Green Scale Inhibitor Research Articles

Synthesis and assessment of fenugreek carbon quantum dots as novel green scale inhibitor

Synthesis and assessment of fenugreek carbon quantum dots as novel green scale inhibitor

Synthesis and evaluation of an environmentally friendly phosphorus-free and nitrogen-free polymer as a scale and corrosion inhibitor

Polyepoxysuccinic acid (PESA) was modified by glycidyl (Gly) to obtain a phosphate-free and nitrogen-free polymer (Gly-PESA), and its scale and corrosion inhibition properties were studied.The effects of Gly-PESA concentration, calcium ion concentration and temperature to scale inhibition performance were studied by static scale inhibition method. The corrosion inhibition performance of Gly-PESA was studied by static weight-loss method. The morphology and structure of calcium scale and steel surface were characterized by spectroscopic and microscopic methods. The scale inhibition efficiency of Gly-PESA for CaCO3 and CaSO4 was 98.06% and 92.6%, respectively. Under the same experimental conditions, the scale inhibition effect of Gly-PESA was obviously better than that of PESA. Gly-PESA could effectively inhibit the growth of CaCO3 and CaSO4 crystals and cause their crystal lattice distortion or crystal dispersion. The corrosion inhibition efficiency of Gly-PESA for carbon steel was 78.17%. The adsorption of Gly-PESA on the surface of the steel test piece followed Langmuir adsorption isotherm, and formed a protective film, which increased the corrosion resistance of the steel test piece, thus effectively protecting the steel test piece. Therefore, Gly-PESA was a green scale and corrosion inhibitor, which solved the problem of environmental pollution.

Synthesis and Mechanism of a Green Scale and Corrosion Inhibitor.

A new green water treatment agent, a poly(aspartic acid)-modified polymer (PASP/5-AVA), was synthesized using polysuccinimide and 5-aminovaleric acid (5-AVA) in a hybrid system. The structure was characterized, and the scale and corrosion inhibition performance were carried out with standard static scale inhibition and electrochemical methods, respectively. The mechanism was explored using XRD, XPS, SEM, and quantum chemistry calculations. The results indicated that PASP/5-AVA exhibited better scale and corrosion inhibition performance than PASP and maintained efficacy and thermal stability of the scale inhibition effect for a long time. Mechanistic studies indicated that PASP/5-AVA interferes with the normal generation of CaCO3 and CaSO4 scales through lattice distortion and dispersion, respectively; the combined effect of an alkaline environment and terminal electron-withdrawing -COOH groups can induce the stable C- ionic state formation in -CH2- of the extended side chain, thus enhancing its chelating ability for Ca2+ ions. At the same time, the extension of the side chain length also enhances the adsorption ability of the agent on the metal surface, forming a thick film and delaying the corrosion of the metal surface. This study provides the necessary theoretical reference for the design of green scale and corrosion agents.

Sustainable Calcite Scale Inhibitors via Oxidation of Lignosulfonates.

Deposition of inorganic scales in wells, flow lines, and equipment is a major problem in the water treatment, geothermal, or upstream oil and gas industries. Deployment of scale inhibitors has been adopted worldwide for oilfield scale prevention. Commercial synthetic scale inhibitors such as polymeric carboxylates and sulfonates or nonpolymeric phosphonates offer good scale inhibition performance but often suffer from one or more limitations including biodegradability, calcium compatibility, and thermal stability. Lignin-based biomaterials such as sodium lignosulfonates are natural, sustainable, and widely available polymers that are accepted for use in environmentally sensitive areas. Here we show that, although lignosulfonates perform relatively poorly as calcite scale inhibitors in dynamic tube blocking tests, oxidized lignosulfonates show a much improved inhibition effect by a factor of 20-fold. The oxidized lignosulfonates are easy to prepare in a 1-step reaction and show excellent calcium compatibility and thermal stability, useful for downhole squeeze treatments in high temperature wells. This present study unequivocally establishes oxidized lignosulfonates as a new class of sustainable green scale inhibitors, thereby bridging the gap between materials derived directly from nature and the classic synthetic polymeric scale inhibitors.

Performance evaluation of glutaraldehyde-modified red onion skin extract as oilfield scale inhibitors

Scale deposition occurs due to changes during injection operations and the mixing of incompatible brines. Scale inhibitors are used to mitigate such occurrences. The inhibition efficiency of the glutaraldehyde-ROSE resin (ROG) was evaluated in synthetic brines containing CaSO4, BaSO4, and CaCO3 under static conditions according to NACE standard methods. The formulated scale inhibitor was compatible with the brine and thermally stable. The inhibition studies of ROG revealed optimal inhibition of 89% at 80 ppm and 58% at 100 ppm at 90 °C and 22 h, respectively, for BaSO4 and CaCO3 scales, while for CaSO4 scales, optimal inhibition of 67% was observed at 100 ppm, 71 °C, and 22 h. On comparison, the Commercial Scale Inhibitor (CSI) showed optimal inhibition of 97% at 100 ppm and 94% at 80 ppm at 71 °C and 22 h, respectively, for BaSO4 and CaSO4 scales, while for CaCO3 scales, optimal inhibition of 98% was observed at 80 ppm, 90 °C, and 22 h, respectively. This indicates that ROG efficiently mitigated the formation of CaSO4, BaSO4, and to some reasonable extent, CaCO3 scales, and its inhibition performance compared favorably with the CSI, thus unveiling its potential for consideration as a green oilfield scale inhibitor.

