Abstract: Thermo-catalytic decomposition of methane is an effective way to produce hydrogen-rich gas. The aim of this work was to study the microwave-assisted decomposition of methane over a char produced from sludge pyrolysis in a fixed-bed quartz-tube reactor. The influencing factors，including microwave power，atmospheric condition，particle size，and CH4 concentration，on the conversion of CH4 to H2 were investigated. CH4 conversion increased with increasing microwave power and decreasing particle sizes. Under different atmospheric conditions，the char exhibited different temperature rising characteristics. A higher average temperature was achieved in N2 or H2 atmosphere than in CH4 atmosphere. CH4 conversion increased with increasing CH4 concentration. SEM results showed that during CH4 decomposition reaction，carbon produced from CH4 decomposition would deposit on the surface of the catalyst. The spent char had lower surface area and larger pore diameter than those of fresh ones. This observation suggests that carbon deposition would prohibit the contact between active center of char and CH4，leading to deactivation of the char.

Key words: microwave-assisted, pyrolysis residue of sewage sludge, methane, decomposition, hydrogen

摘要： 采用石英管固定床反应器，在微波加热条件下分别研究了不同功率、气氛条件、粒径以及进口甲烷浓度对污泥残渣催化甲烷裂解反应的影响。结果表明，污泥残渣对甲烷裂解反应具有良好的催化活性；增加微波功率和减小粒径均能够有效提高甲烷转化率；污泥残渣在不同气氛条件下表现出不同的温度特性，其中氮气和氢气氛围内的温度明显高于甲烷气氛中，表明甲烷裂解过程中气氛条件是影响反应进行的因素之一；进口甲烷浓度越高，甲烷的转化率越大。反应前后污泥残渣电镜扫描分析及物性参数的比较表明，甲烷裂解后产生的大量积炭覆盖在污泥残渣表面，导致比表面积降低、平均孔径增大，表明污泥残渣活性降低的原因可能与积炭覆盖表面，导致甲烷分子无法与活性中心接触所致。

关键词: 微波, 污泥残渣, 甲烷, 裂解, 氢