Coal Requirements of the GE Gasifier

In principle, almost all kinds of coal can be gasified in the GE gasification process, including lignite, bituminous, and anthracite. However, to optimize the performance of the gasifier, bituminous coal with high volatile and high reactivity is recommended. 

There are two kinds of moisture that exist in the coal surface moisture and inherent moisture. Since the CWS is basically a mixture of coal particle and water, the surface moisture of coal does not have too much impact in the GE gasification process. However, a higher surface moisture content means a higher transportation cost. Inherent moisture includes all the moisture that is physically or chemically held within coal. In the CWS preparation step, inherent moisture of the coal plays an important role. With an increase in the inherent moisture, it has been found that the maximum coal concentration possible in a CWS decreases. 

Ash is the inert material contained in the coal. Although ash is not directly involved in the gasification, some of the heat generated in the oxidation reaction is consumed 

To reduce the operating temperature and lengthen the lifetime of the refractory, coals with lower AFTs are recommended in the GE gasification process. 

Technically, GE gasifiers can be used to gasify all kinds of coals. However, coals with low inherent moisture ( 8wt %), low ash content ( 13 wt %), low AFT ( 1300 °C), high heating value ( 25MJ/kg), and low impurities content (Cl, As, S, etc.) are strongly recommended. 

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