甲烷自热重整制氢热力学分析

Thermodynamically favorable operating conditions for production of hydrogen by methane autothermal reforming

为了优化甲烷自热重整制氢过程的反应条件,运用吉布斯自由能最小化方法对过程进行了热力学计算,研究了重整过程的反应温度、空碳比、水碳比对平衡组成的影响。模拟结果表明,适宜的水碳比为2.5~3.5,空碳比2.0~3.5,重整温度700℃~850℃,每摩尔甲烷生成2.17 mol^2.23 mol氢;以水碳比1.5为例,对不同空碳比下的组分的产生和转化的机理进行了分析。

Thermodynamic equilibrium analysis was performed on methane autothermal reforming to generate hydrogen by using the minimization of Gibbs free energy. Effects of operation parameters such as molar ratios of steam to methane （W/M）, air to methane （A/M） and adiabatic temperature on the reforming process were studied. Results showed that the optimal W/M is around 2.5 ～ 3.5 and molar oxygen to methane between 0.4 and 0.7. Thus the reforming temperature lays between 700 ℃ and 850 ℃ and H2 generating per mole methane is around 2.17 mol ～ 2.23 mol. Taking example for the 1.5 of W/M, possible formation or conversion mechanisms were deduced for different constitutes under different A/W through the simulating calculations. The thermodynarnic equilibrium calculations provide optimal operation parameters for methane autothermal reforming to generate hydrogen.