Optimization of Catalytic degradation of Plastic to Aromatics Over HY Zeolite

Abstract

Feedstock recycling methods to convert plastic waste into liquid hydrocarbons products are becoming an important issue since dumping plastic waste into landfill and incineration are not appropriate methods due to legislative and environmental problems. Catalytic degradation of plastics into high quality liquid hydrocarbons is one of the more accepted and promising methods. In this study HY zeolite is used as catalysts and polyethylene as feedstock. The polyethylene melt heated at degradation reaction under a nitrogen atmosphere in the melter was pressed out by pressurized nitrogen (0.11–0.15MPa) into the reactor loaded with 1 - 3 gram of catalyst through a capillary. Nitrogen was flowed as a carrier gas at a rate of 10 ml/min. The product distribution, the yield of liquid products and liquid composition are further investigated. The effects of temperature and weight of zeolite Y on product distribution and composition of liquid products are investigated. The optimum conditions and model are also estimated by Statistica 6.0 software. The Pareto chart indicated that the variable with the largest effect was temperature (X1). From the response surface methodology (RSM) results the optimal liquid yield of 13.3%, which 49.7% aromatics content, at the optimized reaction condition (412oC and 2.25 gram HY catalyst) was obtained.