Gasification of mixed waste at high temperature to enhance the syngas efficiency and reduce gaseous emissions and tar production

Abstract

ABSTRACT The brisk escalation in population, energy demand and waste production are the pivotal dilemma confronted world wide. Thus, gasification could be considered as a favorable, economical and ecofriendly technique to resolve this issue. In this study, upstream fixed bed gasifier was used in the process to convert the refuse derived fuel (RDF) into syngas. It was employed at high temperature of about 900°C with steam-to-biomass ratio of 2.0 and 3 min of residence time. Results showed that the calorific value of RDF was about 4340 Kcal/kg of RDF and carbon conversion efficiency was about 46.31%. The quality and composition of syngas was also determined at different operating conditions.The hydrogen gas was highest in concentration to about 27.01% followed by CO 25.79%, CO2 19.20% and then CH4 11.50%. Moreover, gaseous emissions were also monitored which depicted the level of SO2 at 500 mg/Nm3, NO2 at a100 mg/Nm3, H2S at 7 mg/Nm3, Cl2 at 95 mg/Nm3, particulate matter at 480 mg/Nm3 and smoke about 20%. All of these were under the prescribed limits recommended by Pakistan Environmental Quality Standards (PEQs) and US-EPA.