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Louis Martino - One of the best experts on this subject based on the ideXlab platform.
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Geothermal produced fluids: Characteristics, treatment technologies, and management options
Renewable and Sustainable Energy Reviews, 2015Co-Authors: Molly Finster, Jenna Schroeder, Corrie Clark, Louis MartinoAbstract:Geothermal power plants use geothermal fluids as a resource and create waste residuals as part of the power generation process. Both the geofluid resource and waste stream are considered produced fluids. The chemical and physical nature of produced fluids can have a major impact on the geothermal power industry and influence the feasibility of power development, exploration approaches, plant design, operating practices, and reuse/disposal of residuals. In general, produced fluids include anything that comes out of a geothermal field and must subsequently be managed on the surface. These fluids vary greatly, depending on the reservoir being harnessed, plant design, and life cycle stage in which the fluid exists, but generally include water and fluids used to drill wells, fluids used to stimulate wells in enhanced geothermal systems, and makeup and/or cooling water used during operation of a power plant. Additional geothermal-related produced fluids include many substances that are similar to waste streams from the oil and gas industry, such as Scale, flash tank solids, precipitated solids from brine treatment, hydrogen sulfide, and cooling-tower-related waste. This review paper aims to provide baseline knowledge on specific technologies and technology areas associated with geothermal power production. Specifically, this research focused on management techniques related to fluids produced and used during the operational stage of a power plant, the vast majority of which are employed in the generation of electricity. The general characteristics of produced fluids are discussed. Constituents of interest that tend to drive the selection of treatment technologies are described, including total dissolved solids, noncondensable gases, Scale, Corrosion, silicon dioxide, metal sulfides, calcium carbonate, metals, and naturally occurring radioactive material. Management options for produced fluids that require additional treatment for these constituents are also discussed, including surface disposal; reuse/recycle; agricultural, industrial, and domestic uses; mineral extraction and recovery; and solid waste handling.
Gisle Oye - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical and Engineering Aspects : Study of asphaltenes adsorption onto different minerals and clays : : Part 2. Particle characterization and suspension stability
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2009Co-Authors: Dorota Dudášová, Geir Rune Flaten, Johan Sjöblom, Gisle OyeAbstract:{aUgelstad} Laboratory, Department of Chemical Engineering, Norwegian University of Science and Technology ({NTNU)}, N-7491 Trondheim, Norway {bWare}, {SG12} {9PU}, {UK} In gas and oil production, produced water usually contains dispersed solids along with dissolved and dispersed oil. Solids are of reservoir origin as well as Corrosion products (e.g. {Fe3O4} from pipelines) and waste products of bacterial metabolic activities (e.g. {FeS)} under anaerobic conditions. These particles are coated with surface active components upon contact with oil. In the present paper we studied eight model particles coated with asphaltenes from different oils in order to mimic the wettability changes and behavior in water after contact with oil. The effect of different variables (concentration, temperature and coating) on the suspension stability has been studied with Turbiscan {LabExpert.} Various analysis methods for Turbiscan data have been evaluated, and based on this our data have been analyzed in two modes. Transmission profiles from the middle of the samples have been considered at 75 (overall water quality) and 15.5 min (suspension behavior during a representative time in the separator) time Scales. Furthermore, the clarification rate and time has been evaluated. Principal component analysis ({PCA)} has been used to visualize trends in the data sets as well as identifying the most important variables affecting the systems. At longer time Scales temperature generally has the largest effect on suspension behavior, while asphaltene coating and particle concentration are important at the shorter time Scale. Keywords: Asphaltenes; Minerals; Wettability; Surface modification; Suspension stability; Turbiscan; Multivariate analysis; Principal component analysis Produced water has no direct commercial value but it has an indirect value when it is re-injected. The composition of produced water depends on the type and maturity of the reservoir. It contains dissolved organic compounds (including hydrocarbons), dispersed oil droplets, heavy metals, dissolved inorganic salts, dispersed solids (sand and silt) and a variety of treatment and workover chemicals. The produced water also contains dissolved gases (particularly hydrogen sulfide