Conversion of Waste Plastics to Fuels Zadgaonkars Process

2 CONVERSION OF WASTE PLASTICS TO FUELS ZADGAONKAR S PROCESS 

The graded and cleaned particles of waste plastic are then introduced into a melt-ing/preheating system with an extruder feeder. The hard metal, clay and sand, glass, etc. are separated here by sedimentation, and then the waste plastic is charged in the dechlorination section. The solid metal, glass, etc. is removed from the melting/preheating section periodically. 

The dechlorination section of the plant consists of components which together effect release of chlorine from plastics such as PVC in the presence of coal and additives. The hot viscous waste plastic is fed from the upper end of the vessel and allowed to heat up at 220-250°C. The coal acts as a source of hydrogen required for the reaction. The released gaseous hydrochloride travels upwards through the vessel and is discharged to gaseous product recovery. 

The reactor section of the plant consists of the reactor, which together with other equipment carries out a continuous conversion of waste plastic to fuels. The molten waste plastic, free of chlorine, nitrogen and other organic impurities, is fed in to the reactor at the top end and allowed to flow over a heated surface at 350°C in the presence of the coal and patented additives. Upon contact with the hot surface and the mixture of coal and additives, the viscous waste plastic converts to gaseous form. 

The breaking of chemical bonds under the influence of heat is the result of overcoming bond dissociation energies. Organic substances such as polymers are highly heat sensitive due to the limited strength of the covalent bonds that make np their structures. Scission can occur either randomly or by a chain-end process, often referred to as an unzipping reaction. 

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