Method for preparing low-mercury catalyst by employing high-iodine-value active carbon

Abstract

A provided method for preparing low-mercury catalyst by employing high-iodine-value active carbon comprises processing of active carbon and gas-phase adsorption. The gas-phase adsorption step comprises heating and gasifying high-purity mercuric chloride, so as to enable the gas-phase mercuric chloride to enter an adsorption bed loaded with active carbon, controlling the pressure to be 0.6 MPa, the temperature to be 540 DEG C and the flowvelocity to be 1000 m<3>/h. The prepared low-mercury catalyst contains, in percent by weight, 4.07% of mercuric chloride, 3% of zinc chloride, 2% of manganese chloride, 2% of tetraamminepalladium(II) dichloride, 1% of tetrabutyl ammonium chloride, 1% of potassium tetranitroplatinate(II), and 0.16% of water. The low-mercury catalyst possesses the mechanical strength of 99.1%, the granularity of 3- 6mm (99.3%), the bulk density of 485 g/L, and the mercuric chloride ignition loss of 0.28%. The catalyst does not cause mercury sublimation phenomenon at normal temperature, is high in catalytic activity, low in unit consumption, long in service life and less in usage amount.

Description

technical field [0001] The invention relates to a method for preparing a low-mercury catalyst by using activated carbon with high iodine value, belonging to the technical field of fine chemistry. Background technique [0002] Domestic enterprises use hydrogen chloride gas and acetylene gas for addition reaction to synthesize vinyl chloride. The catalyst is usually prepared by the following method: use activated carbon as a carrier, and under the condition of 85-90 ° C, the activated carbon is impregnated in mercuric chloride aqueous solution for 8-24 Hours, after absorbing mercuric chloride by physical adsorption, and then drying to make the water content in the activated carbon less than 0.3%, and containing 4-6.5% mercuric chloride, the low-mercury catalyst is prepared. [0003] Patent CN02154466.2 introduces an environment-friendly mercury catalyst and its production process. The catalyst uses zeolite or molecular sieve as a carrier and is made by exchanging mercury ions ...

AI Technical Summary

Problems solved by technology

[0005] (1) High mercury content, resource consumption;

[0006] (2) Mercury sublimation loss is fast;

[0007] (3) Low cata...