Production of a bio-gasoline by upgrading biomass flash pyrolysis liquids via hydrogen processing and catalytic cracking

A new procedure is proposed for the effective conversion of biomass flash pyrolysis liquids (BFPLs) to transportation fuels. First, the hydrotreatment sf a BFPL was studied, both in a thermal and in a catalytic mode. The thermal hydrogenation of BFPLs, a modification of the VEBA Combi Cracking process, is a low cost and low severity hydrogenation process without any operational problems. It has been proved to be the less sensitive hydrotreatment process with respect to BFPLs. The liquid product of this process cannot be used in the refinery without further upgrading. However, its heavy fraction, mixed with an aromatic hydrocarbonaceous feedstock (LCO) was considered as a potential FCC feedstock. The direct introduction of BFPLs in the FCC process was so far infeasible, because of their particularly high tendency to coke formation. Commercially available cracking catalysts were found to have an acceptable performance. Acceptable levels of coke on catalyst ( < 1 wt%) and gasoline yields (23-25 wt%) were obtained. Commercial ReUSY catalysts with a Re2O3 content of 0.6, characterized by a narrow pore size distribution (D = 36 Angstrom), were found to be more appropriate for this application. The obtained bio-gasoline meets the EU specifications and is characterized by a high RON value of 96. (C) 1998 Elsevier Science Ltd. Ail rights reserved.