Abstract: The synthesis of methanol from biomass-derived syngas is a complicated reaction system.The dependence of reaction heats and equilibrium constants of each reaction in the system on temperature were obtained.Biomass-derived syngas was simulated with the gas consisting of CO 21.5%, CO₂ 22.8%, H₂ 52.5%, and N₂ 3.2%.The equilibrium composition, carbon equilibrium conversion rate and methanol concentration were calculated at 473.15—553.15 K，3—6 MPa with the equilibrium constants methods.The computing results revealed that methanol was mainly produced from CO+H₂ in the system.Lower temperature and higher pressure favored the promotion of carbon equilibrium conversion rate and methanol concentration.Commercial catalyst C306 was used to verify the calculation result.Because the reaction was controlled by thermodynamics and kinetics, at 3 MPa carbon conversion rate reached the peak at 533.15 K and was close to the carbon equilibrium conversion rate.Space time yield (STY) of methanol and concentration of methanol in the liquid product increased with increasing pressure.

Key words: 生物质气, 甲醇, 平衡常数, 转化率

摘要： 由生物质气合成甲醇是一复杂反应系统，本文计算了其中各个反应的反应热和平衡常数与温度的关系.并以CO 21.5%、CO₂ 22.8%、H₂ 52.5%、N₂ 3.2%的气体模拟生物质气，用平衡常数法计算了在473.15～553.15 K、3～6 MPa下的平衡组成、碳的平衡转化率和所得甲醇的浓度.计算结果表明，这一体系中，主要是CO+H₂生成甲醇.低温和高压有利于提高碳的平衡转化率和甲醇的浓度.并用工业C306催化剂验证了上述规律的正确性.由于反应既受热力学控制，又受动力学控制，在3 MPa时碳的转化率在533.15 K时达到最大，接近平衡转化率.随压力升高，甲醇产率及液相产物中的浓度逐渐升高.

关键词: 生物质气, 甲醇, 平衡常数, 转化率