CaCO3 Scale Formation Research Articles

Study on the Scale and Corrosion Inhibition Effect of Curcumin‐Based Novel Polymers

AbstractThe curcumin‐malic acid‐aspartic acid polymer (PCMA) as a new water treatment agent was prepared by solid phase synthesis of curcumin, malic acid and aspartic acid. The static scale inhibition experiments showed that PCMA can inhibit CaCO3 and CaSO4 scale formation by 100.0 % and had excellent scale inhibition effect under various experimental conditions. The mechanism of action of PCMA was obtained by X‐ray diffraction, scanning electron microscope and molecular dynamics simulation. Electrochemical test showed that PCMA is an anodic corrosion inhibitor that achieves 93.1 % corrosion inhibition by forming a protective film on the surface of Q235 carbon steel. Besides, fluorescence spectra proved that PCMA has stable fluorescence intensity.

Antiscaling Pickering Emulsions Enabled by Amphiphilic Hairy Cellulose Nanocrystals.

Nucleation and growth of sparingly soluble salts, referred to as scaling, has posed substantial challenges in industrial processes that deal with multiphase flows, including enhanced oil recovery (EOR). During crude oil extraction/recovery, seawater is injected into oil reservoirs and yields water-in-oil (W/O) emulsions that may undergo calcium carbonate (CaCO3) scaling. Common antiscaling macromolecules and nanoparticles have adverse environmental impacts and/or are limited to functioning only in single-phase aqueous media. Here, we develop a novel antiscaling cellulose-based nanoparticle that enables scale-resistant Pickering emulsions. Cellulose fibrils are rationally nanoengineered to yield amphiphilic hairy cellulose nanocrystals (AmHCNC), bearing hydrophilic dicarboxylate groups and hydrophobic alkyl chains on disordered cellulose chains (hairs) protruding from nanocrystal ends. The unique chemical and structural properties of AmHCNC render them the first dual functional antiscaling and emulsion stabilizing nanoparticle. AmHCNC stabilize W/O Pickering emulsions at a concentration of 1.00 wt % for 1 week while inhibiting CaCO3 scale formation up to 70% by mass at a supersaturation degree of ∼101 compared with the synthetic surfactant Span 80. To the best of our knowledge, this study presents the first biopolymer-based solution for the long-lasting scaling challenge in multiphase media, which may set the stage for developing sustainable scale-resistant multiphase flows in a broad spectrum of industrial sectors.

Influence of Different Ions on Pulse Electrodeposition of CaCO3 Scales in the Simulated Seawater.

In the circulating water system of coastal power plants, various kinds of ions have a great influence on the formation and growth of CaCO3 scales. This paper focuses on investigating the influence of existing ions on the pulse electrodeposition behaviors of CaCO3 scales. Different concentrations of ions, such as Fe3+, Mg2+, PO43- and SiO32-, are introduced to simulate the actual seawater environment, and their influence on the CaCO3 scale deposition behaviors is assessed by linear sweep voltammetry, chronoamperometry, and electrochemical impedance spectroscopy tests. The surface coverage of the CaCO3 scale layer is evaluated through the residual current density and polarization resistance values, while the crystal structure and surface compactness of the layer are confirmed by the scanning electron microscope and X-ray diffractometer tests. Results indicate that high concentrations of Mg2+, Fe3+, and PO43- ions have the most significant inhibitory effect on the pulse electrodeposition of CaCO3 scales, among which the inhibition effect of Mg2+ ions is mainly reflected in the change of crystal morphology of CaCO3, that is, the crystallization growth process is inhibited. The inhibition effect of PO43- ions is mainly reflected in the gradually reduced coverage and density of CaCO3 crystals on the electrode surface, suggesting that the crystallization nucleation process is inhibited, while Fe3+ ions have a certain inhibition effect on both the crystallization nucleation and growth processes. Furthermore, lower concentrations of SiO32- ions also display a significant inhibition effect on the crystallization nucleation and growth process, and the inhibition effect weakens with increased concentration. This study provides a theoretical basis for exploring the removal of ions in the industrial water softening field.

Adsorption Isotherm and Mechanism of Ca2+ Binding to Polyelectrolyte.

