Research On Nonmercuric Non-noble Metal Catalysts For Hydrochlorination Of Acetylene

Vinyle chloride monomer is used for synthesis of polyvinyl chloride (PVC). Atpresent, acetylene hydrochlorination and ethylene oxychlorination are the mainlysynthesis methods for vinyl chloride monomer. In China, coal resources are relativelyricher than crude oil. So vinyl chloride monomer products are produced mainly fromthe acetylene hydrochlorination process, in which activated carbon supported HgC12is used as main catalysts.The toxicity and volatility of mercury in the catalyst cousesserious pollution to the environment and also bad effects on the health ofmankind.The key of resolving the problem is the preparation of nonmercuric catalystfrom the view point of sustainable development.In this paper, non-noble metals were chosen as the active component to findways to solve this problem. The catalytic activities of different non-noble mental saltswere investigated and various influencing factors, such as pretreatment method of thesupport, active component contents, forms of metal salts, forms of precursor werealso analysized in this work. A non-noble catalyst with relatively high catalyticactivity for acetylene hydrochlorination was developed successfully and deactivationmechanism was investigated.The catalysts were prepared by incipient impregnation and characterized by fieldemission scanning electron microscope, transmission electron microscopy, X-raydiffraction, X-ray photoelectron spectroscopy, fourier transform infrared spectroscopy,X-ray fluorescence spectrometer, inductively coupled plasma and temperatureprogrammed reduction. The results indicate that the monocomponent copper chloridecatalysts are not favorable for the catalytic acetylene hydrochlorination reaction.Addition of second metals salts or third to copper chloride based catalyst were testsand did not give satisfactory results.The results showed that it can form composite saltfor bimetallic catalyst supported on carbon.With the aim to improve the catalytic performance, two-component catalysts ofCuCl2-Cu3(PO4)2/SAC were prepared and their activityes for acetylenehydrochlorination were investigated.The results show the CuCl2-Cu3(PO4)2/SACcatalyst with Cl:P:Cu=18:4:15has relatively high catalytic activity.Optimizedreaction conditions were obtained, feed volume ratio (nHC1/nC2H2)1.1, reaction temperature180℃, space velocity30h-1. In the optimized reaction conditions,CuCl2-Cu3(PO4)2/SAC(15wt%Cu, Cl:P:Cu=18:4:15) catalyst is tested for72h inwhich the acetylene conversion and vinyl chloride selectivity are over99%. Thelifepan of CuCl2-Cu3(PO4)2/SAC catalyst was tested under the optimized reactionconditions and possible deactivation mechanisms were proposed.