Biomass Integrated Gasification Combined Cycle (BIGCC) technology can be used to generate process heat and significant amounts of electricity at dry-grind ethanol facilities by utilizing the ethanol process co-products and other biomass sources. These systems can reduce fuel costs for ethanol plants, improve the renewable energy balance of dry-grind ethanol production, and provide reliable renewable electricity for process use and for sale to the local utility. An Aspen Plus model of the dry-grind ethanol process is used as the basis for a subsequent gasification system model. A twin fluidized bed steam gasification configuration based on the SilvaGas process is used to generate synthesis gas. The results show that a dry-grind ethanol facility with a capacity of 190 million liters per year could produce 30.4 MWe of power while supplying all its process heat needs using ethanol co-products and corn cobs. This configuration results in a three fold improvement in the amount of renewable energy produced per unit of fossil energy used compared to a conventional ethanol production process using natural gas.
Bibliographical noteFunding Information:
We would like to thank Davenport Dryer Company for providing steam tube dryer information. Thanks also to Frank Taylor and Andy McAloon of USDA ARS for their help with the Aspen Plus ethanol process model. This work was supported by a grant from the Xcel Energy Renewable Development Fund as well as funds from the Minnesota Agricultural Experiment Station.
- Combined cycle
- Combined heat and power
- Ethanol production