Catalytic cracking process for producing vinyl chloride by using active carbon as accelerant

A catalytic cracking and activated carbon technology, applied in the direction of dehydrohalogenation preparation, etc., can solve the problems of high energy consumption, short production cycle, easy coking of furnace tubes, etc., and achieve the effects of good selectivity, reduced operating costs, and stable life

Inactive Publication Date: 2012-11-07
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The traditional thermal cracking process of ethylene method needs high temperature of 500℃~600℃, and the conversion rate is only 50%~60%. There are problems such as high energy consumption, easy coking of the furnace tube, and short production cycle.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] After pretreatment, the coal-based activated carbon is dried in a constant temperature box at 100°C for 20 hours, and activated in a nitrogen atmosphere at 200°C for 20 hours to prepare a catalyst. The high-efficiency activated carbon catalyst is loaded into a fixed-bed reactor, and dichloroethane is introduced into a constant-flow pump with a space velocity of 670h-1 and an average reaction temperature of 250°C. After the reaction product is cooled to -15°C, the unreacted dichloroethane liquid in the liquid phase is separated first, and then the hydrogen chloride and liquid vinyl chloride liquid are mainly obtained through separation.

[0028] The single-pass conversion rate of dichloroethane is 7%, and the selectivity of vinyl chloride is over 99%.

[0029] The pretreatment method of coal-based activated carbon is as follows: Column-shaped activated carbon particles with a size of 40 mesh to 200 mesh are immersed in a nitric acid solution with a weight concentration of 10%...

Embodiment 2

[0031] After pretreatment, the coal-based activated carbon is dried in a constant temperature box at 90°C for 24 hours and activated in a nitrogen atmosphere at 250°C for 20 hours to prepare a catalyst. The high-efficiency activated carbon catalyst is loaded into the fixed-bed reactor, and dichloroethane is introduced into the constant flow pump, and the space velocity is 670h -1 , The average reaction temperature is 300°C, the reaction product is cooled to -20°C, and the unreacted dichloroethane liquid in the liquid phase is separated first, and then the hydrogen chloride and liquid vinyl chloride liquid are mainly obtained through separation.

[0032] The conversion rate of dichloroethane per pass is 22%, and the selectivity of vinyl chloride is over 97%.

[0033] The pretreatment method of coal-based activated carbon is as follows: Column-shaped activated carbon particles with a size of 40 mesh to 200 mesh are immersed in a nitric acid solution with a weight concentration of 30% ...

Embodiment 3

[0035] The coal-based activated carbon is pretreated and dried in a constant temperature box at 100°C for 24 hours and activated in a nitrogen atmosphere at 250°C for 20 hours to prepare a catalyst. The high-efficiency activated carbon catalyst is loaded into the fixed-bed reactor, and dichloroethane is introduced into the constant flow pump, and the space velocity is 670h -1 , The average reaction temperature is 350°C, and the reaction product is cooled to -20°C to separate the unreacted dichloroethane liquid in the liquid phase, and then mainly obtain hydrogen chloride and liquid vinyl chloride liquid through separation.

[0036] The conversion rate of dichloroethane per pass is 40%, and the selectivity of vinyl chloride is over 95%.

[0037] The method of coal-based activated carbon pretreatment is the same as in Example 1.

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PUM

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Abstract

The invention discloses a catalytic cracking process for producing vinyl chloride by using active carbon as an accelerant. The method comprises the following steps: introducing dichloroethane into a fixed bed reactor with activated carbon catalyst, and separating the reaction products to obtain products of hydrogen chloride and liquid vinyl chloride. A preparation method of the active carbon catalyst comprises the following steps: pretreating coaly activated carbon, shell activated carbon or coconut shell activated carbon, and drying at a temperature of 80-100 DEG C for 20h-24h; and then activating in an atmosphere with nitrogen as a protective gas at a temperature of 200-250 DEG C for 10-24 h, so as to obtain the activated carbon catalyst. The invention solves problems of low conversion rate, poor selectivity and high energy consumption of dichloroethane high-temperature pyrolysis, and greatly reduces operating costs on the subsequent recovery and rectification separation of dichloroethane.

Description

Technical field [0001] The invention relates to a method for preparing vinyl chloride, in particular to a method for preparing vinyl chloride by gas-phase catalytic cracking of dichloroethane. Background technique [0002] Vinyl chloride monomer (VCM) is a basic chemical raw material with a wide range of applications. The current industrial production methods of vinyl chloride monomer mainly include the acetylene method based on the coal chemical route and the ethylene method based on the petrochemical route. [0003] Acetylene method: first use quicklime and coke-based carbon raw materials to produce calcium carbide, and then use calcium carbide to react with water to produce acetylene. The addition reaction of acetylene and hydrogen chloride produces vinyl chloride. The reaction is: [0004] (1)CaO+3C→CaC 2 +CO [0005] (2)CaC 2 +H 2 O→Ca(OH) 2 +HC≡CH [0006] (3)HC≡CH+HCl→H 2 C≡CHCl [0007] The acetylene method has a simple process and a high conversion rate; the disadvantage is th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C21/06C07C17/25
Inventor 袁向前宋宏宇汪涛冯大龙钟瑛王越田宇江孝平吴同曹松
Owner EAST CHINA UNIV OF SCI & TECH
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