Process design and feasibility study for small scale MSW gasification

A process design study has been carried out to assess the feasibility of installing a small-scale municipal solid waste (MSW) gasifier on a university campus. The objective was to gasify all the non-recyclable MSW produced on campus and then combust the gaseous product to produce energy and electricity for the campus. Five energy generation combination scenarios were studied at two different mass gasification rates. The scenarios involved hot water (based on site demand), electricity (only, less the demand for hot water) and excess hot water for export (with electricity, with no electricity). Due to the high capital cost of generating electricity from a 10 tonnes per day MSW gasifier, the optimum rate of return on capital investment is 14.8%. On a heat basis only a return of 23.4% is achievable. However, this optimum solution is based on being able to export 60% of the hot water off campus. If an additional 10 tonnes per day MSW is imported onto campus the optimum rate of return increases to 36.1% but over 75 % hot water has to be exported. Alternatively, with 400 kW of electricity generation a rate of return of 32.5% can be achieved at this higher mass throughput. (C) 2004 Elsevier B.V. All rights reserved.