Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: January 18, 2006
Publication Date: May 15, 2006
Citation: Holt, G.A., Nakayama, F.S., Coffelt, T.A., Blodgett, T.L. 2006. Characteristics of fuel pellets produced from cotton gin by-products and guayule bagasse. In: Proceedings of the Beltwide Cotton Conferences, January 3-6, 2006, San Antonio, Texas. 2006 CDROM. p. 392-401. Interpretive Summary: Not required.
Technical Abstract: Utilizing agricultural plant wastes/residues from harvesting or agricultural processing operations can be an effective means of turning currently unused biomass into useful commodities. Despite extensive research efforts and the potential volume generated each year, very few uses for cotton gin by-products (CGB) have developed into widespread commercial acceptance. One possible solution is to increase the co-product value by blending two such products to make a product of higher value. The objectives of this study were to fabricate fuel pellets using CGB processed through the COBY Process utilizing different ingredients (including guayule bagasse), and to compare the physical properties and emissions during burning of the resulting pellets with conventional premium grade wood pellets. Two sources of CGB were used in conjunction with other ingredients to produce seven different types of CGB fuel pellets treatments. The names and ingredients used for the different treatments were: (1) Lbk 4, CGB from Lubbock, Texas with 4% added corn starch; (2) Lbk 10, CGB from Lubbock with 10% added corn starch; (3) Lbk 55, CGB from Lubbock with 5% added corn starch and 5% crude cottonseed oil; (4) Miss 4, CGB from Stoneville, Mississippi with 4% added corn starch; (5) Miss 10, CGB from Stoneville with 10% added corn starch; (6) Miss 55, CGB from Stoneville with 5% added corn starch and 5% crude cottonseed oil; (7) Guayule Mix, guayule bagasse (75%) mixed with Lbk 4 (25%); (8) commercial wood pellets. The results revealed that depending on the ingredients used and the method of manufacturing, an acceptable fuel pellet could be produced from CGB. However, when the fuel is burned in a commercial pellet stove without taking into consideration the air-to-fuel ratio necessary for a change in fuel type, the emissions for all CGB fuel pellets exceeded those of the premium grade wood pellet used in this study. One of the fuels used in this study that showed great potential was the Guayule Mix treatment. The emissions from firing the Guayule Mix fuel were the lowest of any of the CGB treatments as well as being closest to the wood pellet emissions. However, the Guayule Mix pellets still had a high ash content that would need to be addressed. The idea of blending one type of biomass to make up for the potential shortcomings of another is one of the items that surfaced when the results were evaluated. Future investigations involving fuel pellets from CGB will focus in the following areas: (1) assisting stove manufacturers in modifying or developing a stove to accommodate biomass fuel pellets that have differing fuel properties from conventional wood pellets, (2) refining the CGB process to minimize the ash content of the fuel, and/or (3) evaluate blending other biomasses with CGB to develop a fuel which can more readily be used in the existing pellet stoves currently available.