碱法合成甲醇钠的热力学分析  

Thermodynamic analysis for synthesizing sodium methoxide by sodium hydroxide method

作　　者：熊孟[1] 王成习[1] 

机构地区：[1]浙江大学化学工程与生物工程学系,浙江杭州310027

出　　处：《化学工程》2014年第10期45-49,共5页Chemical Engineering(China)

摘　　要：氢氧化钠溶解在甲醇中与甲醇反应是制取甲醇钠的主要方法,文中针对该液相反应建立热力学循环,计算了298 K下反应的标准摩尔吉布斯自由能变和标准摩尔焓变,将范特霍夫方程积分后得到化学平衡常数随温度的变化关系式。计算结果表明:该反应的标准摩尔吉布斯自由能变略大于0,说明反应在常温下难以自发进行,需要不断移出生成的水来提高反应转化率;反应微放热,化学平衡常数随温度升高将变小,得到的化学平衡常数与温度的关系式与文献报道的实验结果基本一致,可为工业模拟提供理论计算依据。根据化学平衡常数关系式和汽液平衡模型对生产过程进行分析计算,获得了较适宜的反应温度范围。The reaction of sodium hydroxide with methanol is the main method to obtain sodium methoxide. The thermodynamic cycles were built to calculate the standard molar Gibbs free energy change and enthalpy change at 298 K, and the relationship between chemical equilibrium constant and temperature was obtained by integrating Van＇t Hoff equation. The results show that the reaction is reversible and exothermic, the chemical equilibrium constant decreases with temperature rise, and it is needed to move water out to advance reaction towards synthesis of sodium methoxide; the relationship between the chemical equilibrium constant and temperature is in agreement with the experimental results in literature, which can provide the important data in the modeling synthesis process of sodium methoxide. Based on the chemical equilibrium constant equation and vapor-liquid equilibrium model, the industrial process was analyzed and calculated, and the optimum temperature range for reaction was determined.

关 键 词：氢氧化钠 甲醇钠 热力学分析 

分 类 号：TQ261.1[化学工程—有机化工]