Links to other sections:

• Introduction
  
• Waste Streams and Rural Communities
• What is Waste to Energy

WTE Technologies:

• Plasma Gasification
• Plasma WTE Projects in the U.S.
• Plasma FAQ
• (Other technologies under development)

WTE Technology: Plasma Gasification

Plasma gasification is a high heat technology that converts virtually any waste stream into energy. While not proven on a large scale, plasma can convert any waste stream - including hazardous and radioactive wastes - to energy in a clean and cost effective manner. Small plasma WTE plants are operating in Japan and the first major plant in the US has been permitted in St Lucie Florida

Plasma was developed by NASA in the 1960's to test the heat shields on spacecraft entering the atmosphere. Known as the fourth state of matter, plasma uses heat hotter than the sun (7000C or higher) to reduce waste streams to their essential elements (carbon monoxide and hydrogen). The resulting synthetic gas (syngas)  can be converted into any of a variety of fuels including electricity, steam, ethanol, and others.

In addition to energy, plasma produces an obsidian-like rock (slag) which is roughly 10% of the size of the original waste stream (plasma eliminates 90% of the volume of the waste). This "plasma rock" is inert and can be used for road construction or blown into rock wool for insulation or for cleaning oil spills. Sun Bay Energy (click here) describes studies proving that plasma rock exceeds leachability standards set by the EPA and other world agencies. In Japan, where two small plasma plants have been running for nearly 10 years, plasma rock is mixed with asphalt to harden and improve road surfaces.

Plasma's high heat eliminates germs and other pathogens. Toxins are captured in a closed-loop process and either cleaned or captured in the inert plasma rock. The EPA has suggeted that plasma can be used on various types of waste,  and produce electricity and hydrogen without emitting dioxin, furan and mercury.


Video:  What is Plasma Gasification?

Development and Economics

Plasma plants cost $100-200 million to handle 500-1000 tons of trash a day (Durham and Orange county combined produce about 1000 tons of trash per day) Smaller plants can be built.  The economics depend on the site, proximity to the grid, and the size/composition of waste streams.

With revenues from energy, tipping fees, and the sale of residual byproducts, plasma facilities can profitable business ventures.  Plant construction produces about 200-250 jobs and ongoing operations produce 45-60 professional/technical jobs averaging $50,000 per year.

Ideally, plasma plants are pursued in private/public partnerships where local governments manage zoning and sites,  and agree to provide waste streams. State regulators set standards for plant and environmental safety. Developers and investors build and operate the plant. In addition to profits, investors benefit from tax incentives and credits.

Recycling and other waste management or energy functions can be co-located with a plasma plant to create an eco-industrial park. The park can even include public education about waste, sustainable energy and the environment.

Dr. Lou Circeo of Georgia Tech Research Institute believes that plasma is the most cost effective energy technology available, and with the sale of residual products, tipping fees to use plasma plants are competitive with landfills:

On a cost per KW produced basis, plasma gasification of MSW is the lowest cost energy technology available today. Using plasma gasification, MSW and biomass can produce 5-10% of the nation's power which is more that all the other renewables combined (geothermal. solar, wind). Using the MSW created daily in the US as fuel, plasma gasification plants can produce as much electricity as 25 nuclear power plants.

When you add the benefits of selling the byproducts, a plasma plant can handle MSW for $40 - $60 per ton range – well within striking distance of the cost for landfills. Add in renewable energy credits and sales of plasma mineral wool insulation, plasma gasification becomes the most cost effective method possible to handle trash and other disposables.

Click here for Dr. Circeo's presentation. The Dodge Report (click here) details the economics of a plasma plant.

Suggested Reading

• Young, Gary "Municipal Solid Waste To Energy Conversion Processes" click here
• Blees, Thomas, “Prescription for the Planet” Chapter 7 click here
• Dodge Paper on Plasma Gasification, Cornell University, July 2008, click here
• Sun Bay Energy Website - FAQs on Plasma, click here