Investigation of water and carbon footprint reductions employing best available techniques in the textile sector

Abstract

This study includes a new approach in terms of connecting best available technique (BAT) selection/decision to water and carbon footprint evaluations in addition to economical and environmental performance criteria. This new approach was applied to an integrated textile facility mainly employing cotton fabric finishing and printing-dyeing. After potential implementation of selected 12 BATs, the reduction potentials in the existing water/carbon footprints were calculated. The blue water, grey water and total water footprint values of the facility were found to be 126, 837 and 963 L/kg product, respectively. The total carbon footprint value of the facility was found to be 7.011 kg CO2eq/kg product, and most of this comes from steam use. The optimization of resin regeneration frequency/duration and washing-rinsing steps in the water softening system via online hardness sensors provides 20–30% reductions in blue water footprint values. It was calculated that when BATs from 1 to 7 together are implemented in the facility, an average of 68.5% reduction in the total water footprint could be achieved. Alternatively, when BATs 1–5 and 8 are implemented, such reduction is 45.6%, highlighting the effectiveness of the selected BATs. BAT 9 exhibited the highest reduction in total carbon footprints due to the fact that it is related to minimization of energy losses. If all selected BATs are to be implemented in the facility, a reduction of 1.179 kg CO2eq/kg product could be achieved in the total carbon footprint, corresponding to 16.8% reduction. Significant reductions in energy consumption could be achieved through techniques/applications such as isolation of hot surfaces, reducing reprocesses by improving dyehouse-laboratory coordination, optimizing recipes and applying correct dyeing techniques at once, making lighting systems efficient, process modifications/optimizations in pre-treatment and final finishing processes, and reducing water consumption in processes requiring hot water. This study indicated that selection and application of BATs in industries should be coupled with water/carbon footprint evaluations.