Catalyst for preparing vinyl chloride by low-temperature dehydrochlorination of ethylene dichloride, preparation method and use

Abstract

The invention discloses a catalyst used in low-temperature removal of hydrogen chloride from dichloroethane for preparation of vinyl chloride, and a preparation method and application thereof. The preparation method comprises the following steps: (1) dissolving a quaternary phosphonium salt in a solvent to prepare a quaternary phosphonium salt solution, soaking a catalyst carrier in the quaternary phosphonium salt solution, maintaining the catalyst carrier at a constant temperature in a water bath with a temperature of 30 to 100 DEG C for 2 to 12 h and evaporating the solvent to dryness at 100 to 150 DEG C; and (2) impregnating the quaternary phosphonium salt-loaded carrier obtained in the step (1) with an aqueous solution of metal chloride by using an equivalent-volume impregnation method and carrying out drying. With the catalyst provided by the invention, pyrolysis temperature of dichloroethane is greatly reduced, so energy consumption is reduced, carbon formation and coking of a reactor are alleviated, and the service life of the catalyst is prolonged. In catalysis of removal of hydrogen chloride from dichloroethane for preparation of vinyl chloride, the pyrolysis conversion rate of dichloroethane is 49 to 99%, the selectivity of produced vinyl chloride is 99.5% or above, and the activity of the catalyst has no obvious change in a reaction having lasted for 180 h.

Description

technical field [0001] The invention relates to a preparation method and application of a catalyst used for low-temperature dehydrochlorination of dichloroethane to prepare vinyl chloride. It belongs to the preparation technology and application scope of catalysts for organic synthesis. Background technique [0002] With the development of the national economy, the improvement of people's living standards and the improvement of environmental protection awareness, the demand for PVC (polyvinyl chloride) is increasing. PVC is obtained by polymerization of VCM (vinyl chloride monomer). The production methods of VCM mainly include ethylene process, ethane process and acetylene process. Preparation of PVC by ethylene method, as a technologically mature process route, has always been the mainstream PVC production process in the world, especially in developed countries and countries rich in oil resources. The ethylene production process uses the petrochemical product ethylene as ...

AI Technical Summary

Problems solved by technology

[0006] The activity of the above two catalysts to catalyze the cracking and dehydrochlorination of dichloroethane is still low, especially at low temperature. Although the activity is high at high temperature, the catalyst life is difficult to guarantee.