skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: On-line tests of organic additives for the inhibition of the precipitation of silica from hypersaline geothermal brine III. Scaling measurements and tests of other methods of brine modification

Technical Report ·
DOI:https://doi.org/10.2172/6080883· OSTI ID:6080883

The Lawrence Livermore Laboratory Brine Treatment Test System at Niland, Imperial Valley, California, has been used to evaluate a promising organic compound to the abatement of siliceous scale in brine handling equipment. Three-day scaling tests of Ethoquad 18/25 (Armak) alone (at a concentration of 25 ppM), and Ethoquad in combination with Dequest 2060 (Monsanto) showed a scaling rate reduction of 40 to 80% at 90/sup 0/C, 15 to 40% at 125/sup 0/C, and no reduction of 210/sup 0/C. Changes in the salinity of the brine during the test series were found to have a pronounced effect on the rates of precipitation of silia and scaling, and on the effectiveness of the Ethoquad as an inhibitor. Additional data are reported on the reduction of scale by acidification with hydrochloric acid, and some of the effects of producing acidified brine by the addition of hydrogen peroxide were measured. The influence of brine salinity and pH (altered with sodium hydroxide) on the distribution of monomeric silica in the flash system was examined. Several new compounds were tested as silica precipitation inhibitors and one, PAE HC1 (Dynapol poly(aminoethylene, HC1 salt)), was found to be the most potent yet discovered. Proposals for future studies are outlined.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
6080883
Report Number(s):
UCID-18238
Country of Publication:
United States
Language:
English