Patent ID: 7837975

Claim:
A process for producing hydrogen, comprising the steps of: gasifying a fuel into a raw synthesis gas comprising CO, hydrogen, steam and sulfur and halide contaminants in the form of H 2 S, COS and HX, where X is a halide; injecting said raw synthesis gas, CaO and steam simultaneously into a water gas shift reactor (WGSR) wherein said raw synthesis gas transforms into a shifted gas; allowing said shifted gas to react with said CaO in said water gas shift reactor so as to remove sulfur and halides in a solid-phase calcium-containing product comprising CaCO 3 , CaS and CaX 2 ; separating the solid-phase calcium-containing product from an enriched gaseous hydrogen product; and regenerating the CaO by calcining the solid-phase calcium-containing product at a condition selected from the group consisting of: in the presence of steam, in the presence of CO 2 , in the presence of synthesis gas, in the presence of H 2 and O 2 , under partial vacuum, and combinations thereof.