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6079194 
Journal Article 
Design of Biomass Gasifiers 
Basu, P; Basu, P 
2010 
Academic Press 
Boston 
Biomass Gasification and Pyrolysis 
167-228 
WOS:000311395600007 
Publisher Summary The design of a gasification plant includes the gasifier reactor as well as its auxiliary or support equipment. This chapter deals with the design of the gasifier reactor. Gasifiers are classified mainly on the basis of their gas–solid contacting mode and gasifying medium. Based on the gas–solid contacting mode, gasifiers are broadly divided into three principal types fixed or moving bed, fluidized bed, and entrained flow. One gasifier type is not necessarily suitable for the full range of gasifier capacities. There is an appropriate range of application for each. Entrained flow is the most successful and widely used gasifier type for largescale gasification of coal, petroleum coke, and refinery residues. It is ideally suited to most types of coal except low-rank coal, which, like lignite and biomass, is not attractive because of its large moisture content. High-ash coal is also less suitable because cold-gas efficiency decreases with increasing ash content. For slurry-fed coal, the economic limit is 20% ash; for dry feed it is 40%. The gasification temperature of an entrained-flow gasifier generally well exceeds 1000°C. This allows production of a gas that is nearly tar-free and has a very low methane content. A properly designed and operated entrained-flow gasifier can have a carbon conversion rate close to 100%. The product gas, being very hot, must be cooled in downstream heat exchangers that produce the superheated steam required for gasification. 
Basu, Prabir