Simulation of High-Temperature Water-Gas Shift Reactors

Singh, Chandra Prakash; Saraf, Deoki N.

doi:10.1021/i260063a012

Cited by 68 publications

(37 citation statements)

References 7 publications

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“…Since all the experiments were reported at atmospheric pressures, the kinetic models can be corrected for pressure using the modification recommended by Rase (1977) which also takes care of the diffusional effects of the catalysts or the pressure correction factor of Singh and Saraf (1977).…”

Section: Temkin Modelmentioning

confidence: 99%

A Review of the Water Gas Shift Reaction Kinetics

J¹,

Loganathan²,

Shantha³

2010

International Journal of Chemical Reactor Engineering

195

154

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The world's progression towards the Hydrogen economy is facilitating the production of hydrogen from various resources. In the carbon based hydrogen production, Water gas shift reaction is the intermediate step used for hydrogen enrichment and CO reduction in the synthesis gas. This paper makes a critical review of the developments in the modeling approaches of the reaction for use in designing and simulating the water gas shift reactor. Considering the fact that the rate of the reaction is dependent on various parameters including the composition of the catalyst, the active surface and structure of the catalyst, the size of the catalyst, age of the catalyst, its operating temperature and pressure and the composition of the gases, it is difficult to narrow down the expression for the shift reaction. With different authors conducting experiments still to validate the kinetic expressions for the shift reaction, continuous research on different composition and new catalysts are also reported periodically. Moreover the commercial catalyst manufacturers seldom provide information on the catalyst. This makes the task of designers difficult to model the shift reaction. This review provides a consolidated listing of the various important kinetic expressions published for both the high temperature and the low temperature water gas shift reaction along with the details of the catalysts and the operating conditions at which they have been validated.

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Section: Temkin Modelmentioning

confidence: 99%

A Review of the Water Gas Shift Reaction Kinetics

J¹,

Loganathan²,

Shantha³

2010

International Journal of Chemical Reactor Engineering

195

154

View full text Add to dashboard Cite

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“…The gas-phase reactions occurring in the gasification section have been investigated by Singh and Saraf (1977), Wen and Chaung (1979), and Zahradnik and Grace (1974). Water-Gas Shift Reaction…”

Section: Char-oxygen Reactionmentioning

confidence: 99%

Modeling and simulation of an entrained flow coal gasifier

1984

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A mathematical model has been developed to simulate the Texaco downflow entrained-bed pilot-plant gasifier using coal liquefaction residues and coal-water slurries as feedstocks. This model describes the physical and chemical processes occurring in an entrained coal gasifier. The gasification kinetics describes different complex reactions occurring in the gasifier and the hydrodynamics describes mass, momentum and energy balances for solid and gas phases. Temperature, concentration and velocity profiles along the reactor height were obtained by solving the mass, momentum and energy balances. Parameter studies were made to provide a better understanding of the reactor performance for various inlet feed conditions utilizing the model. RAKESH GOVIND and JOGEN SHAHDepartment of Chemical and Nuclear Engineering University of Cincinnati Cincinnati, OH 45221 SCOPE Entrained-bed gasifiers are cocurrent flow reactors in which pulverized or atomized hydrocarbons react with oxygen and steam to produce gaseous fuels. These reactors are becoming popular in the processing of coal into synthetic fuels and thermal energy since they produce higher coal gasification rates and are easier to operate than fluidized-or fixed-bed reactors. Further, due to the incineration effect they produce a product gas that is relatively free of higher hydrocarbons particularly the tarry materials.In this paper, a mathematical model has been developed to simulate the Texaco downflow entrained-bed pilot-plant gasifier using coal liquefaction residues as feedstocks. Results of the simulation have been compared with experimental data from the gasifier. CONCLUSIONS AND SIGNIFICANCEThe Texaco downflow pilot-plant gasifier was simulated by simultaneously solving the mass, momentum and energy balances-for the solid and gas phases. Good agreement was obtained between the simulation programs and experimental results. The gas composition leaving the gasifier and the final carbon conversion depends on three essential parameters: the fuel rate, the oxygen to fuel ratio, and the steam-fuel ratio. It was found that oxygen-fuel ratio affects carbon conversion more than the steam-fuel ratio. The steam-fuel ratio significantly affects the gas product composition. The optimum oxygen-fuel ratio is between 0.8 and 0.9 to achieve 98-99% conversion. Depending on the oxygen-fuel ratio, the optimum steam-fuel ratio ranges from 0.3 to 0.6 using coal liquefaction residues as feedstocks.

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“…Reaction rate expressions for the FT and the WGS reactions are taken from Sarup and Wojciechowski (1988) and Singh and Saraf (1977), respectively, for a given Co catalyst. However, in order to allow their usage at high pressures, they were expressed in terms of the fugacity coefficients:…”

Section: Reaction Ratesmentioning

confidence: 99%