and carbon dioxide), bacteria and other living organisms, as well as radioactive isotopes. However, the particular concentrations of these components vary over an extremely wide range. The solid particles occurring in produced water are mainly of reservoir rock origin. In sandstone reservoirs, the main contribution is from sand (silica) accompanied by smaller amounts of different minerals and silt. In addition, iron-based salts, either as a product of Corrosion or as a product of anaerobic bacteria in the reservoir, are present. Produced water may also contain Scale. Divalent cations like calcium, magnesium, barium and strontium existing naturally within the reservoir water, can react with anions, like sulfate and carbonate from sea water. Precipitation usually occurs due to changes in pressure and temperature from the reservoir to the production facility. It is known that inorganic particles (very hydrophilic, i.e. low contact angle through water phase) in contact with crude oil will adsorb surface active components like asphaltenes. This adsorption will change the surface properties of the particles, e.g. wettability [7]. Separation of particles from produced water is an important issue because the particles may cause serious operational problems. Sand can accumulate in process vessels and cause undesirable blocking, as well as causing mechanical erosion problems for equipment like control valves or hydrocyclone liners [8]. Furthermore, accumulation of sand can create favorable conditions for bacterial growth, resulting in production of {H2S} and subsequently serious Corrosion problems. There is also an important environmental argument for removing particles from produced water, as oilfield particles are known to stabilize oil-in-water emulsions and complicate the separation of oil from produced water [9]. The effect of solids on the stability of oil in water emulsion is complex; there is general agreement that solids can stabilize emulsions. However, residual (heavy) ends are expected to sink faster in water with increased concentration of suspended solids [10]. The amount of oil in water also usually increases if significant amounts of oil-coated solids are present since solids typically follow the water stream in oil{\textendash}water separators. On the other hand, investigations after the Exxon Valdez spill in 1989 suggest that fine particles can detach oil from sediments and consequent oil-particles associates will float to the surface. Obviously particle properties and their suspension behavior need to be well understood in the order to develop suitable treatment technologies. A useful technique in this respect is multiple light scattering, which can be used for studying aggregation, coalescence and separation phenomena in emulsions and suspensions with concentrations of the dispersed phase up to 95% (v/v) [11]. This principle is applied in the Turbiscan {LabExpert} instrument. Mengual et al. [12] and [13] and Buron et al. [14] have described its principles and theoretical background (using {3D} Monte Carlo simulations) as well as shown examples of detection of different phenomena in various systems. {Ö}stlund et al. [15] studied various oils by Turbiscan measurements and proposed a {\textquotedblleft}stability index{\textquotedblright} based on light transmission changes over time. This parameter was then used to rank the oils/samples according to their stability. Azema compared three different optical methods (granulometric, electrophoretic and Turbiscan measurements) when studying the stability of aluminium fluoride and aluminium hydroxide mixtures in different water/ethanol ratios [16]. Despite different concentration limitations between the methods, the results were in good agreement. However, aggregate formation prior to sedimentation was only detected by Turbiscan. Furthermore, destabilization kinetics of the suspensions were determined by analyzing the clarification peak (transmission change) at the top of the samples. Kaolin suspensions were investigated using Turbiscan by Vie et al. [17], who proposed a parameter they called {\textquotedblleft}phase separation index{\textquotedblright} ({PSI).} {PSI} was defined as the ratio between the sedimentation column height and the sediment height at a given time, multiplied by the average value of the percentage of backscattered light. {PSI} and the clarification rates were used to describe the stability of a set of suspensions with different concentrations. Daoud-Mahammed et al. [18] also used Turbiscan in the study of stability of self-assembling nanogels. The authors took a simple approach, where the destabilization of suspensions with different concentrations was determined by the variation of transmission signal with time. The qualitative comparison of the stability of suspensions was in agreement with measurements of size distributions. This paper is a continuation of our previous study [19] and the third [20] in a series of articles aiming at improved understanding of the alteration of particle surface properties upon adsorption of crude oil components, and how this change influence their behavior in water. In