Synergy of Using Field Peas as an Ethanol Feedstock
Field peas were examined as a potential feedstock for co-fermentation with corn to produce ethanol. Ethanol production in ND is expected to exceed corn production shortly. Field peas are grown more easily in ND and serve as a good rotation crop with corn. Field peas could be mechanically fractionated into a starch-enriched fraction and a protein-enriched fraction. The starch could be used for ethanol production while the proteins could be used as a higher-value animal feed.
A technical and economic analysis was done on field pea fractionation and co-fermentation in a corn ethanol facility.
The economic feasibility of field peas as an ethanol feedstock depends on a number of factors such as the cost of that feedstock relative to corn, and the value of co-products such as pea hulls and a pea fraction rich in high-lysine protein. Four options were evaluated, ranging from a simple pea cleaning and grinding to double-pass milling and air classification. Spreadsheet models were developed to calculate the relative quantities of inputs and outputs for each of the four process scenarios. These models are available to the public at: www.ageng.ndsu.nodak.edu/fieldpea/
Major Results and Conclusions
Field pea starch fermented readily into ethanol with higher fermentation rates and yields than 100% corn fermentations. The economic advantages of these benefits do not outweigh the increased field pea fractionation costs at this time.
Detailed results are reported in:
Wilhelmi, A.J. 2008. Field Peas to Supplement Corn Ethanol: Engineering Process Models, Capital Investment, and Annual Operating Costs, M.S. Thesis, Agricultural & Biosystems Engineering, NDSU.