Thermal Gasification of Polypropylene

Abstract

For an ettective utilization of plastic wastes, thermal gasification of polypropylene was carried out under atmospheric pressure by using a flow system of fixed bed reactor, in which the overheated steam was introduced as a heat carrier.
Pyrolysis conditions were; temperature, 500-650°C; residence time, 1.3-2.7 sec; steam to polymer dilution ratio by weight, 0-3.1.
Gasification easily proceeded even in the range of relative low temperatures and large amounts of olefins containing mainly propylene were obtained.
Under the conditions of residence time, 2.7 sec and steam di lution ratio, 3.1, the maximum propylene amount of about 26 wt% was attained at 600°C, and the total amount of ethylene, propylene and isobutylene of about 40 wt% as well as the total gas amount of about 65 wt% were obtained at 650°C.
In thermal gasifi cation of polypropylene using overheated steam, the reaction temperature is an important operating factor and the amount of product is largely affected by residence time. However, an increase in steam dilution ratio is not so important. Therefore, operating factors are limited to reaction temperature and residence time.