A mixture of post-consumer polyethylene/polypropylene/ polystyrene (PE/PP/PS) with polyvinylchloride (PVC) waste was pyrolyzed over cracking catalysts using a fluidizing reaction system in an FCC process operating isothermally at ambient pressure. The influences of catalyst types and reaction conditions including reaction temperatures, ratios of catalyst to plastic feed, flow rates of fluidizing gas and catalyst particle sizes were examined. A model based on kinetic and mechanistic considerations associated with chemical reactions and catalyst deactivation in the acid-catalyzed degradation of plastics has been developed. The results of this study are useful for determining the effects of catalyst types and reaction conditions on both the product distribution and selectivity from commingled plastic waste, and especially for the utilization of post-use commercial FCC recycled catalysts for producing valuable hydrocarbons in a fluidizing cracking process. Moreover, the use of this recycled/modified FCC spent catalyst (RCat-s1) together with an optimal reaction system can be an adequate option since it may lead to a cheaper process with valuable products and can also be further used as a dual recycling of chlorine-containing hazardous waste plastics and a post-use commercial catalyst waste from FCC refinery. (C) 2011 Elsevier B.V. All rights reserved.