Polyelectrolytes, such as poly(acrylic acid) (PAA), can effectively mitigate CaCO3 scale formation. Despite their success as antiscalants, the underlying mechanism of binding of Ca2+ to polyelectrolyte chains remains unresolved. Through all-atom molecular dynamics simulations, we constructed an adsorption isotherm of Ca2+ binding to sodium polyacrylate (NaPAA) and investigated the associated binding mechanism. We find that the number of calcium ions adsorbed [Ca2+]ads to the polymer saturates at moderately high concentrations of free calcium ions [Ca2+]aq in the solution. This saturation value is intricately connected with the binding modes accessible to Ca2+ ions when they bind to the polyelectrolyte chain. We identify two dominant binding modes: the first involves binding to at most two carboxylate oxygens on a polyacrylate chain, and the second, termed the high binding mode, involves binding to four or more carboxylate oxygens. As the concentration of free calcium ions [Ca2+]aq increases from low to moderate levels, the polyelectrolyte chain undergoes a conformational transition from an extended coil to a hairpin-like structure, enhancing the accessibility to the high binding mode. At moderate concentrations of [Ca2+]aq, the high binding mode accounts for at least one-third of all binding events. The chain's conformational change and its consequent access to the high binding mode are found to increase the overall Ca2+ ion binding capacity of the polyelectrolyte chain.

The effects of calcium carbonate precipitation on high-velocity flow behavior in 3D printed fracture models

A large amount of water is produced in oil and geothermal fields. Produced water is used in water injection for oil displacement and pressure maintenance in oil fields. However, there is a possibility of forming different precipitations when the injected water and formation water combine, which can cause serious problems in the reservoirs. In the world, more than 60% of oil and more than 40% of gas reservoirs are fractured carbonate rocks, and the mineral precipitation observed in these formations is mostly CaCO3 due to temperature and incompatibility between the injected and formation water. There are few techniques available for CaCO3 scaling removal due to their relative hardness and low solubility. In most cases, the scaled-up wells are caused by the formation of carbonate. In the well tests, it is seen that the flow from the matrix to the fracture is quite low, and the flow in the fracture dominates the whole flow. Therefore, it is essential to properly understand the kinetics of CaCO3 scale formation and its detrimental effect on fracture.It is known from studies that kinetic models can give better results in determining precipitation behavior. However, there are not enough experimental studies on the effects of flow on mineral precipitation in fractured media. Therefore, the kinetic and thermodynamic models are used in this study to reliably predict the amount of mineral precipitation. This work investigates the behavior of precipitation in different temperature conditions, laminar or turbulent flow conditions, and fracture properties like high roughness, length, and aperture. The amounts of precipitation in fracture under different conditions that have not been determined in the literature are given. After flow experiments, the amount of CaCO3 precipitation and pressure differences were measured. When the temperature is 80 °C, the flow rate is 4.16 × 10−5 m³/s, and the roughness is high, precipitation is 47.5% higher than when the temperature is 50 °C. Repeating the same fracture characteristics for different flow conditions in fracture flow tests is essential. By using 3D fracture models, the same fracture properties were obtained under different flow conditions.In addition to precipitation amounts, this article presents decreasing crack permeability due to precipitation. Precipitation of minerals can drastically influence the reservoir's permeability and ability to transmit mass and energy. With the pressure differences measured in the experiments, permeability decreases due to precipitation were calculated using Poiseuille's law (cubic law) for laminar flow and Forchheimer's equation for turbulent flow. After 3.5 days of flow, the study's permeability at high roughness and high flow decreased by 23% at 50 °C and 44% at 80 °C. This study's findings can help better understand that the permeability reduction of fracture is greater in turbulent flow conditions compared to laminar flow. In addition, temperature and high roughness are very effective parameters in precipitation and permeability change. At high temperatures and high roughness, more minerals precipitate, and permeability values decrease considerably. In the later injection periods, the decrease in permeability caused by the precipitation can make the fracture impermeable and increase the pressure losses during the injection.

