Gasification processes

Carbon monoxide and excess steam are normally passed over a cobalt catalyst at about 250-300 C resulting in greater than 99% conversion of CO to COj. This conversion reaction is widely used in oil or solid fuel gasification processes for the production of town gas or substitute natural gas. ... 

The gasification plant is equipped with two Texaco gasifiers, each capable of producing all of the synthesis gas required for operation of the complex. Eastman chose an entrained-bed gasification process for the Chemicals from Coal project because of three attractive features. The product gas composition using locally available coal is particularly suitable for production of the desired chemicals. Also, the process has excellent environmental performance and generates no Hquids or tars. EinaHy, the process can be operated at the elevated pressure required for the downstream chemical plants. 

A newer concept has been developed that is given the name mild gasification (33). It is not a gasification process in the tme sense of the word. The process temperature is some several hundred degrees lower, hence the term mild, than the usual gasification process temperature and the objective is not to produce a gaseous fuel but to produce a high value char (carbon) and Hquid products. Gas is produced, but to a lesser extent. 

J. T. Stewart and T. D. Pay, "Coal Gasification Processes and Equipment Available for Small Industrial AppHcations," paper presented at the Fifth Annual International Conference on Coal Gasification Eiquefaction and Conversion to Electricity, University of Pittsburgh, Pa., Aug. 1—3,1978. 

Fig. 4. Coal gasification process. PSA = pressure-swing adsorption.

Methods in Development. The U.S. Department of Energy (DOE) and the American Gas Association (AGA) have sponsored the development of more efficient gasification processes, but as of this writing the plentihil supply of iaexpensive natural gas has precluded commercialization. 

The high cost of coal handling and preparation and treatment of effluents, compounded by continuing low prices for cmde oil and natural gas, has precluded significant exploitation of coal as a feedstock for methanol. A small amount of methanol is made from coal in South Africa for local strategic reasons. Tennessee Eastman operates a 195,000-t/yr methanol plant in Tennessee based on the Texaco coal gasification process to make the methyl acetate intermediate for acetic anhydride production (15). 

Figure 8 shows a schematic of the SheU Gasification process. Preheated hydrocarbon feed and oxygen are mixed with steam and fed to the... 

T. Sueyama and T. Tsujino, "Ammonia Production by a Coal Gasification Process," British Sulphur Feriiliiyer Symposium, British Sulphur Ltd.,... 

Dow Goal Gasification Process. The Dow coal gasification process (Destec) is a two-stage, slurry feed, entrained-flow, slagging gasifier. 

D. Hebden and H. J. F. Stroud, "Coal Gasification Processes," iu M. A. Elliott, ed.. Chemistry of Coal Utilisyation, secoud supplemeutary volume,... 

W. V. Bush, K. R. Loos, and P. F. Russell, "Environmental Characteri2ation of the Shell Coal Gasification Process. I. Gaseous Effluent Streams," Fifteenth BiennialEow-Rank Fuels Symposium, St. Paul, Minn., May 22—25,1989. 

R. T. Perry and co-workers, "Environmental Characteri2ation of the Shell Coal Gasification Process. III. SoHd By-Products," Seventh Annual Jntemational Pittsburgh Coal Conference, Pittsburgh, Pa., 1990. 

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