Title: Co-processing of biomass-methane-CO2 for hydrogen production

Abstract

Transition from fossil fuels to renewable technologies is extremely challenging as renewable energy sources like solar, wind, and biomass are highly unreliable, subject to variation in geography and local climatic conditions. Transition from fossil hydrogen to renewable hydrogen is bridged by the unique ‘natural gas – biomass co-processing. At WVU, hydrogen rich syngas production through renewable hardwood biomass gasification was obtained through synergistic natural gas – biomass co-processing. About 5% methane co-processed with biomass at 850oC on Fe-Mo/CNF catalyst produces H2: CO ratio of 6 with a very low CO2 concentration of < 5% in the syngas. About 60 to 80% hydrogen was obtained in the product gas on the Fe-Mo/CNF, Ni-Mo/CNF, and Mo-Pd/CNF catalysts. Synergistic methane activated biomass gasification could be a promising technology for hydrogen rich syngas production as it requires very low concentrations of methane which could be obtained from flare gas. Flare gas is natural gas flared during commissioning of new wells or maintenance of existing wells in shale gas field. On-site utilization of flare gas with biomass could greatly curb CO2 emission while producing hydrogen rich syngas. CO2 utilization in the methane activated biomass gasification was studied by adding 1% CO2 to the gas feed. CO2 and CH4 activation at high temperature was performed on Fe, Ni, and Pd active sites while Mo active sites are responsible for deoxygenation of oxygen rich biomass. In-situ conversion of raw biomass co-processed with 5% methane produces H2-rich syngas on the carbon nanofiber supported catalyst. CNF support is also obtained from the biomass feedstock by impregnation with metals and pyrolysis at 700oC. This process is 95% renewable with net reduction in CO2 emissions by recycling of CO2. Detailed mechanistic investigation through molecular simulations helped ascertain the unique reaction pathway occurring on dual active sites on a transition metal doped β-Mo2C-CNF catalyst. Application of renewable technologies is on the rise especially in power generation but is still far from being a mainstream source of hydrogen and power.