Theoretical and experimental perspectives in utilizing nanobubbles as inhibitors of corrosion and scale in geothermal power plant

Corrosion and scaling have presented serious technical challenges to make geothermal power reliable and affordable. Due to the large quantities of geothermal water that must be processed to obtain heat, many conventional chemical inhibitors are not economically viable. Moreover, most chemical inhibitors are costly and can readily change the fluid chemistry that results in generating undesired products. Nanobubbles are environment-friendly, inexpensive, and easy-to-use, and thus have been used in a broad area of applications by taking advantage of their unique physicochemical properties. Here we propose that nanobubbles can be used as inhibitors of corrosion and scaling in the geothermal system. First, this paper reviews the mitigation methods for corrosion and scale currently used in a geothermal power system, and second, provides an overview on the novel use of nanobubbles as inhibitors of corrosion and scale from theoretical and experimental perspectives. We suggest that nanobubbles can be powerful, chemically benign, environment-friendly, and inexpensive inhibitors of corrosion and scaling, compared with the chemical products commonly used. The mechanisms on how nanobubbles act as inhibitors and their inhibition effectiveness vary with different chemical conditions of geothermal fluid.