Techno-Economic Modeling of a Corn Based Ethanol Plant in 2011

As studies continue to examine new value added uses for ethanol coproducts, it is important to have means to easily determine the feasibility of the processing steps involved. Many industries widely use computer simulation programs for this purpose, and for planning the use of resources and equipment capacities, and to determine processing costs. The objective of this project was to determine the sensitivity of 40 million gal/y corn-based ethanol plant model to changes in input material prices, product market prices, and various coproduct processing scenarios (i.e., oil extraction and drying of DDGS). The techno-economics of the base case ethanol plant were examined by factorially adjusting material and market costs, as well as adjusting the quantities of distillers wet grains (DWG), distillers dried grains with solubles (DDGS), and corn oil produced. The simulations verified that corn price has the greatest impact on the overall annual operating costs for the ethanol plant, and that the market price of ethanol has the greatest impact on annual revenues. The effect of coproduct processing on utility usage was also observed; oil extraction and drying of DDGS consumed substantially more energy and had higher capital costs than production of DWG alone. It was apparent that coproducts are an essential component to the sustainability of an ethanol plant in that: 1) they have continued marketability to the livestock industry, and 2) processing is not overly-expensive. This study has provided a basis for further exploration of the feasibility of new coproduct processing options, and illustrates the use of the model for determination of processing costs and revenues, as well as mass and energy balances.