Liquid Biofuels by Highly Efficient Liquefaction of Woody Biomass

与石油相比，木质生物质资源体积大，难以处理、运输和储存。因此，液化为超临界乙醇深度利用它们提供了充足的机会。由于酒精本身是一种很好的燃料，所以在酒精中得到的液体产品可以直接用作液体燃料。此外，通过使用生物酒精液化木材，可以100%产生生物质衍生的液体燃料。以甲醇为生物醇，乙醇、正丙醇、正丁醇、正辛醇和正庚醇为生物醇，在不同压力、350℃的条件下，纤维素、半纤维素和木质素三种木材组分均能被有效地分解。此外，烷基链较长的醇，如正辛醇，液化速度更快，仅在3分钟内就能液化约95%的木材。在较短的反应时间内，可以得到高相对分子质量的产物(分子量约为10,000-30,000)。此外，还可以通过改变醇的种类和/或反应条件来调节产物的分子量分布。这些结果表明，超临界乙醇处理可以将木质生物质转化为生物燃料，并通过高能量效率转化为复杂的可生物降解材料。为了开发适用于木材制备生物燃料的技术，需要验证其对各种醇溶部分的可行性，特别是对正辛醇可溶部分的可行性。因此，对它们的着火能力和其他物理性质，如动力学粘度和倾点进行了研究。

Compared to petroleum, woody biomass resources are bulky and difficult to handle, transport and store. Therefore, liquefaction offers ample opportunities for their advanced utilization by supercritical alcohol treatment. The obtained liquid products in alcohol can he used directly as liquid fuel because alcohol itself is a good fuel. In addition, by using bioalcohol to liquefy wood, 100% biomass-derived liquid fuels can be created. As bioalcohols, not only methanol but also ethanol, 1-propanol, 1-butanol, 1-octanol and 1-decanol were selected and, consequently, under the condition of 350℃ with various pressures, all three wood components, cellulose, hemicelluloses and lignin, were decomposed efficiently in all alcohols. Moreover, alcohols with a longer alkyl chain such as 1-octanol exhibited faster liquefaction with about 95% of the entire wood only in a 3 min treatment. In this short reaction time, high molecular weight products (about 10,000-30,000 in molecular weight) could be obtained in liquid form. In addition, the molecular weight distribution of the products could be regulated by changing the kind of alcohol and/or reaction conditions. These results imply that the supercritical alcohol treatment can convert woody biomass into biofuels and also into sophisticated biodegradable material by means of high energy efficiency.For the development of a technology applicable for making biofuel from wood, its feasibility needs to be demonstrated for the various alcohol-soluble portions, especially for the 1-octanol-soluble portion. Therefore, an investigation into their ability to ignite and other physical properties such as kinetic viscosity and pour point was made.