Theoretical Studies of a Silica Functionalized Acrylamide for Calcium Scale Inhibition

The calcium carbonate (CaCO3) scale is one of the most common oilfield scales and oil and gas production bane. CaCO3 scale can lead to a sudden halt in production or, worst-case scenario, accidents; therefore, CaCO3 scale formation prevention is essential for the oil and gas industry. Scale inhibitors are chemicals that can mitigate this problem. We used two popular theoretical techniques in this study: Density Functional Theory (DFT) and Ab Initio Molecular Dynamics (AIMD). The objective was to investigate the inhibitory abilities of mixed oligomers, specifically acrylamide functionalized silica (AM-Silica). DFT studies indicate that Ca2+ does not bind readily to acryl acid and acrylamide; however, it has a good binding affinity with PAM and Silica functionalized PAM. The highest binding affinity occurs in the silica region and not the –CONH functional groups. AIMD calculations corroborate the DFT studies, as observed from the MD trajectory that Ca2+ binds to PAM-Silica by forming bonds with silicon; however, Ca2+ initially forms a bond with silicon in the presence of water molecules. This bonding does not last long, and it subsequently bonds with the oxygen atoms present in the water molecule. PAM-Silica is a suitable calcium scale inhibitor because of its high binding affinity with Ca2+. Theoretical studies (DFT and AIMD) have provided atomic insights on how AM-Silica could be used as an efficient scale inhibitor.

EXTRACT OF MANGOSTEEN PEEL (Garcinia mangostana L.) AS CALCIUM CARBONATE SCALE INHIBITOR

In this research, it has been conducted the participation of mangosteen peel (Garcinia mangostana L.) extract in the calcium carbonate (CaCO3) growth solution to a green inhibitor of CaCO3 scale establishment utilizing unseeded technique at various concentrations of calcium carbonate 0.075, 0.100, and 0.125 M and concentration ranges of inhibitor added were around 0, 50, 150, and 250 ppm. Analysis of functional groups contained in mangosteen peel extract was performed by infrared (IR) spectrophotometer. The result shows that the extract of mangosteen peel may be applied as a green inhibitor to block CaCO3 scale formation with the highest Inhibitor Effectivity Percent (IEP) in blocking the CaCO3 deposit formation of 95.68% at the condition of calcium carbonate growth solution of 0.100 M and the mangosteen peel extract concentration added of 250 ppm. The results based on a qualitative analysis using Scanning Electron Microscope (SEM) showed that calcium carbonate size without the addition of inhibitors is bigger than the addition of inhibitors.

Chain architectures of various cellulose-based antiscalants on the inhibition of calcium carbonate scale

Two series of cellulose-based antiscalants with different chain architectures, i.e., linear carboxymethyl cellulose (CMC) and branch-shaped carboxymethyl cellulose-graft-poly(acrylic acid) (CMC-g-PAA), were synthesized. The carboxyl groups were distributed on CMC backbone but mainly on the grafted chains of CMC-g-PAA. The addition of CMC and CMC-g-PAA can both increase the surface energy of CaCO3 scale and decrease its crystal nucleation rate, thereby inhibiting CaCO3 scale formation. The structural effects of these cellulose-based antiscalants, especially the chain architectures, on the scale inhibition were investigated in detail. High degree of carboxymethyl substitution caused better inhibition effect of linear CMC. However, CMC-g-PAA with an appropriate content of carboxyl groups but high average number of PAA grafted chains can achieve high inhibition performance. Besides, with similar contents of carboxyl groups, CMC-g-PAA showed much better inhibition performance than CMC due to the distinct multi-dimensional spatial structure of graft copolymer in solution, causing the enhanced chelation and dispersion effects. Characterization of CaCO3 crystal by scanning electron microscopy and X-ray diffraction confirmed that crystal distortion effect obviously existed in CMC but quite minor in CMC-g-PAA. The differences between the scale-inhibition performance of CMC and CMC-g-PAA should be attributed to the different scale-inhibition mechanisms originated in their distinct chain architectures.

