Chemical Desulfurization of Coal: Partitioning Sulfur to Gas as H,S (original) (raw)
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Thermal desulfurization of Illinois coals
1990
Organic and pyritic sulfur removal as a function of pyrolysis temperature for three coals 2 Effect of heating rate on sulfur evolution during pyrolysis of-20 + 35 mesh particles of IBC-101 3 Rate of sulfur evolution during charring experiments PH34, PH41, and PH35 4 Magnetic susceptibility measurements of chars prepared at various temperatures under pure N 2 and a 0.1 % 2 /N 2 mixture for coal sample RK-B-5 11 5 Proportions of original organic and pyritic sulfur remaining after charring and partial oxidation 6 Quadrupole gas analyzer data collected during pyrolysis of IBC-101 7 QGA data comparing the evolution of S0 2 and C0 2 during char oxidation at 455°C of IBC-101, experiment QMS8 8 Proportions of original organic and "pyritic" sulfur remaining in treated chars of RK-B-3 coal samples 9 Sulfur removal by charring at 750°C for 5 minutes and hydrotreatment at 800°C for 15 and 60 minutes 10 Removal of organic and "pyritic" sulfur from char by hydrodesulfurization at 800°C for different lengths of time 11 800°C hydrodesulfurization rate data for experiments QMS6, QMS7, and QMS9 prepared for IBC-101 12 Various combinations of the thermal desulfurization treatments investigated 13 Sulfur and carbon evolution versus pyrolysis temperature for four different coals 14 Sulfur evolution versus time for hydrodesulfurization at 800°C of three CR-B-1 chars 21 15 Sulfur evolution versus time for hydrodesulfurization at 800°C of three RK-B-4 chars 16 Sulfur evolution versus time for hydrodesulfurization at 800°C of three RK-B-5 chars 17 Sulfur evolution versus time for hydrodesulfurization at 800°C of three IBC-101 chars 18 QGAdata comparing the evolution of S0 2 and C0 2 during oxidation at 455°C of H 2 + 0.44% H 2 S-treated chars 23 A1 First coal pyrolysis apparatus 26 A2 Second coal pyrolysis-chardesulfurization apparatus 27 A3 pH monitoring system 28 A4 Quadrupole gas analyzer monitoring system 29 A5 Flash pyrolysis apparatus A6 Isotopic mixing relationship of pyritic and organic sulfur in coal sample R-B-3 31 TABLES 1 Chemical analysis, sulfur isotopic composition, and mass balance calculations of Herrin (No. 6) Coal samples used in pyrolysis experiments 2 2 Amount and origin of sulfur removed by pyrolysis of three Illinois coal samples 3 3 Amount and origin of sulfur in the volatile gases of the stepwise pyrolysis of RK-B-3 4 4 Chemical analysis and isotopic composition of float and sink coal fractions of RK-B-3 samples 4 5 Results of 650°C pyrolyses of samples of RK-B-3 containing significantly different pyrite concentrations 5 6 Chemical analyses of two particle sizes of Illinois Basin Coal Sample Program IBC-101 and IBC-103 5 7 Sulfur removal by pyrolysis of IBC-101 6 8 Sulfur removal by pyrolysis of IBC-103 9 Effect of particle size, maximum pyrolysis temperature, and soak time on total sulfur removal and sulfide mineral content for IBC-101 10 Effect of heating rate and particle size on char pore structure (IBC-101 and IBC-103) 11 Sulfide and iron oxide mineral content of chars produced from coals pyrolyzed 18 minutes at 550°C with various amounts of trace oxygen 12 Sulfide and iron oxide mineralogy of RK-B-5 chars produced by heating to various temperatures under pure nitrogen 11 13 Sulfide and iron oxide mineralogy of RK-B-5 chars treated with 0.1 percent oxygen after pure nitrogen treatment and preoxidation treatment 14 Pyrolysis and post-pyrolysis partial oxidation experiments on sink and float coal fractions 15 Post-pyrolysis oxidation results for IBC-101 16 Post-pyrolysis oxidation results for IBC-103 17 Distribution of sulfur forms in hydrogen-treated chars after acid leaching and partial oxidation 18 Pyrolysis and hydrodesulfurization results of coal sample RK-B-3 19 Separate pyrolysis and post-pyrolysis desulfurization experiments for IBC-101 20 Chemical analyses of the four coals used in the combined gas-phase thermal treatment tests 21 Sulfur concentration in chars and total char yields after combined thermal desulfurization treatments 22 Sulfide and associated iron minerals in chars after thermal desulfurization treatments
Study of Sulfur Behavior and Removal During Thermal Desulfurization of Illinois Coals
2017
