 tabs.

Production, properties and utilisation of pyrolysis oil

Energy Technology Data Exchange (ETDEWEB)

Sipilae, K; Oasmaa, A; Arpiainen, V; Solantausta, Y; Leppaemaeki, E; Kuoppala, E; Levander, J; Kleemola, J; Saarimaeki, P [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies

1997-12-01

In this project VTT Energy co-ordinates the EU JOULE Project `Biofuel oil for power plants and boilers` supporting the development projects of Finnish enterprises, and participates in the Pyrolysis Project of IEA Bioenergy Agreement. Presently two pyrolysis devices with capacities of 150 g/h and 1 kg/h are used for the project. Hot gas filtering tests by using one ceramic candle equipment have been carried out with the 1 kg/h device for pyrolysis oil. The solids and alkali contents of the product oil were reduced clearly. Suitable conditions are being defined for continuous hot gas filtering. A PDU device of 20 kg/h is being commissioned. The main aim of the chemical characterisation of pyrolysis oil was to develop as simple a method as possible for differentiating pyrolysis oils and for finding correlations between the characteristics and behaviour of pyrolysis oils. Pyrolysis oils produced from various raw materials (hardwood, pine, straw) were analysed and compared with each other. VTT Energy participates in the pyrolysis network (EU/PYNE) of EU, the aim of which is to collect and disseminate research results of pyrolysis studies, i.e., through a journal with a wide circulation. VTT also participates in the pyrolysis activity of IEA (PYRA), the other partners being Great Britain, EU, Canada and the United States. I.e., quality criteria and improvement, occupational safety and pyrolysis kinetics are discussed in IEA/PYRA

Catalytic biomass pyrolysis process

Science.gov (United States)

Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.; Kataria, Atish; Shen, Jian-Ping

2018-04-17

Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

Dietary mutagen exposure and risk of pancreatic cancer.

Science.gov (United States)

Li, Donghui; Day, Rena Sue; Bondy, Melissa L; Sinha, Rashmi; Nguyen, Nga T; Evans, Douglas B; Abbruzzese, James L; Hassan, Manal M

2007-04-01

To investigate the association between dietary exposure to food mutagens and risk of pancreatic cancer, we conducted a hospital-based case-control study at the University of Texas M. D. Anderson Cancer Center during June 2002 to May 2006. A total of 626 cases and 530 noncancer controls were frequency matched for race, sex and age (+/-5 years). Dietary exposure information was collected via personal interview using a meat preparation questionnaire. A significantly greater portion of the cases than controls showed a preference to well-done pork, bacon, grilled chicken, and pan-fried chicken, but not to hamburger and steak. Cases had a higher daily intake of food mutagens and mutagenicity activity (revertants per gram of daily meat intake) than controls did. The daily intakes of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) and benzo(a)pyrene (BaP), as well as the mutagenic activity, were significant predictors for pancreatic cancer (P = 0.008, 0.031, and 0.029, respectively) with adjustment of other confounders. A significant trend of elevated cancer risk with increasing DiMeIQx intake was observed in quintile analysis (P(trend) = 0.024). A higher intake of dietary mutagens (those in the two top quintiles) was associated with a 2-fold increased risk of pancreatic cancer among those without a family history of cancer but not among those with a family history of cancer. A possible synergistic effect of dietary mutagen exposure and smoking was observed among individuals with the highest level of exposure (top 10%) to PhIP and BaP, P(interaction) = 0.09 and 0.099, respectively. These data support the hypothesis that dietary mutagen exposure alone and in interaction with other factors contribute to the development of pancreatic cancer.

Gasification in pulverized coal flames. Final report (Part I). Pulverized coal combustion and gasification in a cyclone reactor: experiment and model

Energy Technology Data Exchange (ETDEWEB)

Barnhart, J. S.; Laurendeau, N. M.

1979-05-01

A unified experimental and analytical study of pulverized coal combustion and low-BTU gasification in an atmospheric cyclone reactor was performed. Experimental results include several series of coal combustion tests and a coal gasification test carried out via fuel-rich combustion without steam addition. Reactor stability was excellent over a range of equivalence ratios from .67 to 2.4 and air flowrates from 60 to 220 lb/hr. Typical carbon efficiencies were 95% for air-rich and stoichiometric tests and 80% for gasification tests. The best gasification results were achieved at an equivalence ratio of 2.0, where the carbon, cold gas and hot gas efficiencies were 83, 45 and 75%, respectively. The corresponding product gas heating value was 70 BTU/scf. A macroscopic model of coal combustion in the cyclone has been developed. Fuel-rich gasification can also be modeled through a gas-phase equilibrium treatment. Fluid mechanics are modeled by a particle force balance and a series combination of a perfectly stirred reactor and a plug flow reactor. Kinetic treatments of coal pyrolysis, char oxidation and carbon monoxide oxidation are included. Gas composition and temperature are checked against equilibrium values. The model predicts carbon efficiency, gas composition and temperature and reactor heat loss; gasification parameters, such as cold and hot gas efficiency and make gas heating value, are calculated for fuel-rich conditions. Good agreement exists between experiment and theory for conditions of this investigation.

N2 O A greenhouse gas released from the combustion of coals in fluidized beds

International Nuclear Information System (INIS)

Boavida, D.; Lobo, L. S.; Gulyurtlu, I.; Cabrita, I.

1996-01-01

This paper discusses the results of the experimental work investigating the formation of N-2 O and NO during fluidized bed combustion of coals, and of chars and volatiles produced from the pyrolysis of these coals. Ammonia (N H 3 ) and hydrogen cyanide (HCN) are shown to play important roles as gas phase precursors of both NO and N 2 O. The conversion of fuel-N through N H 3 and HCN to N 2 O and NO was studied using a fluidized bed combustor in the temperature range between 973 K and 1273 K, for two different coals. The results suggest that the principal contribution to N 2 O emission Originated from volatile-N, however, char-N could also have an important role, depending upon the temperature. 1 fig., 8 tabs

Effects of diet composition on mutagenic activity in urine.

Science.gov (United States)

Ohara, Akihiro; Matsuhisa, Tsugio

2004-01-01

The effects of dietary habits on mutagenic activity in urine were investigated using the umu test based on the use of the genetically engineered bacteria Salmonella typhimurium TA 1535 pSK1002. Genotoxic effects in sample urine were detected by measuring the activation of the SOS response in the bacteria and recording the beta- galactosidase activity. Human subjects consisted of smokers and non-smokers. Urine from subjects who consumed fish showed the highest mutagenic activity, followed by the urine samples from subjects who ate pork or beef. Chicken induced a low level of mutagenic activity. When the subjects ate fried or roasted animal foods, the urine samples gave higher mutagenicity than the urine samples from the subject who consumed non-fried or non-roasted animal foods. When the subject ate vegetables along with a diet rich in animal foods, the activity in urine decreased. Herbs and spices gave the same tendency toward decline as vegetables. Non-smoker urine shower mutagenic activity than samples from smokers.

Mutagenicity in drug development: interpretation and significance of test results.

Science.gov (United States)

Clive, D

1985-03-01

The use of mutagenicity data has been proposed and widely accepted as a relatively fast and inexpensive means of predicting long-term risk to man (i.e., cancer in somatic cells, heritable mutations in germ cells). This view is based on the universal nature of the genetic material, the somatic mutation model of carcinogenesis, and a number of studies showing correlations between mutagenicity and carcinogenicity. An uncritical acceptance of this approach by some regulatory and industrial concerns is over-conservative, naive, and scientifically unjustifiable on a number of grounds: Human cancers are largely life-style related (e.g., cigarettes, diet, tanning). Mutagens (both natural and man-made) are far more prevalent in the environment than was originally assumed (e.g., the natural bases and nucleosides, protein pyrolysates, fluorescent lights, typewriter ribbon, red wine, diesel fuel exhausts, viruses, our own leukocytes). "False-positive" (relative to carcinogenicity) and "false-negative" mutagenicity results occur, often with rational explanations (e.g., high threshold, inappropriate metabolism, inadequate genetic endpoint), and thereby confound any straightforward interpretation of mutagenicity test results. Test battery composition affects both the proper identification of mutagens and, in many instances, the ability to make preliminary risk assessments. In vitro mutagenicity assays ignore whole animal protective mechanisms, may provide unphysiological metabolism, and may be either too sensitive (e.g., testing at orders-of-magnitude higher doses than can be ingested) or not sensitive enough (e.g., short-term treatments inadequately model chronic exposure in bioassay). Bacterial systems, particularly the Ames assay, cannot in principle detect chromosomal events which are involved in both carcinogenesis and germ line mutations in man. Some compounds induce only chromosomal events and little or no detectable single-gene events (e.g., acyclovir, caffeine

Mutagenic effectiveness and efficiency of gamma rays and ethyl methanesulhonate in Indian mustard

International Nuclear Information System (INIS)

Prasad, Rajendra; Singh, Basudeo

1986-01-01

Mutagenic effectiveness is a measure of the frequency of mutations induced by unit dose of a mutagen while mutagenic efficiency gives the proportion of mutations in relation to other associated undesirable biological effects such as gross chromosomal aberrations, lethality and sterility induced by the mutagen in question (Konzak, et al., 1965). The usefulness of any mutagen in plant breeding depends not only on its mutagenic effectiveness but also on its mutagenic efficiency. The efficiency and effectiveness of ethyl methanesulphonate (EMS) in relation to gamma rays in Indian mustard [Brassica juncea (L.) Czern and Coss] was studied. (author)

Release of nitrogen precursors from coal and biomass residues in a bubbling fluidized bed

Energy Technology Data Exchange (ETDEWEB)

P. Abelha; I. Gulyurtlu; I. Cabrita [Instituto Nacional de Engenharia, Lisbon (Portugal)

2008-01-15

This work was undertaken with the aim of quantifying the relative amounts of NH{sub 3} and HCN released from different residues during their devolatilization under fluidized bed conditions. The results were compared with data collected for bituminous coals of different origin. The relation between amounts of HCN and NH{sub 3} released and the levels of NOX and N{sub 2}O formed during cocombustion was also addressed. The partitioning of nitrogen between volatiles and char was also quantified. The pyrolysis studies were undertaken in a small fluidized bed reactor of 80 mm of ID and 500 mm high using an inert atmosphere (N{sub 2}). The HCN and NH{sub 3} were quantified by bubbling the pyrolysis gases in absorbing solutions which were subsequently analyzed with selective electrodes. The combustion studies were carried out on a pilot installation. The fluidized bed combustor is square in cross section with each side being 300 mm long. There is secondary air supply to the freeboard at different heights to deal with high volatile fuels as almost all waste materials are. The temperatures in the bed and in the freeboard and that of the flue gases leaving the reactor were continuously monitored. The results obtained suggest that, while coal releases nitrogen mostly as HCN, residues like RDF and sewage sludge give out fuel-N in greater quantities as NH{sub 3}. Residues at fluidized bed combustion (FBC) temperatures release more than 80% of the fuel-N with the volatiles. The NH{sub 3} evolved during pyrolysis acted as a reducing agent on NOX emissions. The presence of calcium significantly reduces the emission of N{sub 2}O probably by interfering with HCN chemistry. With high amounts of residues in the fuel mixture, the relative importance of char on the nitrogen chemistry substantially decreases. By using cocombustion, it is possible to reduce fuel-N conversion to NOX and N{sub 2}O, by tuning the amounts of coal and residue in the mixture. 29 refs., 18 figs., 3 tabs.

Mutagenicity of pan residues and gravy from fried meat.

Science.gov (United States)

Overvik, E; Nilsson, L; Fredholm, L; Levin, O; Nord, C E; Gustafsson, J A

1987-02-01

Lean pork meat was fried with or without the addition of frying-fat at 200 or 250 degrees C. The pan residues were collected by washing the hot pan with boiling water. When producing thickened gravy the water was substituted by a mixture of water and flour, milk and flour or cream and flour. The basic extracts were tested for mutagenicity in Ames' Salmonella test on strain TA98 with the addition of S9 mix. High amounts of mutagenicity were found in all samples. The amounts of mutagenicity in the pan residues were at a comparable level of the amounts found in the meat crusts. Thickening of the gravy caused only small changes in the mutagenicity.

Pyrolysis of spent ion-exchanger resins

International Nuclear Information System (INIS)

Slametschka, Rainer; Braehler, Georg

2012-01-01

Initial tests have shown that ion exchangers (IEX) can be decomposed by pyrolysis with very good results, yielding an inert and chemically resistant product. No additives are necessary. The main constituent of the product, the pyrolysis residues or ash, is carbon. It has been discovered that the entire radioactive inventory remains in the pyrolysis residues during pyrolysis of the IEX. This is achieved by relatively low process temperatures that prevent highly volatile nuclides such as the caesium nuclides from passing into the gaseous phase. Sintered metal filters in pyrolysis plant ensure that even the radioactivity bonded to the dust remains in the pyrolysis residues. In addition to the radionuclides, the main constituents of the residue are carbon from the original polystyrene matrix and sulphur from the functional groups. The pyrolysis residues form a flowable solid material and not a melt. It is thus easy to handle and can be compacted or cemented, depending on the requirements for interim and permanent storage. Any further constituents such as inorganic filter materials or even other organic materials do not interfere with the process, they are dried, calcined or also pyrolysed. (orig.)

