Energy uses for cotton ginning in Australia

Ginning is an energy intensive process. This paper evaluates the energy usage inside the cotton gins in Australia. Benchmark electricity use is found to range between 44 and 66 kWh per bale, with average being 52.3 kWh. The electricity consumption for different gins is nearly linearly correlated with bale numbers produced. The electricity network charge is a significant cost in cotton ginning operations. All gins monitored had an overall power factor of higher than 0.85. It is found that drying gas usage is strongly influenced by the cotton moisture reduction and regulated drying temperature. Overall, electricity and gas usage comprises about 61% and 39% respectively of total energy use (GJ/bale). 60.38 kg of CO2 are emitted for ginning each bale of cotton. A method for detailed monitoring of energy performance in cotton gins is developed and described. Detailed monitoring and analysis are carried out at two gin sites. It is found that changes in trash content in the module, degree of moisture and lint quality produced do not have significant influence on electricity usage, while the cotton variety is shown to affect the energy usage. Overall, cotton handling is found to be the largest energy user and it takes up to nearly 50% of power use in both gins. Packaging and handling together use some 70% of total power required.