Environmental-protection mercury catalyst and producing process thereof

Abstract

An environment protection type Hg catalyst is prepared from the carrier (porous spherical zeolite particle or molecular sieve) and Hg ions through ion exchange between Hg ions and Na ions in said carrier. Its advantages are easy exchange of new catalyst without maintenance, high thermal stability of Hg ions, high catalytic power, high strength and no environmental pollution.

Description

technical field [0001] The present invention relates to a special catalyst for producing polyvinyl chloride resin by acetylene method and its production process, especially a mercury catalyst for the addition reaction of hydrogen chloride gas and acetylene gas, an intermediate product before polyvinyl chloride polymerization, to form vinyl chloride and its production process. Background technique [0002] The mercury catalysts currently used in domestic production, commonly known as "mercury catalysts", all use columnar high-quality activated carbon of Φ3.5-4mm and L6-9mm as the carrier, and the activated carbon is impregnated in mercury chloride under the condition of 85-90°C. 8 to 24 hours in aqueous solution, after absorbing mercuric chloride by physical adsorption, and then drying to make the water content in activated carbon less than 0.3%, this kind of mercury catalyst has the following disadvantages: 1. Replace the new catalyst in production I...

AI Technical Summary

Problems solved by technology

[0002] The mercury catalysts currently used in domestic production, commonly known as "mercury catalysts", all use columnar high-quality activated carbon of Φ3.5-4mm and L6-9mm as the carrier, and the activated carbon is impregnated in mercury chloride under the condition of 85-90°C. 8 to 24 hours in aqueous solution, after absorbing mercuric chloride by physical adsorption, and then drying to make the water content in activated carbon less than 0.3%, this kind of mercury catalyst has the following disadvantages: 1. Replace the new catalyst in production It must be maintained for 7 to 20 days afterward, which affects production; 2. Since mercury ions are physically adsorbed on the inner wall of activated carbon micropores, the thermal stability is poor, the sublimation loss is fast, and the catalytic ability decays quickly. Generally, it takes only 1 ton of vinyl chloride to produce It takes 1.4-1.7Kg of mercury catalyst. In a 2.5-ton system reactor, the total catalytic time of the two reactors is only 7000 hours; 3. Due to the sublimation of mercury during production, some mercury elements enter with the reaction gas Air pollutes the environment and enters the product and causes harm to the product; 4. The activated carbon carrier has low mechanical strength and is easy to pulverize. Generally, it must be screened and poured after about 3300-3500 hours of use, which not only increases the workload, but also increases the labor intensity of the workers. , but also delay the normal production time