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

Copyrolysis and hydropyrolysis of coal suspended in waste oil under pressure; Copirolisis e hidropirolisis a presion de mezclas de carbon y aceites pesados

Energy Technology Data Exchange (ETDEWEB)

Moliner, R. [CSIC, Zaragoza (Spain). Inst. de Carboquimica

1998-12-31

The present work studies the copyrolysis of a coal suspended in a waste oil under pressure, with short contact times. The main objective is to show the technical feasibility of the copyrolysis of coal and waste material slurries, in a fluidized bed and to evaluate the efficiency of the copyrolysis to improve quality and quantity of the products in relation to those obtained from the pyrolysis of coal. The work was started with three coals: Samca (subbituminous), HT51 (high-volatile bituminous) and Figaredo (low-volatile bituminous) and four aliphatic wastes from different origins: industrial hydraulic oils (AHU), lube oils (AMU), petroleum vacuum residuum (RP) and solutions of this residuum in vacuum gas-oil, RPG.

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.

Combustion of pulverized coal in vortex structures. Final report, October 1, 1993--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

Gollahalli, S.R.; Butuk, N.

1996-03-01

The objectives of the project were: (i) to understand the effects of heating one of the streams on the characteristics of shear layers, (ii) to investigate the changes in the characteristics of large scale vortex structures in the shear layer caused by the introduction of inert solid particles in one of the feed streams; (iii) to understand the effects of pyrolyzing solids on the shear layer behavior; and (iv) to study the effects of combustion of particles and their pyrolysis products on the shear layer structure, heat release rate, and pollutant emission characteristics. An experimental facility for generating two-dimensional shear layers containing vortex structures has been designed and fabricated. The experimental facility is essentially a low speed wind tunnel designed to (i) provide two gas streams, initially with uniform velocity profiles and isotropic turbulence, mixing at the end of a splitter plate, (ii) introduce vorticity by passively perturbing one of the streams, (iii) allow heating of one of the streams to temperatures high enough to cause pyrolysis of coal particles, and (iv) provide a natural gas flame in one of the streams to result in ignition and burning of coal particles.

Coal Technology Program progress report for April 1976

Energy Technology Data Exchange (ETDEWEB)

1976-06-01

In the Hydrocarbonization Research program, two successful experiments were completed in the bench-scale hydrocarbonizer. A settling test at a lower temperature (390/sup 0/F) using 20 percent toluene in Solvent Refined Coal (SRC) Unfiltered Oil (UFO) produced a 30 percent clarified product in 2 hr. Characterization tests include distillation curves for Wilsonville's SRC-UFO and a particle size distribution of Pittsburg and Midway Coal Mining Company's (PAMCO) SRC-UFO. Studies of intermediate-temperature pyrolysis of large blocks have been maintained with char samples continuing to demonstrate pyrophoricity, even after heating to 700/sup 0/C. Simulated distillation analysis of tars produced by the last eight experiments are being compared with those performed at Laramie upon tars produced by the Hanna No. 2 experiment. In Coal-Fueled MIUS, stainless steel tubing to be used in one of the furnace tube bundles was ordered and the bid package for the furnace completed. Tests continued on the coal feed system and with the cold flow fluidized bed model. For the Synthoil process, flow diagrams, material balances, and utilities requirements were completed for the entire facility. For the Hydrocarbonization process, flowsheets were reviewed for compatibility; equipment lists were brought up to date; and utilities requirements were compiled from the individual flowsheets. The char recovery and storage subsystem flowsheet was completed. (auth)

Micropetrology of peat and soft brown coal in Tengchong Basin, western Yunnan, China

Energy Technology Data Exchange (ETDEWEB)

Qin Yong, Jin Kuili

1988-12-01

The authors study peat and soft brown coal in Tengchong basin from the viewpoints of micropetrology and organic geochemistry by using coal petrography, phytology, pyrolysis-gas chromatography, Fourier infrared absorption spectrum, scanning electron microscope, electron microprobe. The results show that macerals in peat and soft brown coal in Tengchong basin fall into four groups. Of which, liptohuminite is a transitional maceral. Its optical characteristics, chemical composition, chemical-technological properties and origin lie between those of liptinite and vitrinite. New knowledge about other macerals is obtained. For example, phlobaphinite in the shape of a sclerotinite originated from the polyhedral cell tissue in mycorrhiza of plants; attrinite can be classed into three submacerals based on degree of gelatinization; porigelinite, bituminite, terpernite etc. possess different kinds of microstructures; fusinite is of incineration origin; sclerotinite can be divided into three submacerals according to their growth periods, etc. 8 refs., 7 figs., 5 tabs.

Mutagenicity of Flavonoids Assayed by Bacterial Reverse Mutation (Ames Test

Directory of Open Access Journals (Sweden)

Eliana Aparecida Varanda

2012-05-01

Full Text Available The mutagenicity of ten flavonoids was assayed by the Ames test, in Salmonella typhimurium strains TA98, TA100 and TA102, with the aim of establishing hydroxylation pattern-mutagenicity relationship profiles. The compounds assessed were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone. In the Ames assay, quercetin acted directly and its mutagenicity increased with metabolic activation. In the presence of S9 mix, kaempferol and galangin were mutagenic in the TA98 strain and kaempferol showed signs of mutagenicity in the other strains. The absence of hydroxyl groups, as in flavone, only signs of mutagenicity were shown in strain TA102, after metabolization and, among monohydroxylated flavones (3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone, the presence of hydroxyl groups only resulted in minor changes. Luteolin and fisetin also showed signs of mutagenicity in strain TA102. Finally, chrysin, which has only two hydroxy groups, at the 5-OH and 7-OH positions, also did not induce mutagenic activity in any of the bacterial strains used, under either activation condition. All the flavonoids were tested at concentrations varying from 2.6 to 30.7 nmol/plate for galangin and 12.1 to 225.0 nmol/plate for other flavonoids. In light of the above, it is necessary to clarify the conditions and the mechanisms that mediate the biological effects of flavonoids before treating them as therapeutical agents, since some compounds can be biotransformed into more genotoxic products; as is the case for galangin, kaempferol and quercetin.

Fractional condensation of biomass pyrolysis vapors

NARCIS (Netherlands)

Westerhof, Roel Johannes Maria; Brilman, Derk Willem Frederik; Garcia Perez, M.; Wang, Zhouhong; Oudenhoven, Stijn; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

2011-01-01

In this paper, we have investigated the possibilities to steer the composition and, thus, the quality of pyrolysis liquids by the reactor temperature and the pyrolysis vapor condenser temperature. Pine wood was pyrolyzed in a 1 kg/h fluidized-bed pyrolysis reactor operated at 330 or 480 °C. The

Predictive Models for Carcinogenicity and Mutagenicity ...

Science.gov (United States)

Mutagenicity and carcinogenicity are endpoints of major environmental and regulatory concern. These endpoints are also important targets for development of alternative methods for screening and prediction due to the large number of chemicals of potential concern and the tremendous cost (in time, money, animals) of rodent carcinogenicity bioassays. Both mutagenicity and carcinogenicity involve complex, cellular processes that are only partially understood. Advances in technologies and generation of new data will permit a much deeper understanding. In silico methods for predicting mutagenicity and rodent carcinogenicity based on chemical structural features, along with current mutagenicity and carcinogenicity data sets, have performed well for local prediction (i.e., within specific chemical classes), but are less successful for global prediction (i.e., for a broad range of chemicals). The predictivity of in silico methods can be improved by improving the quality of the data base and endpoints used for modelling. In particular, in vitro assays for clastogenicity need to be improved to reduce false positives (relative to rodent carcinogenicity) and to detect compounds that do not interact directly with DNA or have epigenetic activities. New assays emerging to complement or replace some of the standard assays include VitotoxTM, GreenScreenGC, and RadarScreen. The needs of industry and regulators to assess thousands of compounds necessitate the development of high-t

Changes in mutagenicity of protein pyrolyzates by reaction with nitrite.

Science.gov (United States)

Yoshida, D; Matsumoto, T

1978-09-01

Pyrolyzates of protein and related materials were treated with nitrite under acidic conditions, and the mutagenic activity toward Salmonella tester strains was determined. After treatment with nitrite in acidic solution, casein pyrolyzate, an extract of roasted chicken meat, tobacco-smoke condensate and some aromatic amines showed appreciable decreases in their mutagenic activities toward Salmonella typhimurium TA 98. Aromatic amines in the pyrolyzates may be changed by nitrite treatment to other forms having no or lower mutagenic activity toward Salmonella typhimurium TA 98. The contribution by aromatic amines to the total mutagenic activity of the pyrolyzates was as high as 80% in both casein pyrolyzate and extract of roasted chicken meat and 50% in tobacco-smoke condensate. Pyrolyzates of protein and related materials did not show a decrease in the mutagenic activity toward Salmonella typhimurium TA 100 with the same treatment.

Mutagenic effects of β-rays on rice (oryza sativa L.)

International Nuclear Information System (INIS)

Wang Cailian; Chen Qiufang; Shen Mei; Xu Gang

1994-07-01

The mutagenic effects of 14 C and some other mutagenic factors were compared, and the relationships between mutagenic effects of 14 C and treated stages, doses and methods were studied with different rice varieties as test materials. The mutation rates of heading date and plant height were observed in M 2 . The results showed that the mutagenic effects of 14 C were better than those of other mutagenic factors tested. It is most effective for inducing early-maturing mutation to treat plants with the doses of 333 x 10 4 Bq/plant at the stage of pollen mother cell formation; but for dwarf mutation , they were treated with 74 x 10 4 Bq/plant at the stage of pistil and stamen formation to pollen mother cell formation. As a best treating method, Na 2 14 CO 3 solution was injected to plant bases

Mutagenic activity of halogenated propanes and propenes: effect of bromine and chlorine positioning.

Science.gov (United States)

Låg, M; Omichinski, J G; Dybing, E; Nelson, S D; Søderlund, E J

1994-10-01

A series of halogenated propanes and propenes were studied for mutagenic effects in Salmonella typhimurium TA100 in the absence or presence of NADPH plus liver microsomes from phenobarbital-induced rats as an exogenous metabolism system. The cytotoxic and mutagenic effects of the halogenated propane 1,2-dibromo-3-chloropropane (DBCP) has previously been studied in our laboratories. These studies showed that metabolic activation of DBCP was required to exert its detrimental effects. All of the trihalogenated propane analogues were mutagenic when the microsomal activation system was included. The highest mutagenic activity was obtained with 1,2,3-tribromopropane, with approximately 50-fold higher activity than the least mutagenic trihalogenated propane, 1,2,3-trichloropropane. The order of mutagenicity was as follows: 1,2,3-tribromopropane > or = 1,2-dibromo- 3-chloropropane > 1,3-dibromo-2-chloropropane > or = 1,3-dichloro-2-bromopropane > 1-bromo-2,3-dichloropropane > 1,2,3-trichloropropane. Compared to DBCP, the dihalogenated propanes were substantially less mutagenic. Only 1,2-dibromopropane was mutagenic and its mutagenic potential was approximately 1/30 of that of DBCP. In contrast to DBCP, 1,2-dibromopropane showed similar mutagenic activity with and without the addition of an activation system. The halogenated propenes 2,3-dibromopropene and 2-bromo-3-chloropropene were mutagenic to the bacteria both in the absence and presence of the activation system, whereas 2,3-dichloropropene did not show any mutagenic effect. The large differences in mutagenic potential between the various halogenated propanes and propenes are proposed to be due to the formation of different possible proximate and ultimate mutagenic metabolites resulting from the microsomal metabolism of the various halogenated propanes and propenes, and to differences in the rate of formation of the metabolites. Pathways are proposed for the formation of genotoxic metabolites of di- and trihalogenated

Thermogravimetric Analysis of Textile Dyeing Sludge (TDS) in N₂/CO₂/O₂ Atmospheres and its Combustion Model with Coal.

Science.gov (United States)

Zhuo, Zhongxu; Liu, Jingyong; Sun, Shuiyu; Kuo, Jiahong; Sun, Jian; Chang, Ken-Lin; Fu, Jiewen

2018-01-01

  The combustion characteristics of textile dyeing sludge (TDS) in N2/O2, CO2/O2, and N2/CO2 atmospheres, and blends of TDS with coal were analyzed using TGA (thermogravimetric analysis). Results showed that the replacement of N2 by CO2 resulted in negative effects on the combustion and pyrolysis of TDS. Comparing N2/O2 and CO2/O2 atmospheres, combustion of TDS was easier in a N2/O2 atmosphere, but the residual mass after TDS pyrolysis in pure CO2 was less than that in N2 by approximately 4.51%. When the proportion of TDS was 30-50% in the blends of coal with TDS, a synergistic interaction clearly occurred, and it significantly promoted combustion. In considering different combustion parameters, the optimal proportion of TDS may be between 20-30%. The activation energy Ea value decreased from 155.6 kJ/mol to 53.35 kJ/mol with an increasing TDS proportion from 0% to 50%, and it rapidly decreased when the TDS proportion was below 20%.

