Combustion characteristics and energy potential of municipal solid waste in Arusha City-Tanzania

Abstract

Municipal Solid Waste (MSW) generation has been in the increase due to the population growth, changing life style, technology development and increased consumption of goods. The increase of waste generation may lead to environmental and social problems such as water contamination, land and atmospheric pollutions, provide breeding grounds for insects and rats, risk of fire, bad odors and potential cause of illnesses. The combustion properties and study of energy potential from municipal solid waste was undertaken. The energy flow (exothermic and endothermic) and thermal degradation analysis were carried out using differential scanning calorimetry and thermo – gravimetric analyzer respectively. The sample of composition of municipal solid waste examined included papers, cardboard, wood, textile, rubber, polyethylene Teraphthalate (PETE), low density polyethylene (LDPE) and food waste. Composition of these materials were heated in a NETZSCH STA, 409 TGA apparatus and experiments were performed at heating rate of 10○C/min, in the nitrogen atmosphere at temperature between room temperature and 1100 ○C. The thermal degradation characteristics of the MSW were obtained using thermo gravimetric analyzer (TGA) and derivative of thermo gravimetric (DTG). It was observed that municipal solid waste is less reactive to combustion, but its reactivity can be improved through pre-treating process like drying, shredding and removing non combustible materials such as metals. Also pyrolysis and gasification can be used to convert MSW to gaseous fuel. The energy content of the solid waste tested was about 12MJ/kg. The elemental composition shows that Municipal solid Waste contains 50% and 5% of carbon and hydrogen respectively. Keywords: Municipal Solid Waste, Thermal behavior, Thermo gravimetric Analysis