摘要
对环氧乙烷和氨反应生成一乙醇胺(MEA)、二乙醇胺(DEA)和三乙醇胺(TEA)反应进行了研究,拟合实验数据,建立乙醇胺反应动力学模型,并采用模型预测氨的质量分数对反应停留时间和产物分布,以及氨与环氧乙烷物质的量之比对产物分布的影响。结果表明,一乙醇胺的反应活化能为61.52kJ/mol,指前因子与水浓度成二次函数关系,生成一乙醇胺、二乙醇胺和三乙醇胺反应的活化能相近。通过非线性最小二乘法回归得出二乙醇胺、三乙醇胺与一乙醇胺反应速率常数的比值,与水浓度成线性关系,且随水浓度的升高而降低。采用4阶龙格库塔法对得到的反应动力学方程进行积分,计算值与实验数据和工厂生产数据吻合较好。环氧乙烷完全反应所需反应管管长随氨的质量分数的增加先减小后增大;MEA比例随氨烷比的增加而提高,DEA比例随氨烷比的提高先提高后下降,TEA比例随氨烷比的提高而下降; MEA和DEA随氨的质量分数升高而降低,TEA比例随氨的质量分数的降低而增加。
The synthesis of mono-ethanolamine （MEA）, die-ethanolamine（DEA）, and tri-ethanolamine （TEA） from aqueous ammonia and ethylene oxide was studied. The kinetic model was built up by fitting experatimental data. The effect of concentration of ammonia on residence time and distribution of product and the effect of molar ratio of ammonia to ethylene oxide on distribution of product were predicted by the kinetic model. The results showed that the activation energy of producing MEA was 61.25 kJ/mol. The pre-exponential factor was quadratic function of water concentration. The activation energies of producing three ethanolamins were approximate. Reaction rate ratios of di-ethanolamine and tri-ethanolamine to mono-ethanolamine were obtained by using nonlinear least square regression. The relationship between reaction rate ratios of di-ethanolamine and tri-ethanolamine to mono-ethanolamine and water concentration was linear and the ratios decreased with the increase of water concentration. The proposed kinetic equations were integrated by using Runge-Kutta 4 tb-order method, and the predicted values agreed with the experimental and industrial production data well. With the increase of molar ratio of ammonia to ethylene oxide, the mass fraction of MEA in product increased, while the mass fraction of DEA first increased then decreased and the mass fraction of TEA decreased. With the increase of concentration of ammonia, the mass fraction of MEA and DEA first increased then decreased and mass fraction of TEA decreased.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2010年第4期315-321,共7页
Chemical Reaction Engineering and Technology
基金
青岛科技大学博士基金项目(0022061)
关键词
乙醇胺
反应动力学
氨
环氧乙烷
水
催化
ethanolamines
reaction kinetic
ammonia
ethylene oxide
water
catalysis
