Dehydrogenation method of hydrogen chloride raw material gas for acetylene method vinyl chloride synthesis

Abstract

The invention discloses a dehydrogenation method of hydrogen chloride raw material gas for acetylene method vinyl chloride synthesis, which comprises the following steps: 1) taking the hydrogen chloride raw material gas as a heating medium of a graphite heat exchanger, passing through a first-stage spray tower and a second-stage spray tower, and spraying with 95% ethanol for cooling; 2) spraying tower top gas serving as a cooling medium of a graphite heat exchanger and excessive O2 into a combustor for sufficient combustion, arranging a scorching copper net, and introducing the obtained exhaust gas into a cooling tower to obtain acid liquor; 3) adding the acid liquor and the mixed solution I into an azeotropic tower, dehydrating by a dryer, and introducing into a desorption tower to obtain pure HCl gas; and 4) passing the mixed liquid II through a fractionating tower to obtain 95% ethanol. According to the invention, 95% ethanol is used as a spraying absorption liquid of a hydrogen chloride raw material for the first time, and is dried after azeotropic, so that the problem of recycling of the hydrogen chloride absorption liquid-alcohol liquid is thoroughly solved; combustion and oxidation absorption of hydrogen are promoted through combustion-supporting of ethanol, hydrogen is thoroughly removed, and the problem of catalytic poisoning in subsequent vinyl chloride synthesis is avoided.

Description

technical field [0001] The invention relates to the technical field of processing vinyl chloride raw materials in the acetylene process, in particular to a method for dehydrogenating hydrogen chloride raw material gas used in the synthesis of vinyl chloride in the acetylene process. Background technique [0002] In the synthesis process of vinyl chloride by acetylene method, because it is necessary to ensure that no free chlorine is contained in the synthesized hydrogen chloride, the method of excessive hydrogen gas is usually adopted, resulting in a certain amount of hydrogen gas contained in the hydrogen chloride gas. In the existing noble metal catalytic process, the presence of hydrogen will lead to the problem of metal reduction and deactivation, and there is also the problem of catalytic hydrogenation of acetylene, resulting in catalyst deactivation and the formation of ethylene by-products. Therefore, it is desirable to remove hydrogen from hydrogen chloride in noble ...

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Problems solved by technology

However, according to the tests by the team of the present invention, although the obtained gas has a high purity, it still contains more hydrogen chloride in the alcohol liquid at the bottom of the tower. In industrial use, the amount of alcohol solvent is too large, and the water absorption of alcohol solvent is too strong, so it can be recycled. Still laborious and very expensive

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