Biomass Integrated Gasification Combined Cycle for Heat and Power at Ethanol Plants

Abstract

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 coproducts 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 (50 million gallons) per year could produce 30.4 MW of power while supplying all its process heat needs using ethanol coproducts 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.