Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2007
Publication Date: 6/15/2007
Citation: Holt, G.A., Wedegaertner, T. 2007. Gin waste as a fuel source: Segregation is good [abstract]. In: Proceedings of the National Cotton Council Beltwide Cotton Conferences, January 9-12, 2007, New Orleans, Louisiana. 2007 CDROM. p. 2085.
Technical Abstract: Over the past few decades, numerous studies have looked at utilizing the waste from cotton gins as a fuel source. In 2000, a study was performed to quantify various analytical properties of cotton gin byproducts (CGB) generated from select machinery used in the ginning process. In the study, the fuel and sieve analyses of the CGB obtained from specific machinery groups were presented. The presentation of the data emphasized the importance of not recombining the CGB once separated by the various pieces of equipment in the ginning process. However, most CGB generated by cotton gins today are not kept separate, but combined into one location (bur house). Since one of the biggest hindrances to utilizing CGB as a fuel source is the amount of ash in the fuel and since most gins are not separating their gin waste, a study was conducted to reprocess the gin waste generated by most cotton gins across the cotton belt to determine if the waste could be sufficiently cleaned for use as a fuel in either residential or commercial applications. Gin waste was collected from four cotton gins, two in West Texas and two in the south. The objective of this study was to process CGB collected from these four gins using conventional precleaning equipment found in a commercial gin and measure properties relevant to using the material as a fuel source. The equipment used in was: 1) unloading separator, 2) cylinder cleaner, and 3) extractor. Fuel properties were measured on the waste stream from each piece of equipment as well as the output from the extractor ("cleaned" waste). The sieve results showed approximately 76% of the mass with particles larger than 0.023 in (30-mesh screen). Average ash content for materials passing through the 30-mesh screen was 22%. The average percent mass from the precleaning equipment was: separator suction = 17%, cylinder cleaner = 41%, extractor = 27%, "cleaned" waste = 15%. The ash content and heating values for the biomass recovered from each equipment stream were: separator suction (26%, 6421 BTU/lb), cylinder cleaner (13%, 7221 BTU/lb), extractor (6%, 7444 BTU/lb), "cleaned" waste (5%, 7326 BTU/lb). Variation of the data was greatest for the separator suction and cylinder cleaner waste streams. The separator suction data had standard deviations of 15% (ash content) and 1585 BTU/lb (heating value). The extractor and "cleaned" waste data had an ash content standard deviation less than 1% and a heating value standard deviation less than 200 BTU/lb. When using CGB as a fuel, it is best to keep the material separated as it is being generated from the ginning process. When the biomass material has already been combined, the present precleaning equipment currently used in a majority of cotton gins is a good way to clean CGB for commercial fuel use applications.