甲醛+1,3,5-三聚甲醛+硫酸+水体系汽液相平衡实验和理论研究

Experimental and theoretical studies on vapor liquid equilibrium for formaldehyde + 1,3,5-trioxane + sulphuric acid + water system

工业上利用甲醛水溶液在硫酸催化下的反应精馏工艺生产1,3,5-三聚甲醛,因此,1,3,5-三聚甲醛生产工艺的优化和新型催化剂的开发受到了广泛关注。这需建立反应体系的汽-液相平衡模型,研究1,3,5-三聚甲醛合成过程中催化剂可能发挥的多重作用。为此,测定了(甲醛+1,3,5-三聚甲醛+硫酸+水)体系的汽-液相平衡数据,采用扩展型UNIFAC模型对汽-液相平衡数据进行了关联,确定了模型参数,并对该体系进行了系统的计算,揭示了硫酸催化剂在该反应精馏工艺中的三重作用。上述成果对优化1,3,5-三聚甲醛生产工艺和开发1,3,5-三聚甲醛新型催化剂具有重要意义。

1,3,5-Trioxane is industrially produced from aqueous formaldehyde solutions through reaction distillation catalyzed by sulfuric acid.Optimizing industrial process of the synthesis and developing new catalysts have attracted extensive attention.It is necessary to establish a vapor-liquid equilibrium model of the reaction system and reveal the multiple functions that the catalyst may play in the synthesis of 1,3,5-trioxane.For this reason,experimental data for the vapor-liquid equilibrium of(formaldehyde+1,3,5-trioxane+H2SO4+water)system are measured.The extended UNIFAC model is used for correlating the vapor-liquid equilibrium data,and the model parameters are determined,whereby systematic calculation is made.The results show that the sulfuric acid catalyst has triple functions in the reaction distillation process.The above results are of great significance for optimizing the production process of 1,3,5-trioxane and developing new catalysts.