Download or read book Study of Silica Scaling from Geothermal Brines written by United States. Dept. of Energy and published by . This book was released on 1978 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Silica Scaling from Geothermal Brines Final Report 15 November 1974 30 April 1977 written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation of silica from brines supersaturate in silicic acid was studied over a range of pH (4.5 to 6.5), temperature (75 to 105°C), salinity, and silicic acid concentration (700 to 1200 ppM as SiO2). The experimental technique involved analyses for molybdate-reactive silicic acid as a function of time after a supersaturated solution of Si(OH)4 was prepared by mixing aliquots of a stock silicate solution with buffered brine. The isothermal rate of SiO2 condensation is a strong function of supersaturation (C/Ce), pH, and salinity. The overall kinetics follow what is expected from the general theory of phase transitions. The kinetic results suggest that growth of nucleated particles is activation controlled, at least initially. The increase of condensation rate with salt content is attributed to a decrease in equilibrium solubility of SiO2. In effect, higher salt concentrations increase supersaturation and lead to faster nucleation. Higher nucleation and growth rates are observed at higher pH's. An increase of 1 pH unit increases rates by a factor of about 10. The pH dependence is consistent with the hypothesis that SiO(OH)3− is one of the reacting species. Temperature has little effect on condensation rate at a fixed initial silicic acid concentration. This result suggests that the increase in rate of activated steps brought about by increased temperature is essentially counterbalanced by a decrease in supersaturation (because of higher equilibrium solubility at higher temperatures). The kinetic results yield an activation energy of 17 kcal/mol for addition of silicic acid to a nucleated particle and 45 ergs/cm2 for the interfacial energy between precipitated silica and the brine. NaCl, KCl, CaCl2 and MgCl2 had no specific effect on condensation rate. However, NaF had a large effect on rate; a few ppM (15 to 100) of fluoride ion accelerate condensation substantially.
Download or read book Verkaufsf rderung im Lebensmitteleinzelhandel Programmiertes Informationssystem written by and published by . This book was released on 1971 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Brine Chemistry written by Michael R. Hoffmann and published by . This book was released on 1975 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silica Scaling in Simulated Geothermal Brines written by Oak Ridge National Laboratory and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silica Scaling in Simulated Geothermal Brines written by Oak Ridge National Laboratory and published by . This book was released on 1981 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry of Silica in Cerro Prieto Brines written by Oleh Weres and published by . This book was released on 1980 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry of Silica in Cerro Prieto Brines written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The precipitation of amorphous silica from synthetic geothermal brines which resemble the flashed brine at Cerro Prieto has been studied. It was found that part of the dissolved silica quickly polymerizes to form suspended colloidal silica. The colloidal silica flocculates and settles slowly at unmodified brine pH values near 7.35. Raising the pH of the brine to about 7.8 by adding base and stirring for a few minutes causes rapid and complete flocculation and settling. These results have been confirmed in the field using actual Cerro Prieto brine. Both in the laboratory and in the field quaternary amines were found to be effective with some brine compositions but not with others. Polyacrylamides do not work at all. These results suggest the following simple preinjection brine treatment process: age the brine for 10 to 20 minutes in a covered holding tank, add 20 to 30 ppM lime (CaO), stir for 5 minutes, and separate the flocculated silica from the brine using a conventional clarifier. The brine coming out of such a process will be almost completely free of suspended solids. The pilot plant tests needed to reduce this conceptual process to practice are discussed. The rate of deposition of silica scale from synthetic brines was separately studied. It was found that a modest decrease in pH could significantly reduce the scaling rate at a reasonable cost. The equilibrium chemistry of Cerro Prieto brine was studied theoretically. These calculations indicate that increasing the brine pH to remove silica might cause some precipitation of carbonate minerals, but also that this problem could easily be eliminated at a reasonable cost if it did arise.
Download or read book Brine Chemistry written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to recommend a reasonable program of brine chemistry research that will result in the development of methods for predicting and controlling scale deposition, and in guidelines for the selection of corrosion-resistant construction materials. First, background information, which is necessary for the understanding of the problems of scaling and corrosion in the Salton Sea KGRA, is presented through a review of the history of geothermal exploration and development in the Salton Sea. Second, literature relevant to the geochemistry of the Salton Sea field is reviewed and important results are emphasized. Third, current research efforts directed toward actual power plant construction are summarized and evaluated. Fourth, research which has been proposed but is not currently funded is discussed. Fifth, because silica scaling has been the most troublesome problem in the past, the basic chemistry of silica and its relationship to scaling is discussed. Sixth, recommendations for future research are made in which a fundamental engineering approach is emphasized. In this approach, experiments would be conducted on actual process equipment and detailed chemical analyses would be performed on site in well-equipped field laboratories. 88 references.
Download or read book Geothermal Project Summaries written by United States. Energy Research and Development Administration. Division of Geothermal Energy and published by . This book was released on 1976 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Brine Treatment written by Sidney L. Phillips and published by . This book was released on 1977 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Brine Treatment written by Sidney L. Phillips and published by . This book was released on 1977 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Brine Chemistry and Scaling at the Salton Sea Geothermal Field 1977 1979 Final Report written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarized are the results of investigations of brine chemistry, the effects of brine acidification and organic additives on the rate of scale formation and scale composition, and the use of other additives for scale control. A bibliography of reports describing these studies is included. Recommendations are given for techniques and approaches for further testing of additives for silica scale control.
Download or read book OUT Success Stories written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: DOE research helped develop the large, untapped geothermal resource beneath the Salton Sea in California's Imperial Valley. The very hot brines under high pressure make them excellent for electric power production. The brines are very corrosive and contain high concentrations of dissolved silica. DOE worked with San Diego Gas and Electric Company to find a solution to the silica-scaling problem. This innovative brine treatment eliminated scaling and made possible the development of the Salton Sea geothermal resource.
Download or read book Geothermal Energy Update written by and published by . This book was released on 1976 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1991 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silica Scale Formation in Simulated Geothermal Brine 290 to 355 F written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
