Drying and Organic Chlorine Thermal Decomposition Behavior of Municipal Solid Waste using Superheated Steam

Abstract

An experiment on drying and dechlorinating refuse derived fuel (RDF) using superheated steam was carried out and compared with a simple heat and mass transfer model in order to examine the behavior of organic chlorine thermal decomposition in municipal solid waste (MSW). The heat transfer and drying model consists of three parts : a steam condensation period, a constant rate drying period and a decreasing drying period. Either the water content or the temperature of the sample was predicted successfully using the other experimental value. Sample temperatures reached almost the same temperature as 473K superheated steam after about 30 min at the 473K superheated steam temperature, or about 15 min at a 523K temperature. The rate of water content decrease accelerated with the increase in superheated steam temperature. The developed drying model enabled us to predict time-dependent changes in the sample temperature or in the sample water content.
About 90% of the organic chlorine was decomposed in about 60 min in 523K superheated steam. The lower heating value decreased with the decrease in the dry yield, because decomposition of the sample resulted in decreases in carbon and hydrogen along with chlorine.