Waste conversion technologies (WCTs) are non-incineration technologies that are used to convert the non-recyclable portion of the municipal solid wastestream to electricity, fuels, and/or industrial chemical feedstocks. Interest is growing in the demonstration and commercialization of WCTs due to their potential role in addressing renewable energy mandates and green jobs initiatives as well as meeting local solid waste management needs.
There are a number of important reasons why SWANA members and other solid waste managers will benefit by being knowledgeable and current with respect to the progress of WCT demonstration projects in North America:
The federal government has provided almost $500 million in grants and loan guarantees to WCT demonstration projects in the US.
WCTs offer the potential of generating significantly more revenues than traditional waste-to-energy (WTE) technologies. For example, if the fuel from a WCT facility is valued at $3 per gallon, this would provide a WCT facility with $150 per ton in energy revenues compared with $27.50 per ton (550 kilowatt-hours at $0.05 per kilowatt-hour) of revenues from traditional waste-to-energy facilities.
WCTs convert post-recycled MSW to such alternative fuels as syngas or ethanol rather than directly incinerating MSW. These alternative fuels may offer the promise of lower emissions when compared with the emissions associated with the combustion of MSW in traditional waste-to-energy facilities.
WCT project and/or technology developers have proliferated in recent years and have been actively targeting loca0l elected officials who, in turn, rely on their local solid waste managers to provide them professional opinions regarding the proposed projects, often on short notice.
The Solid Waste Association of North America (SWANA) has taken an active role in the evaluation and commercialization of WCTs in North America.
SWANA Report on Waste Conversion Technologies
The SWANA Applied Research Foundation (ARF) has developed a report to provide solid waste managers with up-to-date technical and programmatic data and information regarding waste conversion technologies (WCTs).
This research need, which was submitted by the Metro Waste Authority of Des Moines, Iowa, and voted on for selection by the SWANA Applied Research Foundation’s FY2011 Disposal Group, was described as follows:
“Solid Waste Agencies continually get unsolicited offers by individuals offering the “˜latest and greatest’ system as an alternative to landfilling. Most include plasma torch or some other waste-to-energy technology that, though technically feasible, is not a practical solution.
“What are these new technologies? What phase of development-theory, bench scale, pilot, or full operation? A white paper would give agencies with limited resources the ability to differentiate those technologies that are feasible and practical (operationally and economically) from those needing more development.”
The research-which was conducted by the SWANA ARF staff with input and guidance provided by the ARF Disposal Group Subscribers-consisted of a review and assessment of recently published literature, reports, and presentations.
The waste conversion technologies (WCTs) targeted for investigation are designed to process mixed municipal solid waste (MSW) for energy and materials recovery and are based on the following six processes:
- Plasma arc gasification
- Hydrolysis/fermentation (waste-to-ethanol)
- Anaerobic digestion
- Autoclave/mechanical processing