Wanhua Chemical Group Co., Ltd.

Wanhua Chemical (Ningbo) Co., Ltd.

Wanhua Chemical Co., Ltd.

Tonghe Li

Weiqi Hua

Yuan Li

Yonghua Shang

Qiang Li

Jing Li

Wenbin Li

Shuchang Sun

Jingxu Wang

Pengfei Wang

Jinping Han

A method for preparing an isocyanate in a gaseous phase by feeding, in the presence or absence of an inert gas, an amine-containing gas stream and a phosgene-containing gas stream into a reaction region, allowing the amine and the phosgene to contact in gaseous forms and undergo a phosgenation reaction in the reaction region, thus preparing the target isocyanate in a gaseous form in the reaction region. The phosgene-containing stream is subjected to preheating and warming before being fed into the reaction region, and the phosgene-containing stream comprises a substance A at a mass fraction of &#x3c;1% before being subjected to the preheating and warming up. Substance A is a NCO group-containing substance and/or an olefinic double bond-containing substance. The method reduces the formation of clogging matter in a heat exchanger and a vessel during the preheating and warming of the phosgene and during the reaction process.

Method for preparing isocyanate in gaseous phase

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Shandong, China

Tonghe Li