Wanhua Chemical Group Co., Ltd.

Wanhua Chemical (ningbo) Co., Ltd.

Ningbo Wanhua Polyurethanes Co., Ltd.

Shuang Hu

Weiqi Hua

Jiansheng Ding

Yonghua Shang

Hao Chen

Deqiang Ma

Zhongying Chen

Wangshun Qi

Zilin Ni

Peicheng Luo

Xudong Wang

Zhanyu Zhao

Yong Hua Shang

Jingquan Hao

Zhiyuan Liu

The present invention discloses a method for intermittently producing 4,4'-diaminodicyclohexyl methane (HMDA) with a low amount of the trans-trans isomer thereof, which comprises: controlling the reaction process by stopping the reaction when, except for a solvent, the reaction solution comprises MDA of 0-5 wt % and HMDA of 1-20 wt %; and b) separating the reaction solution obtained from step a) by conventional means to obtain HMDA product with desired purity, and allowing the un-reacted material and intermediate product to be recycled to the reactor after being accumulated. The method of the present invention decreases the amount of the trans-trans isomer in HMDA, increases the yield of the reaction, and reduces the production cost. The present invention also provides a post treatment process of the reaction mixture.

Method for intermittently producing 4,4'-diaminodicyclohexylmethane with a low amount of the trans-trans isomer

The present invention relates to a hole-jetting type reactor and its applications, in particular to a process for the production of isocyanates by the phosgenation of aliphatic or aromatic diamines or triamines in the gas phase using this reactor. The present invention achieves a good mixing and reacting result of the gas-phase phosgenation reaction at a high temperature by improving the mixing of reactants in the reactor to reduce the possibility of forming swirls and eliminate negative pressure produced at a local jet area, which can finally reduce back-mixing and formation of solid by-products.

Hole jet reactor and a process for the preparation of an isocyanate using the reactor

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Yantai, China

Shuang Hu