Gasification of Plastic and Rubber Wastes

Most of the processes so far proposed for the gasification of polymeric wastes have been directly derived from earlier processes developed for the conversion of coal, natural gas and heavy petroleum fractions. However, certain details must be taken into account when processing plastic and rubber wastes in the gasification units, for instance the heterogeneity of the starting material, the problem of feeding the highly viscous melted plastics, and the possible formation of corrosive compounds, mainly HC1 from PVC. 

Closely related to the previous process is the plastic waste gasification facility being set up at Rotterdam with a capacity of 150 tonnes day-1 of plastic wastes.13 The feed of this plant will be a mixture of polyethylene, polypropylene and polystyrene with minor amounts of other polymers (2.4 wt% of PVC) and a significant proportion of cellulose. The plan is that an injection of ammonia into the gasifier will neutralize the chlorides entering with the plastic wastes, which will lead to the formation of ammonium chloride salt as a by-product. A production of 350 000 m3 day -1 of synthesis gas is estimated, which will be used in chemical synthesis. 

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