Multifaceted effects of HZSM-5 (Proton-exchanged Zeolite Socony Mobil-5) on catalytic cracking of pinewood pyrolysis vapor in a two-stage fixed bed reactor

摘要

The pinewood was pyrolyzed in the first reactor at a heating rate of 10 degrees C min(-1) from room temperature to 700 degrees C, and the vapor was allowed to be cracked through the second reactor in a temperature range of 450-750 degrees C without and with HZSM-5. Attempts were made to determine a wide spectrum of gaseous and liquid products, as well as the mass and element partitions to gas, water, bio-oil, coke and char. HZSM-5 showed a preferential deoxygenation effect via the facilitated decarbonylation and decarboxylation with the inhibited dehydration at 550-600 degrees C. This catalyst also displayed a high selectivity for the formations of aromatic hydrocarbons and olefins by the promoted hydrogen transfer to these products at 550-600 degrees C. The bio-oil produced with HZSM-5 at 500-600 degrees C had the yields of 14.5-16.8%, the high heat values of 39.1-42.4 MJ kg(-1), and the energy recoveries of 33-35% (all dry biomass basis). (C) 2016 Elsevier Ltd. All rights reserved.