Hydrogen from biomass gasification for fuel cell systems by application or the sponge iron/iron oxide process cycle

摘要

Commercially available fuel cells are fed with hydrogen as fuel (Phosphoric Acid Fuel Cell, PAFC). One way of producing hydrogen is the conversion of synthesis gas, which may be derived from the gasification of biomass. The conversion of synthesis gas to hydrogen by means of the Steam Iron Process is discussed here. The chemical processes are limited by thermodynamic equilibria. Consequently the efficiency of the conversion of the synthesis gas remains on a low level. The rest of the heating value of the synthesis gas must be utilized to produce electricity by conventional means. Thus the process is always a combined one with e.g. a gas turbine system. Two different reactor concepts are mathematically simulated and discussed here, the fixed bed and the moving bed reactor. Fixed bed reactors are of a simple construction, but the Outlet gas conditions are not constant with time. The moving bed reactor provides fairly constant outlet gas conditions, but it requires additional transport facilities for the solid material.