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Method for simultaneously preparing 1,1,1,2-tetrafluoroethane and difluoromethane

A technology of difluoromethane and tetrafluoroethane, applied in the field of preparation of hydrofluorocarbons (HFC), can solve the problems of high equipment investment, low conversion rate, complicated process, etc., and achieves good selectivity, small equipment investment, simple craftsmanship

Active Publication Date: 2015-04-15
ZHEJIANG QUHUA FLUOR CHEM +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The disadvantage is that the process is complex, the equipment investment is high, and because the temperature of the first reactor is lower than that of other reactors, the conversion rate of 1,1,1-trifluoro-2-chloroethane returned to the first reactor is low , so a large amount of 1,1,1-trifluoro-2-chloroethane circulates in the system, and the energy consumption is relatively high

Method used

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  • Method for simultaneously preparing 1,1,1,2-tetrafluoroethane and difluoromethane
  • Method for simultaneously preparing 1,1,1,2-tetrafluoroethane and difluoromethane
  • Method for simultaneously preparing 1,1,1,2-tetrafluoroethane and difluoromethane

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Embodiment 1～26

[0044] Load 150ml of compressed chromium-based catalyst into the reactor, raise the temperature to 350°C, bubbling in nitrogen for drying for 6 hours, and then lower the temperature to 260°C, passing in anhydrous hydrogen fluoride diluted with nitrogen for activation treatment. Anhydrous hydrogen fluoride has obvious hot spots in the reactor bed. The hot spot in the catalyst bed should not exceed 380°C by controlling the amount of nitrogen. After 4 hours of activation, the reactor temperature is raised to 350°C, and the nitrogen is turned off for activation. No more water vapor overflows from the outlet, the catalyst activation is completed, and the entire activation process takes 48 hours.

[0045] Adjust the temperature of the reactor to the reaction temperature, mix HCC-30, HCFC-133a and anhydrous hydrogen fluoride and pass it into the vaporizer. After vaporizing to slightly lower than the reactor temperature, enter the reactor for reaction. Adjust the reaction temperature, pre...

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Abstract

The invention discloses a method for simultaneously preparing 1,1,1,2-tetrafluoroethane (HFC-134a) and difluoromethane (HFC-32). 1,1,1,2-tetrafluoroethane and difluoromethane are simultaneously prepared through the gas-phase fluorination catalysis of a one-step reaction of raw materials comprising 1,1,1-trifluoro-2-chloroethane (HCFC-133a), dichloromethane (HCC-30) and anhydrous hydrogen fluoride (AHF). The method has the advantages of simple process, high yield, good selectivity, small equipment investment and low energy consumption.

Description

Technical field [0001] The present invention relates to a preparation method of hydrofluorocarbon (HFC). Specifically, it relates to a method for simultaneously preparing 1,1,1,2-tetrafluoroethane and difluoromethane. Background technique [0002] Difluoromethane has an ODP value of 0 and a GWP value of 0.12. It has good environmental protection performance. It is generally mixed with other HFC products according to different component contents to form R407, R410 and other mixed working fluids. [0003] There are two production methods for difluoromethane industry: [0004] 1. In the presence of an antimony-based catalyst, liquid phase fluorination with HF and dichloromethane. [0005] 2. In the presence of a chromium-based catalyst, gas phase fluorination with HF and dichloromethane. [0006] Most of the prior art industrial equipment adopts the process route of liquid phase fluorination, which has disadvantages such as equipment corrosion. Gas phase fluorination causes high energy c...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C19/08C07C17/20
Inventor 张彦雷俊贺辉龙白忠诚
Owner ZHEJIANG QUHUA FLUOR CHEM