Influence of simulating deep-sea environmental factors on cathodic performance of seawater battery

A metal-dissolved oxygen seawater battery (SWB) uses metal and dissolved oxygen as the reactants, and it is ideal for use as a long-time low-power distributed power supply in deep sea, due to its advantages of open structure in service without electrolyte. However, several simulating deep-sea environmental factors, such as flow rate, dissolved oxygen concentration, and temperature of seawater may affect the oxygen reduction reaction (ORR) rate and the stability of electrochemically modified polyacrylonitrile-based carbon fiber brush (MPAN-CFB) cathode, which was studied by steady-state polarization and galvanostatic discharge methods. In addition, the scales formed on MPAN-CFB surface were characterized by SEM and XRD. Results show that the ORR rate increased quickly with the increase of the seawater flow rate up to 3 cm/s, and then gradually stabilized. Moreover, the ORR rate was largely affected by dissolved oxygen concentration, and the concentration of >3 mg/L was favorable. Compared with surface layer temperature of 15°C, the low temperature of deep sea (4°C) has a negligible effect on ORR rate. When the working current is too high, it will lead to the formation of CaCO3 scales (aragonite) of at the cathodic surface, resulting in the decrease of ORR rate, and consequently the damage to the long-time stability of MPAN-CFB.

Scale Inhibition by a Carboxylate-Terminated Double-Hydrophilic Block Copolymer in Industrial Recycling Water

Acrylic acid (AA)-allylpolyethoxy carboxylate (APEL) copolymer was synthesized. The performance of AA-APEL on inhibition of Ca3(PO4)2, CaCO3 and CaSO4 precipitation was compared with that of current commercial inhibitors. It was shown that AA-APEL exhibited excellent ability to control inorganic minerals, with approximately 95.6% CaSO4 inhibition and 99.8% Ca3(PO4)2 inhibition at levels of 3 and 6 mg/L, respectively. AA-APEL also displayed ability to prevent the formation of CaCO3 scales. Surface morphology characterization of Ca3(PO4)2, CaCO3 and CaSO4 was investigated with scanning electronic microscopy. The inhibition mechanism was proposed that the formation of the excellent solubility of AA-APEL-Ca complexes due to high hydrophilic PEG segments in the AA-APEL matrix.

The Kinetic Aspect of CaCO3 Scale Formation in the Solenoid Magnetic Field in the Various Temperatures of Solution in Piping System

Abstract The influence of frequency 5,000 Hz, 2,000 Gauss sawtooth wave of solenoid magnetic field in the kinetic aspect of 3,500 ppm CaCO3 solution on scale formation in piping system was investigated. Citric acid (C6H8O7) 5; 10 ppm was added to inhibit the scale in house experimental rig which completed by computer program to control the flow rate at 30 ml/minute, temperature at 30; 40; 50 0C. The Induction times were found as 16; 14 and 12 minutes and the deposition rates were found as 0.0625; 0.0735 and 0.0896 gr/hr. Using SEM shows that the phases mostly vaterite, aragonite and some of calcite.

Laboratory study on efficiency of three calcium carbonate scale inhibitors in the presence of EOR chemicals

Chemical flooding has been widely used in the oil industry since the 1980s for enhanced oil recovery (EOR) process. Previous studies have shown that the effectiveness of calcium carbonate scale inhibitors is affected by many factors, such as water composition, system pressure, temperature, production rates, pH etc. The breakthrough of the EOR chemicals in the production well could also affect scale formation process and interfere with the scale treatment program as well. However, the studies on the impacts of injected EOR chemicals to scale inhibitor performances are very limited. This paper presents the comprehensive laboratory study on the impacts of the EOR chemicals on CaCO3 scale formation and prevention using static bottle and dynamic tube blocking methods. The EOR chemicals used in this study are a combination of surfactants and polymers. Three different types of inhibitors were evaluated: tri-phosphonate, penta-phosphonate, and polyacrylate based chemicals. Inhibition (%) from the bottle test and minimum effective dose (MED) based on the tube blocking method were determined for each inhibitor at 160 °F. Scale precipitates from the bottle tests were also characterized for morphology and polymorphs using environmental scanning electron (ESEM) and X-ray diffraction (XRD) techniques. Results suggest that the performance of scale inhibitors could be substantially affected by the EOR chemicals. In dynamic tube blocking tests, the MED values of inhibitors were increased roughly 10 times with the EOR chemicals. The static bottle tests showed considerable changes under the test conditions. The impact of EOR chemicals were also demonstrated by the remarkable ranges of crystal morphologies, changing from simple aragonite columns to nanorod, distorted spheroid, and flower-like superstructure in the presence of EOR chemicals and inhibitors.