this paper particles that have been in contact with crude oil (i.e. asphaltene coated particles) have been characterized and particular focus have been put their behavior in brine water. The stabilization mechanisms of particles with different surface properties and the effect of different factors (temperature and particle concentration) on their suspension stability have been studied. The particles used in this study were chosen to represent typical particles occurring in produced water (sand, clays, Scale, Corrosion products): kaolin (fine powder) (Aldrich, {USA/Germany);} {CaCO3} (98.2%) (Specialty Minerals Inc., {USA);} {FeS} (99.7%) ({DLFTZ}, Chang Hing, China); {BaSO4} (99%) and {Fe3O4} (98+%) (Nanoamor, {USA)}, as well as model oxides: fumed {SiO2} (both 99.8%, Aerosil{\textregistered}150 and {Aerosil{\textregistered}R} 104) and {TiO2} (99.5%, Aeroxide{\textregistered} {TiO2} P25) (Degussa, Germany). Aerosil{\textregistered}150 is hydrophilic (named {SiO2_i} in this paper) and {Aerosil{\textregistered}R} 104 is hydrophobic fumed silica (named {SiO2_o)} due to treatment with octamethylcyclotetrasiloxane. The carbon content is 1.0{\textendash}2.0 wt%. The basic properties of all the studied particles are listed in Table 1. Surface coated particles were prepared by asphaltene adsorption onto the pure particles. Asphaltenes from different crude oils were precipitated by adding an excess of pentane (1:40, vol.%) according to the {ASTM} D2007-80 procedure [21]. Further experimental details are reported elsewhere [19]. After precipitation, the asphaltenes were redissolved in heptane/toluene (50/50, vol.%) in amounts required to saturate the particle surface. These concentrations were chosen based the plateau region of adsorption isotherms reported in a previous paper [19]. Pure, dry particles were added to the asphaltene solutions and left in contact for 24 h. Next, the coated particles were filtrated and washed thoroughly with solvent to remove excess asphaltenes, and finally they were left to dry under nitrogen atmosphere. The presence of hydrocarbons was checked visually; originally white particles changed to a brown or brown-black color (except {Fe3O4} and {FeS} which were both black originally). This was confirmed by {FT-IR} spectroscopy. The spectra (see Fig. 1) were collected from 600 cm-1 to 4000 cm-1 with a Tensor 27 {FT-IR} spectrometer (Bruker Optics), using a {MKII} Golden Gate diamond {ATR} unit (Specac) and a N2-cooled {MCT} detector. Each measurement was the average of 32 scans at a resolution of 1 cm-1. The prese
Molly Finster - One of the best experts on this subject based on the ideXlab platform.
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Geothermal produced fluids: Characteristics, treatment technologies, and management options
Renewable and Sustainable Energy Reviews, 2015Co-Authors: Molly Finster, Jenna Schroeder, Corrie Clark, Louis MartinoAbstract:Geothermal power plants use geothermal fluids as a resource and create waste residuals as part of the power generation process. Both the geofluid resource and waste stream are considered produced fluids. The chemical and physical nature of produced fluids can have a major impact on the geothermal power industry and influence the feasibility of power development, exploration approaches, plant design, operating practices, and reuse/disposal of residuals. In general, produced fluids include anything that comes out of a geothermal field and must subsequently be managed on the surface. These fluids vary greatly, depending on the reservoir being harnessed, plant design, and life cycle stage in which the fluid exists, but generally include water and fluids used to drill wells, fluids used to stimulate wells in enhanced geothermal systems, and makeup and/or cooling water used during operation of a power plant. Additional geothermal-related produced fluids include many substances that are similar to waste streams from the oil and gas industry, such as Scale, flash tank solids, precipitated solids from brine treatment, hydrogen sulfide, and cooling-tower-related waste. This review paper aims to provide baseline knowledge on specific technologies and technology areas associated with geothermal power production. Specifically, this research focused on management techniques related to fluids produced and used during the operational stage of a power plant, the vast majority of which are employed in the generation of electricity. The general characteristics of produced fluids are discussed. Constituents of interest that tend to drive the selection of treatment technologies are described, including total dissolved solids, noncondensable gases, Scale, Corrosion, silicon dioxide, metal sulfides, calcium carbonate, metals, and naturally occurring radioactive material. Management options for produced fluids that require additional treatment for these constituents are also discussed, including surface disposal; reuse/recycle; agricultural, industrial, and domestic uses; mineral extraction and recovery; and solid waste handling.
Dorota Dudášová - One of the best experts on this subject based on the ideXlab platform.
