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ARS Home » Research » Publications at this Location » Publication #202495

Title: Engineering process and cost model for a conventional corn wet milling facility

Author
item Ramirez, Edna
item Johnston, David
item McAloon, Andrew
item Yee, Winnie
item SINGH, VIJAY - UNIV. OF ILLINOIS, URBANA

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/17/2007
Publication Date: 11/30/2007
Citation: Ramirez, E., Johnston, D., Mcaloon, A.J., Yee, W.C., Singh, V. 2008. Engineering process and cost model for a conventional corn wet milling facility. Industrial Crops and Products 27, p.91-97.

Interpretive Summary: Conventional wet milling of corn is a process designed for the recovery and purification of starch and coproducts (germ, gluten, fiber and steep liquor). The process includes grain cleaning, steeping, germ separation and recovery, fiber separation and recovery, gluten separation and recovery and starch separation. To date, there is not a published model available to help understand the engineering and cost impact of the wet milling process. Based on this need, process engineering and cost models for a corn wet milling process have been developed for a "generic" processing plant with a capacity of 100,000 bushels per day. The models were developed using process and cost simulation software (SuperPro Designer®). Using the information from the model, we can estimate the cost of production per pound of starch using the input prices for corn and other wet milling coproducts. We can also use the models to test other processing technologies, to scale-up new wet milling technologies and to predict the impact of changes in process inputs, products and unit operations. This model will be useful for educational, non-commercial and research purposes by government research scientists, academia and the corn industry.

Technical Abstract: Conventional wet milling of corn is a process designed for the recovery and purification of starch and several coproducts (germ, gluten, fiber and steep liquor). The total starch produced by the wet milling industry in the USA in 2004 equaled 21.5 billion kilograms, including modified starches and starches used for sweeteners and ethanol production. Process engineering and cost models for a corn wet milling process have been developed for a "generic" processing plant with a capacity of 2.54 million kg of corn per day (100,000 bu/day). The process includes grain cleaning, steeping, germ separation and recovery, fiber separation and recovery, gluten separation and recovery and starch separation. Information for the development of the models was obtained from a variety of technical sources including commercial wet milling companies, industry experts, suppliers of technology and equipment to the corn wet milling industry and others knowledgeable in the wet milling of corn. The models were developed using process and cost simulation software (SuperPro Designer®) and include processing information such as the composition and the size of the various process streams, descriptions of the various unit operations and detailed breakdowns of the operating and capital cost of the facility. Based on the information from the model, we can estimate the cost of production per pound of starch using the input prices for corn and other wet milling coproducts. We have also used the model to conduct a variety of sensitivity studies utilizing modifications such as feedstock costs, corn compositional variations, and the sale of wet corn gluten feed. The model is also being used as a base-case for the development of models to test alternative processing technologies and to help in the scale-up and commercialization of new wet milling technologies. This model is available upon request from the authors for educational, non-commercial and research uses.