Zero discharge desalination with mineral recovery using multiple-effect vapor adsorption

Desalination is a key tool to address the global water scarcity crisis. Current technologies cannot meet the need for desalination due to high energy demands and toxic brine discharge. For example, global electricity production would need to increase by 5% to power current desalination plants. No commercially viable solutions exist for treating brine, therefore is often discharged into the environment. Additionally, moderate temperature (90-150) geothermal aquifers are attractive potential feed waters for desalination due to their mineral content as well as heat. GreenBlu, Inc. is developing and commercializing a distiller and zero liquid discharge crystallizer that solve the major drawbacks of current desalination technologies. Our patented Vapor Adsorption Distillation with Energy Recycling (VADER™) technique is a thermally- driven cycle can use any source of heat (geothermal, solar, waste) at temperatures in the range of 90-150°C. The distiller and crystallizer respectively produce fresh water, and convert concentrated brine to valuable solids. In this Phase I effort we will adapt our technology to produce water and strategic minerals from geothermal sources. The tasks include designing a cost-effective combined heat exchanger and degasser to produce the thermal drive and conditioned feed water for our distillation and crystallization technologies. We will also demonstrate feasibility of key chemical processing steps required for commercial recovery of valuable minerals from concentrated brine. Additionally, we will identify geothermal aquifers with commercially viable combinations of extractable volume, temperature and water chemistry. Technologies we develop in this Phase I award will lead to several commercial applications with important strategic and environmental benefits. Most important among these are enabling wide application of inland desalination where brine disposal costs severely impair commercial deployment, and development of domestic sources of some minerals identified as critical by the Department of Energy.