Comprehensive exergy, exergoeconomic, exergoenvironmental and energy audit assessment in a textile factory

In the industry, the discussion of energy and exergy analysis has gained increasing importance due to human needs from the past to the present. In the textile industry, this analysis has only been implemented in a limited manner and in isolated units. Specifically, in the dyeing, printing, and finishing units, steam and hot oil energy is utilized for heating processes. This heating requirement is met by steam boilers and hot oil boilers, which are essential for the operation of an integrated system. Identifying factors of energy loss and pollutant production, along with applying energy improvement techniques in textile factories, can significantly reduce the problems associated with fossil fuels. To identify potential energy and environmental improvements, an energy audit was conducted throughout the Borujerd Textile Factory in Iran, which goes beyond previous fragmented and isolated assessments to provide a comprehensive review of the entire system. This audit integrated thermography and flue gas analysis to enhance the accuracy and effectiveness of performance evaluation. By performing exergy, exergoeconomic, and exergoenvironmental (4E) analyses, the performance of the existing system was evaluated, providing a comprehensive overview of efficiency and the potential for improvements and optimizations. Environmental impact analysis was conducted using life cycle assessment in SimaPro for different sections of the plant. The results indicate that the most significant exergy destruction occurs in steam boilers and hot oil boilers, totaling 33.5 MW and 91%, respectively, as well as the washing after printing machine in the dyeing department, accounting for 3% of total exergy destruction due to high energy wastage and low efficiency in these devices. The cost rate of overall exergy destruction is estimated at $61.1 per hour. The highest environmental impacts were observed for steam boilers and the pad steam machine in the dyeing department, primarily due to the equipment's structure and the use of polluting materials that contribute to emissions from these devices. After the energy audit, the most effective solutions to the identified problems were proposed. It was also determined that the most significant heat loss occurs in pad steam machines, washing after printing, and bleaching washing machines.