Catalytic Cracking Of 1,2-dichloroethane To Vinyl Chloride

Polyvinylchloride(PVC) is one of the most widely used plastic in the world. PVC’s monomer, vinyl chloride monomers(VCM), can be commercially produced by the pyrolysis of 1, 2-dichloroethane(DCE) and by the hydrochlorination of acetylene on HgC l2 catalyst. Mercury is a potent toxin and the United Nations Environment Programme let through The MINAMATA CONVEN TION ON MERCURY in 2013 on reducing mercury emissions, convention request C hina`s PVC reduce mercury, mercury free. So the dichloroethane pyrolysis prepatation of VCM technology is of great significance.Now the pyrolysis of DC E is the most popular commercialized way to produce VCM. This process is run in temperature about 500 oC and gives a reasonable conversion of 50 % and a high selectivity to desired VCM of 98% on an industrial scale. However, there is a problem of coke formation which is believed to be caused partly from the pyrolysis of 1, 2-DCE itself via acetylene through its radical chain conversion. The cokes deposit on the reactor wall, transfer lines and heat-exchangers which leads to mass and heat transfer limitations and unprofitable pressure increase in reactor. This problem interrupts the long term industrial operation and requires a decoking treatment every two months by burning coke deposit. Therefore, it remains vital to develop active, selective and stable catalyst which can work in much lower temperatures and result less coke deposition.In this study we report a novel nitrogen-doped active carbon catalyst(AC-N) and its catalytic performance on the dehydrochlorination of 1, 2-dichloroethane. The conversion of 1, 2-dichloroethane on AC-N exceeds 100 % and the selectivity of vinyl chloride is over 99 % at a temperature of 300 oC, EDC LHSV 0.313 h-1. Stability tests reveal the good stable performance of AC-N over dehydrochlorination of 1, 2-dichloroethane. This novel N itrogen doped active carbon is a potential catalyst for the industrial dehydrochlorination of 1, 2-dichloroethane into vinyl chloride. Furthermore, 1,2-dichloroethane catalytic cracking reaction kinetics research showed that the surface reaction is the rate-controlling step.