SU541835A1 - The method of producing tetrafluoroethylene - Google Patents

Description

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This invention relates to a process for the preparation of tetrafluorothylene used in the synthesis of polytetrafluoroethylene and cyclobutane octafluorine used as a refrigerant in turbo-compressor installations and heat pumps, sometimes for the replacement of freon-21 and freon-142.

Known is 1 method of producing tetrafluoroethylene by the pyrolysis of chlorodifluoromethane in a melt of metal hydroxide at 50 ~ 800 C.

In this case, a significant amount of bottoms is formed, approximately 7O% of which is a hardly separated azeotropic mixture of chlorotrafluoroethane and octafluoropiclobutane.

There is also known 2 a method for producing lower fluorostilines by reacting fluorine containing hydrocarbons with a solution of an alkali metal hydroxide or ammonium in dimethylsulfoxide (DMSO) at 18-150 ° C.

However, the known method is expensive and complicated.

In order to increase the resource base and

It is proposed to use additionally octafluorocyclobutane as fluorine containing hydrogen chloride vaginal residues from tetrafluoroethylene production, containing chchotetrafluoroethane and octafluorocyclobutane, preferably azeotropic mixture of chlorotetrafluoroethane and octafluoropiclobutane, and conduct the process at 80130 ° C.

Depending on the process temperature and the time of contact of the initial mixture with the solution (suspension) of α-hydroxide hydroxide (metal or ammonium in DMSO, predominantly tetrafluoroethylene is formed (yield up to 60%) or octafluorocyclobutane (yield up to 90 ° :). Pure tetrafluoroethylene and octafluorocyclobutane are separated rectification.

PRI and MER 1. The reactor (vertical glass column with a diameter of 30 mm to a height of 270 mm, equipped with a mesh; 1koy) is loaded with 10–10 pooboobrana hydroxide sodium hydroxide 80 ml / МMCO, heated on a water bath to. 5.5 g of a mixture of chlorotetrafluoroethane and octafftorgdipo-butane containing (in vol.%): 39.72.1 cyclo-C P; 59, S (38C2F HC and 0.421 impurities) are fed over a glass booster (diameter 6 mm) 1 hour Get 4.62 l of a neutral product containing (in vol.%):: 31.652 17.286 50.655 cyclo-C F 8 CF HCE and 0.407 impurities. The yield of tetrafluoroethylene and octafluorocyclobutane is 58.658 and 41.326%, respectively. measure 2. 30 g of powdered sodium hydroxide and 100 ml of DMSO are heated in a glycerin bath to 130 ° C and a bubbler serves 0.07 l of a mixture of chlorotetrafluoroethane and octafluorocyclobutane containing (in% by volume): 39.721 niklo- C .F 59,868 and 0.421 impurities. One gets 0.4 l of a product containing (in vol.% 12.16 C; 85.243 cyclo; 2.527 C F and 0.7 impurities. Yield of tetrafluoroethylene and ectafluorocyclobutane 11, 83 and 88D, 8%, respectively. Formula and a shade 1. Method for producing tetrafgorethylene by reacting fluorinated hydrocarbons with a solution of an alkali metal hydroxide or ammonium in dimethyl sulfoxide, characterized in that, in order to broaden the raw material base and obtain additional octafluorocyclobutane, as an initial raw materials use vat residues tetrafluoroethylene containing chlorotetrafluoroethane and octafluorocyclobutane. 2. The method according to claim 1, that is, an azeotropic mixture of chlorotetrafluoroethane and octafluorocyclobutane is taken as bottoms from the production of tetrafluoroethylene. 3. The method according to claim 1, of which is carried out at the temperature of 80-130 ° C. Sources of information taken into account in the examination: 1. Japan Patent No. 2О611 / 66, 16 В 220, 1966. 2. England Patent № 1246О68, С 2 С, 15.09.71.