Development and Performance Evaluation of a Small Scale Municipal Solid Waste Incineration Plant

摘要

This study presents the design and testing of a waste-to-energy plant by incineration of small scale municipal solid waste to produce steam for electricity production. The average total waste generated within the study area was found to be 55,800kg/day, with an estimated calorific value of 13,958kJ/kg. The waste samples were collected, dried, shredded and weighed in order to reduce the moisture content to the acceptable minimum and decreases the surface area of the sample that will allow easier penetration of heat. The incinerator was designed using CATIA-5 software. The key performance indices of the developed plant are maximum furnace temperature, residence time, mass flow rate, steam pressures and amount of steam generated keeping the mass of waste constant per test but varying the air flow. The moving grate is inclined at an angle of 12° while the volume of the incineration combustion chamber was calculated to be 0.267m3. 150kg of small scale waste was fed into the combustion chamber of the incinerator to produce heat in order to fire the boiler filled to 70 litre capacity level. Tests were carried out with natural air flow and forced air supplied through the primary air nozzles at an air velocity of 6.2m/s. The obtained temperature/pressure results were: 464°C/5 bar and 528°C/7 bar and 542°C/7 bar for tests 1, 2 and 3 respectively. The steam produced in the boiler was able to run a steam turbine used to generate electricity. Preliminary results showed that such a plant could be used to complement the power supplied to the University as a set of 36 - 12V DC bulbs were powered for 15 minutes.