Catalytic upgrading of pyrolytic oils to fuel over different zeolites

The upgrading of wood pyrolysis oils produced in the ENEL fast-pyrolysis pl ant located in Bastardo, Italy, and in the Union Fenosa fast-pyrolysis plan t located in La Coruna, Spain, was studied by using HZSM-5 and H-Y zeolites in a fixed-bed laboratory scale reactor, at different temperatures and res idence times. The products of the catalytic upgrading were a liquid fractio n, char, coke, tar and gas. While the upgraded liquid obtained by using the HZSM-5 consisted of easily separable organic and aqueous layers, the liqui d obtained by using the HY zeolite consisted of a single phase in which the organic components were either dispersed or dissolved in the water. The ef fect of temperature, catalyst type and residence time in the reactor on the yields of the fractions obtained (oil, char, tar, coke, gas and aqueous fr action) and on the characteristics of the upgraded oils was examined. (C) 1 999 Elsevier Science Ltd. All rights reserved.