BENSON -- Building a biomass gasifier to fuel the production of ethanol at the Chippewa Valley Ethanol Co. is taking longer than first anticipated.
"It has taken us longer than expected to work on the design elements and the permitting process," said Bill Lee, general manager of Chippewa Valley Ethanol Co. Original plans, announced last year, set the gasifier startup for next month. Now, officials are planning a fall startup.
The gasifier will burn biomass to create synthetic gas that will replace the natural gas now used to power the 45 million-gallon ethanol plant.
The big hurdle right now is permitting from the Minnesota Pollution Control Agency, he said. The company is pushing the state agency into new territory with the gasifier, which is the second in the state.
The first gasifier installation was at the Central Minnesota Ethanol Cooperative in Little Falls. However, the permitting process for the Benson gasifier is different than at Little Falls, Lee explains. That gasification system, which uses wood waste products, was incorporated in the plant's installation of thermal oxidization equipment.
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In 2002, 12 Minnesota ethanol plants, including the Little Falls plant, reached an agreement with MPCA and the federal Environmental Protection Agency that required the installation of pollution control systems, such as a thermal oxidizer, which destroys 95 percent of the volatile organic compounds emitted from the facilities.
While Chippewa Valley Ethanol Co. waits for the permit, company officials and their partner, Frontline Bioenergy of Ames, Iowa, are finalizing designs, working on programming and steel fabrication.
"We are using the time to analyze the design to help improve the quality of the project," Lee said.
The site work for the gasifier, just west of the existing buildings on the property, was completed last fall. Lee expects concrete work to begin in March.
All of the major equipment needed for the gasifier is either on order or has been delivered, Lee said. The actual construction work will take six to seven months.
The gasifer is the first phase of a larger project to replace up to 90 percent of the natural gas used by the plant with synthetic gas produced with biomass. When complete, the pilot gasifier will burn about 70 tons of biomass per day to generate about 25 percent of the gas needs of the ethanol plant.
The timeline for the next phase of the project, a larger gasifier that will also create a "clean" gas that can be burned in multiple burners at the plant, remains on schedule, Lee said.
The gasifier is just part of the changing face of the Benson plant. Chippewa Valley Ethanol Co. is also planning the construction of a 40 million-gallon ethanol plant, to be built by Fagen Inc. of Granite Falls, beginning in July 2008. The new plant will be built on the plant's property near the existing 45 million-gallon plant, but will operate independently from the original plant, which has been operating for more than 10 years. That project is in the pre-engineering phase, Lee said.
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Natural gas is the second largest input into ethanol production. Corn is the largest. Currently, the plant buys $15 million to $20 million of natural gas each year.
The plant will be able to use any combination of synthetic gas and natural gas, according to Andrew Zurn, Chippewa Valley Ethanol Co.'s plant engineer. In addition, the char ash created from the gasifier is not waste. Instead, it has a nutrient value that can be used as fertilizer, continuing the green cycle of renewable energy.
Chippewa Valley Ethanol Co. is also researching ways to improve the process to harvest, transport and handle biomass for gasification. The company has done baling trials of wheat straw, corn stover, switchgrass and soybean straw. The goal is to find an economical, reliable and sustainable stock of biomass fuel, Lee said. More research is needed to find ways to concentrate the bulky biomass product into smaller, denser and more economically handled commodity.
"We need some breakthroughs in the harvesting and transportation," he said. "Ideally, you'd come out of the field not with a round bale, but with a more condensed form."
