This study is concerned with thermal processing of polyvinylchloride (PVC) in the presence of alkaline oil shale ash. solid heat carrier (Galoter process)type oil shale retorting units, where the feedstock is heated by mixing with ash from retorted feed-stock combustion, are potentially,an alternative for polyvinylchloride waste recycling. A bench-scale experimental study was performed to investigate the fate of chlorine in co-pyrolysis of kukersite oil shale ash and PVC waste. Experiments. were conducted by applying, two sequential laboratory-scale batch processes: pyrolysis of PVC waste (70% PVC) with oil shale ash in a Fischer retort (standard method) followed by solid residue combustion in a muffle furnace.