Pressurized Hydrogasification of Raw Coal In a Dilute-Phase Reactor

Feldmann, H.F.; Mima, J.A.; Yavorsky, P.M.

doi:10.1021/ba-1974-0131.ch008

Cited by 8 publications

(7 citation statements)

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“…These kinetic parameters were quantitatively evaluated, based on data obtained from the gasification (in hydrogen and in inert gas) of a Montana lignite, Montana subbituminous coal, and North Dakota lignite, as well as on data reported by Feldmann et al (1974) for the gasification of R13 is a gas phase hydrogenation reaction. Reactions R1, R5, R7, and R8 always went to completion under the time-temperature histories studied by Johnson.…”

Section: Discussionmentioning

confidence: 99%

Modeling of entrained flow coal hydropyrolysis reactors. 1. Mathematical formulation and experimental verification

Goyal¹,

Gidaspow²

1982

Ind. Eng. Chem. Proc. Des. Dev.

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A mathematical model has been developed to describe physical and chemical processes occurring in an entrained fbw coal hydropyrolysis reactor. The model is onedimensional and incorporates a detailed multistep reaction kinetic model developed by Johnson for hydropyrolysis supplemented by Suuberg's pyrolysis model for rapid reactions, reactions of hydropyrolysis products in the gas phase, hydrodynamics of the gas-solid system, sweliinghhrinking of the coal particles, and the heat transfer between the coal-char particles, gases, and reactor walls.

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Section: Discussionmentioning

confidence: 99%

Modeling of entrained flow coal hydropyrolysis reactors. 1. Mathematical formulation and experimental verification

Goyal¹,

Gidaspow²

1982

Ind. Eng. Chem. Proc. Des. Dev.

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“…Although some investigators have suggested that this process occurs simultaneously with thermal pyrolysis reactions, studies done with a greater time resolu tion indicated that this rapid-rate methane formation occurs at a rate which is at least an order of magnitude slower than devolatilization (4,5). In this sense it occurs after devolatilization.…”

Section: Kinetic Modelsmentioning

confidence: 99%

“…The amount of carbon gasified to methane during the transient high reactivity increases significantly with increases in hydrogen partial pres sure (4,5,6). Experimental evidence indicates that at sufficiently high hydrogen partial pressures virtually all of the carbon not evolved during devolatilization can be gasified quickly to methane by this process (6).…”

Section: Kinetic Modelsmentioning

confidence: 99%

Kinetics of Bituminous Coal Char Gasification with Gases Containing Steam and Hydrogen

Johnson

1974

Advances in Chemistry

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Quantitative correlations developed to describe coal char gasification kinetics are consistent with experimental data obtained under a wide range of conditions with both differential and integral contacting systems. The correlations are developed using data obtained at constant environmental conditions with a thermobalance apparatus and a differential fluid bed system at 1500°-2000°F and 1-70 atm with a variety of gases and gas mixtures. The correlations are based on an idealized model of the gasification process which consists of three consecutively occurring stages: devolatilization, rapid-rate methane formation, and low-rate gasification./Correlations to define quantitatively the effects of pertinent intensive ^ variables on the kinetics of coal or coal char gasification reactions are necessary for the rational design of commercial systems to convert coal to pipeline gas. The available information which can be applied to the development of such correlations is relatively limited, particularly be cause the data reported from many studies conducted with integral contacting systems reflect, in part, undefined physical and chemical behavior peculiar to the specific experimental systems used. Although some differential rate data have been obtained with various carbonaceous materials, they cover only narrow ranges of the conditions potentially applicable to commercial gasification systems.For the last several years the Institute of Gas Technology (IGT) has been conducting a study to obtain fundamental information on the gasification of coals and coal chars; this information could be used with selected literature information to develop engineering correlations which 145

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“…Following Dent's lead ofjust 40 years ago (6) and with methane as the objective, researchers have treated coal with hydrogen at pressure in experiments with slow heating (7) (1-3, 5, 6, 8), and with flash heating (about 1 second or less) (9)(10)(11)(12). Except in the processes described in (1,2,5,9,11), gas residence time in the reaction zone was long, generally running to minutes.…”

mentioning

confidence: 99%

“…Except in the processes described in (1,2,5,9,11), gas residence time in the reaction zone was long, generally running to minutes. At long gas residence times, with either rapid or flash heating, the usual products are methane, ethane, and a little heavy tar [for example, see (12)]. …”

mentioning

confidence: 99%