运行参数对甲醇重整制氢的热力学特性影响研究

Effect of Operating Parameters on the Thermodynamic Characteristics of Hydrogen Production from Methanol Reforming

针对以氢气为燃料的动力系统运行条件需求,构建了甲醇重整反应热力学和化学平衡反应体系,以某功率型号燃料电池/燃气轮机(Solid Oxide Fuel Cell/Gas Turbine,SOFC/GT)混合动力系统为研究对象,分析其额定工况、变工况运行时,温度、水碳比和压力对各重整产物分布及产氢率的影响。结果表明:额定运行工况下,重整产物中H2摩尔分数为49.8%,碳沉积现象消失;在变工况运行时温度对重整反应的热力学特性和化学平衡特性影响较大,当温度为912 K时产氢率达到峰值2.547,当温度为910 K时碳沉积现象消失,当温度高于912 K时不利于H2的产生;水碳比增加有利于提升产氢率,降低H2摩尔分数,减少积碳和CO的产生,当水碳比为2时产氢率达到2.48,当水碳比为1.25时碳沉积现象消失;压力对重整结果的影响相对较小,在温度为650-910 K时,降低压力有利于提高产氢率。

Aiming at the operating conditions of the power system with hydrogen as fuel,the thermodynamic and chemical equilibrium reaction systems for methanol reforming reaction were constructed.Taking a certain power solid oxide fuel cell/gas turbine(SOFC/GT)hybrid power system as the research object,the effects of its temperature,water-carbon ratio and pressure on the distribution of reformed products and hydrogen production rate under rated and variable operating conditions were analyzed.The results show that under the rated operating conditions of the power system,the reformed product H2 mole fraction in the reforming product accounts for 49.8%,and the carbon deposition phenomenon disappears.Under variable operating conditions,the temperature has a great impact on the thermodynamic and chemical equilibrium characteristics of the reforming reaction.When the temperature is 912 K,the hydrogen production rate reaches the peak of 2.547.When the temperature is 910 K,the carbon deposition phenomenon disappears.When the temperature is higher than 912 K,the thermodynamic environment is not conducive to the generation of H2.The increase in the water-carbon ratio is conducive to increase the hydrogen production rate,reduce the H2 mole fraction and the production of carbon and CO.When the water-carbon ratio is 2,the hydrogen production rate reaches 2.48,and when the water-carbon ratio is 1.25,the carbon deposition phenomenon disappears.The influence of pressure on the reforming result is relatively small.When the temperature is about 650-910 K,reducing the pressure is beneficial to increase the hydrogen production rate.