Hydrothermal recycling of PVC in a bubbling fluidized bed reactor : the influence of bed material and temperature

Hydrothermal recycling is conversion of poly(vinyl chloride) (PVC) at high temperatures in a steam atmosphere into hydrogen chloride, a mixture of hydrocarbons and syngas. Hydrochloric acid can be recovered and the mixture of hydrocarbons and syngas can be used for energy recovery. A bench-scale bubbling fluidized bed has been constructed to investigate this process. The experiments show that the choice of type of bed material is essential for the product outcome. The use of catalytic inactive solid quartz as bed material results in the production of large amounts of char and tar, whereas the application of catalytic active material such as porous alumina results in a high conversion of PVC into syngas. Also temperature seems to have a large impact on the composition of the products. The carbon to gas conversion improved from about 70% at 1150¿K to 98% at 1250¿K