Sewage sludge pyrolysis for thermal utilisation in furnaces; Pyrolyse von Klaerschlamm als Aufbereitungsverfahren zur thermischen Nutzung in Feuerungsanlagen

Energy Technology Data Exchange (ETDEWEB)

Storm, C; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

1998-09-01

The degassing rate of sewage sludges increases with the pyrolysis temperature. Already at 900 degrees centigrade, the glow loss wil be less than 5 percent. The gas composition changes with increasing temperatures, and there are larger fractions of light gases like hydrogen and carbon monoxide. Non-volatile inorganic compounds are not released during pyrolysis. Volatile inorganic components behave differently: Eluation experiments with sewage sludge pyrolysis residues showed that all components under investigation are immobilized in the residue matrix and there is now washout. When the product gases were used as reduction fuels in coal furnaces, nitric oxide emissions will be reduced to less than 200 mg per cubic metre. The pyrolysis temperature was found to have an effect only at low fuel/air ratios, when gases produced at high pyrolysis temperatures resulted in lower emissions. (orig./SR) [Deutsch] Mit steigender Pyrolysetemperatur steigt die Entgasungsrate der Klaerschlaemme. Bei der Klaerschlammpyrolyse wird schon bei Temperaturen ab 900 C ein Gluehverlust von unter 5% erreicht. Die Pyrolysegaszusammensetzung aendert sich mit steigender Temperatur zugunsten von leichten Gasen wie Wasserstoff und Kohlenmonoxid. Schwerfluechtige anorganische Verbindungen werden waehrend der Pyrolyse nicht freigesetzt. Leichtfluechtige anorganische Bestandteile zeigen ein unterschiedliches Verhalten. Bei Eluierungsversuchen von Klaerschlammpyrolyseresten wurde festgestellt, dass alle untersuchten Komponenten fest in die Reststoffmatrix eingebunden werden und keine Auswaschung erfolgte. Bei der thermischen Nutzung von Gasen aus der Klaerschlammpyrolyse als Reduktionsbrennstoff in Kohlefeuerungen koennen NO{sub x} Emissionen von unter 200 mg/m{sup 3} erreicht werden. Ein Einfluss der Pyrolysetemperatur auf die NO{sub x} Emissionen konnte nur bei niedrigen Luftzahlen festgestellt werden. Hier wiesen Gase, die bei hohen Pyrolysetemperaturen entstanden, geringere Emissionen auf. (orig./SR)

Pyrolysis technologies for municipal solid waste: A review

Energy Technology Data Exchange (ETDEWEB)

Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

2014-12-15

Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

Effect of physical and chemical mutagens on morphological parameters in garlic

International Nuclear Information System (INIS)

Choudhary, A.D.; Dnyansagar, V.R.

1980-01-01

Cloves of garlic (Allium sativum Linn.) were treated with various doses of gamma rays and different concentrations of ethylmethane sulphonate, diethyl sulphate and ethyleneimine. The effect of mutagens was studied in respect of morphological parameters such as sprouting, survival, sprout height, plant height, number and size of leaves, number of cloves and weight of bulb. In case of mutagen treatment the percentage of sprouting and survival as well as sprout height were found to be decreased with an increase in the dose/concentration of the mutagen. The effect of mutagen on leaf size and number was inhibitory. However, the number of cloves and weight of bulb were found to be increased at lower dose concentration of mutagens. (author)

Mutagenicity of heated sugar-casein systems : effect of the Maillard :reaction

NARCIS (Netherlands)

Brands, C.M.J.; Alink, G.M.; Boekel, van M.A.J.S.; Jongen, W.M.F.

2000-01-01

The formation of mutagens after the heating of sugar-casein model systems at 120 C was examined by the Ames test, using Salmonella typhimurium strain TA100. Several sugars (glucose, fructose, galactose, tagatose, lactose, and lactulose) were compared in their mutagenicities. Mutagenicity could be

Mutagenicity assessment of aerosols in emissions from wood combustion in Portugal

International Nuclear Information System (INIS)

Vu, B.; Alves, C.A.; Gonçalves, C.; Pio, C.; Gonçalves, F.; Pereira, R.

2012-01-01

Polycyclic aromatic hydrocarbon (PAH) extracts of fine particles (PM 2.5 ) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods were Pinus pinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (golden wattle), Quercus faginea (Portuguese oak), Olea europea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start conditions. A mutagenic response was recorded for all species except golden wattle, maritime pine, and briquettes. The mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. These extracts were obtained both from two burning appliances and start-up conditions. However, fireplace seemed to favour the occurrence of mutagenic emissions. The negative result recorded for golden wattle was interesting, in an ecological point of view, since after confirmation, this invasive species, can be recommended for domestic use. - Highlights: ► Both woodstove and fireplace, either with a cold or hot start, produce emissions with mutagenic potential. ► The high level of carcinogenic PAHs in combustion emissions was not correlated with mutagenicity. ► The golden wattle, an invasive species, produced no mutagenic emissions. - Wood smoke from fireplace burning of dominant forest species displayed strong mutagenic activity without a significant correlation with carcinogenic PAHs emission factors.

Quantitative comparison of genotoxic (mutagenic and carcinogenic) risks and the choice of energy sources

International Nuclear Information System (INIS)

Latarjet, R.

1983-01-01

For 25 years, pollution for radiation has been governed by restrictive rules enacted and periodically revised by an international commission, and adopted by all countries. Nothing similar exists for mutagenic and carcinogenic chemicals. Since these substances affect the genetic material in the cells with reactions often similar to those caused by radiation, quantitative comparisons are possible, in particular for some of those compounds produced by the combustion of coal, oil and gaz. This paper describes the main results obtained at the Institut Curie, since 1975, with ethylene, ethylene oxide and vinyl chloride monomer. The consequences are discussed for: a) the establishement of control rules for the main genotoxic chemical pollutions; b) the assessment of long term risks in the cases of nuclear energy and of the energies obtained by combustion [fr

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

Science.gov (United States)

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

OpenAIRE

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

Radiation/turbulence interactions in pulverized-coal flames. Second year technical progress report, September 30, 1994--September 30, 1995

Energy Technology Data Exchange (ETDEWEB)

Menguec, M.P.; McDonough, J.M.; Manickavsagam, S.; Mukerji, S.; Wang, D.; Ghosal, S.; Swabb, S.

1995-12-31

Our goal in this project is to investigate the interaction of radiation and turbulence in coalfired laboratory scale flames and attempt to determine the boundaries of the ``uncertainty domain`` in Figure 3 more rigorously. We have three distinct objectives: (1) To determine from experiments the effect of turbulent fluctuations on the devolatilization/pyrolysis of coal particles and soot yield, and to measure the change in the ``effective`` radiative properties of particulates due to turbulence interactions; (2) To perform local small-scale simulations to investigate the radiation-turbulence interactions in coal-fired flames starting from first principles; and (3) To develop a thorough and rigorous, but computationally practical, turbulence model for coal flames, starting from the experimental observations and small scale simulations.

Carbon abatement via treating the solid waste from the Australian olive industry in mobile pyrolysis units: LCA with uncertainty analysis.

Science.gov (United States)

El Hanandeh, Ali

2013-04-01

The olive oil industry in Australia has been growing at a rapid rate over the past decade. It is forecast to continue growing due to the steady increase in demand for olive oil and olive products in the local and regional market. However, the olive oil extraction process generates large amounts of solid waste called olive husk which is currently underutilized. This paper uses life-cycle methodology to analyse the carbon emission reduction potential of utilizing olive husk as a feedstock in a mobile pyrolysis unit. Four scenarios, based on different combinations of pyrolysis technologies (slow versus fast) and end-use of products (land application versus energy utilization), are constructed. The performance of each scenario under conditions of uncertainty was also investigated. The results show that all scenarios result in significant carbon emission abatement. Processing olive husk in mobile fast pyrolysis units and the utilization of bio-oil and biochar as substitutes for heavy fuel oil and coal is likely to realize a carbon offset greater than 32.3 Gg CO2-eq annually in 90% of the time. Likewise, more than 3.2 Gg-C (11.8 Gg CO2-eq) per year could be sequestered in the soil in the form of fixed carbon if slow mobile pyrolysis units were used to produce biochar.

Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases

Science.gov (United States)

Shuai, Yanhua; Douglas, Peter M. J.; Zhang, Shuichang; Stolper, Daniel A.; Ellis, Geoffrey S.; Lawson, Michael; Lewan, Michael D.; Formolo, Michael; Mi, Jingkui; He, Kun; Hu, Guoyi; Eiler, John M.

2018-02-01

Multiply isotopically substituted molecules ('clumped' isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation temperatures of several natural materials. However, kinetic processes during generation, modification, or transport of natural materials can also affect their clumped-isotope compositions. Herein, we show that methane generated experimentally by closed-system hydrous pyrolysis of shale or nonhydrous pyrolysis of coal yields clumped-isotope compositions consistent with an equilibrium distribution of isotopologues under some experimental conditions (temperature-time conditions corresponding to 'low,' 'mature,' and 'over-mature' stages of catagenesis), but can have non-equilibrium (i.e., kinetically controlled) distributions under other experimental conditions ('high' to 'over-mature' stages), particularly for pyrolysis of coal. Non-equilibrium compositions, when present, lead the measured proportions of clumped species to be lower than expected for equilibrium at the experimental temperature, and in some cases to be lower than a random distribution of isotopes (i.e., negative Δ18 values). We propose that the consistency with equilibrium for methane formed by relatively low temperature pyrolysis reflects local reversibility of isotope exchange reactions involving a reactant or transition state species during demethylation of one or more components of kerogen. Non-equilibrium clumped-isotope compositions occur under conditions where 'secondary' cracking of retained oil in shale or wet gas hydrocarbons (C2-5, especially ethane) in coal is prominent. We suggest these non-equilibrium isotopic compositions are the result of the expression of kinetic isotope effects during the irreversible generation of methane from an alkyl

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants

International Nuclear Information System (INIS)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-01-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500 deg. C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal.

Mutagenicity of urine from nurses handling cytostatic drugs, influence of smoking

Energy Technology Data Exchange (ETDEWEB)

Bos, R P; Leenaars, A O; Theuws, J L; Henderson, P T

1982-01-01

Mutagenicity towards Salmonella typhimurium TA 100 of urine from smoking nurses, who were occupationally involved in the treatment of patients with cytostatic drugs, was significantly increased in comparison with that of smoking control subjects. Mutagenicity towards Salmonella typhimurium TA 100 was not increased in exposed non-smokers when compared to control non-smokers. In smoking subjects urinary mutagenicity appeared increased towards Salmonella typhimurium TA 1538 in the presence of S-9 mix. Rats pretreated with Aroclor 1254 showed higher mutagenicity in their urine than untreated rats after cyclophosphamide administration. Therefore, the synergistic effect of smoking might be due in part to induction of enzymes involved in the mutagenic activation of cytostatic drugs. Further, the animal experiments showed that cyclophosphamide (the most frequently used mutagenic cytostatic drug) can be absorbed after oral or percutaneous administration. Therefore, it is not excluded that differences in working hygiene between smokers and non-smokers also play a role.

Interaction and the structures of coal

Science.gov (United States)

Opaprakasit, Pakorn

The origin of a decrease in the amount of soluble material from coal upon a reflux treatment has been investigated in an attempt to obtain insight into the nature of the interaction in the macromolecular network structure of coal. This decrease in the extractable material is a result of an increase in the amount of physical cross-links associated with secondary interactions. The alternate possibility of covalent cross-link formation by ether linkage was found to be unlikely because the coal hydroxyl content remains unchanged upon heat treatment. The functional groups responsible for forming these physical cross-links and their contents vary from coal to coal with coal rank. Carboxylate/cation complexes, similar to those found in ionomers, dominate in low rank coal. In high rank coal, the clusters involving pi-cation interactions were observed. Both mechanisms seem to play a role in mid rank coals. These physical cross-links are responsible for a lowering of the extraction yield of coal, but are disrupted by a treatment with acid solution, resulting in an increase in the extraction yield. As a consequence, the cross-links in coal structure should be classified into two types; a "permanent" covalent cross-link, which break under extreme conditions such as chemical reaction and pyrolysis, and "reversible" cross-links, largely associated with ionomer-like structure and pi-cation interactions. The interaction between a "magic" solvent of N-methylpyrollidone and carbon disulfide (NMP/CS2) and its role in the unusual extractability enhancement of Upper Freeport coal has also been investigated. The results strongly suggest that NMP/CS2 mixed solvents form complexes with cations. These mixed solvents are capable of forming a solid complex with cations from NaOH and some simple salts, such as NaCl and LiCl. Given that Upper Freeport coal contains a large amount of mineral matter, it is not surprising that these types of complexes could be formed in the present of the mixed

FY1995 development of economical and high efficient desulfurization process using low rank coal; 1995 nendo teitankadotan wo mochiita ankana kokoritsu datsuryuho no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The objective of this study is to develop a new efficient desulfurization technique using a Ca ion-exchanged coal prepared from low rank coal and calcium raw material as a SO{sub 2} sorbent. Ion-exchange of calcium was carried out by soaking and mixing brown coal particles in milk of lime or slurry of industrial waste from concrete manufacture process. About 10wt% of Ca was easily incorporated into Yallourn coal. The ion-exchanged Ca was transformed to ultra-fine CaO particles upon pyrolysis of coal. The reactivity of CaO produced from Ca-exchanged coal to SO{sub 2} was extraordinary high and the CaO utilization of above 90% was easily achieved, while the conversion of natural limestone was less than 30% under the similar experimental conditions. High activity of Ca-exchanged coal was appreciably observed in a pressurized fluidized bed combustor. Ca-exchanged coal was quite effective for the removal of hydrogen sulfide. (NEDO)

Mutagenicity of irradiated solutions of nuclei acid bases and nucleosides in Salmonella typhimurium

International Nuclear Information System (INIS)

Wilmer, J.; Schubert, J.

