Recent progress, economic potential, and environmental benefits of mineral recovery geothermal brine treatment systems

In the last few years, geothermal energy filled a critical spot as a reliable, environmentally friendly, and weather-independent thermal energy resource for use in several critical applications. Among the main challenges encountered in maintaining geothermal power plants are the scale and corrosion that damage the interior of the power plant elements due to the harsh chemical compositions existing in the geofluid as the working fluid for geothermal power plants. These problematic chemical elements can be of great use if extracted from the geofluid and utilized either by selling them as raw materials or by producing end-user products, thus achieving higher economic benefits. The economic and environmental aspects of these systems were not discussed in detail previously; thus, a work that covers this gap is highly needed. This work summarizes the progress done on treatment of geothermal brine by removal and recovery of minerals. Discussions of the methods used to remove various elements, namely boron, arsenic, silica, radionuclides, high value metals, lithium, and sulfur, are presented, and future research directions are included. Next, the environmental aspects and economic benefits of selling and reutilization of the recovered minerals are discussed. The authors concluded that these treatment systems are of high economic attractiveness, yet more pilot-scale studies in existing geothermal power plant are required. Furthermore, these treatment systems result in significantly reducing the environmental hazards and health risk associated with such fluids. However, experimental studies that discuss the safe use of treated geothermal brine are still required.