Densification of corn residues for producing pelletized biomass fuels

Abstract

Corn is one of the main agricultural and economic crops in many countries whose residues after harvesting are generated in huge amounts. These corn residues can potentially be used as a renewable feedstock for the production of fuels, heat, power, and chemicals. For ease of handling and use, the bulk approach, storage, and transport properties of these corn residues should be enhanced with densification into pellets. In this work, palletization and pellet properties of corn residues (cobs and corn husks) were studied. The ground corncobs and corn husks at different moisture contents (10 to 30%) were fed into a flat die pelletizing mill. The pellets were then dried using a solar-powered greenhouse dryer for 3 days. The properties of the dried pellets obtained were analyzed. It was observed that the corncobs and corn husks with initial moisture content in the range of 15% - 20% provided a positive effect for the densification process. About 45% of the corncobs were successfully formed into pellets with a length of 10-30 mm and bulk density of 213-232 kg/m3, while about 56 to 77% was obtained for the corn husk pellets under a similar range of moisture content with the same pellet length and bulk density of 244 – 304 kg/m3. This result showed that the bulk approach properties of both corn cobs and corn husks can be improved through densification. Further study will focus on the improvement of densification by adding binders.