1981-01-01

Solutions of nucleic acid bases, nucleosides and a nucleotide, saturated with either N 2 , N 2 O or O 2 , were irradiated and tested for mutagenicity towards Salmonella typhimurium, with and without pre-incubation. Irradiated solutions of the nuclei acid bases were all non-mutagenic. Irradiated solutions of the nucleosides showed mutagenicity in S. typhimurium TA100 (pre-incubation assay). Generally, the mutagenicity followed the order: N 2 O > N 2 > O 2 . The results show that the formation of mutagenic radiolytic products is initiated by attack of mainly solutions of the nucleotide thymidine-5'-monophosphate, no mutagenicity could be detected. (orig.)

Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

Energy Technology Data Exchange (ETDEWEB)

Wang, Ruixue; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

2016-01-25

Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min{sup −1} and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

International Nuclear Information System (INIS)

Wang, Ruixue; Xu, Zhenming

2016-01-01

Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min"−"1 and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

Operational experiences of (in)direct co-combustion in coal and gas fired power plants in Europe

International Nuclear Information System (INIS)

Van Ree, R.; Korbee, R.; Meijer, R.; Konings, T.; Van Aart, F.

2001-02-01

The operational experiences of direct and indirect co-combustion of biomass/waste in European coal and natural gas fired power plants are addressed. The operational experiences of mainly Dutch direct co-combustion activities in coal fired power plants are discussed; whereas an overview of European indirect co-combustion activities is presented. The technical, environmental, and economic feasibility of different indirect co-combustion concepts (i.e. upstream gasification, pyrolysis, combustion with steam-side integration) is investigated, and the results are compared with the economic preferable concept of direct co-combustion. Main technical constraints that limit the co-combustion capacity of biomass/waste in conventional coal fired power plants are: the grindability of the biomass/coal blend, the capacity of available unit components, and the danger of severe slagging, fouling, corrosion and erosion. The main environmental constraints that have to be taken into account are the quality of produced solid waste streams (fly ash, bottom ash, gypsum) and the applicable air emission regulations. 6 refs

MINIMIZATION OF CARBON LOSS IN COAL REBURNING

Energy Technology Data Exchange (ETDEWEB)

Vladimir M. Zamansky; Vitali V. Lissianski

2001-09-07

This project develops Fuel-Flexible Reburning (FFR), which combines conventional reburning and Advanced Reburning (AR) technologies with an innovative method of delivering coal as the reburning fuel. The overall objective of this project is to develop engineering and scientific information and know-how needed to improve the cost of reburning via increased efficiency and minimized carbon in ash and move the FFR technology to the demonstration and commercialization stage. Specifically, the project entails: (1) optimizing FFR with injection of gasified and partially gasified fuels with respect to NO{sub x} and carbon in ash reduction; (2) characterizing flue gas emissions; (3) developing a process model to predict FFR performance; (4) completing an engineering and economic analysis of FFR as compared to conventional reburning and other commercial NO{sub x} control technologies, and (5) developing a full-scale FFR design methodology. The project started in August 2000 and will be conducted over a two-year period. The work includes a combination of analytical and experimental studies to identify optimum process configurations and develop a design methodology for full-scale applications. The first year of the program included pilot-scale tests to evaluate performances of two bituminous coals in basic reburning and modeling studies designed to identify parameters that affect the FFR performance and to evaluate efficiency of coal pyrolysis products as a reburning fuel. Tests were performed in a 300 kW Boiler Simulator Facility to characterize bituminous coals as reburning fuels. Tests showed that NO{sub x} reduction in basic coal reburning depends on process conditions, initial NO{sub x} and coal type. Up to 60% NO{sub x} reduction was achieved at optimized conditions. Modeling activities during first year concentrated on the development of coal reburning model and on the prediction of NO{sub x} reduction in reburning by coal gasification products. Modeling predicted that

Formation of new heterocyclic amine mutagens by heating creatinine, alanine, threonine and glucose.

Science.gov (United States)

Skog, K; Knize, M G; Felton, J S; Jägerstad, M

1992-08-01

A mixture of alanine, threonine, creatinine and glucose was heated in diethylene glycol and water (5:1, v/v) for 15 min at 200 degrees C. The mutagens formed were purified by high-performance liquid chromatography using the Ames/Salmonella mutagenic activity to guide the purification. The structures of the purified mutagens were determined using UV absorption, mass and NMR spectrometry. A new mutagenic compound with a mass number of 217 was found and its mass spectrum did not correspond to any known mutagen derived from food. This new compound accounted for 4% of the total mutagenic activity. Other mutagenic compounds were identified as MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline), and a new mutagen 4,7,8-TriMeIQx (2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline) with a mutagenic activity of 73,000 TA98 revertants per microgram. The percentage of the mutagenic activity attributable to MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10%, 70% and 3%, respectively. The yield of MeIQx, 4,8-DiMeIQx and 4,7,8-TriMeIQx was 10, 36 and 6 nmole/mmole creatinine. The formation of TriMeIQx from natural meat components suggests that this new quinoxaline mutagen may be present in cooked foods.

Cooking with Fire: The Mutagenicity- and PAH-Emission ...

Science.gov (United States)

Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. We evaluated two categories of solid-fuel cookstoves for 8 pollutant- and 4 mutagenicity-emission factors, correlated the mutagenicity-emission factors, and compared them to those of other combustion emissions. We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS); we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella. Other than NOx the emission factors per MJd correlated highly among each other (r2 ≥ 0.92); NOx correlated 0.58-0.76 with the other emission factors. Excluding NOx, the NDS and FDS reduced the emission factors on average 68 and 92%, respectively, relative to the TSF. Nonetheless, the mutagenicity-emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was intermediate to that of a large diesel bus engine and a small diesel generator. Both mutagenicity- and pollutant-emission factors may be informative for characterizing cookstove

Hydrodeoxygenation of coal using organometallic catalyst precursors

Science.gov (United States)

Kirby, Stephen R.

2002-04-01

The objective of this dissertation was to determine the desirability of organometallic compounds for the hydrodeoxygenation (HDO) of coal during liquefaction. The primary focus of this study was the removal of phenol-like compounds from coal liquids for the production of a thermally stable jet fuel. Investigation of the HDO ability of an organometallic compound containing both cobalt and molybdenum (CoMo-T2) was achieved using a combination of model compound and coal experiments. Model compounds were chosen representing four oxygen functional groups present in a range of coals. Electron density and bond order calculations were performed for anthrone, dinaphthyl ether, xanthene, di-t-butylmethylphenol, and some of their derivatives to ascertain a potential order of hydrogenolysis and hydrogenation reactivity for these compounds. The four model compounds were then reacted with CoMo-T2, as well as ammonium tetrathiomolybdate (ATTM). Products of reaction were grouped as compounds that had undergone deoxygenation, those that had aromatic rings reduced, those that were products of both reaction pathways, and those produced through other routes. ATTM had an affinity for both reaction types. Its reaction order for the four model compounds with respect to deoxygenated compounds was the same as that estimated from electron density calculations for hydrogenolysis reactivity. CoMo-T2 appeared to show a preference toward hydrogenation, although deoxygenated products were still achieved in similar, or greater, yields, for almost all the model compounds. The reactivity order achieved for the four compounds with CoMo-T2 was similar to that estimated from bond order calculations for hydrogenation reactivity. Three coals were selected representing a range of coal ranks and oxygen contents. DECS-26 (Wyodak), DECS-24 (Illinois #6), and DECS-23 (Pittsburgh #8) were analyzed by CPMAS 13C NMR and pyrolysis-GC-MS to determine the functional groups comprising the oxygen content of these

Kaempferol, a mutagenic flavonol from Helichrysum simillimum.

Science.gov (United States)

Elgorashi, Ee; van Heerden, Fr; van Staden, J

2008-11-01

Helichrysum simillimum is native to South Africa. It is used for the treatment of coughs, colds, fever, infections, headache, and menstrual pain. Extracts of this species showed mutagenic effects in the Salmonella/microsome assay. The aim of this study was to isolate and determine the mutagenic constituents of H. simillimum. Bioassay-guided fractionation of 90% aqueous methanol extracts, using Salmonella typhimurium TA98, led to the isolation of the flavonol kaempferol.

Studies on mutagenic effectiveness and efficiency in Fenugreek ...

African Journals Online (AJOL)

shagufta

2013-05-01

May 1, 2013 ... improvement, the basic studies on effectiveness and efficiency of a mutagen in a crop are necessary to recover high frequency of desirable mutations (Kumar and Mani, 1997; Badere and Chaudhary, 2007). Mutagenic effectiveness is an index of the response of a genotype to the increasing doses of the ...

Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

Energy Technology Data Exchange (ETDEWEB)

Antonakou, E.V. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kalogiannis, K.G.; Stephanidis, S.D. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Triantafyllidis, K.S. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Lappas, A.A. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Achilias, D.S., E-mail: axilias@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2014-12-15

Highlights: • Thermal and catalytic pyrolysis is a powerful method for recycling of WEEEs. • Liquid products obtained from the pyrolysis of PC or HIPS found in waste CDs are very different. • Mainly phenols are obtained from pyrolysis PC based wastes while aromatics from HIPS. • Use of MgO catalyst increases the amount of phenols from CD recycling compared to ZSM-5. • Use of MgO or ZSM-5 catalysts reduces the amount of styrene recovered from HIPS. - Abstract: Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

How stable are the mutagenic tautomers of DNA bases?

Directory of Open Access Journals (Sweden)

Brovarets’ O. O.

2010-02-01

Full Text Available Aim. To determine the lifetime of the mutagenic tautomers of DNA base pairs through the investigation of the physicochemical mechanisms of their intramolecular proton transfer. Methods. Non-empirical quantum chemistry, the analysis of the electron density by means of Bader’s atom in molecules (AIM theory and physicochemical kinetics were used. Results. Physicochemical character of the transition state of the intramolecular tautomerisation of DNA bases was investigated, the lifetime of mutagenic tautomers was calculated. Conclusions. The lifetime of the DNA bases mutagenic tautomers by 3–10 orders exceeds typical time of DNA replication in the cell (~103 s. This fact confirms that the postulate, on which the Watson-Crick tautomeric hypothesis of spontaneous transitions grounds, is adequate. The absence of intramolecular H-bonds in the canonical and mutagenic tautomeric forms determine their high stability

Use of a fluidized bed combustor and thermogravimetric analyzer for the study of coal ignition temperature

International Nuclear Information System (INIS)

Ávila, Ivonete; Crnkovic, Paula M.; Luna, Carlos M.R.; Milioli, Fernando E.

2017-01-01

Highlights: • Coal ignition tests were conducted in a fluidized bed and thermogravimetric conditions. • The use of two different ignition criteria showed a similar coal ignition temperature. • Coal ignition temperature was obtained by the changes of gas concentrations in FBC. • Ignition temperatures were associated with the activation energy of coal combustion. - Abstract: Ignition experiments with two bituminous coals were carried out in an atmospheric bubbling fluidized bed combustor (FBC) and a thermogravimetric analyzer (TGA). In the FBC tests, the rapid increase in O_2, CO_2, and SO_2 concentrations is an indication of the coal ignition. In the TGA technique, the ignition temperature was determined by the evaluation of the TGA curves in both combustion and pyrolysis processes. Model-Free Kinetics was applied and the coal ignition temperatures were associated with changes in the activation energy values during the combustion process. The results show the coal with the lowest activation energy also showed the lowest ignition temperature, highest values of volatile content and a higher heating value. The application of two different ignition criteria (TGA and FBC) resulted in similar ignition temperatures. The FBC curves indicated the high volatile coal ignites in the freeboard, i.e. during the feeding in the reactor, whereas the low volatile coal ignites in the bed. Finally, the physicochemical characteristics of the investigated coal types were correlated with their reactivities for the prediction of the ignition temperatures behaviors under different operating conditions as those in FBC.

Effect of mutagen combined action on Chlamydomonas reinhardtii cells. I. Lethal effect dependence on the sequence of mutagen application and on cultivation conditions

Energy Technology Data Exchange (ETDEWEB)

Vlcek, D; Podstavkova, S; Dubovsky, J [Komenskeho Univ., Bratislava (Czechoslovakia). Prirodovedecka Fakulta

1978-01-01

The effect was investigated of single and combined actions of alkylnitrosourea derivatives (N-methyl-N-nitrosourea and N-ethyl-N-nitrosourea) and UV-radiation on the survival of cells of Chlamydomonas reinhardtii algae in dependence on the sequence of application of mutagens and on the given conditions of cultivation following mutagen activity. In particular, the single phases were investigated of the total lethal effect, i.e., the death of cells before division and their death after division. The most pronounced changes in dependence on the sequence of application of mutagens and on the given conditions of cultivation were noted in cell death before division. In dependence on the sequence of application of mutagens, the effect of the combined action on the survival of cells changed from an additive (alkylnitrosourea + UV-radiation) to a protective effect (UV-radiation + alkylnitrosourea).

Structural features of nitroaromatics that determine mutagenic activity in Salmonella typhimurium

International Nuclear Information System (INIS)

Vance, W.A.; Levin, D.E.

1984-01-01

Seventeen structurally homologous nitroaromatics were tested for direct-acting mutagenic potency in nine strains of Salmonella typhimurium. The following four structural features were determined to have a strong influence on mutagenic activity: physical dimensions of the aromatic rings, isomeric position of the nitro group, conformation of the nitro group with respect to the plane of the aromatic rings, and ability to resonance-stabilize the utimate electrophile. Progressive addition of five- and six-membered rings to a nitrobenzene nucleus demonstrated that mutagenic activity was a direct function of size. Nitroaromatics with a nitro group oriented along the long axis of symmetry of the molecule were more potent mutagens that those with the nitro group oriented along the short axis. These results are discussed in light of the insertion-denaturation model for intercalation of certain DNA adducts. Finally, structural features that contribute to resonance stabilization of the reactive nitrenium ion enhance mutagenic potency. The predictive value of these structure-activity relationships should permit a first approximation in the assessment of mutagenic potency of nitroaromatics

Time resolved pyrolysis of char

DEFF Research Database (Denmark)

Egsgaard, H.; Ahrenfeldt, J.; Henriksen, U.B.

pyrolysis, and slow heating in direct combination with mass spectrometry, gas chromatography/mass spectrometry and flame ionization detection, respectively. Characteristic ions derived from the flash pyrolysis-gas chromatography/mass spectrometry data enable the release of volatiles to be time and, hence...

