Climate Change and the Textile Industry: The Carbon Footprint of Dyes

Dyes play an important role in textile production, but their contribution to air pollution and harming human health have raised concerns and remain an international problem. The key to overcoming this challenge is to assess how much greenhouse gases are being generated and the hotspots which guide decision-making process toward more sustainable options. This article established a carbon footprint calculation method for disperse dyes. First, the system boundary description and the functional unit were discussed. Second, the carbon footprint inventory analysis was determined. What’s more, the calculation method, allocation method and emission factors were proposed. It was intended to be practical and effective based on three typical disperse dyes in China. The results showed that the carbon footprints of Disperse Blue 79, Disperse Red 167, and Disperse Orange 61 corresponded to 8.28 t CO ₂ eq/t, 8.07 t CO ₂ eq/t, and 7.48 t CO ₂ eq/t, respectively. For the three disperse dyes, the carbon emissions of dispersing agent melamine-formaldehyde resin and liquid ammonia consumption were the dominant emission sources. The steam and electricity were the two major sources of carbon emissions caused by energy usage. The homogenization and the wastewater treatment process were the two largest emission emitters. The sensitivity analysis showed that the total product carbon footprint was mostly sensitive to dispersing agent melamine-formaldehyde resin changes, followed by steam, liquid ammonia, and electricity. The results show that disperse dye production have great potential for improvement. The reduction options for the emissions of the disperse dyes production can be concluded by the optimization of the production process and technology for dispersing agent melamine-formaldehyde resin, liquid ammonia, electricity, and steam. Through the calculation, the influencing factors for the carbon footprint can be analyzed and highlighted. The method provides a comprehensive understanding of environmental impacts with dyes, driving the adoption of sustainable dyeing practices.