Effect of Torrefaction on Bio-oil Upgrading over HZSM-5. Part 1: Product Yield, Product Quality, and Catalyst Effectiveness for Benzene, Toluene, Ethylbenzene, and Xylene Production

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• 作者：Roger N. Hilten ; Richard A. Speir ; James R. Kastner ; Sudhagar Mani ; K. C. Das
• 刊名：Energy & Fuels
• 出版年：2013
• 出版时间：February 21, 2013
• 年：2013
• 卷：27
• 期：2
• 页码：830-843
• 全文大小：602K
• 年卷期：v.27,no.2(February 21, 2013)
• ISSN：1520-5029

文摘

A three-step bio-oil production process involving torrefaction pretreatment (at 225, 250, or 275 掳C with a 20 min hold time), pyrolysis (at 500 掳C with two heating rates), and secondary catalytic processing over HZSM-5 (at 400, 450, or 500 掳C) was studied to determine process effects, particularly of torrefaction, on the yield of liquid and aromatic hydrocarbons and the quality of upgraded bio-oil. When bio-oils derived from torrefied biomass were catalytically cracked, average yields (%, w/w of feed) of reactor char (100% reduction), catalyst coke (21.4%), and catalyst tar (8.1%) were significantly reduced relative to the best-case conditions using non-torrefied feedstock. The reduction in coke (%, w/w of feed) as a result of torrefaction was 28.5% relative to the respective control for slow-pyrolysis bio-oil upgrading and 34.9% for fast-pyrolysis bio-oil upgrading. The concentration of aromatic product (benzene, toluene, ethylbenzene, and xylene, i.e., BTEX) was highest at 95 g L^鈥? for upgraded (at 500 掳C) fast-pyrolysis bio-oil derived from biomass torrefied at 275 掳C. Catalyst effectiveness for BTEX production significantly increased with increased torrefaction and catalytic cracking temperatures.