Gasifier Classification

Coal gasification technologies can be classified according to the flow configuration of the gasifier unit. The primary configurations are  

Typical operating characteristics of coal gasifiers are as follows  

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Some technologies produce fly ash, which should be recycled back into the gasifier. If this is not possible, it can be used as additive for concrete. Because fly ash has a very small particle size (<10 pm), a high fraction of cenospheres, and cementing properties, it is referred to as a valuable product for the cement industry. If such use is, however, not possible, it must be disposed with unfevorable classification [32]. 

Gasification processes are most commonly sorted according to bed type. This is equivalent to a classification according to the largest particles size that the gasifier can accept. The type of bed chosen places restrictions on many process parameters. An overview is given in Table 4.2. 

The classification of gasifiers is commonly done according to the bed type. Based on this, three groups of gasifiers are known moving bed, fluidized bed, and entrained flow. These reactor types are currently in commercial operation. 

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