生物质发酵法制备甲烷存在甲烷收率低、CO2含量高等问题。本研究以纤维素为原料,在温和条件下采用水热催化转化的方法制备甲烷。对一系列催化剂进行了考察,发现Ru/C对该反应的催化活性最高。采用Ru/C催化剂进一步考察了一系列反应条件,结果表明,升高反应温度、延长反应时间、增加催化剂用量以及提高氢气初始压力对甲烷的生成具有促进作用。在1 MPa H2、220℃、12 h反应条件下,甲烷碳摩尔收率最高,达88%,反应过程中无CO2产生。采用TEM、BET、XRD和FT-IR等对催化剂进行了表征,结果表明,Ru/C催化剂的高催化活性可能与催化剂本身比表面积大、钌粒子颗粒小且分散均匀的特性有关。本研究采用的催化转化方法具有甲烷收率高、CO2排放量小（<5%）、反应条件更为温和等特点。
Preparation of methane by biomass fermentation is usually with problems of low CH4 yield and high CO2 content. Herein, cellulose was directly converted into CH4 by hydrothermal catalytic method under mild conditions. A series of catalysts for the conversion were studied, Ru/C was found to show the superior performance. The influence of reaction time, temperature, initial H2 pressure and Ru/C catalyst dosage on cellulose methanation in water were investigated in detail, and the maximum CH4 yield of 88.1% (no detectable CO2 formation) was produced at the condition of 1 MPa initial H2, 220°C, 12 h. TEM, BET, XRD and FT-IR characterizations showed that the highly activity of Ru/C catalyst was probably related to the large surface area and highly dispersed tiny Ru particles on the carbon surface. The method developed in this study presents obvious advantages according to the high CH4 yield, low CO2 emission (<5%) and mild reaction conditions.
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