Organic and pyritic sulfur removal as a function of pyrolysis temperature for three coals 2 Effect of heating rate on sulfur evolution during pyrolysis of-20 + 35 mesh particles of IBC-101 3 Rate of sulfur evolution during charring experiments PH34, PH41, and PH35 4 Magnetic susceptibility measurements of chars prepared at various temperatures under pure N 2 and a 0.1 % 2 /N 2 mixture for coal sample RK-B-5 11 5 Proportions of original organic and pyritic sulfur remaining after charring and partial oxidation 6 Quadrupole gas analyzer data collected during pyrolysis of IBC-101 7 QGA data comparing the evolution of S0 2 and C0 2 during char oxidation at 455°C of IBC-101, experiment QMS8 8 Proportions of original organic and "pyritic" sulfur remaining in treated chars of RK-B-3 coal samples 9 Sulfur removal by charring at 750°C for 5 minutes and hydrotreatment at 800°C for 15 and 60 minutes 10 Removal of organic and "pyritic" sulfur from char by hydrodesulfurization at 800°C for different lengths of time 11 800°C hydrodesulfurization rate data for experiments QMS6, QMS7, and QMS9 prepared for IBC-101 12 Various combinations of the thermal desulfurization treatments investigated 13 Sulfur and carbon evolution versus pyrolysis temperature for four different coals 14 Sulfur evolution versus time for hydrodesulfurization at 800°C of three CR-B-1 chars 21 15 Sulfur evolution versus time for hydrodesulfurization at 800°C of three RK-B-4 chars 16 Sulfur evolution versus time for hydrodesulfurization at 800°C of three RK-B-5 chars 17 Sulfur evolution versus time for hydrodesulfurization at 800°C of three IBC-101 chars 18 QGAdata comparing the evolution of S0 2 and C0 2 during oxidation at 455°C of H 2 + 0.44% H 2 S-treated chars 23 A1 First coal pyrolysis apparatus 26 A2 Second coal pyrolysis-chardesulfurization apparatus 27 A3 pH monitoring system 28 A4 Quadrupole gas analyzer monitoring system 29 A5 Flash pyrolysis apparatus A6 Isotopic mixing relationship of pyritic and organic sulfur in coal sample R-B-3 31 TABLES 1 Chemical analysis, sulfur isotopic composition, and mass balance calculations of Herrin (No. 6) Coal samples used in pyrolysis experiments 2 2 Amount and origin of sulfur removed by pyrolysis of three Illinois coal samples 3 3 Amount and origin of sulfur in the volatile gases of the stepwise pyrolysis of RK-B-3 4 4 Chemical analysis and isotopic composition of float and sink coal fractions of RK-B-3 samples 4 5 Results of 650°C pyrolyses of samples of RK-B-3 containing significantly different pyrite concentrations 5 6 Chemical analyses of two particle sizes of Illinois Basin Coal Sample Program IBC-101 and IBC-103 5 7 Sulfur removal by pyrolysis of IBC-101 6 8 Sulfur removal by pyrolysis of IBC-103 9 Effect of particle size, maximum pyrolysis temperature, and soak time on total sulfur removal and sulfide mineral content for IBC-101 10 Effect of heating rate and particle size on char pore structure (IBC-101 and IBC-103) 11 Sulfide and iron oxide mineral content of chars produced from coals pyrolyzed 18 minutes at 550°C with various amounts of trace oxygen 12 Sulfide and iron oxide mineralogy of RK-B-5 chars produced by heating to various temperatures under pure nitrogen 11 13 Sulfide and iron oxide mineralogy of RK-B-5 chars treated with 0.1 percent oxygen after pure nitrogen treatment and preoxidation treatment 14 Pyrolysis and post-pyrolysis partial oxidation experiments on sink and float coal fractions 15 Post-pyrolysis oxidation results for IBC-101 16 Post-pyrolysis oxidation results for IBC-103 17 Distribution of sulfur forms in hydrogen-treated chars after acid leaching and partial oxidation 18 Pyrolysis and hydrodesulfurization results of coal sample RK-B-3 19 Separate pyrolysis and post-pyrolysis desulfurization experiments for IBC-101 20 Chemical analyses of the four coals used in the combined gas-phase thermal treatment tests 21 Sulfur concentration in chars and total char yields after combined thermal desulfurization treatments 22 Sulfide and associated iron minerals in chars after thermal desulfurization treatments
Effect of pyrolysis temperature on desulfurization performance of high organic sulfur low rank coal
Journal of Mining and Metallurgy A: Mining, 2021
The sulfur in coal not only influences the coke quality but also pollutes the environment during the combustion. The desulfurization of high organic sulfur coal is a key issue in coal cleaning science. As the pyrolysis has been used in low-rank coal conversion to obtain gas/liquid products and coal char, the desulfurization effects of pyrolysis on the low-rank coal with high organic sulfur requires further studies. This study investigated the desulfurization performance of high organic sulfur low-rank coal by the pyrolysis and the changes in the coal calorific value and sulfur forms during the pyrolysis. The XPS was applied to analyze the changing regulation of sulfur that forms on coal surface. The results indicated certain amount of FeS was newly created during the pyrolysis and high amounts of sulfate sulfur was transferred to pyrite sulfur and formed more FeS2 when compared to the distribution of raw coal. The total sulfur content of coal was reduced from 2.32% for raw coal to 1...
