Principal component analysis found the impact of controlled and uncontrolled drying system variables.
Cotton gin fuel use can be minimized by avoiding excessive drying and minimizing conveying air.
Post-harvest processors should minimize the length of, and insulate, the duct from the burner to the mix point.
Abstract.Fuel price volatility and variable incoming cotton moisture levels make drying costs unpredictable, threatening cotton gin profitability. One means for managing this risk is improving fuel use efficiency. Fuel use audits were conducted in 26 commercial cotton gins over three seasons to elucidate industry best practices. Material flow and changes in moisture content were used to estimate beneficial drying energy. Airflow and temperature data were used to estimate fuel consumption. The ratio of these quantities, defined as fuel use efficiency, was included with twelve other variables in a multivariate statistical analysis. Principal component analysis identified two controlled variables that inversely correlated to fuel use efficiency: the length of the duct between the burner and the seed cotton mix point, and the volume of conveying air per unit mass of seed cotton. Minimizing these two variables could reduce the cost of fuel energy, provided that the air volume is sufficient to maintain material flow, drying, and gin processing rate even when receiving very wet cotton. Keywords: Drying, Energy conservation, Fuel consumption, Postharvest processing, Principal component analysis.