Waste conversion into fuel skyrockets

Last June it was announced that the City of Edmonton, the Alberta government and two technology companies would invest $70 million dollars to build the world’s first and largest chemical processing plant to convert municipal waste into methanol, ethanol and other biochemical derivatives.

In following up on the story, American Recycler learned that this project is actually happening. This project could become the prototype for handling municipal waste in the future.

According to the U.S. Departments of Agriculture and Energy, approximately two-thirds of everything that is dumped into landfills contains cellulose and is a potential source of fuel. More importantly, cellulosic ethanol yields approximately 80 percent more energy than is required to grow and convert it.

Ethanol, of course, is a renewable transportation fuel that today is largely made from grains such as corn and wheat, but cellulose ethanol can be made from agricultural byproducts, such as straw, corn cobs, and corn stalks, which are often discarded as waste, or made from new crops like switchgrass, the tall, native grass that once covered most of the North American prairie.

Test plots of switchgrass at Auburn University have produced up to 15 tons of dry biomass per acre, and five-year yields average 11.5 tons, enough to make 1,150 gallons of ethanol per acre each year. And, switchgrass thrives with little or no irrigation or fertilizer.

Many researchers, environmentalists and economists believe that making ethanol from cellulose fibers harvested from biomass and landfill waste is preferable to fuel made from what would otherwise be food.

Plans for the Edmonton waste-to-ethanol plant are complete and being reviewed by government regulators. Construction will begin by the end of this year and the plant could be operational by 2011. The estimated 40,000 square foot plant is projected to ingest 100,000 tons of processed municipal waste feedstock each year to yield 10 million gallons of ethanol. Of the 100,000 tons processed, about 85 percent will be converted into useful chemicals, the balance being inert residue that may find recycling markets as aggregates for brick or concrete manufacturing. The feedstock for the waste-to-ethanol facility will consist largely of residuals from the City’s Materials Recovery Facility and Composting Facility from materials that cannot be recycled or composted.

Most surprising, the project developers are convinced it will be a profitable enterprise for both the public and private partners. “It has to make money, that’s the principle objective,” said Marie-Hélène Labrie, vice president of communications at Enerkem, Inc., one of the technology partners in the project. The other technology partner is GreenField Ethanol, Inc., Canada’s leading ethanol producer. When methanol, ethanol, and other chemicals begin to flow to market the partners will share the profits to recover their respective investments.

In order to get this innovative waste-to-ethanol plant, the City of Edmonton signed a 25 year agreement with Enerkem and GreenField Ethanol to supply the 100,000 tons of processed municipal solid waste annually. This is believed to be the only long-term feedstock agreement of its kind. The feedstock will include contaminated paper and cardboard, textiles and plastics that are not recycled. Edmonton already has one of the most advanced recycling operations and the largest composting facility in North America. Enerkem and GreenField have formed a joint partnership in the project, the former providing the chemical processing technology and the latter to build and manage the plant and to market the products.

Enerkem and GreenField will pay approximately $50 million of the construction costs. The City of Edmonton and the Government of Alberta through the Alberta Energy Research Institute (AERI) are contributing $20 million to the facility. The City of Edmonton will also invest an additional $50 million into an upgraded materials recovery facility and build a related research facility. AERI’s total contribution to all the components is $29 million. “Our investment is not just for waste-to-fuel, but also a facility to do research and development and test and demonstrate all matters of technology with different waste feeds like agricultural and forest waste in addition to municipal waste,” said Edy Isaacs, executive director of AERI. “There is already a research facility at the Edmonton site associated with the University of Alberta and the Alberta Research Council that both do research on waste treatment. This new facility will be designed to look at municipal waste from the point of view of converting waste into biofuels.”

The chemical process to be used in Edmonton that takes garbage-to-fuel was developed and proven practical at Enerkem’s pilot plant in Sherbrooke, Quebec, just across the border from Vermont. In operation since 2003, the pilot plant has allowed the company to test many types of feedstock including sorted municipal solid waste. The company is now entering the commercial phase with the start-up of its first commercial plant located in Westbury, near the pilot plant.

