|
Poster Presentation 5-10 Overall Energy Balance for the Corn Stover to Ethanol Process Brianna G. Atherton, Mark F. Ruth, John L. Jechura National Renewable Energy Laboratory 1617 Cole Blvd. Golden, CO 80401
Telephone: (303) 384-6874; Fax: (303) 384-6827; E-mail: mark_ruth@nrel.gov
The National Renewable Energy Laboratory (NREL) has modeled biomass-to-ethanol production processes for over ten years. The most recent generation of the process model utilizes a corn stover feedstock that is processed using co-current dilute acid prehydrolysis with simultaneous enzymatic saccharification and co-fermentation of the sugars to ethanol. In addition to the core process, all ancillary areas (feed handling, product recovery and purification, wastewater treatment, lignin burner, boiler and turbogenerator, and utilities) are included in a single ASPEN Plus process simulation.
Aspen Plus performs material and energy balances throughout the process but the energy calculations do not use a single reference state. A single reference state is necessary to put all the energy flows on a common basis for comparison purposes. In this analysis, the reference state is based upon the higher heating values (HHV) of the individual components allowing the energy content of all feed, intermediate, and product streams to be compared. This analysis yields important results such as the magnitude of energy available in entry and exit streams and the energy yield to ethanol. These results are compared to energy yields in other fuel and chemical production processes.
|