Making Clean Energy from Waste

Recycling, reusing and reducing are preferred option, and have diverted much of the waste stream, but better options than landfills are needed for what remains. One approach to dealing with waste is incineration, burning the material for energy. In 2007 the US had 87 waste to energy plants burning 12.5 of US waste (International Herald Tribune, July 6 2008). Incineration produce energy, but critics raise the concern of toxic material in the exhaust, and the lost energy of material that would better recycled.

InEnTec has developed an alternative solution for waste. Rather than incinerating waste, InEnTec uses its Plasma Enhanced Melter (PEM) Systems to heat waste to very high temperatures using electrically charged gas (plasma), breaking down organic material and creating a variety of products.

The distinction from incineration with the PEM system is important. While incineration can produce toxins like dioxins, there is no combustion in the InEnTec system and they have found that dioxin levels in the exhaust from the system are lower than in the surrounding air. Testing of PEM environmental emissions by a variety of groups has verified the low emissions produced.

The PEM system creates several products while processing waste. One valuable product is clean energy in the form of hydrogen rich syngas from organic material. By creating fuels, or burning the syngas, a PEM system can produce more energy than goes into the system, adding energy as one source of revenue in addition to the value of waste destruction. Alternatively, the hydrogen produced can also be used for fuel cells or other uses.

"The process is very adaptable to a wide variety of waste streams," said Gary Cook, CEO of InEnTec Chemical LLC. InEnTec Chemical LLC was created as a joint venture between InEnTec and Lakeside Energy to facilitate the construction of large scale PEM facilities.

"We've handled chemical waste, medical waste, industrial waste including batteries, asbestos, PCBs, and municipal waste," said Cook.

Remaining material gets trapped in non-toxic glass that be used for blasting grit, roofing tiles, construction materials and roads. Even problematic electronic waste can be handled with the system, producing syngas. Halogens from flame retardants can be recovered in a non-toxic form to be reused, and metals collected to separated and reused as well.

One form of revenue for the system is to remove the cost for hazardous waste disposal in situations like the chemical industry. "With chemical waste we are changing the paradigm," Cook said. Instead of costing a chemical plant money for hazardous waste material, the wastes can be converted in feedstocks to make new chemicals. To help build a plant, InEnTec secures long term contracts to take waste and to supply feedstocks. "With those we build the plant," Cook said.

Waste to Ethanol

Coskata Inc. of Warrenville Illinois is also deploying plasma gasification of organic waste, targeted the production of ethanol. The input material Coskata uses includes organic landfill waste and biomass, which undergoes plasma gasification to produce syngas, followed in this case by microbial conversion to ethanol. Coskata's plasma gasification route to ethanol provides an alternative to the many competitors developing enzymatic and microbial methods of producing cellulosic ethanol.

The Coskata route provides many potential advantages, saving money by avoiding the use of enzymes and preprocessing of biomass. The Coskata method produces less waste, since essentially all of the input plant material can be gasified, can use a wider variety of input material, and uses less water as well.

"With all of that in our advantage, we are likely well below our competitors in cost however you look at it," said Wes Bolsen, Chief Marketing Officer and Vice President at Coskata. "Add all of this up and it gets you to less than one dollar per gallon for the ethanol production."

Using microbes rather than chemical catalysis to convert syngas into ethanol also helps to reduce costs. A pilot facility to demonstrate production of ethanol for $1 per gallon on a commercial scale is currently under construction and is expected to be operational in early 2009.

Many are wondering about the impact of the credit crunch on the development of renewable energy, but in October InEnTec secured a commitment from Lakeside Energy with backing from American Securities, a private equity firm, for US $150 million for new plant construction. A number of PEM plants have already been built, and this new funding will help with the construction of a PEM facility for Dow Corning in Midland, Michigan. The PEM facility will process chlorinated chemicals into chemicals and energy to be reused by Dow.

"Private equity is still out there and still looking for opportunities to invest," Cook said. "It will be a difficult time to raise money, but I've been involved in cleantech for ten years and it keeps moving forward. As the need grows and the technology improves, it keeps on moving forward."

Coskata, InEnTec and others developing renewable energy technologies that prove commercially viable should continue to attract funding even in times like these.

Glenn Croston is a biologist, father and author fighting climate change and working toward a greener world at home and at work.  He is the author of 75 Green Businesses You Can Start to Make Money and Make a Difference, a book that describes businesses for innovative eco-entrepreneurs to join the booming green economy in renewable energy, green buildings, food, water, services, transportation, farms, and other areas, scheduled to come out with Entrepreneur Press in August 2008. Glenn is also developing Starting Up Green as a support resource for green entrepreneurs and holds a PhD in biology from the University of California, San Diego.