Production of Heavy Oils with High Caloric Values by Direct Liquefaction of Woody Biomass in Sub/Near-critical Water
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- 作者：Chunbao Xu ; Nimisha Lad
- 刊名：Energy & Fuels
- 出版年：2008
- 出版时间：January 2008
- 年：2008
- 卷：22
- 期：1
- 页码：635 - 642
- 全文大小：1366K
- 年卷期：v.22,no.1(January 2008)
- ISSN：1520-5029
文摘
Direct liquefaction of a woody biomass (Jack pine sawdust) in sub/near-critical water without and with catalysts (alkaline earth and iron ions) has been investigated at temperatures of 280–380 °C. Heavy oils with a high caloric value of 30–35 MJ/kg (much greater than that of the crude wood sample used) were obtained, along with water soluble oils with a caloric value of 19–25 MJ/kg. The yields of heavy oil and total oil products tended to maximize in the temperature range of 280–340 °C for all the liquefaction operations regardless of the presence of a catalyst or the type of catalyst. All the catalysts tested, i.e., Ca(OH)2, Ba(OH)2, and FeSO4, were found effective for enhancing the formation of heavy oil products at 280–340 °C, while they significantly promoted the formation of gas and water at >340 °C. The yield of heavy oil in the operation at 300 °C for 30 min was improved significantly from around 30% without catalyst to greater than 45% by Ba(OH)2. The maximum yield of total oil products reached 51% in the operation without catalyst, while it increased to about 65% with Ca(OH)2 at 300 °C. The GC/MS measurements for the heavy oil products revealed that the oils contain mainly carboxylic acids, phenolic compounds and derivatives, and long-chain alkanes.