The Desulfurization of Organic Sulfur and the Transformations of Organic Sulfur Functional Groups in Coal Pyrolysis

Attar, Amir; Messenger, Lance

doi:10.1080/00986448308940581

Cited by 12 publications

(6 citation statements)

References 10 publications

(3 reference statements)

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“…The kinetic data available in the literature for H2S evolution in coal pyrolysis is fairly limited (Carcia-Labiano et al, 1995;Attar and Messenger, 1983;Lester et al, 1982), but also the kinetic information is insufficient to use in the present model. Several reported correlations for pyrolysis yield of sulphur-and nitrogencontaining gases as a function of temperature (Ma et al ,1989;Fine et al, 1974) have been tested, but they give too large yields of sulphur-containing gases in the present system.…”

Section: Sulphur-and Nitrogen-containing Casesmentioning

confidence: 99%

Three‐stage well‐mixed reactor model for a pressurized coal gasifier

Song

Watkinson

2000

Can J Chem Eng

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asification tests were performed in a small scale (0.1-m dia.) spouted bed gasifier on three Canadian coals to determine their G conversion behaviour, gas quality and yield, and the effect of added sorbent on the level of gaseous sulphur and nitrogen emissions. The development of a mathematical model for the gasifier was considered essential to interpret results. Modelling a fluidized/spouted bed coal gasification reactor involves simulating devolatilization, combustion, and gasification kinetics and reactor hydrodynamics, In view of limited understanding of the phenomena occurring in a coal gasifier, a number of simplifying assumptions have to be made in mathematical modelling. A systematic analysis of the influence of these assumptions on the model prediction will be helpful to understand a gasification system. Because of the scale of the unit, and the mixture of sorbent and char in the bed, the hydrodynamics of spouting were not considered. Instead, the present work adopts a well-mixed reactor model using the approach of Caram and Amundson (1 979) to permit predictions of gasifier performance, and to study the influence of model assumptions on the comparison between prediction and experimental data. ExperimentalA detailed description of the spouted coal gasification reactor was presented previously (Sue-A-Quan et at., 1991). The lncolloy reactor, with a diameter of 0.1 m, is enclosed in a refractory lined 0.305 m diameter steel pressure shell. Coal, screened to 1 to 3 mm diameter, is fed from a pressurized hopper a t a flow rate range of 1.9 to 8.1 kg/h, depending on the coal reactivity. The coal, transported by nitrogen, is carried into the reactor bed along with the compressed air via a 14 mm diameter tube which is located at the apex of the 60" conical base. Superheated steam produced in a propane-fired fluid bed furnace enters through a concentric tube and, together with the air blast, provides the spouting gas flow. Superficial velocities of 0.5 to 0.8 m/s provide adequate spouting and bed circulation. The product gas is cooled and depressurized, and its composition determined by chromatography.Where an inert bed i s employed, 0.3 to 0.5 kg of 1 mm sand is first introduced. Once the coal flow is started, it takes about 0.5 h to reach a thermal steady state, by which time the gas composition is also constant. Temperatures, pressures and flow rates are monitored continuously by personal computer, and gas samples withdrawn intermittently for analysis. After shutting down the gasifier, the bed and cyclone products are analyzed for moisture, carbon, and ash content.'Author to whom correspondence may be addressed. E-mail address: apw&hml. u bc.ca char combustion reactions, and arbon conversion of the slow char gasification reactions is comparatively small. The incorporation of tar decomposition into the model provides significantly closer predictions of experimental gas composition than is obtained otherwise.Trois charbons canadiens de differents grades ont ete gazeifies avec des melanges air-vapeur dans un rea...

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Section: Sulphur-and Nitrogen-containing Casesmentioning

confidence: 99%

Three‐stage well‐mixed reactor model for a pressurized coal gasifier

Song

Watkinson

2000

Can J Chem Eng

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“…Yang et al found that iron-rich sulfide concentrate showed a stronger propensity for spontaneous combustion than sulfur-rich sulfide concentrate. Pyritic sulfur and organic sulfur differ in terms of reaction rate …”

