CO_(2)与绿氢合成甲醇的过程模拟及储能性能分析

Process simulation and energy storage performance analysis of methanol synthesis from CO_(2) and green hydrogen

文章模拟了CO_(2)与绿氢合成甲醇的过程,提出了CO_(2)储能密度指标,研究了多个参数对甲醇储能性能的影响。研究结果表明:系统能效和甲醇能量产率随着电解水效率、单程CO_(2)转化率、电解水压力和CO_(2)初始压力的升高而升高,随着甲醇合成压力的升高而降低;CO_(2)储能密度随以上参数的变化趋势与系统能效和甲醇能量产率相反;电解水效率和单程CO_(2)转化率是敏感关键的参数;在最优组合工况下,基于甲醇高位和低位热值的系统能效分别为68.0%和59.6%,CO_(2)储能密度为6.07 k W·h/kg,能量产率为0.108 kg/(k W·h),表明以CO_(2)为原料的电制甲醇的系统能效不够理想,但储能密度优势显著。

This paper studied the simulation of methanol synthesis from CO_(2) and green hydrogen,and proposed an indicator of the energy storage density of CO_2.Then influences of multiple variables on the performance indicators were analyzed.The results show that the systematic energy efficiency and energetic yield of methanol increase with the increase in the electrolysis efficiency,per pass CO_(2) conversion rate,electrolysis pressure,and initial CO_(2) pressure.However,these indicators decrease with the increase in the methanol synthesis pressure.The variations of the energy storage density of CO_(2) with these variables are opposite to the systematic energy efficiency and energetic yield.The electrolysis efficiency and per pass CO_(2) conversion rate are the sensitive and key variables of this process.Under the optimal conditions,the systematic energy efficiencies based on the higher and lower heating values are 68.0% and 59.6%,respectively,the energy storage density of CO_(2) is 6.07 kW·h/kg,and the energetic yield of methanol is 0.108 kg/(kW·h),indicating the power-to-methanol system using CO_(2) as feedstock is unsatisfactory in term of systematic energy efficiency,but has significant advantage in the energy storage density.