CATALYTIC ADSORBENTS FOR THE ABATEMENT OF CHLORINATED HYDROCARBONS

A NOVEL EMISSION CONTROL PROCESS FOR CHLORINATED HYDROCARBONS PRODUCES NO TOXIC OR CORROSIVE SECONDARY GASES. CATALYTIC ADSORBENT MATERIALS WILL BE DEVELOPED TO DESTROY LOW CONCENTRATIONS OF CHLORINATED HYDROCARBON IN GASEOUS EFFLUENTS WITHOUT THE RELEASE OF HYDROCHLORIC ACID AND CHLORINE GAS. INSTEAD THE ADSORBENT WILL FIX THE CHLORINE ATOMS AS HARMLESS NONVOLATILE CHLORIDE SALT AT TEMPERATURES WELL BELOW CONVENTIONAL CATALYTIC INCINERATION. LOW TEMPERATURE OPERATION AND NONTOXIC SECONDARY WASTE WILL MAKE THIS AN ATTRACTIVE ECONOMICAL ABATEMENT PROCESS FOR CHLORINATED HYDROCARBONS. CHLORINATED ORGANICS ARE AMONG THE MOST DIFFICULT WASTES TO DESTROY, AND THEY CONSTITUTE A LARGE PORTION OF THE VOCS ASSOCIATED WITH OZONE NONABATEMENT. WHEN THEY ARE OXIDIZED,HYDROCHLORIC ACID (HC1) IS FORMED, WHICH RETARDS THE CATALYTIC ACTIVITY OF METAL CATALYSTS, AND IT UNDERGOES FURTHER OXIDATION TO FORM CHLORINE GAS (CL2). THE HC1 ALSO ATTACKS INCINERATION EQUIPMENT. CHLORINE AND ACID RESISTANTCATALYSTS CURRENTLY USED OPERATE AT HIGH TEMPERATURES AND REQUIRE LARGE AMOUNTS OF FUEL. THE CATALYTIC ADSORBENT WILL BE PRODUCED BY FORMING AN ACTIVE METAL OXIDE IN INTIMATE CONTACT WITH AN ACTIVE LIMESTONE SURFACE. THE LIMESTONE WILL ACT AS A DISPERSING MEDIUM FOR THE CATALYST. ANY HC1 FORMED ON THE CATALYST WILL IMMEDIATELY REACT WITH THE CALCIUM CARBONATE (LIMESTONE) TO REGENERATE THE METAL OXIDES. THIS STOPS THE HC1 FROM OXIDIZING TO CHLORINE AND RESULTS IN NO FREE HC1. THIS IS THE IMPORTANT NOVEL FEATURE OF THE PROCESS WHICH DISTINGUISHES IT FROM CONVENTIONAL CATALYTIC OXIDATION. THEEFFLUENT GAS FROM THE PROCESS CONTAINS ONLY WATER AND CARBONDIOXIDE.