Pilot scale thermolysis of municipal solid waste: Combustibility of the products of the process and gas cleaning treatment of the combustion gases

Abstract

This paper describes the process of thermolysis of the organic fraction of municipal solid waste in a pilot scale reactor and the results are compared with others obtained under laboratory conditions (semi-pilot scale). The aim of this study was to get the energetic valorisation of the products. Owing to the specific characteristics of the plant, two products were obtained from the process: gas and carbonized solid, no liquid fraction was obtained, so the gas fraction is a greater percentage made up both condensable and non-condensable compounds, while at the laboratory scale were obtained separately. The pilot plant was designed so that the gases produced by thermolysis were burnt continuously in a combustion chamber, while the carbonized fraction was fed in batches for co-combustion. To determining composition and combustibility a chromatographic analysis of the gas fraction was undertaken, the solid fraction also being subjected to analyses. The gas composition, rich in light hydrocarbons, and the carbon present in the carbonized fraction make possible the energetic valorisation of these products. The combustion gases were subjected to a cleaning process and their composition analysed twice: before and after the gas cleaning treatment. An energy production system based on the Rankine cycle is proposed. The study led to a positive assessment of the possible use of the process products as fuel, provided that the combustion gases are treated. The neutralization treatment used was seen to be effective in the cleaning of combustion gases. Electricity production yields would have to be raised by means of a co-generation process.