The plant’s feedstock is old utility poles that have been treated with creosote and other chemical preservatives. First the poles are sawn to recover center cut 4” x 4” lumber that is recycled for construction. The outer, chemical soaked slabs are chipped and sent into the thermo-chemical process that combines gasification, conditioning and cleaning of the gas, and a three-step catalytic conversion that creates a synthetic gas called “syngas”. Syngas is then cleaned to remove impurities such as particulates, tar, and ammonia. It is also conditioned through a reforming step to produce an H2CO (Formaldehyde) tailored syngas. The tailored syngas is the production platform from which fuels and chemicals are produced. Catalysts are used to cause a reaction in the syngas that rearranges carbon atoms into methanol, ethanol and other products, such as acetic acid, acetates and olefins – polymers of high industrial value used to make plastics such as polyethylene and polypropylene.

This technology was further proven in 2008 at Enerkem’s Westbury, Quebec commercial demonstration plant that yielded only 1.3 million gallons a year. Now the technology is ready to be scaled up to industrial-sized production. “We did an analysis of all the gasification technologies and found that Enerkem’s was the best to produce clean gas. If you want to treat the syngas, you don’t want a mixture of oils, charcoal and pollutants because it poisons the subsequent steps. It appeared to us that their technology was the cleanest,” said Frank Dottori, managing director of GreenField.

The City of Edmonton considers itself a world leader in waste management practices. Its Edmonton Waste Management Centre (EWMC) is North America’s largest collection of advanced, sustainable waste processing and research facilities. EWMC has a 575-acre site with facilities for materials recovery, composting, electric-electronic waste, construction and demolition, and research. Their landfill has a leachate treatment plant and a landfill-to-gas powered electric system. They have achieved a landfill diversion rate of 60 percent but hope to reach 80 to 90 percent diversion once the waste-to-ethanol plant becomes operational. “If you want to do a project like this and have any hope of getting financing these days you have to have a guaranteed feedstock, which we have for 25 years at a per ton fee that they will pay us to recycle the sorted waste,” said GreenField’s Dottori. “This will save the city money because it avoids capital investment for new landfills. In addition, the city is hoping to pay us less than it costs to create new landfill sites. And, it’s good for us because it justifies the capital investment for the technology.”

GreenField Ethanol built and operates four plants that produce over 500 million liters of ethanol annually markets and distributes products to various petroleum companies. GreenField ethanol is available at more than 1,300 gas stations.The company also has the largest industrial ethanol distribution system in North America that serves the chemical industry, hospitals and pharmaceutical companies. GreenField is actively involved in the development of biochemical process technology to produce cellulosic ethanol at its research facilities in Chatham, Ontario and is working with Enerkem to develop more thermo-chemical cellulosic ethanol plants.

“This unique partnership with private companies and the provincial government builds on our global leadership in municipal waste management,” said Edmonton mayor, Stephen Mandel. “It will enable us to make a noted contribution to reducing greenhouse gases and become the first major city in North America to achieve 90 percent residential waste diversion from landfill.”

The interest by cities and municipalities throughout North American to convert municipal waste into biofuels is growing, especially in the United States with the passage of the Energy Independence and Security Act of 2007. It boosted the requirements for renewable fuel use to 36 billion gallons by 2022. The act requires advanced biofuels that are defined as fuels to cut greenhouse gas emissions by at least 50 percent to provide 21 billion gallons of fuel by 2022, or about 60 percent of the total requirement. Such advanced biofuels include ethanol derived from­ cellulosic biomass through processes similar to those being employed by Enerkem and GreenField at Edmonton.

In 2007, the United States Department of Energy pledged $385 million to six domestic companies to encourage building cellulosic demonstration plants. The grants are designed to help with the upfront capital costs for plant construction.

With increasing emphasis on producing more renewable energy by governments in the United States and Canada backed by funding and coupled with the environmental and cost challenges associated with landfills, it looks as though landfill waste-to-biofuel is a viable option. Only the technology and time will tell.