Integration of biomass feed stocks into petroleum refinery operations is an important step towards energy independence, growth of the bio-economy, and proper management of the global carbon cycle. Successful deployment of biomass technologies at the commercial scale requires rigorous investigation of numerous process variables that are only feasible at smaller scales. W.R. Grace developed the Davison Circulating Riser (DCR) to match the conditions of a commercial FCC unit in the laboratory. In particular, it is widely used to develop and test new FCC methods and catalysts for the petroleum industry, so we developed a front-end pyrolyzer to deliver fast pyrolysis vapors to a DCR Mark IV to explore biofuel integration into petroleum refinery operations. Our hypothesis is that fresh vapors will contain fewer oligomers and thus be more amenable to upgrading when compared to re-volatilized pyrolysis oil. In this work, we investigated the impact of fast pyrolysis conditions on the efficiency, oxygen reduction, and hydrocarbon yield of the upgrading process. The fast pyrolysis of biomass was carried out in a 2” fluidized bed reactor for 1.5s at 500 C and 37 psia, employing nitrogen as the primary fluidization gas in a sand bed. Upgrading in the riser was nominally 1s, and the reactor was operated adiabatically at 550 C and 32 psia. First, the impact of hardwood vs. softwood was tested at a 0.5 biomass to nitrogen ratio (mixed hardwoods and clean loblolly pine) over a metal-modified ZSM5-based catalyst. Second, the concentration of pyrolysis vapor in nitrogen was increased to determine the role of vapor density on the upgrading process. The third area of investigation involved the addition of a catalytic hot gas filter (300-425 C) to remove select oxygenates from the vapor before proportioning the stream between the quench system and the DCR riser (metered, 0.5-1.5 kg/hr). Average yields from the pyrolyzer system showed ~65 wt% liquid, ~18 wt% gas, and ~18 wt% char. Pyrolysis oils had a density of 1.12 g/mL. NREL’s unique molecular beam mass spectrometry (MBMS) system was employed to provide real time analysis of the vapor stream entering the DCR to ensure the fast pyrolysis conditions were consistent as possible and that cracking to light gases (CO, CO<sub>2</sub>, and CH<sub>4</sub>) were minimized. Primary oxygenates in the stream were typical for fast pyrolysis and were attributed to guaiacol (124 amu) and other methoxyphenols, sugars, furans, and acetic acid.

Ex-situ catalytic fast pyrolysis in a DCR – Effect of pyrolysis conditions

253rd National Meeting (2017)

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