Vol.4 No.6 (November 2014)
Hydrolysis of Toluene Diisocyanate Residue at Atmosphere Pressure for Toluene Diamine Recovery
Toluene diisocyanate (TDI) is an important organic compound, usually manufactured from toluene diamine (TDA) as the main raw material through phosgenation. The purification of the phos-genation products by distillation results in high molecular weight and insoluble waste materials in quite a large amount. This residue, often called TDI distillery residue, has been an environment threat and different strategies have been set up for their processing. The most common process currently employed is its hydrolysis under high pressure and high temperature, which also allows recovery of TDA in considerable amount. This paper provides a novel and simple process for the hydrolysis of TDI residue without need for high pressure, and toluene diamine, the important raw material in the production of TDI, was also recovered at the same time. In this process, TDI residue was dispersed in either ethylene glycol, triethylene tetramine or their mixture, along with sodium hydroxide as a catalyst. Heated to the refluxing temperature of the mixture, the hydrolysis was conducted by refluxing at temperature varied from 140˚C to 290˚C under atmosphere pressure. Experimental conditions, including the medium solvent and its amount, reflux time and tempera-ture as well as the amount of alkali solution for the hydrolysis, were studied, and the hydrolysis was optimized with regard to the yield of TDA. Under the optimized conditions, a TDA yield of 54.44% based on the residue mass was achieved. This work therefore presents a reliable and facile process for the hydrolysis of TDI residue. Based on the results, mechanism of the hydrolysis is proposed.
张春光 , 刘 骁 , 姜绪宝 , 朱晓丽 , 孔祥正 (2014) 甲苯二异氰酸酯蒸馏残渣常压水解回收甲苯二胺。 化学工程与技术， 4， 86-94. doi: 10.12677/HJCET.2014.46012
 任宇环 (2008) TDI生产技术及市场分析. 上海化工, 9, 34-37.
 于燕, 镇涛, 李家玲, 张香文 (2001) 异氰酸酯的绿色新工艺. 化工进展, 7, 18-21.
 马建军, 冯辉霞, 裴先武, 魏云 (2009) 甲苯二异氰酸酯生产工艺、现状及其应用. 应用化工, 3, 429-434.
 吴礼定 (2011) TDI的生产现状和研究进展. 中国氯碱, 10, 19-21.
 张雅萍, 庞雅薇, 刁望君 (1999) 甲苯二异氰酸酯的生产和应用. 氯碱工业, 1, 36-38.
 于飞 (2013) TDI的生产技术及市场现状. 山东化工, 1, 30-32.
 Resischl, A. (1982) Process for working up cross-linked isocyanate distillation residues containing urea groups and use of the products of the process as starting components for the pro-duction of synthetic resins. US Patent No. 4311800.
 钱伯章,朱建芳 (2012) 甲苯二异氰酸酯的国内外市场分析. 化学推进剂与高分子材料, 6, 86-90.
 Kober, E.H., Hamden and Schnabel, W.J. (1970) Toluene Diisocyanate process. US Patent No. 3449021.
 Goldstein, S.L. and Babiec, J.S. (1978) Process for preparing dihydroxytoluene. US Patent No. 4118586.
 Cooper, J.R. and Perkins, G.T. (1972) Separation of distillable isocyanates from their phosgenation masses. US Patent No. 3694323.
 李贵贤, 李晓明, 张义新, 滕志君, 毛丽萍, 范宗良 (2010) 一种回收TDI残渣中DEIP的方法. 中国专利: 101717335A.
 Nemoto, M. and Tokugawa, Y. (1976) Tar urethane composition. US Patent No. 4000099.
 Wolf, H.O. (1965) Preparation of polyamines by steam hydrolysis of polyisocyanate reaction products. US Patent No. 3225094.
 Van Horn, I.B. and Powers, E.L. (1967) Recovery of tolylenediamines. US Patent No. 3331876.
 Cassata, J.R. (1979) Process for toluene diamine recovery. US Patent No. 4137266.
 H.V.施瓦茨, M.莫勒, M.桑德, E.斯特罗福, R.勒特霍德, B.汉特尔, S.里克特, J.塞里 (2004) 甲苯二异氰酸酯合成的蒸馏残余物的处理. 中国专利: 1165520C.
 韩基道, 韩柱熙, 郑畅模, 申暎浩, 都承会, 韩基雨 (2008) 从甲苯二异氰酸酯制备过程排放的高沸点焦油残渣中回收甲苯二胺的方法. 中国专利: 100384811C.