Chloride removal for plastic waste conversion

Abstract

Systems and methods are provided for reducing or minimizing the chloride content of products generated during co-processing of a plastic feedstock (such as plastic waste) in a refinery process. The reduction in chloride is achieved by mixing the plastic feedstock with one or more additional feedstocks for co-processing in a mixing and/or holding vessel that is maintained at a dechlorination temperature that allows for decomposition of chlorine from the plastic feedstock to form HCl, while reducing or minimizing other conversion of the plastic feedstock and/or the additional feedstock. A purge gas can be passed through the mixing/holding vessel to remove the evolved HCl from the vessel. Because the dechlorination temperature is selected to reduce or minimize conversion of the feedstocks in the mixture, the amount of carbon-containing products that are removed with the purge gas can be reduced or minimized. The dechlorinated mixture of plastic feedstock and additional feedstock(s) can then be processed in a convenient refinery process, such as a thermal cracking process (e.g., coking, visbreaking, other types of pyrolysis) or a catalytic conversion process (e.g., fluid catalytic cracking).