Organic geochemical studies of the transformation of gymnospermous xylem during peatification and coalification to subbituminous coal

Science.gov (United States)

Hatcher, P.G.; Lerch, H. E.; Verheyen, T.V.

1990-01-01

It is generally recognized that xylem from trees that are buried in peat swamps is transformed first to huminite macerals in brown coal and then to vitrinite macerals in bituminous coal by processes collectively known as coalification. In order to understand the chemical nature of coalification of xylem and the chemical structures that eventually evolve in coal, we examined a series of gymnospermous xylem samples coalified to varying degrees. The samples included modern fresh xylem, modern degraded xylem in peat, and xylem coalified to ranks of brown coal (lignite B), lignite A, and subbituminous coal. The organic geochemical methods used in this study included solid-state 13C nuclear magnetic resonance (NMR) and pyrolysis/gas chromatography/mass spectrometry. The NMR method provided average compositional information, and the pyrolysis provided detailed molecular information. Although the samples examined include different plants of different geologic ages, they all share a common feature in that they are gymnospermous and presumably have or had a similar kind of lignin. The data obtained in this study provide enough details to allow delineation of specific coalification pathway for the xylem is microbial degradation in peat (peatification), leading to selective removal of cellulosic components. These components constitute a large fraction of the total mass of xylem, usually greater than 50%. Although cellulosic components can survive degradation under certain conditions, their loss during microbial degradation is the rule rather than exception during peatification. As these components of xylem are degraded and lost, lignin, another major component of xylem, is selectively enriched because it is more resistant to microbial degradation than the cellulosic components. Thus, lignin survives peatification in a practically unaltered state and becomes the major precursor of coalified xylem. During its transformation to brown coal and lignite A, lignin in xylem is altered

Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

OpenAIRE

Seed, J L

1982-01-01

The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

Induction of forward gene mutations in saccharomycetes. Comparison of efficiencies of different mutagens

International Nuclear Information System (INIS)

Zakharov, I.A.; Gracheva, L.M.; Ivanov, E.L.; Koval'tsova, S.V.; Kozhina, T.N.; Korolev, V.G.; Fedorova, I.V.; Shanshiashvili, T.A.; Yadgarov, Kh.T.

1981-01-01

The data on the induction of forward mutations in locus ade 2 of the wild haploid of Saccharomyces cerevisiae yeasts by three types of mutagens-chamical mutagens, various radiations and defferent isotopes incorporated in the cell - are generalyzed. The ratio of mutation frequency observed at different doses of mutagen to the survival rate logarithm for the same doses is expressed as rectilinear regression M=m(-1 nS). The application of the same mutation system in the case of all studied mutagens allows to consider the inclination value ''m'' to be the characteristic of mutagen efficiency. We propose to call the ratio of the efficiency of a given mutagen to the efficiency of γ-rays (msub(x)/msub(γ)) - the relative mutagenous effifiency (RME). According to the decrease of this index the studied mutagens have stood in the following succession: ethylene imine (EI), nitrosomethylurea (NMU) 89 Sr, UV rays, 35 S, 91 Y, 33 P, 32 P, acridine-yprite, β-radiation ( 32 P), γ-rays, hard X-rays, 3 H, soft X-rays, neutrons, 125 I [ru

Nitric oxide reduction over a synthetic coal char

Energy Technology Data Exchange (ETDEWEB)

C. Pevida; A. Arenillas; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

2003-07-01

In the present work, the mechanisms involved in the NO heterogeneous reduction have been investigated. A synthetic coal char was used as the carbon source. This synthetic coal was made from a mixture of model compounds and provides well-known functionalities, including nitrogenated ones, similar to those found in a high volatile bituminous coal. The char was obtained by pyrolysis of the synthetic coal, up to 1123 K, under helium atmosphere in a fixed bed reactor. Char texture and structure were characterised by N{sub 2} and CO{sub 2} adsorption isotherms at 77 and 273 K, respectively, X-ray diffraction, immersion calorimetry in C{sub 6}H{sub 6} and scanning electron microscopy (SEM). Temperature programmed reactions (TPR) were carried out in a thermogravimetric analyser using 400 ppm NO diluted in Ar as the reactant gas. The char was heated at 15 K min{sup -1} from room temperature to 1273 K. Gaseous products were simultaneously analysed by mass spectrometry (MS) and Fourier transform infrared spectroscopy (FTIR). The influence of nitrogen in the solid phase on the reduction mechanism was evaluated by comparing the results for chars with and without nitrogen in their composition. The results of this preliminary study showed that the presence of nitrogen in the chars composition did not favour the heterogeneous NO reduction. In addition, low temperature NO chemisorption on the carbon surface creates complexes that take an active part in the subsequent reactions with NO. 5 refs., 4 figs., 3 tabs.

Study of ammonia removal from coal-gasified fuel

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Takeharu; Sato, Mikio [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan)

1998-07-01

In integrated coal gasification combined-cycle power-generation (IGCC) systems, ammonia in gasified fuel is passed through a hot/dry type gas clean-up facility into a gas turbine. The ammonia is converted to nitrogen oxides in the gas turbine combustion process. Therefore, ammonia removal from coal-gasified fuel effectively reduces NO{sub x} emissions in IGCC systems. The authors clarified the optimum NO/NH{sub 3} ratio, the optimum concentration of added O{sub 2}, and the influence of CO, H{sub 2}, and CH{sub 4} in the coal-gasified fuel on NH{sub 3} decomposition and NO reduction through experiments using a tubular flow reactor and numerical analysis based on reaction kinetics. The main results were as follows: (1) The optimum NO/NH{sub 3} ratio for maximizing NH{sub 3} decomposition and NO reduction was about 1. (2) The NH{sub 3} decomposition ratio depended only on H{sub 2}, and decreased rapidly with increasing H{sub 2} concentration. (3) The NO reduction ratio decreased with an increasing H{sub 2} concentration. (4) The remaining CH{sub 4}, which was not decomposed by pyrolysis, increased with an increasing CH{sub 4} concentration and caused the reaction temperature to rise, as opposed to cases of CO and H{sub 2}. (5) The method was effective in decreasing total fixed nitrogen (TFN) by up to 40% and minimizing the total concentration of remaining NH{sub 3} and NO in air-blown, coal-gasified fuel.

Mutagenic effects of alkylating agents on prophage lambda

Energy Technology Data Exchange (ETDEWEB)

Bresler, S.; Kalinin, V.L.; Kuznetsova, L.V.

1984-06-01

An evaluation was made of the relative contribution of repair and reparative mechanisms to the mutagenic potency of several alkylating agents on thermoinducible prophage lambdacI857 ind/sup -/ in several stains of E. coli. Following treatment of lysogenic E. coli with the mutagens and heat induction, 0.02 N-nitroso-N-methylurea (NMU) induced c mutations with a high frequency (ca. 10%) in both wild type E. coli and cells with repair mutations (recA13, lexA102, uvrA6, umuC36, xthA9, recF143, polA1, uvrD3, uvrD502). It appears that NUM-induced mutations are stabilized as replicative errors due to mismatched, altered bases. Delay in induction following exposure to NMU improves prophage survival and diminishes c mutant formation, regardless of the E. coli genotype. Evidently, carbamoylation is not involved in NMU mutagenicity since 0.02 M KNCO is nonmutagenic and is virtually without effect on prophage viability. Replicative mechanisms are also involved in N-methyl-N'-nitro-N-nitrosoguanidine (15%) and ethyl methanesulfonate (2%) induced mutations, since the maximum yield of mutants was independent of recA/sup +/ genotype. However, the mutagenicity of methyl methanesulfonate was abolished by the recA mutation, indicating that the mutagenicity of this agent is repair-dependent. Mitomycin C (0.1%) and acridine mustard (0.3%) induce c mutations regardless of recA/sup +/ and, therefore, appear to do so by intercalation. 26 references, 6 figures.

Conversion of different ash content brown coal in fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Osipov, P.; Chernyavskiy, N.; Ryzhkov, A.; Remenuk, A. [Ural Federal Univ., Ekaterinburg (Russian Federation). Dept. of Thermal Power Plants; Dulienko, S. [National Academy of Science of Ukraine, Kiev (Ukraine). Coal Energy Technology Inst.

2013-07-01

Available equations used to determine combustion specific rate of coal-derived cokes describe the burning of carbon particles well enough but are not accurate in case of ash-containing coke particles combustion. This study is an attempt to account for the influence of both initial ash content and its increase in the course of carbon conversion in specific rate calculations. The results of experimental study of burn-out dynamics of Volchanskiy field (North Urals) brown coal and its coke with different ash content under conditions of fluidized bed combustion at impulse-type non-gradient reactor RSC-1 and dynamic installation Pyrolysis-M are summarized. Diffusion and heterogeneous (kinetic) components of carbon combustion rate are identified separately by using diffusion and kinetics equation with correction for carbon mass fraction in particles. Burning particle overheating values and heterogeneous combustion rate constants at different temperatures are estimated.

A CHARACTERIZATION AND EVALUATION OF COAL LIQUEFACTION PROCESS STREAMS

International Nuclear Information System (INIS)

G.A. Robbins; R.A. Winschel; S.D. Brandes

1999-01-01

This is the first Annual Technical Report of activities under DOE Contract No. DE-AC22-94PC93054. Activities from the first three quarters of the fiscal 1998 year were reported previously as Quarterly Technical Progress Reports (DOE/PC93054-57, DOE/PC93054-61, and DOE/PC93054-66). Activities for the period July 1 through September 30, 1998, are reported here. This report describes CONSOL's characterization of process-derived samples obtained from HTI Run PB-08. These samples were derived from operations with Black Thunder Mine Wyoming subbituminous coal, simulated mixed waste plastics, and pyrolysis oils derived from waste plastics and waste tires. Comparison of characteristics among the PB-08 samples was made to ascertain the effects of feed composition changes. A comparison also was made to samples from a previous test (Run PB-06) made in the same processing unit, with Black Thunder Mine coal, and in one run condition with co-fed mixed plastics

Pyrolysis model for an alpha waste incinerator prototype

International Nuclear Information System (INIS)

Orloff, D.I.

1978-01-01

The development of a theoretical model of the pyrolysis stage of an SRL prototype alpha waste incinerator is discussed. Pyrolysis rates for single component porous beds of Teflon (Registered trademark of Du Pont) and natural rubber have been measured on a bench-scale furnace. Experimental pyrolysis rates compare favorably to the predictions of a quasi-steady regression model. In addition, the pyrolysis rate is shown to be a weak function of the thermal diffusivity of the porous polymer bed. As a consequence, pyrolysis is controlled by thermal degradation kinetics rather than by diffusion or conduction

Radiation-induced mutagenicity and lethality in tryptophan-requiring auxotrophs of escherichia coli

International Nuclear Information System (INIS)

Xu Rong; Qian Hongwei; Yao Fenying; Gu Shuzhu; Xu Jiaxin; Bi Hekan; Liu Yuying

1989-01-01

Mutation and killing caused by X-ray radiation and 60 Co γ-ray radiation were studied in three different tryptophan-requiring auxotrophs (WP2, Wp2A, Cm 891) of Escherichia coli. These testers are sensitive to base pair substitution mutagens. Cm891 carries a R-factor and is more sensitive than WP2 and WP2A to radiation-induced mutation and lethality. The results of the study show that (1) ionizing radiation was mutagenic to E. coli, (2) the order of mutagenic sensitivity among three strains to ionizing radiation was Cm891 > WP2A > WP2, (3) the dose rate of γ-ray influences mutagenicity and lethalty of E. coli strain, (4) the toxicity and mutagenicity of γ-ray were similar to X-ray when Cm891 was tested, however, γ-ray was more toxic and mutagenic than X-ray to WP2A ang WP2

Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

Directory of Open Access Journals (Sweden)

Zhigang Li

2013-01-01

Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

Hygiene assessment of irradiated potato mutagenic activity

International Nuclear Information System (INIS)

Uralova, M.; Grunt, J.; Patzeltova, N.

1977-01-01

Albino rat males were fed on gamma-irradiated potatoes for one month and mated with two intact female rats each. The dominant lethal mutation method was then used for the study of possible mutagenic activity of the irradiated potatoes. No statistically significant differences were observed and no mutagenic activity was found. Thus, the test showed that potatoes irradiated with a dose of 10 krad of gamma radiation does not present genetic hazards for albino rats. (L.O.)

Exploratory studies on fast pyrolysis oil upgrading

NARCIS (Netherlands)

Mahfud, Farchad Husein

2007-01-01

Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy

Biomass pyrolysis for chemicals

Energy Technology Data Exchange (ETDEWEB)

De Wild, P.

