Tests of Proprietary Chemical Additives as Antiscalants for Hypersaline Geothermal Brine. Final Report

摘要

The Lawrence Livermore Laboratory brine treatment test system has been used to carry out a short-term evaluation of a number of proprietary chemical additives as antiscalants for the hypersaline brine of the Salton Sea Geothermal Field. In addition, a test of sludge seeding was conducted as a technique for scale control. The effect of each additive on the rate of precipitation of silica from the effluent brine at 90 exp 0 C was measured, and scaling rates of brine treated with nine of the additives were measured at 125 and 210 exp 0 C. Corrosion rates of mild steel in the treated brines were estimated using Petrolite linear polarization resistance equipment. None of the additives had a direct effect on the rates of silica precipitation, and none had a beneficial effect on the scale formed at 210 exp 0 C. At 125 exp 0 C, two additives, Drewsperse 747 (Drew Chemical) and SC-210 (Southwest Specialty Chemicals) afforded a marginal degree of scale reduction. The Austral-Erwin additive diminished the adherence of scale formed at points of high velocity fluid flow but increased solids accumulation at other points. Sludge seeding shows some promise because it reduces the degree of silica supersaturation of the brine. Results of analyses of solids precipitated from effluent brines (Woolsey No. 1 and acidified Magmamax No. 1) are presented. (ERA citation 06:000656)