Rethinking Salt Supply Chains: Cost and Emissions Analysis for Co-production of Salt and Freshwater from U.S. Seawater

Abstract

Is it feasible to build desalination plants for the co-production of salt and freshwater 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 freshwater. 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 co-production plants, we have collected data on current desalination practices and salt imports in the U.S., along with the manufacturing costs and energy requirements for co-production plants. We have used this data to build an optimization model to determine an optimal number and location of co-production plants in the U.S. and their potential markets for the sale of co-produced salt. In our analysis, we have considered a different total number of co-production facilities, and for each configuration we evaluated the resulting net water cost and carbon emissions impact. Our results indicate that there exists the potential for building several co-production plants in the U.S. 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.