Theses and Dissertations

Issuing Body

Mississippi State University


Srinivasan, Radhakrishnan

Committee Member

To, Filip Suminto D.

Committee Member

Davis, Jeremiah D.

Committee Member

Prewitt, M. Lynn

Date of Degree


Document Type

Dissertation - Open Access


Biological Engineering

Degree Name

Doctor of Philosophy (Ph.D)


James Worth Bagley College of Engineering


Department of Agricultural and Biological Engineering


Corn is widely used as animal feed as well as for fuel ethanol production. Fiber present in corn is not digested well by non-ruminants such as chicken and swine. Also, this fiber does not participate in conversion of starch to ethanol. Fiber separation from corn flour using the Elusieve process, a combination of sieving and air classification, would result in high starch animal feed and increase ethanol productivity. The objective of the first part of this dissertation was to understand the effect of retention screen size in the hammer mill on fiber separation from corn flour using the Elusieve process. Four different retention screen opening sizes were studied. The highest starch content of 65.2% was in the enhanced flour obtained by using 3.2 mm (8/64") retention screen; starch content of the original corn flour was 62.5%. The objective of the second part was to evaluate Elusieve process for sorghum flour. The combination of hammer milling and Elusieve process was less effective for sorghum flour compared to corn flour. The objectives of the third part were to determine the operating air velocities for corn particles and to compare physical properties of corn particles with that of Distillers’ dried grains with soluble (DDGS) particles. The operating air velocities for large, medium and small corn size fractions were 2.9 to 3.8, 2.8 to 3.0 and 2.5 to 2.6 m/s, respectively. Densities of nonfiber particles for corn flour were higher than for DDGS (earlier study). Compared to DDGS, the difference between fiber and nonfiber particle terminal velocities was higher for corn, signifying relative ease of operability for fiber separation from corn flour. The objective of the fourth part was to study the effect of corn moisture content on fiber separation. There was no effect of moisture content on fiber separation. The objective of the fifth part was to assess the economics of the Elusieve process. For ethanol plant of 50 million gallons/year capacity (50 MGY), payback period would be 3.1 years. The payback period for implementing Elusieve process in an integrated broiler operation with 8 million birds capacity would be 0.4 to 1.3 years.