Plasma Cracking

Process Description

The process of cracking halogenated chlorofluorocarbons by plasma with recovery of the primary materials differs to reactor cracking mainly only by the use of a high energy plasma torch. The recovery system could be the same. The waste materials are injected into the water steam plasma torch by cracking the CFCs. For the complete reaction a high-temperature reactor is mounted beneath the plasma burner. To prevent recombination of dioxins and furans the reactor gas must be quenched to low temperatures.

A big advantage of the plasma technique for cracking CFCs is to select the plasma gas and additional substances. One then can influence the chemistry of the process as well as avoiding typical pollutants of combustion such as NO_x.

The plasma process can be influenced in a wide range by selecting the plasma gas and the reaction temperature by the electrical input energy. For cracking of CFCs a water plasma is best suited. Using a water-steam plasma, the halogens react in the plasma reactor with hydrogen and are converted to hydrogen chloride and hydrogen fluoride. These materials can be separated and recovered or neutralized. The carbon is converted to carbon monoxide or carbon dioxide, depending on the addition of oxygen and the residence time.

To avoid higher electrode erosions, using gases containing oxygen some argon gas is added to the plasma gas.