Achieving Sustainable Development in Small Communities via Combined Heat and Power Systems

Abstract

The design of a feasible Combined Heat and Power plant for a small community is presented. Of the many alternatives solid-waste disposal methods available, incineration of solid waste is recommended due to its potential energy recovery of the heat released during solid waste incineration and recovery of valuable by-products that can either be reused, re- cycled or marketed, among other advantages. Hence, an attempt is made to use the heat energy released during incin- eration of solid waste to produce steam in a boiler, which in turn powers a turbine for eventual generation of electricity. The two processes involved in the generation of electricity for in-plant use or for a small community via a steam turbine-generator combination and a gas compressor-gas turbine-generator are presented. The analysis of the amount of energy produced from the solid waste energy-conversion system using an incinerator-boiler-steam turbine-electric generator combination with a capacity of 4.5 tons/day is also presented. The net electric power for a small community was found to be 148.24 kW with an overall efficiency of about 21% having taken cognisance of the process power needs and unaccounted process heat losses. Moreover, exergy analysis of the proposed CHP plant was carried out whereby the respective energy and exergy efficiencies of 83.2% and 62.1% were obtained.