Preliminary results of tests of proprietary chemical additives, seeding, and other approaches for the reduction of scale in hypersaline geothermal systems

Technical Report · Thu Feb 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/6435972· OSTI ID:6435972

Harrar, J E; Locke, F E; Otto, Jr, C H; Deutscher, S B; Lim, R; Frey, W P; Quong, R; Lorensen, L E

The LLL field brine-scaling test system and a variety of measurement techniques have been used to test a group of eight proprietary additives from eight different companies, a hydroxyethylcellulose previously found to retard silica precipitation, and geothermal sludge as a seeding agent to reduce scaling. For each additive, scaling rates at both 210 and 125/sup 0/C and on three different materials--mild steel, Teflon, and Hastelloy C-276--were measured using test coupons. Sections of steel pipe and perforated screens also were exposed to the treated brine, silica precipitation rates in the effluent brine were measured by means of the electrochemical linear polarization resistance technique. Examination of the pipe sections and chemical analyses of the scales are not complete, thus only preliminary conclusions are reported here. It appears that, although none of the additives effected a dramatic reduction in scaling rates, several decreased the rate of scaling of mild steel at 125/sup 0/C by a factor of 2 to 3. Only hydroxyethylcellulose retards the rate of precipitation of silica in the effluent brine. Scaling rates could not be measured accurately in the seeding experiment because of its short duration, but this brine treatment had the desired effect, at 125/sup 0/C, of reducing the level of dissolved silica and hence the scaling tendency of the brine. Further experiments of this type will be conducted.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6435972
• Report Number(s): UCID-18051
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150903* -- Geothermal Engineering-- Corrosion
Scaling & Materials Development
ADDITIVES
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BRINES
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBOHYDRATES
CARBON COMPOUNDS
CARBONATES
CELLULOSE
CHALCOGENIDES
CHEMICAL ANALYSIS
CHROMIUM ALLOYS
FLUIDS
FLUORINATED ALIPHATIC HYDROCARBONS
GEOTHERMAL FLUIDS
Geothermal Legacy
HALOGENATED ALIPHATIC HYDROCARBONS
HASTELLOY C
HASTELLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
MINERALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
OXIDES
OXYGEN COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PIPES
PLASTICS
POLYETHYLENES
POLYMERS
POLYOLEFINS
POLYSACCHARIDES
POLYTETRAFLUOROETHYLENE
SACCHARIDES
SCALE CONTROL
SCALING
SCREENS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
STEELS
SULFIDES
SULFUR COMPOUNDS
TEFLON
TUNGSTEN ALLOYS