Past and Present Research Systems on Green Chemistry

Biography

Biography: Kim Magrini

Abstract

NREL’s thermochemical biomass conversion research is focused on ex-situ catalytic fast pyrolysis as a potentially efficient and economical route to pyrolysis-based fuel precursors, fuels and chemicals. In this approach, biomass vapors are generated via fast pyrolysis (FP) and destabilizing vapor components (char, inorganics, tar aerosols) are removed by hot gas filtration with the conditioned vapors more amenable to catalytic upgrading via emerging and industrially available zeolites. We use a Davison circulating riser (DCR), a petroleum industry standard, for vapor phase upgrading while a close coupled pyrolyzer system produces consistent pyrolysis vapors as feed to the DCR. Concurrent upgrading catalyst development is focused on identifying and evaluating modifications to ZSM5-based catalysts that increase carbon content of the condensed product while also reducing catalyst coking and increasing deoxygenation activity. Catalyst screening for vapor upgrading showed marked differences in product composition with catalyst type while similar liquid product was obtained with both mixed hardwood and clean pine feedstocks using the same catalyst and process conditions. Ash, aerosols and char removal were additionally quantified for selected experiments. The work presented here will show 1) the impact on product composition from pure vapor upgrading with a suite of catalysts comprising unmodified, and P- and metal-modified zeolites, 2) comprehensive physical and chemical product composition, 3) the impact of catalyst acidity on vapor phase upgrading, and 4) ash and char retention on hot gas filters. Two liters of CFP oil were produced from a modified zeolite. Subsequent hydrotreating produced 48% gasoline and 37% diesel fuels. These results will be discussed and compared with other work conducted in riser systems to produce biomass derived hydrocarbon fuels.