Life cycle assessment of a hybrid reverse osmosis hydrate-based desalination process

Abstract

Trends in desalination technologies are shifting toward reducing the environmental impact of energy consumption while increasing economic feasibility. Accordingly, this study conducted a life cycle assessment (LCA) and an environmental life cycle cost (ELCC) analysis of a hybrid desalination process that combines reverse osmosis (RO) and hydrate-based desalination (HBD). The environmental impact assessment was conducted using the ReCiPe 2016 midpoint and endpoint methodology. Moreover, an ELCC analysis considering environmental cost (EC) was conducted to elucidate the influence of environmental impacts on economic performance. Case studies analyzed the environmental and economic differences arising from the use of four different feedstocks (natural gas liquid, soybean oil, palm oil fatty acid distillate, and used cooking oil) for propane as a hydrate former in HBD and assessed the impact of selling renewable energy certificates (RECs). The global warming potential (GWP) of the hybrid desalination process ranged from −2.66 to 0.04 kg CO2 eq/m3, with the lowest GWP when using used cooking oil and not selling RECs. This can be attributed to the energy savings compared to conventional desalination and indicates the importance of using sustainable feedstock to reduce the environmental impact of chemicals. The production costs when considering EC ranged from −2.86 to −2.29 $/m3, with the sale of electricity and RECs resulting in profits in all cases. In addition, using natural gas liquids and selling RECs was the most economical option. This study provides a comprehensive analysis of the environmental and economic impact of hybrid desalination technologies and highlights their potential as an alternative to conventional methods in terms of sustainability and profitability.