National Pulse: Recovering Thermal Energy from Textile Processing Wastewater to Tackle the Energy Crisis in the Textile Sector of Bangladesh

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The Civil and Environmental Engineering Department at North South University has pioneered an innovative solution to address the scarcity of natural gas in Bangladesh’s textile industries. Their research focused on harnessing heat energy from high-temperature wastewater in textile processing to preheat boiler water, proposing a heat exchanger to recover heat from treated wastewater before it enters the boiler. This process aims to elevate groundwater temperature before it reaches the boiler, reducing the energy needed to heat water for texturing and dyeing.

Textile production heavily relies on water and energy, using groundwater at 27.33 ± 1.46 oC for various processes. Currently, the wastewater discharged at a high temperature of 40.4 ± 8.7 oC doesn’t recover its thermal energy. Recovering this energy presents a renewable alternative to using natural gas and coal in boiler operations. The analysis suggests a potential annual energy recovery of 102 T kWh, saving 8.6 billion cubic meters of natural gas and 6,87,794 tons of coal, translating to 1.35 billion USD in energy cost savings annually. This reduction in coal and gas usage could decrease CO2 emissions by 24.8 million tons per annum, contributing significantly to a greener textile industry. This study was conducted by surveying 150 textile facilities in Bangladesh.

Additionally, new guidelines introduced in ECR 2023 impose restrictions on textile wastewater temperatures, emphasizing wastewater treatment upgrades to meet these standards. Employing waste-heat technologies can reduce emissions, improve energy efficiency, and cut production costs by minimizing resource waste.

This groundbreaking research differs from previous studies by focusing on harnessing energy from treated wastewater and establishing its direct correlation with reduced fossil fuel usage and CO2 emissions. Published in the Q1 Scopus Index Journal “Modelling of Earth Systems and Environment” by Springer Nature, the article titled “Energy Recovery Potential in Bangladesh from Elevated Temperature Textile Processing Wastewater: An Analysis of Energy Recovery, Energy Economics, and Reduction in Carbon Dioxide Emission”. The study was conducted by research assistants Md. Sahil Rafiq and Mohammad Shakhawat Hosen Apurba and supervised Professor Dr Nadim Reza Khandaker, Associate Professor Dr Mohammad Moshiur Rahman, and Senior Lecturer Haniyum Maria Khan.