Processing Mixed Salts and CO2 Utilization

There are abundant, valuable mineral resources available in mixed sea salts, bitterns, and brines. These mineral resources are generally not being exploited because the separating products from these salt mixtures is challenging and cost prohibitive. In some cases, these mixed salt systems are not considered as waste because they have simply been stockpiled and are awaiting a practical processing technology. The salt industry needs a versatile, cost effective process that convert unused mixed salt systems into valuable chemical feedstocks on the scale of millions of tons per year in domestic markets. While many processes have been previously proposed in journal and patent literature, they remain unapplied by the salt industry because they use additives that are costprohibitive at such large scales. As an option, this processing capability should be able to also profitably consume millions of tons of carbon dioxide per year to produce salable carbonate minerals. The solution: Achieve cost effective processing of mixed salt systems by avoiding cost-prohibitive additives and extracting additional products, such as hydrochloric acid. Luna has developed a simple, energy efficient process to separate chemical feedstocks from mixed salt systems with this approach. The Phase I work: Luna developed innovative and effective acid/base chemistries and materials for dual phase membranes. The hybrid membrane concept was reduced to practice. The Phase II work: Luna will improve the performance and manufacturing of key materials and components and then scale up the separation technology to the benchtop scale. The technical work will be accompanied by process engineering and a detailed techno-economic analysis. This program will result in technology intensification and a well-developed assessment regarding the potential for industrial scale application. The commercial applications and benefits: The large scale production of hydrochloric acid, basic minerals, and other valuable chemicals from previously unusable salt commodities would enhance the productivity of the salt industry, improve resource management, and increase energy efficiency in domestic manufacturing. With potential process scales on the order of several million tons of mixed salt per year, the resulting byproducts of the process will lower the feedstock costs for fertilizer, plastics, water treatment, metal/steel, paper/pulp, and carbon sequestration industries.