OSU team developing Gas and Biomass to Liquids (GBTL) technology for production of liquid hydrocarbons
Researchers at Oklahoma State University are developing a novel natural Gas and Biomass to Liquids (GBTL) technology that will synergistically use biomass (e.g. switchgrass and eastern red cedar) and methane to produce liquid hydrocarbons that are compatible with existing infrastructure.
The work is led by Dr. Ajay Kumar in collaboration with Dr. Allen Apblett. The team uses a synergistic reaction system consisting of activation of methane and deoxygenation of pyrolysis-derived volatiles with metal-loaded HZSM-5 catalysts.
Bio-oil produced from biomass fast pyrolysis technology can be converted into hydrocarbons; however, this process is challenging due to the instability of bio-oil. The bio-oil must be de-oxygenated and additional hydrogen must be added to maximize hydrocarbon production. Traditional bio-oil upgrading usually involves extensive hydrotreating, which is energy intensive and costly.
We found that methane significantly improved the yield and selectivity for the formation of aromatic hydrocarbons in the bio-oil obtained from catalytic pyrolysis of biomass. Methane did not show effective improvement in the yield of aromatic hydrocarbons from cellulose and hemicellulose in the presence of molybdenum modified HZSM-5 catalysts, but significantly improved the aromatic hydrocarbons from lignin.—Ajay Kumar
Torrefaction pretreatment on switchgrass did not increase the aromatic hydrocarbon yield; the pretreatment process unfavorably altered the biomass composition by reducing cellulose content while increasing lignin content. The aromatic hydrocarbon yield decreased as the torrefaction temperature increased from 230 to 270 ˚C, Kumar said.
The project shows that direct co-conversion of biomass and methane with an appropriately designed catalyst leads to significant improvements in hydrocarbon yields.
The direct conversion of biomass pyrolysis volatiles and methane in a catalytic reactor is a unique approach that makes it possible to produce hydrocarbon fuels more efficiently than traditional pyrolysis-based refinery processes.—Ajay Kumar
Demonstration of the proof-of-concept through optimization and analysis of economic feasibility is underway. Dr. Kumar collaborated with two other OSU Professors from the Department of Agricultural Economics, Drs. Francis Epplin and Phil Kenkel, for this part of the study. Funding of this project was provided by the US Department of Agriculture-National Institute of Food and Agriculture (USDA-NIFA) through the South Central Sun Grant Program.
Zixu Yang, Ajay Kumar, Allen W. Apblett and Ahmed M. Moneeb (2017) “Co-Pyrolysis of torrefied biomass and methane over molybdenum modified bimetallic HZSM-5 catalyst for hydrocarbons production” Green Chemistry 19, 757-768 doi: 10.1039/C6GC02497A
Zixu Yang, Ajay Kumar, Allen Apblett (2016) “Integration of biomass catalytic pyrolysis and methane aromatization over Mo/HZSM-5 catalysts,” Journal of Analytical and Applied Pyrolysis, Volume 120, Pages 484-492 doi: 10.1016/j.jaap.2016.06.021