A kind of process of calcium carbide producing pvc

Abstract

The invention discloses a process of using calcium carbide to produce PVC. The method is characterized by including: enabling calcium carbide slag slurry going out of an acetylene generator to overflow into a settling basin for settling, discharging bottom slag slurry for other use, and returning supernatant after being cooled into the acetylene generator to serve as reaction water for preparing acetylene from calcium carbide; returning wastewater used for dedusting acetylene gas and after being cooled into the acetylene generator to serve as reaction water for preparing acetylene from calcium carbide; enabling hot water going out of a converter shell layer and after exchanging heat through a heat exchanger to enter the upper portion of a steam absorption tower to absorb heat evaporated by a hot water tank and then automatically flow into the hot water tank, wherein the heat exchanger is used in other processes. By the process, effective utilization of water resources is realized fully, and environment pollution caused by wastewater discharge is avoided; conversion heat of chloroethylene is utilized reasonably, so that energy conservation and consumption reduction are realized.

Description

technical field [0001] The invention relates to a process for producing PVC from calcium carbide, which belongs to the technical field of polymer material science and engineering. Background technique [0002] Polyvinyl chloride, referred to as PVC, is a thermoplastic resin polymerized by vinyl chloride under the action of an initiator. It is a homopolymer of vinyl chloride. The physical appearance is white powder, non-toxic, odorless, and its chemical stability is very high. Has good plasticity. Polyvinyl chloride resin is the most widely used variety among the five general-purpose resins. It is widely used in many fields such as construction, automobiles, high-speed rail, ships, aerospace, and national defense. It plays a very important role in national economic and social development. There are currently two commonly used processes for preparing PVC, namely the calcium carbide acetylene method and the petroleum ethylene oxychlorination method. [0003] At present, the v...

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Problems solved by technology

In the preparation process of calcium carbide and water to generate acetylene, a large amount of carbide slag slurry will be produced. After mechanical drying, solid carbide slag can be used instead of lime for comprehensive utilization in road construction, etc. The supernatant part of the supernatant is alkaline High and containing chemical components such as sulfur and phosphorus, direct discharge will have a greater impact on the environment. At the same time, acetylene gas needs to go through processes such as dust removal, desulfurization, and purification before reacting with hydrogen chloride. These processes will generate a large amount of wastewater. The traditional process is It is directly discharged, and these wastewaters still contain sulfur, phosphorus and other substances that are extremely polluting to the environment. Therefore, the treatment of wastewater in traditional processes not only causes a lot of waste of water resources, but also seriously pollutes the environment.

At the same time, in the conversion and synthesis of vinyl chloride, acetylene and hydrogen chloride complete the synthesis of vinyl chloride in the converter, and the heat generated by the conversion is taken away by the hot water in the shell of the converter, and is vaporized after entering the hot water tank, which not only causes waste of heat At the same time, due to the high temperature of the incoming hot water, the hot water tank evaporates excessively, thus greatly increasing the water replenishment amount of the desalinated water in the hot water tank

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