US 5,611,896 A · Production of fluorocarbon compounds

Abstract

The invention provides a method and installation for the production of a desired fluorocarbon compound, which includes the steps of providing a high temperature zone; and feeding at least one input material into the high temperature zone to generate a body of hot gas including fluorine-containing species and carbon-containing species. The molar C:F ratio in the body of hot gas is controlled at a selected value between about 0.4 and 2; and the specific enthalpy of the body of hot gas is controlled between about 1 kWh/kg and about 10 kWh/kg for a time interval, so that a reactive thermal gaseous mixture forms, containing reactive species including reactive fluorine-containing precursors and reactive carbon-containing precursors. Thereafter the reactive thermal mixture is cooled at a cooling rate and to a cooling temperature selected to produce an end product including the desired fluorocarbon compound. The input material is typically a C.sub.1 -C.sub.10 perfluorinated carbon compound of the general formula C.sub.n F.sub.m in which 0<n.ltoreq.10, and m=2n, 2n+2, or 2n-2 where n>1, for example a gaseous fluorocarbon such as tetrafluoromethane (CF.sub.4).

Claims24

Dependent claims

A method for producing a fluorocarbon compound, the method comprising the steps of:

(a) generating, in a high temperature zone, an electrical arc between at least one pair of essentially non-consumable electrodes;
(b) feeding into the high temperature zone at least one input material with which to generate a thermal plasma having fluorine-containing species and carbon-containing species;
(c) generating, in the high temperature zone, the thermal plasma having fluorine-containing species and carbon-containing species;
(d) providing a particulate carbon-containing substance;
(e) mixing, under controlled enthalpy conditions, the particulate carbon-containing substance with the thermal plasma to form a reactive thermal mixture thereof having molar C:F ratio between about 0.4 and 2, the reactive thermal mixture having a specific enthalpy between about 1 kWh/kg and about 10 kWh/kg;
(f) controlling said specific enthalpy for a time interval to cause the reactive thermal mixture to be gaseous, the reactive thermal gaseous mixture containing reactive species including reactive fluorine-containing precursors and reactive carbon-containing precursors, said precursors being derived from the fluorine-containing species, the carbon-containing species, and the particulate carbon-containing substance;
and
(g) cooling the reactive thermal gaseous mixture at a cooling rate and to a cooling temperature selected to produce an end product including the fluorocarbon compound.

5 more elements

A method for producing a fluorocarbon compound, the method comprising the steps of:

(a) providing a high temperature zone by providing an electrical arc between essentially non-consumable electrodes;
(b) providing a mixing zone adjacent the high temperature zone;
(c) feeding an input gas stream containing at least one fluorocarbon substance into the high temperature zone and generating a thermal plasma in the high temperature zone, the thermal plasma having fluorine-containing species and carbon-containing species, the thermal plasma having a molar C:F ratio, x, and a specific enthalpy, y;
(d) controlling the molar C:F ratio, x in the thermal plasma at a selected value between about 0.4 and 2;
(e) controlling in the high temperature zone the specific enthalpy, y, of the thermal plasma between about 1 kWh/kg and about 10 kWh/kg;
(f) introducing a particulate carbon-containing substance into the mixing zone to mix with the thermal plasma while maintaining the C:F ratio at the selected value to form a reactive thermal mixture in which the carbon-containing particles reach temperatures of between about 2000 K. and 3000 K., the reactive thermal mixture having reactive species including reactive fluorine-containing precursors and reactive carbon-containing precursors, the reactive thermal mixture having a specific enthalpy of not less than about 3 kWh/kg;
(g) maintaining the reactive thermal mixture at the conditions defined in step (f) for a time interval;
and
(h) rapidly cooling the reactive thermal mixture in a cooling zone in a manner to produce a product mixture having at least one fluorocarbon compound.

6 more elements

An installation for producing fluorocarbon compounds, the installation comprising:

(a) a high temperature zone suitable for containing a thermal plasma;
(b) a pair of essentially non-consumable electrodes for creating an electrical area in the high temperature zone for converting an input material fed into the zone into a thermal plasma, the thermal plasma having fluorine-containing species and carbon-containing species;
(c) an input material feed means for introducing an input material into the high temperature zone;
(d) a mixing zone for allowing the thermal plasma to mix with a particulate material to form a reactive thermal mixture;
(e) a particulate material introduction means for introducing under controlled enthalpy conditions a particulate carbon-containing substance into the mixing zone to form the reactive thermal mixture, the reactive thermal mixture containing reactive species including reactive fluorine-containing precursors and reactive carbon-containing precursors;
(f) a reaction zone means for permitting the reactive thermal mixture to form a reactive thermal gaseous mixture under controlled enthalpy conditions and with a controlled C:F ratio, the reactive thermal gaseous mixture containing reactive species including reactive fluorine-containing precursors and reactive carbon-containing precursors;
(g) a control means for controlling specific enthalpy and the C:F ratio in the reactive thermal mixture;
and
(h) a cooling means for cooling the reactive thermal mixture in a controlled manner to produce an end product containing at least one specified fluorocarbon compound.

6 more elements

Dependencies are inferred from the claim text.

Production of fluorocarbon compounds

Life of this patent

Production of fluorocarbon compounds

Life of this patent

Abstract

Claims24