Multistage incineration of halogenated hydrocarbon containing waste streams

Abstract

Abstract A method and apparatus for disposing of waste material by means of a multi-stage reaction favoring desired reaction products. The rate at which different reactions reach equilibrium at different temperatures and the effects of reaction stoichiometry are controlled by the process to promote desired reactions and discriminate against undesired ones. In the preferred embodiment, the present invention is a method of incinerating chlorinated hydrocarbons comprising reacting the chlorinated hydrocarbon at high temperature with less than a stoichiometric amount of oxygen for a period of time minimizing generation of nitrogen oxides; quenching the reacting chlorinated hydrocarbon-air mixture with water, whereby phosgene generated in the first part of the reaction is hydrolized, free chlorine is minimized and the temperature of the reacting chlorinated hydrocarbon-air mixture is reduced to a lower temperature to minimize generation of nitrogen oxides; further reacting the chlorinated hydrocarbon-air-steam reaction mixture at said lower temperature for a period of time not long enough to allow the formation of a significant amount of nitrogen oxides; adding additional air to the reacting chlorinated hydrocarbon-air-steam mixture to further reduce the temperature of said reacting mixture and to provide a stoichiometric excess of oxygen and lower the reaction temperature; further reacting said chlorinated hydrocarbon-air-water mixture with said stoichiometric excess of oxygen at said still lower temperature for a period of time long enough to fully react said chlorinated hydrocarbon to HCl, CO 2 and H 2 O, but still sufficiently short to prevent formation of a significant amount of nitrogen oxides; heating water and generating steam from indirect heat exchange with the effluent gas stream; and scrubbing hydrogen chloride gas out of said effluent gas stream. Apparatus is provided to permit this stage-wise reaction and to control the addition of quench water and air, as well as the addition of any additional hydrocarbon fuel, as needed, to insure minimum generation of nascent oxygen and chlorine and nitrogen oxides while insuring substantially all the chlorine in the combustion gas stream is converted into hydrogen chloride.

Inventors

• 👤 Sam P. Robinson

Bibliographic Details