The Pathways for Thermal Decomposition of Coals with High Con-tent of Sulphur and Oxygen
geolines.gli.cas.cz
This study was undertaken to obtain more definite information about the peculiarity of chemical reactions under the pyrolysis of coals with different content of heteroatoms using the pairs of low-and high-sulphur samples of the same rank (~76-88 % C daf ) in parallel experiments. Products were characterized by the standard chemical methods, FT-IR spectroscopy, extraction, liquid and gas chromatography and others. The results suggest that the sensitivity of pyrolysis products yield to changes of coal genetic type as well a coal rank is related to competing rates of volatile release and resolidification processes. The high content of active oxygen-and sulphur-containing groups appears to shift this competition in favour of greater volatile products release and slower resolidification. Phenolic OH (and SH) groups take part in ether bonds or C-C bonds creation by a dehydration reaction in a temperature range of 300-500 °C. This agrees with the high contents of H 2 O, CO, CO 2 in gas and asphaltenes in liquid and many -O-, -S-type bridges in solid semicoking products. In contrast, pyrolysis of the good coking coals results in predominant formation of aromatic structures of semi-coke with polymethylene bridges and produces the gaseous products with high portion of H 2 and CH 4 .
Pyrolysis of high sulfur Indian coals
Energy & Fuels, 2007
Pyrolysis experiments under laboratory conditions for five numbers of high sulfur coal samples from the states of Meghalaya and Nagaland, India, were carried out at temperatures of 450, 600, 850, and 1000°C, respectively. The yield of products and thermal release of sulfur from these coals are investigated. The distribution of sulfur in the pyrolyzed products, i.e., char/coke, gas, and tar, is also reported. Hydrocarbon and sulfurous gases released at different temperatures were analyzed by a gas chromatograph (GC) with an FID (flame ionized detector) and an FPD (flame photometric detector), respectively. H 2 S evolution during coal pyrolysis was found to be a function of temperature up to 850°C. The low concentration of SO 2 detected for some of the samples is due to decomposition of inorganic sulphates present. Evolution of methane for the coals tested increases with the increase of temperature. Maximum sulfur release was found in the range of 600-850°C and has a decreasing tendency from 850-1000°C, which might be due to the incorporation of sulfur released into the coal matrix. Activation energies for sulfur release were found in the range of 38-228 KJ mol -1 , which were higher than the reported activation energies for lignites and bituminous coals mainly due to highly stable organic sulfur functionalities.
The paper presents a review of relevant literature on coal pyrolysis.
… in Chemical Engineering …, 1999
Particle size and heat transfer eflects on organic and inorganic sulphur transformations during pyrolysis are investigated using temperature-programmed pyrolysis and fured-bed pyrolysis (700 -90OOC) of pulverised Bowmans coal, and fluidised bed pyrolysis at 800OC of 6, 8 and 1 Omm diameter cylindrical coal pellets. Results are interpreted using a heat transfer model [ 8 ] . The pyrolysis experiments reveal that during the initial devolatilisation stage, organic and sulphate sulphur decomposition occurs at a rate directly proportional to heating rate and inverse& proporrional ro particle size. Towardrs the end of the devolatilisation stage, the transportation of volatiles out of the coal decreases so that sulphate undergoes solidstate transformations to form organic sulphur in the char. The reincorporation process is accelerated by higher reaction temperatures or heating rates which allows greater decomposition of sulphate and longer periods of slow devolatilisation to support the solid-state reactions. Smaller particles in the fluidised bed reveal a similar efect due to faster internal heating rates. Larger particle sizes also facilitate organic sulphur increase due to slow internal heating rates and hence slow and extended devolatilisation and sulphate reincorporation.
Energy & Fuels, 2002
Two low-rank coals with high sulfur contents (Gediz subbituminous coal: 7.6 wt % S:dry basis. Ç ayirhan lignite: 5.7 wt% S:dry basis.) were subjected to hydroliquefaction. Liquefaction conditions included dry or solvent mediated runs under pressurized hydrogen without added catalyst or with the impregnated catalyst precursor ammonium heptamolybdate (AHM). Gediz coal having higher sulfur content gave 90% conversion in the absence of catalyst and solvent. Maximum conversion (98%) and maximum oil + gas yield (70%) from this coal were obtained by impregnating AHM onto coal and carrying out liquefaction in H 2 /tetralin system at 450°C for 30 min. Under the same conditions, Ç ayirhan lignite gave 85% conversion and 70.5% oil + gas yield. The superior hydrodesulfurization effect of impregnated AHM on the oil fraction when used in the absence of solvent (less than 0.1% S in lignite's oil and less than 1% S in subbituminous coal's oil following one-stage hydrogenation) is a promising finding of this work. AHM was found to be much more effective in liquefaction of Ç ayirhan lignite and this has been ascribed to the well-dispersion of AHM throughout this lignite's structure via a cation-exchange mechanism through oxygen functionalities. Strong evidence for the catalytic effect of clay minerals in coal structure on char-forming reactions during liquefaction was observed by making use of liquefaction reactions of demineralized coal samples. It was also observed that tetralin had a retarding effect on the condensation and subsequent cross-linking reactions.