An environmental assessment of recovering methane from municipal solid waste by anaerobic digestion.

摘要

The full scale development of an experimental process which produces synthetic natural gas (SNG) or biogas by anaerobic digestion of municipal solid waste (MSW) is evaluated. This technology, if implemented, would be utilized in lieu of incineration or directly landfilling waste. An environmental assessment describing the principal impacts associated with operating the MSW anaerobic digestion process is presented. Variations in process configurations provide for SNG or electricity production and digester residue incineration, composting, or landfilling. Four process configurations are compared to the conventional solid waste disposal alternatives of mass burn incineration and landfilling.;Each configuration and alternative waste disposal system is assumed to have a 2000 ton/week capacity. Emissions are characterized, effluents quantified, and landfill areas predicted. The quantity of SNG and electricity recovered, and aluminum and ferrous metals recycled is predicted along with the emissions and effluents avoided by recovering energy and recycling metals.;Air emissions are the primary on-site concern with the anaerobic digestion process. However, when compared to mass burn incineration, the projected particulate emissions for the anaerobic digestion process range from 2.9 ;Landfills are needed to receive wastes which may bypass the anaerobic digestion process, or for ash disposal from residue incineration. When wastes are directly landfilled, 2.6 acres per year of landfill area is consumed compared with 1.1 acres per year for mass burn and 0.8-1.3 acres per year for anaerobic digestion.;The various configurations and disposal alternatives were also compared by value analysis techniques. The anaerobic digestion process was found to be preferred to mass burn incineration or direct landfilling of MSW.