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Physicochemical and Engineering Aspects : Study of asphaltenes adsorption onto different minerals and clays : : Part 2. Particle characterization and suspension stability
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2009Co-Authors: Dorota Dudášová, Geir Rune Flaten, Johan Sjöblom, Gisle OyeAbstract:{aUgelstad} Laboratory, Department of Chemical Engineering, Norwegian University of Science and Technology ({NTNU)}, N-7491 Trondheim, Norway {bWare}, {SG12} {9PU}, {UK} In gas and oil production, produced water usually contains dispersed solids along with dissolved and dispersed oil. Solids are of reservoir origin as well as Corrosion products (e.g. {Fe3O4} from pipelines) and waste products of bacterial metabolic activities (e.g. {FeS)} under anaerobic conditions. These particles are coated with surface active components upon contact with oil. In the present paper we studied eight model particles coated with asphaltenes from different oils in order to mimic the wettability changes and behavior in water after contact with oil. The effect of different variables (concentration, temperature and coating) on the suspension stability has been studied with Turbiscan {LabExpert.} Various analysis methods for Turbiscan data have been evaluated, and based on this our data have been analyzed in two modes. Transmission profiles from the middle of the samples have been considered at 75 (overall water quality) and 15.5 min (suspension behavior during a representative time in the separator) time Scales. Furthermore, the clarification rate and time has been evaluated. Principal component analysis ({PCA)} has been used to visualize trends in the data sets as well as identifying the most important variables affecting the systems. At longer time Scales temperature generally has the largest effect on suspension behavior, while asphaltene coating and particle concentration are important at the shorter time Scale. Keywords: Asphaltenes; Minerals; Wettability; Surface modification; Suspension stability; Turbiscan; Multivariate analysis; Principal component analysis Produced water has no direct commercial value but it has an indirect value when it is re-injected. The composition of produced water depends on the type and maturity of the reservoir. It contains dissolved organic compounds (including hydrocarbons), dispersed oil droplets, heavy metals, dissolved inorganic salts, dispersed solids (sand and silt) and a variety of treatment and workover chemicals. The produced water also contains dissolved gases (particularly hydrogen sulfide and carbon dioxide), bacteria and other living organisms, as well as radioactive isotopes. However, the particular concentrations of these components vary over an extremely wide range. The solid particles occurring in produced water are mainly of reservoir rock origin. In sandstone reservoirs, the main contribution is from sand (silica) accompanied by smaller amounts of different minerals and silt. In addition, iron-based salts, either as a product of Corrosion or as a product of anaerobic bacteria in the reservoir, are present. Produced water may also contain Scale. Divalent cations like calcium, magnesium, barium and strontium existing naturally within the reservoir water, can react with anions, like sulfate and carbonate from sea water. Precipitation usually occurs due to changes in pressure and temperature from the reservoir to the production facility. It is known that inorganic particles (very hydrophilic, i.e. low contact angle through water phase) in contact with crude oil will adsorb surface active components like asphaltenes. This adsorption will change the surface properties of the particles, e.g. wettability [7]. Separation of particles from produced water is an important issue because the particles may cause serious operational problems. Sand can accumulate in process vessels and cause undesirable blocking, as well as causing mechanical erosion problems for equipment like control valves or hydrocyclone liners [8]. Furthermore, accumulation of sand can create favorable conditions for bacterial growth, resulting in production of {H2S} and subsequently serious Corrosion problems. There is also an important environmental argument for removing particles from produced water, as oilfield particles are known to stabilize oil-in-water emulsions and complicate the separation of oil from produced water [9]. The effect of solids on the stability of oil in water emulsion is complex; there is general agreement that solids can stabilize emulsions. However, residual (heavy) ends are expected to sink faster in water with increased concentration of suspended solids [10]. The amount of oil in water also usually increases if significant amounts of oil-coated solids are present since solids typically follow the water stream in oil{\textendash}water separators. On the other hand, investigations after the Exxon Valdez spill in 1989 suggest that fine particles can detach oil from sediments and consequent oil-particles associates will float to the surface. Obviously particle properties and their suspension behavior need to be well understood in the order to develop suitable treatment technologies. A useful technique in this respect is multiple light scattering, which can be used for studying aggregation, coalescence and separation phenomena in emulsions and suspensions with concentrations of the dispersed phase up to 95% (v/v) [11]. This principle is applied in the Turbiscan {LabExpert} instrument. Mengual et al. [12] and [13] and Buron et al. [14] have described its principles and theoretical background (using {3D} Monte Carlo simulations) as well as shown examples of detection of different phenomena in various systems. {Ö}stlund et al. [15] studied various oils by Turbiscan measurements and proposed a {\textquotedblleft}stability index{\textquotedblright} based on light transmission changes over time. This parameter was then used to rank the oils/samples according to their stability. Azema compared three different optical methods (granulometric, electrophoretic and Turbiscan measurements) when studying the stability of aluminium fluoride and aluminium hydroxide mixtures in different water/ethanol ratios [16]. Despite different concentration limitations between the methods, the results were in good agreement. However, aggregate formation prior to sedimentation was only detected by Turbiscan. Furthermore, destabilization kinetics of the suspensions were determined by analyzing the clarification peak (transmission change) at the top of the samples. Kaolin suspensions were investigated using Turbiscan by Vie et al. [17], who proposed a parameter they called {\textquotedblleft}phase separation index{\textquotedblright} ({PSI).