Nitrogen and sulfur concentrations and flow rates of corn wet-milling streams

Nitrogen (N) and sulfur (S) concentrations can affect the market value of coproducts from corn wet-milling. The composition of parent streams would be expected to affect composition of the resulting coproducts but there are few published data available to examine this relationship. Concentration and flow data are needed to determine which streams are important in modifying N and S coproduct concentrations. The objective was to measure concentrations and flows of N and S in corn wet-milling streams. Samples were taken from 21 process streams from 3 wet-milling plants during two periods of three weeks each; N and S concentrations of each sample were determined. There were large differences in N and S concentrations among processing streams; within most streams, N and S concentrations were similar among plants. Concentrations of N and S were related inversely to flow rates. Steepwater and gluten streams contained most of the N and S flow and provide an opportunity for modification. The process water stream carried large quantities of N and S and represents another opportunity for improving process efficiency and coproduct value.