2,4-二氨基甲苯、尿素和甲醇合成甲苯-2,4-二氨基甲酸甲酯反应精馏过程研究  

Synthesis of Dimethyl Toluene-2,4-dicarbamate from 2,4-Toluene Diamine, Urea, and Methanol by Reaction Distillation

作　　者：孙帅[1] 粱宁 安华良[1] 赵新强[1] 王桂荣[1] 王延吉[1] 

机构地区：[1]河北工业大学绿色化工和高效节能河北省重点实验室,天津300130

出　　处：《高校化学工程学报》2014年第6期1236-1242,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(20976035);天津市自然科学基金(12JCYBJC12800);河北省应用基础研究计划重点基础研宄项目(12965642D)

摘　　要：甲苯-2,4-二氨基甲酸甲酯（TDC）是非光气合成甲苯二异氰酸酯（TDI）的重要中间体,2,4-二氨基甲苯（TDA）、尿素和甲醇一步合成TDC是一条绿色的反应工艺.今在反应精馏装置上研究了操作条件对非催化合成TDC反应的影响,得出适宜操作条件为：反应温度190℃,压力0.7～0.75 MPa,反应原料分为两股进料,其中一股进料为TDA、尿素和甲醇的混合液（nTDA∶nUrea∶nMeOH=1∶5∶80）,进料位置为反应段上方,速率为0.3 mL.min-1,另一股为纯甲醇,进料位置在反应段下方,速率为5.0 mL·min-1,塔顶回流比0.75,塔釜采出比90∶2.在该条件下,TDA的转化率62％,TDC的收率和选择性分别为36％和58％.与高压釜上所得结果相比,TDC的选择性提高了17％.Dimethyl toluene-2,4-dicarbamate （TDC） is a key intermediate for the manufacture of toluene diisocyanate （TDI） by non-phosgene method. One-step synthesis of TDC from 2,4-toluene diamine （TDA）, urea and methanol is a green reaction pathway. In this work, the effect of operation conditions on non-catalytic synthesis of TDC was investigated in a reaction distillation unit. The optimal temperature and pressure were found to be at 190℃ and in a range of 0.7-0.75 MPa, respectively. Under these conditions, a TDA conversion ratio of 62% can be achieved with one feed stream having a molar ratio of TDA：urea： methanol=1：5：80 and a rate of 0.3 mL.min-1 at the upper section of the reaction zone, another feed stream of methanol having a rate of 5 mL-min-1 at the lower section of the reaction zone, reflux ratio of 0.75 and reboiler recovery ratio of 90：2. A yield of 36% and a selectivity of 58% can be obtained for TDC, respectively. Compared with the results obtained by using a stainless steel autoclave, the selectivity of TDC is increased by 17%.

关 键 词：反应精馏 甲苯-2 4-二氨基甲酸甲酯 2 4-二氨基甲苯 尿素 甲醇 

分 类 号：TQ246.3[化学工程—有机化工]