Abstract: Gasification of cellulose, hemicellulose, lignin and their mixtures with K₂CO₃ as catalyst in supercritical water was conducted at 450℃ and 27.5MPa in a high-pressure batch autoclave.The experimental results showed that the gasification performance was in the order of cellulose>hemicellulose>lignin, which could be explained by the difference in molecular framework.The existence of lignin in the mixture could inhibit the generation of hydrogen and methane but had little effect on the generation of carbon dioxide.The inhibition effect weakened with decreasing amount of lignin.The reason might be associated with the hydrogenation of lignin in the course of hydrolysis.The interaction between cellulose and hemicellulose was so week that it could be ignored.In addition, equations to predict gas yield were developed.The results showed that the estimated values thus calculated agreed well with the values from actual gasification experiments and the deviation of prediction from experiment for hydrogen and methane was 5.77% and 4.74% respectively.

Key words: 生物质, 模型化合物, 氢气, 超临界水, 气化

摘要： 在间歇式高压反应釜中，以K2CO3为催化剂，在450℃，27.5MPa条件下对生物质的三种主要成分纤维素、半纤维素、木质素以及它们的混合物在超临界水中进行了气化制氢的实验研究，初步讨论了气化反应机理.研究结果表明：相同反应条件下，纤维素的气化效果最佳、半纤维素次之、木质素最差;混合物中木质素的存在会抑制H2和CH4的生成，但抑制作用随着其质量分数的减少而减弱.纤维素和半纤维素之间没有明显的相互作用.同时，获得了预测产气量与混合物中纤维素、半纤维素和木质素质量分数之间关系的关联式，实验证明，关联式预测精度在±10%以内.

关键词: 生物质, 模型化合物, 氢气, 超临界水, 气化