The Influence of CaCO3 Scale Formation on AC Corrosion Rates of Pipeline Steel Under Cathodic Protection

In this paper, the influence of CaCO3 scale formation on the AC corrosion rate of pipeline steel under cathodic protection was investigated. The CaCO3 layer was deposited on X65 steel electrochemically and then studied in a soil simulant. A method for determining the fractional surface coverage of the scale based on either deposition current or electrochemical impedance spectroscopy data is presented. After the deposition process, samples were exposed to 3 V root mean square (RMS) AC potential at 60 Hz and varying degrees of cathodic protection at DC potentials of −770, −700, −650, and −600 mV vs. saturated calomel electrode. It was demonstrated that the scale acts as a simple barrier and the corrosion rate of steel, exposed at the base of pores in the scale, is equal to that of boldly exposed samples. These results are discussed in the light of the previously developed theoretical model for AC corrosion.

Fiber Optic Sensor with an Optically Transparent Electrode for Monitoring CaCO3 Scale Formation in Geothermal Water

Herein, we present a fiber optic sensor with an optically transparent electrode for monitoring calcium carbonate scale formation in geothermal water. The proposed sensor was fabricated by coating indium tin oxide onto the surface of an unclad multimode fiber core. The surface charge of the sensor could be controlled by applying potentials. The transmittance change for scale formation varied as a function of the applied potential. The proposed sensor was used to monitor the scale formation in natural geothermal water at Matsushiro, Japan.

Inhibition of calcium carbonate (CaCO3) scale formation by calix [4] resorcinarene compounds

Inhibition effect of tetrakis{(dimethylamino)methyl}C-methyl calix [4] resorcinarene (TDMACMKR) compound on calcium carbonate (CaCO3) scale formation has been studied using seeded experiment and bottle roller bath method. The effect of the addition TDMACMKR as inhibitor on CaCO3 scale formation was analyzed by measuring the weight of precipitation of CaCO3 formed. The morphology and particle size distribution of obtained CaCO3 crystals caused by the addition of (TDMACMKR) were analyzed by scanning electron microscopy (SEM), and particle size analyzer. The data obtained show that the TDMACMKR inhibits formation of CaCO3 scale at various inhibitor concentrations added. Keywords: Calix [4] resorcinarene; Scale inhibitor; Calcium carbonate

Experimental analysis of calcium carbonate scale formation and inhibition in waterflooding of carbonate reservoirs

Deposition of inorganic salts such as calcium carbonate (CaCO3) can cause formation damage and production equipment failure during the development of a reservoir. In case of waterflooding, complex geochemical processes between the injection water, formation water and rock occur and the concentration of ions increases. Major contribution of scale control concentrates on understating the conditions scale formation and its inhibition.In this paper, we analyze experimentally the effect of oil composition and flow conditions on CaCO3 scale formation. We measured the induction period of CaCO3 crystallization in a stirred vessel with different Reynold numbers and the interfacial tension at the boundary between the aqueous scale inhibitor and oil at different percentages of organic components. In addition, we determined the performance of CaCO3 scale inhibition under different static and dynamic conditions in some Iranian carbonate core samples.The experimental results showed that if the interfacial tension was reduced by increasing the concentration of organic components to 1.5%, the CaCO3 precipitation decreases more than 30%. In addition, increasing the flow velocity (Reynolds number) had a great influence on the increase in the induction period of CaCO3 crystallization. However, the induction period was insignificantly changed at higher values.Using a recently developed scale inhibitor, we kept the CaCO3 formation at a constant concentration of 30mg/L. The efficiency of the inhibitor was insignificantly reduced if the temperature is increased up to 120°C. Core flooding experiments show that formation damage due to CaCO3 precipitation depends on the injection rate of the solution. In addition, the formation damage was mitigated to the 93% of initial permeability of the core samples. The results of this work improve our understanding from CaCO3 formation and can be used to predict and prevent it during waterflooding process in carbonate reservoirs.