2011-07-15

The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to an array of useful chemicals. Examples are furfural and acetic acid from hemicellulose, levoglucosan from cellulose and phenols and biochar from lignin. Since the three major biomass polymers hemicellulose, cellulose and lignin possess dissimilar thermal stabilities and reactivities, type and amount of degradation products are tunable by proper selection of the pyrolysis conditions. To determine if step-wise pyrolysis would be suitable for the production of chemicals, staged degasification of lignocellulosic biomass was studied. Due to limited yields, a hot pressurized water pre-treatment (aquathermolysis) followed by pyrolysis was subsequently developed as an improved version of a staged approach to produce furfural and levoglucosan from the carbohydrate fraction of the biomass. Lignin is the only renewable source for aromatic chemicals. Lignocellulosic biorefineries for bio-ethanol produce lignin as major by-product. The pyrolysis of side-streams into valuable chemicals is of prime importance for a profitable biorefinery. To determine the added-value of lignin side-streams other than their use as fuel for power, application research including techno-economic analysis is required. In this thesis, the pyrolytic valorisation of lignin into phenols and biochar was investigated and proven possible.

Thermal and catalytic pyrolysis of plastic waste

Directory of Open Access Journals (Sweden)

Débora Almeida

2016-02-01

Full Text Available Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. Zeolites can be used as catalysts in catalytic pyrolysis and influence the final products obtained.

Fuels Combustion Research: Supercritical Fuel Pyrolysis

National Research Council Canada - National Science Library

Glassman, Irvin

2001-01-01

.... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

Fuels Combustion Research: Supercritical Fuel Pyrolysis

National Research Council Canada - National Science Library

Glassman, Irvin

2000-01-01

.... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

Use of genetic toxicity data in GHS mutagenicity classification and labeling of substances.

Science.gov (United States)

Ball, Nicholas S; Hollnagel, Heli M

2017-06-01

One of the key outcomes of testing the potential genotoxicity or mutagenicity of a substance is the conclusion on whether the substance should be classified as a germ cell mutagen and the significance of this for other endpoints such as carcinogenicity. The basis for this conclusion are the criteria presented in classification and labelling systems such as the Globally Harmonized System for classification and labeling (GHS). This article reviews the classification criteria for germ cell mutagenicity and carcinogenicity and how they are applied to substances with evidence of mutagenicity. The implications and suitability of such a classification for hazard communication, risk assessment, and risk management are discussed. It is proposed that genotoxicity assessments should not focus on specifically identifying germ cell mutagens, particularly given the challenges associated with communicating this information in a meaningful way. Rather the focus should be on deriving data to characterize the mode of action and for use in the risk assessment of mutagens, which could then feed into a more robust, risk based management of mutagenic substances versus the current more hazard based approaches. Environ. Mol. Mutagen. 58:354-360, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Induction of Abasic Sites by the Drinking-Water Mutagen MX in Salmonella TA100

Science.gov (United States)

Mutagen X (MX) is a chlorinated furanone that accounts for more of the mutagenic activity of drinking water than any other disinfection by-product. It is one of the most potent base-substitution mutagens in the Salmonella (Ames) mutagenicity assay, producing primarily GC to TA mu...

Assessment of Cellular Mutagenicity of Americano Coffees from Popular Coffee Chains.

Science.gov (United States)

Liu, Zhen-Shu; Chen, Po-Wen; Wang, Jung-Yu; Kuo, Tai-Chen

2017-09-01

Coffee is a popular beverage worldwide, but coffee beans can be contaminated with carcinogens. The Ames Salmonella mutagenicity test is often used for analysis of carcinogens for mutagenicity. However, previous studies have provided controversial data about the direct mutagenicity of coffee beans based on Ames test results. This study was conducted to determine the mutagenicity of popular Americano coffee based on results from the Ames test. Coffee samples without additives that were served by five international coffee chain restaurants were subjected to the analysis using Salmonella Typhimurium tester strains TA98, TA100, and TA1535. The levels of bacterial revertants in samples from coffee chains were lower than the twofold criterion of the control sets, and no significant dose-response effect was observed with or without rat liver enzyme activation. These data indicate that Americano coffees from the selected coffee chains possessed no direct mutagenic activity with or without enzyme activation. These findings suggest a low mutagenic risk from Americano coffees served by the selected coffee chains and support the use of other methods to confirm the nonmutagenicity of coffee products. These results are consistent with most recent epidemiological reports.

Evaluation of different treatment processes with respect to mutagenic activity in drinking water

Energy Technology Data Exchange (ETDEWEB)

Kool, H J; Hrubec, J; van Kreijl, C F; Piet, G J

1985-12-01

Treatment processes which are applied in The Netherlands during the preparation of drinking water have been evaluated with regard to introduction and removal of organic mutagens as well as halogenated organics. It appeared that the most efficient processes in reducing mutagenic activity were activated carbon filtration and artificial dune recharge. In general these processes were also the most efficient in removing halogenated organics. Using low doses of chlorine dioxide (less than 1 mg C1O2/l) for safety disinfection of drinking water, no change or substantial less mutagenic activity than by chlorination (1 mg Cl/l) was found. This counts too for the formation of halogenated organics. Transport chlorination of stored river Meuse water was able to introduce or activate mutagenic nitro organics which have not been found previously. Ozone treatment under field conditions showed mostly a tendency to decrease the activity of organic mutagens. It was also shown that dependent on the water quality and treatment conditions a slight increase of mutagenic activity occurred, but this activity would be reduced by increasing the ozone dose. It seems possible to optimize the ozone treatment conditions regarding the level of ozone dose and the contact time to avoid an increase of mutagenic activity. Furthermore it was shown that when a mutagenic raw water source was used a proper combination of treatment processes is able to produce drinking water in which no mutagenic activity could be detected under the test conditions. Finally it is stated that before far-reaching decisions with respect to use mutagenicity data for a selection of water sources or treatment processes will be made, more information on the relation mutagenic activity from drinking water and effects on human health should become available.

Nitrogen emissions during pyrolysis and combustion; Einfluesse auf die Stickstofffreisetzung bei der Pyrolyse und Verbrennung

Energy Technology Data Exchange (ETDEWEB)

Koepsel, R F; Friebel, J; Halang, S [Technische Univ. Bergakademie Freiberg (Germany). Inst. IEC

1998-09-01

Reduction of nitric oxide emissions during brown coal combustion is an important contribution to clean utilisation of this very important domestic primary energy source. In modern processes, the nitrogen contained in the fuels is the main source of oxides. The distribution of this nitrogen in the products can be influenced by modifying the degassing parameters especially in the first phase of combustion, i.e. pyrolysis. The heat-up rate, pressure, as well as the genesis and mineral content of the coal were found to be the main influencing paramters. Depending on the fuel characteristics (degree of coalification, concentration of volatile matter, ash composition), the nitrogen released during pyrolysis and the nitrogen retained in the solid residue contribute to the total emissions of nitric oxides in different degrees. (orig.) [Deutsch] Die Verminderung der Stickoxidemission bei der Verbrennung von Braunkohle stellt einen wichtigen Beitrag zur sauberen Verwertung dieses bedeutendsten einheimischen Primaerenergietraegers dar. In modernen Prozessen bildet dabei der im Brennstoff gebundene Stickstoff die Hauptquelle der Oxide. Insbesondere durch Einflussnahme auf die Entgasungsbedingungen waehrend der ersten Phase der Verbrennung - der Pyrolyse - kann die Verteilung dieses Stickstoffes auf die Produkte beeinflusst werden. Als wesentliche Einflussgroessen auf die Einbindung in den verbleibenden Koks und die Freisetzung fluechtiger N-haltiger Gase (HCN, NH{sub 3}) wurden die Aufheizgeschwindigkeit, der Druck und die Mineralsubstanz der Kohle gefunden. Eine wesentliche Einflussgroesse stellt daneben auch die Herkunft der Kohlen dar. In Abhaengigkeit von den Brennstoffeigenschaften (Inkohlungsgrad, Gehalt an fluechtigen Bestandteilen, Aschezusammensetzung) tragen der waehrend der Pyrolyse freigesetzte und der im festen Rueckstand verbleibende Stickstoff in unterschiedlichem Masse zur Gesamtemission an Stickoxiden bei. (orig.)

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants.

Science.gov (United States)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-03-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500°C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal. Copyright © 2010 Elsevier Ltd. All rights reserved.

Genotoxic effects in wild rodents (Rattus rattus and Mus musculus) in an open coal mining area.

Science.gov (United States)

León, Grethel; Pérez, Lyda Espitia; Linares, Juan Carlos; Hartmann, Andreas; Quintana, Milton

2007-06-15

Coal is a mixture of a variety of compounds containing mutagenic and carcinogenic polycyclic aromatic hydrocarbons. Exposure to coal is considered as an important non-cellular and cellular source of reactive oxygen species that can induce DNA damage. In addition, spontaneous combustion can occur in coal mining areas, further releasing compounds with detrimental effects on the environment. In this study the comet assay was used to investigate potential genotoxic effects of coal mining activities in peripheral blood cells of the wild rodents Rattus rattus and Mus musculus. The study was conducted in a coal mining area of the Municipio de Puerto Libertador, South West of the Departamento de Cordoba, Colombia. Animals from two areas in the coal mining zone and a control area located in the Municipio de Lorica were investigated. The results showed evidence that exposure to coal results in elevated primary DNA lesions in blood cells of rodents. Three different parameters for DNA damage were assessed, namely, DNA damage index, migration length and percentage damaged cells. All parameters showed statistically significantly higher values in mice and rats from the coal mining area in comparison to the animals from the control area. The parameter "DNA Damage Index" was found to be most sensitive and to best indicate a genotoxic hazard. Both species investigated were shown to be sensitive indicators of environmental genotoxicity caused by coal mining activities. In summary, our study constitutes the first investigation of potential genotoxic effects of open coal mining carried out in Puerto Libertador. The investigations provide a guide for measures to evaluate genotoxic hazards, thereby contributing to the development of appropriate measures and regulations for more careful operations during coal mining.

Mutagenic and carcinogenic properties of drinking water

International Nuclear Information System (INIS)

Kool, H.J.; van Kreijl, C.F.; Hrubec, J.

1985-01-01

In this chapter results of oxidation treatments with chlorine, ozone, chlorine dioxide, and ultraviolet (UV), with respect to their effects on activity (Ames test) in drinking water supplies are reviewed. In addition, the authors present the preliminary results of a pilot plant study on the effects of chlorine and chlorine dioxide on mutagenicity. Furthermore, results of several carcinogenicity studies performed with organic drinking water concentrates are discussed in relation to the results of a Dutch carcinogenicity study with mutagenic drinking water concentrates

THE GENOTOXICITY OF AMBIENT OUTDOOR AIR, A REVIEW: SALMONELLA MUTAGENICITY

Science.gov (United States)

The genotoxicity of ambient outdoor air, a review: Salmonella mutagenicityAbstractMutagens in urban air pollution come from anthropogenic sources (especially combustion sources) and are products of airborne chemical reactions. Bacterial mutation tests have been used ...

The detection and analysis of mutagens: Final report, 1968--1986

International Nuclear Information System (INIS)

Ames, B.N.

1989-01-01

Our main objectives are: to develop and improve the Salmonella test for detecting environmental mutagens; to investigate the relationship between carcinogens and mutagens and to validate the Salmonella test for detecting carcinogens; to uncover significant unsuspected environmental mutagens/carcinogens; to investigate the theory of mutagenesis; to develop new methods for determining DNA damage by particular chemicals in individual people; to understand the role of oxygen radicals in DNA damage, cancer, and aging; and to investigate the role of anti-carcinogens in preventing DNA damage

Mass spectrometric studies of fast pyrolysis of cellulose

Energy Technology Data Exchange (ETDEWEB)

Degenstein, John; Hurt, Matt; Murria, Priya; Easton, McKay; Choudhari, Harshavardhan; Yang, Linan; Riedeman, James; Carlsen, Mark; Nash, John; Agrawal, Rakesh; Delgass, W.; Ribeiro, Fabio; Kenttämaa, Hilkka

2015-01-01

A fast pyrolysis probe/linear quadrupole ion trap mass spectrometer combination was used to study the primary fast pyrolysis products (those that first leave the hot pyrolysis surface) of cellulose, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, as well as of cellobiosan, cellotriosan, and cellopentosan, at 600°C. Similar products with different branching ratios were found for the oligosaccharides and cellulose, as reported previously. However, identical products (with the exception of two) with similar branching ratios were measured for cellotriosan (and cellopentosan) and cellulose. This result demonstrates that cellotriosan is an excellent small-molecule surrogate for studies of the fast pyrolysis of cellulose and also that most fast pyrolysis products of cellulose do not originate from the reducing end. Based on several observations, the fast pyrolysis of cellulose is suggested to initiate predominantly via two competing processes: the formation of anhydro-oligosaccharides, such as cellobiosan, cellotriosan, and cellopentosan (major route), and the elimination of glycolaldehyde (or isomeric) units from the reducing end of oligosaccharides formed from cellulose during fast pyrolysis.

Effect of mutagen combined action on Chlamydomonas Reinhardtii cells. I

International Nuclear Information System (INIS)

Vlcek, D.; Podstavkova, S.; Dubovsky, J.

