262963 In-Situ Catalytic Upgrading of Pinewood Pyrolysis Vapors: Effect of Process Variables

Thursday, November 1, 2012: 4:55 PM
334 (Convention Center )
Vamshi Krishna Guda1, Hossein Toghiani1, Rebecca K. Toghiani1 and Charles U. Pittman Jr.2, (1)Dave C. Swalm School of Chemical Engineering, Mississippi State University, Mississippi State, MS, (2)Department of Chemistry, Mississippi State University, Mississippi State, MS

The main objective of this research effort was to produce high quality (i.e., deoxygenated, less acidic) bio-oil through in-situ catalytic modification (upgrading) of pine wood pyrolysis vapor. In-situ catalytic upgrading of pine wood pyrolysis vapors was performed using an integrated reactor set-up where fast pyrolysis of pine wood chips was carried out in an auger reactor followed by catalytic upgrading in a packed bed reactor mounted on the top of auger reactor. The pyrolysis process was carried out at 450 °C under a nitrogen atmosphere. The effects of process variables such as catalyst composition (γ-Al2O3, Si/Al, HY, HZSM-5), temperature and Weight Hourly Space Velocity (WHSV) were studied. The WHSV was varied by changing the biomass feed rate while holding the amount of catalyst constant. Compared to non-catalytic experiments, deoxygenated products increased over all the tested acid catalysts.  While Si/Al and γ-Al2O3 yielded higher amounts of liquid product, the zeolites (HZSM-5, HY) favored the formation of aromatic hydrocarbons and higher gaseous yield. The GC-MS results, elemental analysis, acid value and Karl-Fisher titration analysis showed that the liquid fuel was deoxygenated to the largest degree.  The largest concentrations of gasoline-range hydrocarbons were obtained using the HZSM5 catalyst at low WHSV (6 h-1) and moderate reaction temperatures (370-400 oC).  The occurrence of deoxygenation could be noticed through the reduced oxygen content in the form of H2O (significant increase in water yield), CO, CO2.

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