1983 International Symposium On Wood and Pulping Chemistry PYROLYSIS AND COMBUSION BEHAVIOR OF CHLORINATED ORGANICS IN BLEACH PLANT EFFLUENT

Pyrolysis of chlorinated phenolics and thiolignin was investigated to elucidate the principle step occurring during combustion of organic material in bleach plant effluent. Chlorinated phenolics found in bleach plant effluent. such as chlorophenols, chloroguaiacols, chlorovanillins and chlorosyringaldehydes, were completely decomposed at 700 to 900°C with alkali and oxygen. Organically bound chlorine with lignin was ely eliminated as inorganic salt by alkali addition at low pyrolysis temperature. Without alkali, more than 90% of chlorine was eliminated as hydrogen chloride., the others as methyl chloride and tar-like material. Ether-soluble part of tar-like material contained various chlorinated phenolics, Which were not completely decomposed at a high temperature. Organic matter isolated from spent alkali extraction liquor was also pyrolyzed under a condition, which seemed to be probable in a conventional recovery furnace. Almost whole chlorine in organic matter Was recovered in solid residue. It was confirmed that the technique used in this work was useful to investigate the thermal behavior of chlorinated organics in bleach plant effluent.