1978-01-01

The effect was investigated of single and combined actions of alkylnitrosourea derivatives (N-methyl-N-nitrosourea and N-ethyl-N-nitrosourea) and UV-radiation on the survival of cells of Chlamydomonas reinhardtii algae in dependence on the sequence of application of mutagens and on the given conditions of cultivation following mutagen activity. In particular, the single phases were investigated of the total lethal effect, i.e., the death of cells before division and their death after division. The most pronounced changes in dependence on the sequence of application of mutagens and on the given conditions of cultivation were noted in cell death before division. In dependence on the sequence of application of mutagens, the effect of the combined action on the survival of cells changed from an additive (alkylnitrosourea + UV-radiation) to a protective effect (UV-radiation + alkylnitrosourea). (author)

Kinetics of Pyrolysis and Gasification Using Thermogravimetric and Thermovolumetric Analyses

Directory of Open Access Journals (Sweden)

Czerski Grzegorz

2016-03-01

Full Text Available The carbon dioxide gasification process of Miscanthus giganteus biomass was examined using two methods. First an isothermal thermovolumetric method was applied. The measurement was conducted at 950°C and pressure of 0.1 MPa. Based on the continuous analysis of different kinds of gases formed during the gasification process, the thermovolumetric method allowed the determination of yields and composition of the resulting gas as well as the rate constant of CO formation. Then a non-isothermal thermogravimetric method was applied, during which the loss of weight of a sample as a function of temperature was recorded. In the course of the measurement, the temperature was raised from ambient to 950°C and the pressure was 0.1 MPa. As a result, a change in the carbon conversion degree was obtained. Moreover, TGA methods allow distinguishing various stages of the gasification process such as primary pyrolysis, secondary pyrolysis and gasification, and determining kinetic parameters for each stage. The presented methods differs from each other as they are based either on the analysis of changes in the resulting product or on the analysis of changes in the supplied feedstock, but both can be successfully used to the effective examination of kinetics of the gasification process. In addition, an important advantage of both methods is the possibility to carry out the gasification process for different solid fuels as coal, biomass, or solid waste in the atmosphere of a variety of gasification agents.

[Mutagenicity of radon and radon daughters

International Nuclear Information System (INIS)

1990-01-01

The current objective of our research is to investigate the dose-response relationship of the lethal and mutagenic effects of exposure of cells to radon and its decay products. Dose-rate dependence will be studied, as well as the nature of the DNA lesions. The effect of DNA repair on the lethal and mutagenic effects of exposure and on the character of the DNA lesions will be investigated by comparing the response of L5178Y strains which differ in their ability to rejoin X radiation-induced DNA double-strand breaks. This report discusses progress incurred from 4/1/1988--10/1/1990. 5 refs., 9 figs., 6 tabs

A contribution to the study on the mutagenicity of atmospheres

International Nuclear Information System (INIS)

Blaise, Philipp

1986-01-01

Following a review of the literature, the genotoxic hazards of atmospheric pollutants at various locations (rural sites, motorway tolls, paint shops...) were evaluated by in vitro mutagenicity assays (Ames' test and SOS chromo-test) and analytical methods (gas chromatography and mass spectrometry). Instrumentation and procedures were developed for the sampling of volatile organic pollutants: adsorption on XAD 2 followed by acetone extraction of the compounds trapped. A comparative study allowed to assess the relative mutagenic action of the volatile organic compounds and to establish a mutagenicity scale. (author) [fr

[Smoked sausages and food additives: evaluation of total mutagenic activity].

Science.gov (United States)

Dugan, A M; Tkacheva, D L

2011-01-01

The paper deals with the evaluation of the total mutagenic activity of samples of the inorganic and organic fractions of three technology smoked sausages (boiled-smoked, semi-smoked, and raw-smoked) and some food additives used to manufacture the above sausages. Their mild and moderate mutagenic effects were recorded in a Salmonella typhimurium bacterial test system with a metabolic activation system. Physicochemical analysis of the fractions of the smoked sausages has shown that their study samples are substantially contaminated with heavy metals and representatives of polycyclic aromatic hydrocarbons, partially causing the mutagenic effects observed.

Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay

Science.gov (United States)

Liu, Li; Chen, Ling; Floehr, Tilman; Xiao, Hongxia; Bluhm, Kerstin; Hollert, Henner; Wu, Lingling

2015-01-01

Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (−) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components. PMID:26606056

Vacuum pyrolysis of waste tires with basic additives

International Nuclear Information System (INIS)

Zhang Xinghua; Wang Tiejun; Ma Longlong; Chang Jie

2008-01-01

Granules of waste tires were pyrolyzed under vacuum (3.5-10 kPa) conditions, and the effects of temperature and basic additives (Na 2 CO 3 , NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 deg. C to 600 deg. C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48 wt% was achieved at 550 deg. C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50 wt% was achieved at 480 deg. C by adding 3 wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) ∼205 deg. C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39 wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na 2 CO 3 addition. Pyrolysis gas was mainly composed of H 2 , CO, CH 4 , CO 2 , C 2 H 4 and C 2 H 6 . Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5 wt%) was much higher

Quantitative mammalian cell mutagenesis and mutagen screening: study with CHO cells

International Nuclear Information System (INIS)

Hsie, A.W.; O'Neill, J.P.; San Sebastian, J.R.; Brimer, P.A.

1979-01-01

The CHO/HGPRT system has been developed and defined for quantifying mutation induced by various physical and chemical agents at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in Chinese hamster ovary (CHO) cells. In all direct-acting chemical mutagens studied, mutation induction increases linearly as a function of the concentration, with no apparent threshold. Some chemicals induce mutation at non-cytotoxic concentrations. The mutagenicity of ethyl methanesulfonate has been quantified as a function of exposure concentration x treatment time. The sensitive and quantitative nature of the system enables studies of the structure-activity (mutagenicity) relationships of various classes of chemicals, including alkylating agents, heterocyclic nitrogen mustards, and platinum compounds. When rat liver S 9 -mediated metabolic activation is present, procarcinogens such as benzo(a)pyrene, 2-acetylaminofluorene, and dimethylnitrosamine are mutagenic, whereas their noncarcinogenic structural analogues pyrene, fluorene, and dimethylamine are not. The system has been shown to be useful in determining the interactive effects between physical and chemical agents, and in screening for mutagenicity of fractionated organic mixtures and industrial chemicals in both liquid and gaseous state. For the system to be used successfully in routine screening, further studies should be directed toward the development of a metabolic activation system suitable for a broad spectrum of chemicals, a sensitive and reliable statistical method, and an experimental design to determine compounds with low mutagenicity. The system has been expanded for determination of mutagen-induced chromosome aberration, sister-chromatid exchange, and micronucleus formation in addition to gene mutation and cytotoxicity; it can also be used to study inhibition of DNA synthesis

Novel sorbent materials for environmental remediation via Pyrolysis of biomass

Science.gov (United States)

Zabaniotou, Anastasia

2013-04-01

One of the major challenges facing society at this moment is the transition from a non-sustainable, fossil resources-based economy to a sustainable bio-based economy. By producing multiple products, a biorefinery can take advantage of the differences in biomass components and intermediates and maximize the value derived from the biomass feedstock. The high-value products enhance profitability, the high-volume fuel helps meet national energy needs, and the power production reduces costs and avoids greenhouse-gas emissions From pyrolysis, besides gas and liquid products a solid product - char, is derived as well. This char contains the non converted carbon and can be used for activated carbon production and/or as additive in composite material production. Commercially available activated carbons are still considered expensive due to the use of non-renewable and relatively expensive starting material such as coal. The present study describes pyrolysis as a method to produce high added value carbon materials such as activated carbons (AC) from agricultural residues pyrolysis. Olive kernel has been investigated as the precursor of the above materials. The produced activated carbon was characterized by proximate and ultimate analyses, BET method and porosity estimation. Furthermore, its adsorption of pesticide compound in aqueous solution by was studied. Pyrolysis of olive kernel was conducted at 800 oC for 45min in a fixed reactor. For the production of the activated carbon the pyrolytic char was physically activated under steam in the presence of CO2 at 970oC for 3 h in a bench scale reactor. The active carbons obtained from both scales were characterized by N2 adsorption at 77 K, methyl-blue adsorption (MB adsorption) at room temperature and SEM analysis. Surface area and MB adsorption were found to increase with the degree of burn-off. The surface area of the activated carbons was found to increase up to 1500 m2/g at a burn-off level of 60-65wt.%, while SEM analysis

Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases

Science.gov (United States)

Shuai, Yanhua; Douglas, Peter M.J.; Zhang, Shuichang; Stolper, Daniel A.; Ellis, Geoffrey S.; Lawson, Michael; Lewan, Michael; Formolo, Michael; Mi, Jingkui; He, Kun; Hu, Guoyi; Eiler, John M.

2018-01-01

Multiply isotopically substituted molecules (‘clumped’ isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation temperatures of several natural materials. However, kinetic processes during generation, modification, or transport of natural materials can also affect their clumped-isotope compositions. Herein, we show that methane generated experimentally by closed-system hydrous pyrolysis of shale or nonhydrous pyrolysis of coal yields clumped-isotope compositions consistent with an equilibrium distribution of isotopologues under some experimental conditions (temperature–time conditions corresponding to ‘low,’ ‘mature,’ and ‘over-mature’ stages of catagenesis), but can have non-equilibrium (i.e., kinetically controlled) distributions under other experimental conditions (‘high’ to ‘over-mature’ stages), particularly for pyrolysis of coal. Non-equilibrium compositions, when present, lead the measured proportions of clumped species to be lower than expected for equilibrium at the experimental temperature, and in some cases to be lower than a random distribution of isotopes (i.e., negative Δ18 values). We propose that the consistency with equilibrium for methane formed by relatively low temperature pyrolysis reflects local reversibility of isotope exchange reactions involving a reactant or transition state species during demethylation of one or more components of kerogen. Non-equilibrium clumped-isotope compositions occur under conditions where ‘secondary’ cracking of retained oil in shale or wet gas hydrocarbons (C2-5, especially ethane) in coal is prominent. We suggest these non-equilibrium isotopic compositions are the result of the expression of kinetic isotope effects during the irreversible generation

Pyrolysis model for an alpha waste incinerator prototype

International Nuclear Information System (INIS)

Orloff, D.I.

1979-01-01

The development of a theoretical model of the pyrolysis stage of a Savnnah River Laboratory prototype alpha waste incinerator is discussed. pyrolysis rates for single-component porous bed of Teflon (registered trademark of Du Pont de Nemours and Co.) have been measured on a bench-scale furnace. Experimental pyrolysis rates compare favorably to the predictions of a quasisteady regression model. In addition, the pyrolysis rate is shown to be a weak function of the thermal diffusivity of the porous polymer bed. 13 refs

40 Years of the Salmonella Mutagenicity Assay: Implications for 21st Century Toxicology

Science.gov (United States)

The Salmonella (Ames) mutagenicity assay was developed and introduced by Bruce Ames and colleagues in 1971. Since then, it has become the standard assay for hazard identification of mutagens worldwide. It is a first-tier test for mutagenic activity in the pharmaceutical and chemi...

Expert advice in case of exposure to mutagens or teratogens

International Nuclear Information System (INIS)

Steuber, E.D.

1982-01-01

To answer the question of any induced hazards in progeny by an exogeneous factor it is necessary to differentiate between mutagenic and teratogenic action. Mutations can be caused by ionisizing radiations and chemicals, e.g. cytostatic drugs. After exposure to mutagenic agents a conception should be prevented for a time of 3 months to avoid a fertilization of a germ cell that has been effected during a very sensible phase. In case of conception during mutagenic exposure it is possible to detect chromosome aberrations by prenatal diagnosis after amniocentesis. The spectrum of possible teratogens is extensive and less specific than that of mutagenic agents. Factors established as embryotoxic in man are for instance radiation, several drugs and some virus infections. They have been known to cause malformations in the fetus, if these events take place during a certain critical period of organogenesis. (orig.) [de

Mutagenicity of basic fractions derived from lamb and beef cooked by common household methods.

Science.gov (United States)

Barrington, P J; Baker, R S; Truswell, A S; Bonin, A M; Ryan, A J; Paulin, A P

1990-03-01

Mutagen production was examined in lamb and beef in relation to certain common household cooking methods. Mutagenicity was assessed, after extraction of the basic fraction of cooked meat samples, using Salmonella typhimurium strain TA1538 with added rat-liver S-9 homogenate. Little or no mutagenicity was found in barbecued lamb chops, in microwave-cooked lamb chops, sirloin steak, leg of lamb, or rolled beef loaf, in roasted leg of lamb or rolled beef loaf, in stewed blade steak or in boiled chuck steak. However, the basic fraction from well-done, edible fried or grilled meat contained mutagenic activity equivalent to approximately 30,000 TA1538 revertants/100 g cooked meat. It was found tht the mutagenic activity of grilled lamb chops, sirloin and rump steaks was directly related to the average surface temperatures attained during cooking. Use of butter as a frying medium was particularly associated with higher mutagenicity in meat samples. Fried meats (rump and fillet steaks) generally yielded higher mutagenic activity than did grilled meats (rump steak, lamb chops) at comparable temperatures of the cooking medium. Using similar cooking procedures, lamb did not differ markedly from beef in mutagenic activity.

Mutagenicity of comfrey (Symphytum Officinale) in rat liver

OpenAIRE

Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

2005-01-01

Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

Mutagenicity of comfrey (Symphytum Officinale) in rat liver.

Science.gov (United States)

Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

2005-03-14

Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant.

Role of ozone and granular activated carbon in the removal of mutagenic compounds.

