Thermal degradation of municipal plastic waste for production of fuel-like hydrocarbons

Abstract

Fuel-like utilization is one way of chemical recycling of liquids from waste polymers. The degradation of different mixtures of the most frequently occurring waste polymers (polyethylene, polypropylene, polystyrene, polyamide, ethylene-propylene copolymer and polyurethane rubber) was investigated in a horizontal tube reactor. The effects of cracking temperature and residence time on the yields and structure of the products were studied. The gas and liquid products formed were analysed by gas chromatography. The operating parameters affected mostly the quantity of degradation products, whereas their chemical structure was not affected. In addition, the chemical structure of waste polymer had a considerable effect on the properties of the products. With increasing temperature, the carbon atom distribution of the hydrocarbons obtained became wider and the residence time had a significant effect upon the structure of the products. The liquid products had low heteroatom content (sulphur, nitrogen), but 2% of polyurethane rubber and 2% of polyamide in the raw material polyamide increased the concentration of sulphur and nitrogen in the products.