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From a global perspective, the production of VC has basically been converted from a calcium carbide route to an oil route. The main reason for this process route is that it is conducive to large-scale production; the source of raw materials is easy, and the cost is much lower than that of calcium carbide; with the expansion of production scale, unit investment and product costs can be further reduced. China's oil (gas) resources are abundant, the petroleum industry is developing rapidly, and the petroleum route is also the development direction of China's PVC industry.
The main raw materials currently used for the production of VC are acetylene, ethylene, hydrogen chloride and oxygen (or air). Different combinations of them form different processes. According to their basic chemical reactions, they can be summarized as follows: CH-CH+HCI->CHz-CHCI Acetyl chloride Hydrogen chloride VC uses acetylene and hydrogen chloride as raw materials to synthesize vinyl chloride through a chemical reaction. This is called B-fast method. Before the 1950s, acetylene occurred from calcium carbide and was known as the acetylene method of calcium carbide. Now combined with petroleum raw materials, acetylene has been converted to high temperature cracking or partial oxidation production using various hydrocarbon compounds.
Jiuzhi Plastics Network
Talking about the production principle of polyvinyl chloride in China's plastic products network
In PVC production, the synthesis of monomer VC is the key. Its synthetic process route, according to the source of basic raw materials, can be divided into electric right route and oil route. The calcium carbide route uses calcium carbide as raw material, first hydrolyzes acetylene, then mixes acetylene and hydrogen chloride, and synthesizes VC through mercury chloride catalyst. This is the old method for producing monomer VC. It has the characteristics of simple equipment, simple process, low investment and small scale operation. However, there are large power consumption, high raw material cost, limited production scale due to safety problems, and coke with the steel industry, which will cause mercury pollution problems, and thus cannot meet the shortcomings of the development of PVC. Since the 1950s, it has rapidly developed into a petroleum-based process route. The calcium carbide acetylene method has gradually been eliminated, but most factories in China still use this method, and the petroleum oxychlorination method based on petroleum has just begun to develop on a large scale.