Biomass gasification

At the E3 conference on November 7, 2011, Lowell Rasmussen from the U of MN Morris spoke about the 15 million BTU biomass gasification plant which uses corn cobs and wood chips to provide steam heat and chill water for the 1 million square foot campus. The process of getting the boiler up and operating was not easy as caked mineral deposits had to be physically removed from the boiler when the temperature of the operation was not properly controlled.

Initial research had focused on the use of loose corn stover as a fuel.  There were problems as this material needed to be compacted to burn properly.  As the cost of natural gas has come down, they needed a material that could be used without additional processing.   Corn cobs were the best fit.   The cobs could be stored during the winter, they did not require additional equipment during harvesting and the cobs remove fewer nutrients out of the soil than the corn stover.   The contract with the farmer fixed the price of the corn cobs  to the BTU cost of natural gas. The farmer supplying the corn cobs reapplies the char left over from the process to the soil to reduce the soil nutrient loss.

For a virtual tour of the biomass facility go to this link from the web site on U of MN Renewable Energy Initiatives.

Model of the biomass facility