Rethinking Salt Supply Chains: Cost and Emissions Analysis for Coproduction of Salt and Fresh Water from U.S. Seawater

Is it feasible to build desalination plants for the coproduction of salt and fresh water from U.S. seawater that could lead to a restructuring of supply chains for salt imports? As it is predicted that climate change will increase water stress worldwide, an increasing number of countries are using desalination plants to generate fresh water. In most such cases, residual concentrates must be disposed of, and the disposal cost is increasing as countries are becoming more environmentally conscious. Selective salt recovery can help to alleviate this issue as it reduces the need for concentrate disposal and generates additional revenue. To gain some insights into the costs and benefits of coproduction plants, we have collected data on current desalination practices and salt imports in the United States along with the manufacturing costs and energy requirements for coproduction plants. We have used this data to build an optimization model to determine an optimal number and location of coproduction plants in the United States and their potential markets for the sale of coproduced salt. In our analysis, we consider a different total number of coproduction facilities, and for each configuration, we evaluate the resulting net water cost and carbon emissions impact. Our results indicate that there exists the potential for building several coproduction plants in the United States that would be both financially competitive with existing desalination plants and lead to a reduction in carbon emissions. This information might be of use to both governments and businesses when they make decisions about the type of desalination facilities built and the implemented “polluter pays” policies.