Chippewa Valley Ethanol Co. (CVEC), a 45 MMgy ethanol plan in Benson, Minn., has proven its innovative abilities once again.

The company recently partnered with Frontline BioEnergy, a biomass gasification equipment provider in Ames, Iowa, to install a gasifier at the ethanol plant to make a "producer gas" that would replace natural gas. CVEC has taken an ownership position in Frontline and will work with Frontline, employees to design a gasifier that meets specific ethanol plant needs, according to Jason Jerke, CVEC process engineer. "Not only will we implement it here at CVEC, but we'll have firsthand input in the design and integration into other existing facilities," Jerke told EPM. "We see biomass utilization being an integral part of ethanol's future."

CVEC will develop the gasifier design in three phases. In phase one, CVEC will build a pilot unit that will take in 35 to 70 tons of biomass per day. Initially, the plant will use modified distillers grains produced at the ethanol plant as a test feedstock. In the future, Jerke said CVEC wants to develop a "flexible fuel" gasifier that could use corn stover and wood chips as well. "We're ready to take the technology up to demonstration scale right now but not necessarily commercial scale. We'll work out any integration and design issues here on the pilot."

In phase two, CVEC and Frontline will develop technologies to clean the producer gas. Conventional gasifiers convert biomass into a producer gas that can be used as fuel, but it typically contains ash and tar as well. "Our plan is to produce a cleaner producer gas—a true syngas—which should improve the efficiency of the conversion and allow us to distribute the fuel through ductwork to multiple burner sites."
Phase three will be to implement a commercial-scale gasifier into plant operations. It would "replace essentially all natural gas here at CVEC," Jerke said. He wasn't able to give an exact timeline as to when each phase will be completed, but he estimated the entire project will be complete within the next three years, with sales of gasifiers at other sites beginning within two years.

Not only will a gasifier spare CVEC from highly volatile and expensive natural gas prices, it will also allow CVEC to begin to develop a biomass infrastructure. This is necessary for producing cellulosic ethanol in the future, according to CVEC General Manager Bill Lee. "Relief from the high cost of natural gas is the immediate opportunity," Lee told EPM. "Whether it's converting cellulose to energy or to products, it seems obvious to us that gasification is going to be a key unit operation in the biorefinery of the future. Producing ethanol from cellulose is in the back of our mind, but we're not quite there yet. This project puts a couple pieces in play at our facility that would be needed for that."