Section: Introductionmentioning

confidence: 99%

“…Oxidation promotes the enrichment of sulfur on the surface of coal . Attar and Messenger investigated the retention of organic sulfur in char and the transformation of sulfur functional groups during the vacuum pyrolysis of coal at 200–800 °C and found that thiolic sulfur decomposed first, followed by the aryl sulfides, and eventually aliphatic sulfides decomposed into H 2 S and hydrocarbon. However, the type of bonds in organic sulfur in the char could not be determined.…”

Section: Introductionmentioning

confidence: 99%

“…Pyritic sulfur and organic sulfur differ in terms of reaction rate. 14 The organic sulfurs play an important role in the oxidation reaction, combustion, and pyrolysis of coal. Zhou and Chriswell 15 reported that disulfides are easily oxidized; aliphatic sulfides, aliphatic and aromatic thiols are less reactive; and thiophenes and aromatic sulfides are relatively stable.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the Adsorption Behavior of Organic Sulfur in Coal via Density Functional Theory (DFT) Calculation and Molecular Simulation

Zhang

Zhuo

et al. 2021

J. Phys. Chem. A

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In this paper, we have investigated the chemical adsorption behavior of O 2 on five types of organic sulfur (thiol, sulfoxide, thioether, sulfone, and thiophene) in polycyclic aromatic hydrocarbon (PAH) sheets using density functional theory (DFT) calculations. Here, the adsorption energy of O 2 -organic sulfur exceeds that of O 2 -PAH. Sulfone tends to be more favorable for oxidation reactions than other organic sulfur compounds and PAH by energy gap and deformation charge density analyses. A large charge transfer occurs between O 2 and organic sulfur compounds by charge analysis. A radical distribution function (RDF) analysis shows that O 2 /CO 2 /N 2 is preferentially adsorbed on nitrogen/ sulfur/oxygen-containing functional groups in coal. To inhibit the reaction of sulfur-containing coal with oxygen, the physical adsorption of pure gas (CO 2 / O 2 /N 2 ) and binary mixed gases (CO 2 + O 2 /N 2 + O 2 /CO 2 + N 2 ) is conducted at different temperatures and geological depths using molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The adsorption capacities of five types of organic sulfur with respect to the pure gases decrease with increasing temperature and increase with increasing depth. For O 2 /CO 2 , CO 2 /N 2 , and O 2 /N 2 binary gas systems, the order with respect to adsorption amount is CO 2 > O 2 > N 2 . The factor of adsorption capacities is also evaluated, and the results show that pore volume plays a key role in adsorption behavior.

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“…Coal decomposition and secondary gasification reactions also lead to the formation of other sulfur gas species including carbonyl sulfide (COS), carbon disulfide, and various thiophenes and mercaptans. Studies of coal desulfurization chemistry have been reported by Zielke et al (1954) (1977), Huang and Pulsifer (1977), Attar (1978Attar ( , 1979, Torrest and VanMeurs (1980), and Yeboah et al (1982), and kinetic studies of H2S evolution have been performed for coal pyrolysis (Solomon, 1977;Lester et al, 1982;Attar and Messenger, 1983) and coal hydrogasification (Vestal et al, 1969(Vestal et al, ,b, 1972; ; Yergey et al, 1974).…”

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confidence: 99%

Evolution of hydrogen sulfide in a fluidized bed coal gasification reactor

Ma¹,

Felder²,

Ferrell³

1989

Ind. Eng. Chem. Res.

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maximum sorbent utilization efficiency.These pilot test results indicate that S02 capture by entrained hydrated lime particles occurs by two different mechanisms: a gas/solid reaction mechanism for particles which do not interact with droplets; a gas/solid/droplet reaction mechanism for particles interacting with water droplets.Accordingly, the sorbent injection process performance may be improved by enhancing either of these two reaction mechanisms. The lime properties may be improved to enhance the sorbent's intrinsic activity for the gas/solid reaction mechanism. The humidifier may be designed to provide increased particle-droplet interactions to promote

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The Desulfurization of Organic Sulfur and the Transformations of Organic Sulfur Functional Groups in Coal Pyrolysis

Cited by 12 publications

References 10 publications

Three‐stage well‐mixed reactor model for a pressurized coal gasifier

Three‐stage well‐mixed reactor model for a pressurized coal gasifier

Investigation of the Adsorption Behavior of Organic Sulfur in Coal via Density Functional Theory (DFT) Calculation and Molecular Simulation

Evolution of hydrogen sulfide in a fluidized bed coal gasification reactor

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