Science.gov (United States)

Bourbigot, M M; Hascoet, M C; Levi, Y; Erb, F; Pommery, N

1986-01-01

The identification of certain organic compounds in drinking water has led water treatment specialists to be increasingly concerned about the eventual risks of such pollutants to the health of consumers. Our experiments focused on the role of ozone and granular activated carbon in removing mutagenic compounds and precursors that become toxic after chlorination. We found that if a sufficient dose of ozone is applied, its use does not lead to the creation of mutagenic compounds in drinking water and can even eliminate the initial mutagenicity of the water. The formation of new mutagenic compounds seems to be induced by ozonation that is too weak, although these mutagens can be removed by GAC filtration. Ozone used with activated carbon can be one of the best means for eliminating the compounds contributing to the mutagenicity of water. A combined treatment of ozone and activated carbon also decreases the chlorine consumption of the treated water and consequently reduces the formation of chlorinated organic compounds. PMID:3816720

Reprint of: Pyrolysis technologies for municipal solid waste: A review

Energy Technology Data Exchange (ETDEWEB)

Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

2015-03-15

Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

Catalytic pyrolysis of hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Vail' eva, N A; Buyanov, R A

1979-01-01

Catalytic pyrolysis of petroleum fractions (undecane) was performed with the object of clarifying such questions as the mechanism of action of the catalyst, the concepts of activity and selectivity of the catalyst, the role of transport processes, the temperature ranges and limitations of the catalytic process, the effect of the catalyst on secondary processes, and others. Catalysts such as quartz, MgO, Al/sub 2/O/sub 3/, were used. Analysis of the experimental findings and the fact that the distribution of products is independent of the nature of the surface, demonstrate that the pyrolysis of hydrocarbons in the presence of catalysts is based on the heterogeneous-homogeneous radical-chain mechanism of action, and that the role of the catalysts reduces to increasing the concentration of free radicals. The concept of selectivity cannot be applied to catalysts here, since they do not affect the mechanism of the unfolding of the process of pyrolysis and their role consists solely in initiating the process. In catalytic pyrolysis the concepts of kinetic and diffusive domains of unfolding of the catalytic reaction do not apply, and only the outer surface of the catalyst is engaged, whereas the inner surface merely promotes deletorious secondary processes reducing the selectivity of the process and the activity of the catalyst. 6 references, 2 figures.

Assessment of the mutagenic potential of cyanobacterial extracts and pure cyanotoxins.

Science.gov (United States)

Sieroslawska, Anna

2013-11-01

The aim of the study was to assess the mutagenic potential of extracts obtained from the cyanobacterial bloom-forming cells harvested from the water body located in Lubelszczyzna region of southeastern Poland. Three cyanotoxins, microcystin-LR, cylindrospermopsin and anatoxin-a were detected in some of the studied samples in different concentrations. All extracts were assessed for their potential mutagenic effects with the use of a short-term bacterial assay, the Ames test. Mutagenic activity was observed in four of all ten studied extracts, mainly toward the Salmonella typhimurium TA100 strain. On the contrary, the cyanotoxins in purified forms occurred not to be mutagenic or cytotoxic towards S. typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2 uvrA and WP2 [pKM101] up to a concentration of 10 μg/ml. Similarly, there were no effects after bacteria exposure to the mixture of purified toxins. It has been also detected that after fractionation, genotoxic impact of previously mutagenic extracts was weaker and the highest potency in revertant induction possessed fractions containing very hydrophilic compounds. The results indicate, that while tested cyanotoxins were not directly responsible for the observed mutagenicity of the extracts analysed, some synergistic interactions with other unidentified cyanobacterial-derived factors involved in the process are possible. Copyright © 2013 Elsevier Ltd. All rights reserved.

Production of activated char from Illinois coal for flue gas cleanup

Science.gov (United States)

Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

1997-01-01

Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

Structure-Activity Relationship Models for Rat Carcinogenesis and Assessing the Role Mutagens Play in Model Predictivity

Science.gov (United States)

Carrasquer, C. Alex; Batey, Kaylind; Qamar, Shahid; Cunningham, Albert R.; Cunningham, Suzanne L.

2016-01-01

We previously demonstrated that fragment based cat-SAR carcinogenesis models consisting solely of mutagenic or non-mutagenic carcinogens varied greatly in terms of their predictive accuracy. This led us to investigate how well the rat cancer cat-SAR model predicted mutagens and non-mutagens in their learning set. Four rat cancer cat-SAR models were developed: Complete Rat, Transgender Rat, Male Rat, and Female Rat, with leave-one-out (LOO) validation concordance values of 69%, 74%, 67%, and 73%, respectively. The mutagenic carcinogens produced concordance values in the range of 69–76% as compared to only 47–53% for non-mutagenic carcinogens. As a surrogate for mutagenicity comparisons between single site and multiple site carcinogen SAR models was analyzed. The LOO concordance values for models consisting of 1-site, 2-site, and 4+-site carcinogens were 66%, 71%, and 79%, respectively. As expected, the proportion of mutagens to non-mutagens also increased, rising from 54% for 1-site to 80% for 4+-site carcinogens. This study demonstrates that mutagenic chemicals, in both SAR learning sets and test sets, are influential in assessing model accuracy. This suggests that SAR models for carcinogens may require a two-step process in which mutagenicity is first determined before carcinogenicity can be accurately predicted. PMID:24697549

Preconception exposures to potential germ-cell mutagens

International Nuclear Information System (INIS)

Draper, G.

2008-01-01

Radiation and other agents can cause germ-cell mutations in animal systems. No human germ-cell mutagen has been identified, but this does not mean that human germ-cells are not vulnerable to mutagenesis. There has been particular concern about the possible health effects on offspring following parental preconception exposure to ionizing radiation - both occupational and therapeutic. A strong association with preconception radiation exposure in the fathers of the cases was found in a case-control study of young people with leukaemia living near the Sellafield nuclear plant in the UK. Subsequent studies of workers occupationally exposed to ionizing radiation have failed to confirm these findings. No statistically significant effects have been reported from studies of possible indicators of germ-cell mutagenesis in the A-bomb survivors. Studies of offspring of cancer survivors who receive radiotherapy and mutagenic chemotherapy have found no evidence of germ-cell mutagenesis. Failure to detect human germ-cell mutagenic agents may be a consequence of inadequate study sizes or insufficiently sensitive laboratory techniques. (authors)

Feasibility of Technologies to Produce Coal-Based Fuels with Equal or Lower Greenhouse Gas Emissions than Petroleum Fuels

Science.gov (United States)

2014-12-22

in operating pipeline compressors), and a negligible amount from coal; just under five percent was produced from biomass—mostly in the form of corn ...as is commonly reported for soy- and corn -based biofuels), and/or if biofuel production results in land use change causing deforestation (as has...produced via F-T synthesis are already approved for incorporation into commercial and military fuels, but other pathways (e.g., pyrolysis ) would

Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

International Nuclear Information System (INIS)

Ishidate, M. Jr.; Yoshikawa, Kunie; Sofuni, Toshio; Iwahara, Shigeo; Sibuya, Tohru.

1981-01-01

The alcohol extracts freshly prepared from gamma-irradiated potatoes were examined for their mutagenic activity in bacterial and mammalian cell systems. Negative results were obtained from all following test systems: Mutation assays with Salmonella typhimurium His - strains such as TA 100, TA 98, TA 1535, TA 1537, and streptomycin-dependent mutant (SM sup(d)) strain, TA 100 - 10, inductests with Escherichia coli strains, K 12 GY 5027 and K 12 C600, chromosomal aberration tests with Chinese hamster cells in culture, as well as micronucleus tests in mice. In addition, no difference in the mutagenic activities was found between extracts prepared from the irradiated and the unirradiated potatoes, suggesting that no mutagenic substance was produced in potatoes following gamma-irradiation. (author)

Sources of mutagenic activity in urban fine particles

International Nuclear Information System (INIS)

Stevens, R.K.; Lewis, C.W.; Dzubay, T.G.; Cupitt, L.T.; Lewtas, J.

1990-01-01

Samples were collected during the winter of 1984-1985 in the cities of Albuquerque, NM and Raleigh NC as part of a US Environmental Protection Agency study to evaluate methods to determine the emission sources contributing to the mutagenic properties of extractable organic matter (EOM) present in fine particles. Data derived from the analysis of the composition of these fine particles served as input to a multi-linear regression (MLR) model used to calculate the relative contribution of wood burning and motor vehicle sources to mutagenic activity observed in the extractable organic matter. At both sites the mutagenic potency of EOM was found to be greater (3-5 times) for mobile sources when compared to wood smoke extractable organics. Carbon-14 measurements which give a direct determination of the amount of EOM that originated from wood burning were in close agreement with the source apportionment results derived from the MLR model

Desulfurized gas production from vertical kiln pyrolysis

Science.gov (United States)

Harris, Harry A.; Jones, Jr., John B.

1978-05-30

A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

Science.gov (United States)

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2013-02-01

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low

Pyrolysis of biofuels of the future: Sewage sludge and microalgae – Thermogravimetric analysis and modelling of the pyrolysis under different temperature conditions

International Nuclear Information System (INIS)

Soria-Verdugo, Antonio; Goos, Elke; Morato-Godino, Andrés; García-Hernando, Nestor; Riedel, Uwe

2017-01-01

Highlights: • Pyrolysis of microalgae and sewage sludge is studied by thermogravimetric analysis. • Accurate values of the kinetic parameters of the pyrolysis reaction are reported. • Pyrolysis is modeled for parabolic and exponential temperature increases. • Estimations of the model are compared with experimental measurements in TGA. • Excellent agreement is reached between the model estimations and the experiments. - Abstract: The pyrolysis process of both microalgae and sewage sludge was investigated separately, by means of non-isothermal thermogravimetric analysis. The Distributed Activation Energy Model (DAEM) was employed to obtain the pyrolysis kinetic parameters of the samples, i.e. the activation energy E_a and the pre-exponential factor k_0. Nine different pyrolysis tests at different constant heating rates were conducted for each sample in a thermogravimetric analyzer (TGA) to obtain accurate values of the pyrolysis kinetic parameters when applying DAEM. The accurate values of the activation energy and the pre-exponential factor that characterize the pyrolysis reaction of Chlorella vulgaris and sewage sludge were reported, together with their associated uncertainties. The activation energy and pre-exponential factor for the C. vulgaris vary between 150–250 kJ/mol and 10"1"0–10"1"5 s"−"1 respectively, whereas values ranging from 200 to 400 kJ/mol were obtained for the sewage sludge activation energy, and from 10"1"5 to 10"2"5 s"−"1 for its pre-exponential factor. These values of E_a and k_0 were employed to estimate the evolution of the reacted fraction with temperature during the pyrolysis of the samples under exponential and parabolic temperature increases, more typical for the pyrolysis reaction of fuel particles in industrial reactors. The estimations of the relation between the reacted fraction and the temperature for exponential and parabolic temperature increases were found to be in good agreement with the experimental values

Counteracting quasispecies adaptability: extinction of a ribavirin-resistant virus mutant by an alternative mutagenic treatment.

Directory of Open Access Journals (Sweden)

Celia Perales

Full Text Available BACKGROUND: Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. METHODOLOGY AND PRINCIPAL FINDINGS: Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. CONCLUSIONS: (i When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a

Effect of total pressure on sulfur capture of Ca-ion exchanged coal; Kaatsu jokenka ni okeru Ca-tanjitan no datsuryu koka

Energy Technology Data Exchange (ETDEWEB)

Lin, S.; Benjamin, G.; Abe, H.; Harano, A.; Takarada, T. [Gunma University, Gunma (Japan). Faculty of Engineering

1996-10-28

In relation to coal gasification and combustion under high pressure as highly efficient coal utilization, the effect of total pressure and sintering on the SO2 capture ability of Ca-ion exchanged coal and other desulfurizing agents were studied. In experiment, specimens were filled into a small pressurized reactor to heat them under high-pressure N2 atmosphere. After the completion of combustion reaction of char at 850{degree}C, SO2, CO2 and CO gases were measured at an outlet while flowing SO2/N2. As the experimental result, all of the S content in Ca-ion exchanged coal was not absorbed by Ca content in coal during pyrolysis and combustion, resulting in discharge of 36% of the S content. Since Ca-ion exchanged coal is fast in combustion reaction, most of the S content was desulfurized by coal ash. The ash content yielded from Ca-ion exchanged coal was more excellent in SO2 capture ability than limestone even under higher pressure. In the case of CO2 partial pressure lower than equilibrium CO2 pressure for CaCO3 decomposition, the capture ability decreased with an increase in total pressure, while in higher CO2 partial pressure, it was improved. 1 ref., 7 figs., 2 tabs.

New structural concept for carbonized coals

Energy Technology Data Exchange (ETDEWEB)

Marzec, A. [Polish Academy of Sciences, Gliwice (Poland). Inst. of Coal Chemistry

1997-07-01

The aim of this study was to present a model of structure for solid products of bituminous coal carbonization carried out at end temperatures (ETCs) in the 600-750{degree}C range. The products are of interest since they are used as raw materials for production of activated carbons. Moreover a layer of such products occurring in coke ovens seems to play a crucial role in generation of excessive coking pressure in industrial coking. The experimental data used in modeling were derived from the following: carbonization studies of coals and individual aromatic hydrocarbons, X-ray diffraction, transmission electron microscopy, pyrolysis-field ionization mass spectrometry, and electrical resistivity measurements. The final step of model preparation relied on application of computational chemistry for search of stable conformers and for calculations of molecular orbitals. According to the model, semicokes contain two structural components: (1) oligomers that form nonplanar 3D networks of aromatic clusters (an extended system of conjugated {pi}-orbitals unites clusters of the networks despite the fact they are not coplanar) and (2) planar aggregates that arise from products of dehydrocyclization reaction (the aggregates fill space between oligomeric networks). The two structural components represent optically isotropic and anisotropic phases, respectively. 21 refs., 7 figs.

Modelling Underground Coal Gasification—A Review