Combined Cycle Power Plants Water Purification Unit Life Cycle Assessment for Replacing Water Wastage

ABSTRACT The increasing global population has led to a growing demand for energy across various sectors. This increased demand is met by enhancing the capacity of power generation facilities, such as combined cycle power plants (CCPPs). As the capacity of these plants increases, so does the volume of water lost during power generation. Replenishing this lost water requires energy for seawater treatment, contributing to higher greenhouse gas emissions worldwide. These emissions exacerbate climate change—one of today's most pressing global challenges. Given that the environmental impacts of water treatment processes in CCPPs have been addressed in only a limited number of studies, the present research analyzes these impacts using life cycle assessment (LCA) at the Neka power plant in Iran. The assessment was performed using SimaPro software, with results presented for 18 midpoints and three endpoints according to the ISO 14040‐44 standards. The midpoint results indicate that for each cubic meter of treated water produced, the thermal method releases 8.85 kg of CO₂, while the reverse osmosis method releases only 3.2 kg of CO₂. Regarding the endpoint impacts, the thermal method results in final impacts of 0.0000355 DALY for human health, 0.000000122 species·yr for ecosystems, and 1.2 (USD2013) for resources. In contrast, the reverse osmosis method shows impacts of 0.0000536 DALY for human health, 0.000000374 species·yr for ecosystems, and 0.422 (USD2013) for resources. These findings indicate that the thermal water treatment process has lower detrimental effects on human health and ecosystems compared to the reverse osmosis process, making it the more environmentally favorable option.