千瓦级 PEMFC 甲醇水蒸气重整制氢过程热力学模拟

摘要

The thermodynamic simulation analysis for methanol steam reforming hydrogen production system of kilowatt proton exchange membrane fuel cell was researched by Aspen Plus software.The influences of water to methanol mole ratio (0.8~1.6),reaction temperature (140~400 ℃),and pressure (101.325~506.625 kPa)on methanol steam reforming process were investigated.The results show that the methanol equilibrium conversion and CO mole fraction increase when the temperature is raised,while the H 2 mole fraction decreases at the same time.The equilibrium conversion of methanol decreases with pressure increasing,but the pressure has little effect on the mole fraction of H 2 and CO.The equilibrium conversion of methanol is improved with the water to methanol mole ratio raising.However,a large number of water vapor will increase the load of the system and lower the thermal efficiency.Therefore,the appropriate range of water to methanol mole ratio is between 1.2 and 1.4.It can be found that H 2 mole fraction is 64.27% and CO content is below 10 -5 ultimately through simulation of the hydrogen source system,which can provide hydrogen source for kilowatt proton exchange membrane fuel cell.%运用 Aspen Plus 软件对千瓦级质子交换膜燃料电池甲醇水蒸气重整制氢系统进行热力学模拟分析,考察不同水醇物质的量比(0.8~1.6)、反应温度(140~400℃)及压力(101.325~506.625 kPa)对甲醇水蒸气重整过程的影响。结果表明,升高反应温度可以提高甲醇平衡转化率和 CO 摩尔分数,但会降低重整气中 H 2摩尔分数；增大压力会降低甲醇平衡转化率,但对 H 2和 CO 摩尔分数的影响较小；增加水醇物质的量比 n (W)/n (M),甲醇平衡转化率增大,但大量水蒸气的使用会增加系统的负荷,降低热效率,所以合适的 n (W)/n (M)为1.2~1.4；通过对整个氢源系统的模拟发现,经甲醇水蒸气重整、水汽变化和选择性氧化后,出口气中 H 2摩尔分数为64.27%,CO 摩尔分数小于10-5,可为千瓦级质子交换膜燃料电池提供氢源。