Journal of Analytical and Applied Pyrolysis 58–59 (2001) 491–501 Catalytic pyrolysis of biomass: influence of the catalyst pretreatment on gas yields L. Garcı ´a, M.L. Salvador, J. Arauzo, R. Bilbao * Department of Chemical and Enironmental Engineering, Uniersity of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain Received 7 April 2000; accepted 17 July 2000 Abstract This experimental study of biomass catalytic pyrolysis at low temperatures (650 and 700°C) was carried out in an installation based on the Waterloo Fast Pyrolysis Process (WFPP) technology, with a Ni/Al coprecipitated catalyst introduced into the reaction bed where the thermochemical decomposition of biomass took place. The influence of the calcination temperature (750 – 850°C) and the activation conditions (hydrogen flow rate) of the catalyst were analyzed. The calcination temperature significantly influences the properties and performance of the catalyst. For the two reaction temperatures, 650 and 700°C, and with the catalyst calcined at 850°C, higher H 2 and CO yields were obtained with the reduced catalyst (flow rate 3080 cm 3 (STP)/min; WHSV =0.826 h -1 ) than without reduction. However, the catalyst calcined at 750°C without reduction showed a good performance at the reaction temperature of 700°C. Considering the characterization and experimental results, it can be deduced that the catalyst calcined at 750°C is reduced by the reaction atmosphere forming a stable active phase, whereas for the catalyst calcined at 850°C more severe reduction conditions are necessary. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Pyrolysis; Biomass; Nickel-alumina catalyst; Catalysis www.elsevier.com/locate/jaap 1. Introduction Pyrolysis is an important process in energy recovery from biomass and also as a previous stage to other processes such as gasification. For about 20 years there has been considerable interest in liquid production by pyrolysis. Different technologies * Corresponding author. Tel.: +34-976-761150; fax: +34-976-762142. 0165-2370/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S0165-2370(00)00114-5