Progress on cleaner production of vinyl chloride monomers over non-mercury catalysts

Abstract

Polyvinyl chloride (PVC) has become the third most used plastic after polyethylene and polypropylene and the worldwide demand continues to increase. Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer (VCM), which is manufactured industrially via the dehydrochlorination of dichloroethane or the hydrochlorination of acetylene. Currently PVC production through the acetylene hydrochlorination method accounts for about 70% of the total PVC production capacity in China. However, the industrial production of VCM utilizes a mercuric chloride catalyst to promote the reaction of acetylene and hydrogen chloride. During the hydrochlorination, the highly toxic mercuric chloride tends to sublime, resulting in the deactivation of the catalyst and also in severe environmental pollution problems. Hence, for China, it is necessary to explore environmental friendly non-mercury catalysts for acetylene hydrochlorination as well as high efficiency novel reactors, with the aim of sustainable PVC production via the acetylene-based method. This paper presents a review of non-mercury heterogeneous and homogeneous catalysts as well as reactor designs, and recommends future work for developing cleaner processes to produce VCM over nonmercury catalysts with high activity and long stability.

Influence of chlorine coordination number on the catalytic mechanism of ruthenium chloride catalysts in the acetylene hydrochlorination reaction: a DFT study

“…At present, three methods, namely, balanced oxychlorination of ethylene, oxychlorination of ethane and calcium carbide acetylene method, are used to produce PVC. 1,2 In Chinese regions that are rich in coal, calcium carbide acetylene method is the dominant method. Currently used industrial catalyst for acetylene hydrochlorination is the activated-carbon supported mercuric chloride.…”

Activated Carbon Supported Mo-Ti-N Binary Transition Metal Nitride as Catalyst for Acetylene Hydrochlorination

“…However, its manufacturing process still faces an environmental issue, namely, in the synthesis of vinyl chloride monomer (VCM), which is the monomer of PVC, Hg used as the catalyst easily accumulates, which simultaneously brings about hazards to the environment. This problem has been the subject of heated discussion among scholars in recent years [1,2]. Some metals have already been found to replace Hg as a catalyst for the preparation of VCM.…”

The Preparation of Cu-g-C3N4/AC Catalyst for Acetylene Hydrochlorination

“…On the other hand, the catalyst cannot generally be reactivated after deactivation. To achieve the efficient and clean production of VCM, the development of new non-mercury catalyst must be urgently addressed [2].…”