In cases where the goal is to produce hydrogen (H2) from coal without power export, the overall flow arrangement can be further simplified. Figure 3 is a block flow diagram for producing H2 from coal with minimal power generation. Onsite power generation is kept to a level to meet internal consumption, and if necessary, some power can also be imported. Key differences from H2 co-production in integrated gasification combined cycle (IGCC) with carbon sequestration (Figure 1) are:
Table 1 lists some of the published overall performance and efficiency values for coal-to-H2 production only design studies that correspond to this process arrangement. Results are shown for variations with and without carbon dioxide (CO2) capture scenarios, and are for minimal power co-production without the use of gas turbines.
|Table 1: Hydrogen Production Only Plant Performance & Efficiency 1,2|
|1.||Polygeneration of SNG, Hydrogen, Power, and Carbon Dioxide from Texas Lignite (Dec 2004)
D. Gray, S. Salerno, G. Tomlinson & J. J. Marano, Mitretek Technical Report for NETL
|2.||Capital and Operating Cost of Hydrogen Production from Coal Gasification (Apr 2003)
Final Report by Parsons for NETL