Inhibitory effect of glutamic acid on the scale formation process using electrochemical methods

ABSTRACTThe formation of calcium carbonate CaCO3 in water has some important implications in geoscience researches, ocean chemistry studies, CO2 emission issues and biology. In industry, the scaling phenomenon may cause technical problems, such as reduction in heat transfer efficiency in cooling systems and obstruction of pipes. This paper focuses on the study of the glutamic acid (GA) for reducing CaCO3 scale formation on metallic surfaces in the water of Bir Aissa region. The anti-scaling properties of glutamic acid (GA), used as a complexing agent of Ca2+ ions, have been evaluated by the chronoamperometry and electrochemical impedance spectroscopy methods in conjunction with a microscopic examination. Chemical and electrochemical study of this water shows a high calcium concentration. The characterization using X-ray diffraction reveals that while the CaCO3 scale formed chemically is a mixture of calcite, aragonite and vaterite, the one deposited electrochemically is a pure calcite. The effect of temperature on the efficiency of the inhibitor was investigated. At 30 and 40°C, a complete scaling inhibition was obtained at a GA concentration of 18 mg/L with 90.2% efficiency rate. However, the efficiency of GA decreased at 50 and 60°C.

The Influence of Vibration on CaCO3Scale Formation in Piping System

Carbonate scale is a common problem found in a piping system of industrial process. The presence of mechanical equipment such as turbine, compressor, blower, mixer and extruder produce a mechanical vibration on the piping system which is placed near these equipments. The influence of vibration on the CaCO 3 scale formation in the piping system was experimentally investigated in the present study. The aim of the research was to understand the effect of vibration on the kinetics, deposition rates and the crystals formation in the synthetic solution. The solution was prepared using CaCl 2 and Na 2 CO 3 for concentration of calcium of 3.500 ppm, while the induction time, deposition rate, crystal growth were investigated at temperature of 25°C. In generating the vibration force, the mechanical equipment consisting of electrical motor, crankshaft, connecting rod and a vibration table were employed, including four coupons inside the pipe for investigating the scale formed. Frequency of the vibration was set at 0.00, 1.00 Hz and 2.00 Hz, respectively. A dosing pump with two inlets and two outlets was used to circulate the solutions at flowrate of 30 ml/min from each vessel to the coupons. After running for three hours, the induction time was recorded at 17; 10 and 8 minute with vibration frequency of 0.00; 1.00 and 2.00 Hz, respectively. The scale formed was then characterized using SEM/EDX for crystal morphology and elemental analysis. The results show that the deposition rates were 0.9457 and 3.3441 gram/h for the frequency of 1.00 and 2.00 Hz. The carbonate crystals found in coupon and filter were vaterite.

Performance of inhibitors on CaCO3 scale deposition in stainless steel & copper pipe surface

Novel low molecular weight copolymers (termed as YMR-series polymers) prepared through reaction of maleic anhydride with n-alkylacrylamide monomers via nitroxide-mediated radical polymerization (NMRP), atom transfer radical polymerization (ATRP) and free radical polymerization have shown feasibility as a new generation scale inhibitor. The scale inhibition property of these YMR-polymers towards CaCO3 in the artificial cooling water was studied in steel (316L) and copper (90/10, CuNi alloy) pipes using a pipe flow system at various temperatures. The relationship between deposited scale mass and temperature was deduced from experimental data. The effect on formation of CaCO3 scales was investigated with scanning electronic microscopy (SEM) and X-ray powder diffraction (XRD) analysis. The results showed that the low molecular weight YMR-polymers were excellent calcium carbonate scale inhibitor in copper and steel pipe flow system showing inhibition up to 98% at 60°C.

Fundamental study on the development of fiber optic sensor for real-time sensing of CaCO3 scale formation in geothermal water.

This study proposes an optical fiber sensor for calcium carbonate (CaCO3) scale formation in water. The sensor is easily fabricated by removing the cladding of a multimode fiber to expose the core towards the surrounding medium in order to detect refractive index change. A variation of the transmittance response from the high refractive index of CaCO3 which precipitated on the fiber core surface was observed. The proposed setup can be used to analyze the transmittance response over wide range of wavelength using white light as a source and also a spectroscopy detector. The curve of the transmittance percentage over time showed that a fiber core with 200 μm has higher sensitivity as compared to a fiber core with 400 μm. The findings from this study showed that the sensor detection region at near infrared (NIR) wavelengths showed better sensitivity than visible light (VIS) wavelengths. Field tests were conducted using natural geothermal water at Matsushiro, Japan in order to verify the performance of the proposed sensor. The optical response was successfully evaluated and the analytical results confirmed the capability of monitoring scale formation in a geothermal water environment.