DEVELOPMENTS IN GEOTHERMAL-ENERGY IN MEXICO .39. EXTRACTION OF USEFUL HEAT AND SILICA REMOVAL FROM GEOTHERMAL BRINE UTILIZING LIQUID FLUIDIZED-BED HEAT-EXCHANGERS

Liquid fluidized bed heat exchangers can be utilized for the recovery of heat from geothermal brine in order to avoid scaling. At the same time, these heat exchangers remove silica from the geothermal brine. A new parameter, obtained from the bed expansion and referred to as the porosity of transition, is defined. This parameter contributes to a better understanding of systems utilizing liquid fluidized bed heat exchangers. From the model proposed by Goto [J. Phys. Chem. 60, 1007-1008 (1956)] for silica polymerization and modified by Axtmann [Geothermics 15, 185-191 (1986)] for silica removal, the rate of reaction constant is expressed as a function of silica equilibrium monomer concentration (solubility).