Energy & Fuels 2009, 23, 3767–3772
3767
Bio-oil from Sawdust: Pyrolysis of Sawdust in a Fixed-Bed System E. Salehi, J. Abedi,* and T. Harding Chemical and Petroleum Engineering, UniVersity of Calgary, Calgary, Alberta T2N 1N4, Canada ReceiVed February 5, 2009. ReVised Manuscript ReceiVed June 8, 2009
Sawdust was pyrolyzed in a fixed-bed tubular reactor. The roles of the pyrolysis temperature, sweep gas flow rate, condensation temperature, and heating rate in the yields of the products were investigated. The obtained char, gas, and bio-oil yields ranged between 20 and 27, 36 and 45, and 33 and 45 wt %, respectively, at different pyrolysis conditions. According to the results obtained under the conditions of this study, the effects of the pyrolysis temperature, sweep gas flow rate, and heating rate on the yields are more significant than the effect of the condensation temperature. The chemical characteristics of the pyrolysis bio-oil and char obtained under optimal operational conditions were identified by elemental and calorific analyses. The bio-oil was analyzed using chromatographic and spectroscopic techniques.
1. Introduction The importance of renewable energy is ever increasing in order to satisfy environmental concerns over fossil fuel usage and its contribution to the greenhouse effect. Wood and other forms of biomass are some of the main renewable energy resources available.1 Biomass for producing energy has a special place among all other renewable energy sources, and it is estimated to contribute 10-14% to the world’s total energy supply.2-6 In contrast to other renewable sources that give heat and power, biomass represents the only source of liquid, solid, and gaseous fuels.1 Biomass can be used in a variety of ways to provide energy: biochemical (fermentation and anaerobic digestion) and thermochemical (combustion, gasification, and fast pyrolysis). Pyrolysis, a promising route for biomass utilization, has been widely used for converting biomass into fuel gases, liquids, and solids among the thermochemical methods because of its unique ability to produce liquid product compared to the other methods. Generally, there are two approaches for pyrolysis technology. One approach, referred to as conventional or traditional pyrolysis, is to maximize the yield of fuel gas at the preferred conditions of high temperature, low heating rate, and long gas resistance time or to enhance the char production at low temperature and low heating rate. Another approach, known as flash or fast pyrolysis, is to maximize the yield of liquid product at the processing conditions of (1) very high heating rate (>1000 °C/min) and heat transfer rate, (2) finely ground biomass feed * To whom correspondence should be addressed. Tel: 403-220-5594. E-mail:
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