Method for preparing tetrafluoroethane by virtue of trichloroethylene

A technology for trichloroethylene and tetrafluoroethane, which is applied in the field of preparing tetrafluoroethane from trichloroethylene, can solve the problems of low total yield of HFC-134a, strong corrosiveness of the reaction medium, inapplicability, etc., so as to reduce the reaction heat effect. , the effect of delaying the carbonization rate and improving the selectivity

Active Publication Date: 2017-10-20
ZHEJIANG SANMEI CHEM IND
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Problems solved by technology

[0003] The method that tetrafluoroethane is produced at present mainly contains liquid-phase method and gas-phase method, but there is obvious shortcoming in liquid-phase method: the one, reaction is carried out in autoclave, especially second-step reaction, owing to require higher reaction temperature and pressure, the reaction medium is highly corrosive, the waste catalyst pollutes the environment, and is not suitable for continuous industrial production; the second is that the conversion rate of TCE and HCFC-133a is not high, and the total yield of HFC-134a is low
Both the liquid phase method and the gas phase method will produce the olefin impurity HCFC-1122, which has high toxicity and will form azeotropic olefin impurities with HFC-134a, which will cause separation difficulties

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  • Method for preparing tetrafluoroethane by virtue of trichloroethylene
  • Method for preparing tetrafluoroethane by virtue of trichloroethylene
  • Method for preparing tetrafluoroethane by virtue of trichloroethylene

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Embodiment Construction

[0028] Such as Figure 1 to Figure 3 Shown, for a kind of trichlorethylene of the present invention prepares the method for tetrafluoroethane, comprises the steps:

[0029](a) Mixing preheating: Pre-activation is carried out by passing a mixed gas of hydrogen fluoride and nitrogen into the first reactor 1 and the second reactor 2 equipped with alumina, the activation temperature is 30-40°C, and the activation time is 1 ~2h, the flow rate of the mixed gas of hydrogen fluoride and nitrogen is 100-120mL / min, and the catalyst aluminum fluoride is generated through the activation reaction of hydrogen fluoride and aluminum oxide. Since the activation reaction of the catalyst is a strong exothermic process, the pore structure of the catalyst, The specific surface area and crystal phase composition change, and the reaction is carried out under the condition of diluting hydrogen fluoride with nitrogen gas, which can improve the activity of the catalyst, and is beneficial to improve the...

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Abstract

The invention discloses a method for preparing tetrafluoroethane by virtue of trichloroethylene. The method comprises the following steps: (a) mixing, and carrying out preheating; (b) carrying out circular reaction; (c) absorbing tail gas; (d) carrying out extractive distillation; and (e) purifying a product. The reaction process is simple and easy to control, and the method has the characteristics of few synthesis steps and byproducts, high selectivity, cheap catalysts and the like and is applicable to industrial continuous production.

Description

technical field [0001] The invention relates to a method for preparing tetrafluoroethane from trichlorethylene. Background technique [0002] Tetrafluoroethane (CF 3 CH 2 F, HFC-134a) has excellent thermodynamic properties, low boiling point, large refrigeration coefficient, almost zero ODP value, and small GWP greenhouse effect coefficient. It is recognized as an ideal ODS substitute, as a third-generation refrigerant It has been widely developed and applied internationally. It has excellent physical and chemical properties, non-toxic, colorless, odorless, non-explosive, non-flammable, and has zero ozone depletion potential. Aerosol propellants, flame retardants and foaming agents in industries such as cleaning and cleaning. [0003] The method that tetrafluoroethane is produced at present mainly contains liquid-phase method and gas-phase method, but there is obvious shortcoming in liquid-phase method: the one, reaction is carried out in autoclave, especially second-ste...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/21C07C19/08C07C17/38C07C17/386
CPCC07C17/21C07C17/38C07C17/386C07C19/08Y02P20/10
Inventor 胡有团王洪祥叶雪勇林寿洪马鑫川李飞
Owner ZHEJIANG SANMEI CHEM IND
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