Experimental investigation on hydrogen production by agricultural biomass gasification in supercritical water

Hydrogen can be obtained by thermochemical gasification of biomass in supercritical water. Agricultural biomass, including corn stalk, corn cob, wheat stalk, rice straw, rice shell, peanut shell, wood sawdust and broomcorn stalk, mixed in sodium carboxymethylcellulose, were gasified successfully at 650°C, 25 MPa in a tubular flow reactor with formation of hydrogen, carbon dioxide, carbon monoxide, methane and a small amount of ethane and ethylene. The influences of operation time, type of biomass, particle size and reactor wall on biomass gasification were investigated. The experimental results show that the similar gas composition is obtained from gasification of different agricultural biomass on the same operation conditions. The volume fraction of carbon monoxide in product gas is about 1%, the volume of methane is in excess of 10% and the maximal volume fraction of hydrogen reaches to 41.28%. And small particle is favorable to hydrogen yield and the reactor wall catalyzes obviously the biomass gasification.