Wanhua Chemical Group Co., Ltd.

Weijia Wang

Weiqi Hua

Yuan Li

Xin Li

Lei Tang

Qingmei Jiang

Hao Chen

Congying Zhang

Jinhong Song

Zhenguo Liu

Hao Ding

Zhipeng Liu

Shan Gao

Disclosed is a method for preparing diamino-dicyclohexyl methane (HMDA) by hydrogenation of diamino-diphenyl methane (MDA). In the process, 4,4'-MDA used as the starting material is firstly hydrogenated to prepare 4,4&#x2032;-HMDA. When the activity of the catalyst is reduced, the feed is switched from 4,4&#x2032;-MDA to the mixture of 2,4&#x2032;-MDA and 4,4&#x2032;-MDA, and then when the conversion is stabilized, the feed is switched to 4,4&#x2032;-MDA again. The deactivated catalyst is activated on line by switching the feed to the mixture of 2,4&#x2032;-MDA and 4,4&#x2032;-MDA. 4,4&#x2032;-HMDA having the trans-trans isomer content of 16&#x2dc;24 wt % is produced, and the mixture of 2,4&#x2032;-HMDA and 4,4&#x2032;-HMDA is also produced, wherein the content of 2,4&#x2032;-HMDA in the mixture is 4&#x2dc;15 wt %.

Method for preparing diamino-dicyclohexyl methane

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Shandong, China

Weijia Wang