HIGHER DEGREE DECOMPOSITION OF HARMFUL ORGANIC COMPOUNDS CONTAINING CHLORINE BY USING MOLTEN SALTS

摘要

The decomposition of C_6H_5Cl, which is similar to harmful compounds such as PCBs, was investigated using the basic molten salt mixtures, KOH-K_2CO_3 and NaOH-Na_2CO_3. A sample of C_6H_5Cl was injected, together with a carrier gas, either imitation air (N_2-21%O_2) or N_2, into the molten salts in the temperature range from liquidus to 700°C. The exhaust was analyzed by using GC/MS both quantitatively and qualitatively. The concentration of C_6H_5Cl remaining in the exhaust was extremely low and the decomposition efficiency was at least 99.999% for both imitation air and N_2 as carrier gas. However, C_6H_5Cl was not completely decomposed to CO_2 and H_2O if the concentration of oxygen was lower than the stoichiometric ratio: instead many intermediate compounds were formed, and all were chlorine-free. The results indicated that the chlorine in C_6H_5Cl was effectively removed by the alkali hydroxide-carbonate mixtures even if oxygen is not contained in the carrier gas. Potassium salts are somewhat better than the sodium salts in their capacity for decomposition.