} {PSI} was defined as the ratio between the sedimentation column height and the sediment height at a given time, multiplied by the average value of the percentage of backscattered light. {PSI} and the clarification rates were used to describe the stability of a set of suspensions with different concentrations. Daoud-Mahammed et al. [18] also used Turbiscan in the study of stability of self-assembling nanogels. The authors took a simple approach, where the destabilization of suspensions with different concentrations was determined by the variation of transmission signal with time. The qualitative comparison of the stability of suspensions was in agreement with measurements of size distributions. This paper is a continuation of our previous study [19] and the third [20] in a series of articles aiming at improved understanding of the alteration of particle surface properties upon adsorption of crude oil components, and how this change influence their behavior in water. In this paper particles that have been in contact with crude oil (i.e. asphaltene coated particles) have been characterized and particular focus have been put their behavior in brine water. The stabilization mechanisms of particles with different surface properties and the effect of different factors (temperature and particle concentration) on their suspension stability have been studied. The particles used in this study were chosen to represent typical particles occurring in produced water (sand, clays, Scale, Corrosion products): kaolin (fine powder) (Aldrich, {USA/Germany);} {CaCO3} (98.2%) (Specialty Minerals Inc., {USA);} {FeS} (99.7%) ({DLFTZ}, Chang Hing, China); {BaSO4} (99%) and {Fe3O4} (98+%) (Nanoamor, {USA)}, as well as model oxides: fumed {SiO2} (both 99.8%, Aerosil{\textregistered}150 and {Aerosil{\textregistered}R} 104) and {TiO2} (99.5%, Aeroxide{\textregistered} {TiO2} P25) (Degussa, Germany). Aerosil{\textregistered}150 is hydrophilic (named {SiO2_i} in this paper) and {Aerosil{\textregistered}R} 104 is hydrophobic fumed silica (named {SiO2_o)} due to treatment with octamethylcyclotetrasiloxane. The carbon content is 1.0{\textendash}2.0 wt%. The basic properties of all the studied particles are listed in Table 1. Surface coated particles were prepared by asphaltene adsorption onto the pure particles. Asphaltenes from different crude oils were precipitated by adding an excess of pentane (1:40, vol.%) according to the {ASTM} D2007-80 procedure [21]. Further experimental details are reported elsewhere [19]. After precipitation, the asphaltenes were redissolved in heptane/toluene (50/50, vol.%) in amounts required to saturate the particle surface. These concentrations were chosen based the plateau region of adsorption isotherms reported in a previous paper [19]. Pure, dry particles were added to the asphaltene solutions and left in contact for 24 h. Next, the coated particles were filtrated and washed thoroughly with solvent to remove excess asphaltenes, and finally they were left to dry under nitrogen atmosphere. The presence of hydrocarbons was checked visually; originally white particles changed to a brown or brown-black color (except {Fe3O4} and {FeS} which were both black originally). This was confirmed by {FT-IR} spectroscopy. The spectra (see Fig. 1) were collected from 600 cm-1 to 4000 cm-1 with a Tensor 27 {FT-IR} spectrometer (Bruker Optics), using a {MKII} Golden Gate diamond {ATR} unit (Specac) and a N2-cooled {MCT} detector. Each measurement was the average of 32 scans at a resolution of 1 cm-1. The prese
Hua Li - One of the best experts on this subject based on the ideXlab platform.
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large Scale fabrication of superhydrophobic polyurethane nano al2o3 coatings by suspension flame spraying for anti Corrosion applications
Applied Surface Science, 2014Co-Authors: Xiuyong Chen, Jianhui Yuan, Jing Huang, Shaoyang Lu, Hua LiAbstract:This study aims to further enhance the anti-Corrosion performances of Al coatings by constructing superhydrophobic surfaces. The Al coatings were initially arc-sprayed onto steel substrates, followed by deposition of polyurethane (PU)/nano-Al2O3 composites by a suspension flame spraying process. Large-Scale Corrosion-resistant superhydrophobic PU/nano-Al2O3-Al coatings were successfully fabricated. The coatings showed tunable superhydrophilicity/superhydrophobicity as achieved by changing the concentration of PU in the starting suspension. The layer containing 2.0 wt.%PU displayed excellent hydrophobicity with the contact angle of similar to 151 degrees and the sliding angle of similar to 6.5 degrees for water droplets. The constructed superhydrophobic coatings showed markedly improved anti-Corrosion performances as assessed by electrochemical Corrosion testing carried out in 3.5 wt.% NaCl solution. The PU/nano-Al2O3-Al coatings with superhydrophobicity and competitive anti-Corrosion performances could be potentially used as protective layers for marine infrastructures. This study presents a promising approach for fabricatiing superhydrophobic coatings for Corrosion-resistant applications. (C) 2014 Elsevier B.V. All rights reserved.
