A brief introduction to the calcium carbide method

Calcium carbide method: use calcium carbide (calcium carbide CaC2) to generate acetylene (C2H2) in contact with water, synthesize acetylene and hydrogen chloride (HCl) to produce vinyl chloride monomer (CH2CHCl), and then polymerize vinyl chloride to generate polyvinyl chloride—[ CH CHCI]n—chemical reaction method.

The specific representative manufacturers are: Chiping Xinfa, Xinjiang Tianye, Xinjiang Zhongtai, Qingdao Haijing, etc.

Ethylene method: ethylene (C2H4) is extracted from petroleum, and chlorine gas is substituted with ethylene to obtain vinyl chloride monomer, which is then polymerized to generate polyvinyl chloride resin. Representative manufacturers are: Qilu Petrochemical, Shanghai Chlor-Alkali, etc.

The calcium carbide method is lower in cost than the petroleum method, but the vinyl chloride monomer produced by the calcium carbide method is slightly worse in quality than the petroleum method (which makes the petroleum method PVC slightly better than the calcium carbide method), and the calcium carbide method causes more pollution. However, the continuous rise of oil prices makes the living space and profit space of the calcium carbide method continue to expand. A considerable number of enterprises or investors are entering this industry, especially those in the western region. In terms of resources (calcium carbide is mostly produced by western enterprises, and coal mines are also abundant), energy consumption (low cost of water and electricity), and labor (low labor cost) etc. have advantages. In the past two years, millions of tons of calcium carbide PVC will be put into production in the west, and the industry competition will intensify. At the same time, with the adjustment of PVC export tax rebate (from 11% to 5%) and the state's restrictions on two high-level and one-funded enterprises (calcium carbide will be extremely nervous), the domestic market will be extremely tragic.

The emerging production process has not yet seen mass production. Although the current production process is technically mature, the investment is relatively large (generally several hundred million yuan), and the approval is difficult. It is also impossible to use waste plastic to produce. Waste PVC products can be re-plasticized to produce PVC products after being crushed and pulverized, but PVC resin powder cannot be produced.