Preliminary Evaluation of Cashew Gum Exudate as a Green Scale Inhibitor

Preliminary Evaluation of Cashew Gum Exudate as a Green Scale Inhibitor

Evaluating the Potential of Biodegradable Carbohydrates and the Aqueous Extract of Potato Pulp to Inhibit Calcium Carbonate Scale in Petroleum Production

Summary Scale is a significant operational concern in petroleum production that is commonly addressed by using chemical inhibitors. However, commercial inhibitors can potentially be pollutants depending on their composition and method of disposal. Consequently, evaluating the potential of biodegradable molecules to inhibit scale has gained attention. This study evaluates the effect of a series of carbohydrates (i.e., glucose, fructose, sucrose, maltose, maltodextrin, and soluble starch) and the aqueous extract of potato pulp on calcium carbonate precipitation and scale formation. Precipitation tests were conducted by combining aqueous solutions of sodium bicarbonate (3000 mg L−1) and calcium chloride (4000 mg L−1) in the presence of each carbohydrate, the aqueous extract of potato pulp, or a commercial inhibitor (1000 mg L−1). The precipitation was monitored through RGB (red, green, and blue) image analysis and pH measurements. The induction time in the presence of glucose, fructose, maltose, and sucrose is two to three times longer than in the blank test (in the absence of an inhibitor). This effect is slightly more pronounced in the presence of maltodextrin and soluble starch (approximately four times longer). However, the drop in pH and the mass of solids recovered is similar for all the carbohydrates tested (~0.5 mg and 120 mg, respectively), suggesting that carbohydrates slightly influence the precipitation kinetics but do not affect the precipitation equilibrium. Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) analysis reveals that calcium carbonate precipitates as calcite and vaterite in the blank test. In the presence of glucose, fructose, maltose, and maltodextrin, calcium carbonate exclusively precipitates as calcite. However, in the presence of sucrose and soluble starch, calcium carbonate precipitates as both calcite and vaterite. Interestingly, a more prominent amount of vaterite was observed in the presence of soluble starch. All carbohydrates decrease the crystallite size of calcite, while sucrose and soluble starch increase the crystallite size of vaterite. The crystalline phases were also identified by Raman spectroscopy, ruling out the presence of any amorphous calcium carbonate phase. The inhibitory effect of soluble starch and the aqueous extract of potato pulp on calcium carbonate scale formation was evaluated in a dynamic scale loop (DSL) system. Soluble starch slightly delays scale formation even at high concentrations (1000 mg L−1). Conversely, the aqueous extract of potato pulp demonstrates enhanced performance by delaying scale formation by approximately 20 minutes for a 1-psi increase in the pressure of the tube and by more than 40 minutes for a 4-psi increase. As a result, it exhibited an impact on the kinetics of solid deposition. This agrees with the precipitation test in the presence of the potato extract (PE), which increases the induction time (from 2 minutes to 32 minutes), decreases the mass of solids (from 116 mg to 35 mg), and forms more distorted and smaller particles of calcite. These findings suggest a promising approach for the development of green scale inhibitors utilizing aqueous extracts of starchy foods or even starchy foods waste water.

The oligosuccinimide and modified polysuccinimide as green corrosion and scale inhibitors

Corrosion and scale formation are crucial issues in the petroleum industry. They can inflict metal or other materials breakdown, leading to environmental pollution. Applying scale and corrosion inhibitors is a cost-effective and efficient way of controlling corrosion and scale formation in a fluid system. Much research has been conducted to obtain cheap and safe corrosion or scale inhibitors. Modified polysuccinimides (PSI) are among the organic compounds reported as effective and environmentally friendly corrosion as well as scale inhibitors. The use of various novel green corrosion and scale inhibitors from modified PSI for controlling corrosion reactions or scale formation has not been extensively reviewed. Hence, this review highlights recent studies on preparing PSI/OSI, modifying PSI, and analyzing their performance as corrosion and scale inhibitors. Adsorption study, biodegradation performance, computational quantum study, limitations, and prospects of the inhibitors are also discussed. Therefore, i this work provides an overview of novel modified PSI as effective and safe corrosion or scale inhibitors in different media, for various metals, and on a different scale.

Combined quantum mechanics and molecular dynamics study on the calcite scale inhibition mechanism of carboxymethyl dextran

The scale inhibition mechanism of carboxymethyl dextran (CMD), a new green scale inhibitor, was studied via quantum mechanical calculations and molecular dynamics (MD) simulations. Specifically, the interactions between the functional groups of CMD and calcite (104), (110), and (1–10) surfaces in aqueous solution were modelled at different degrees of polymerization (DP) of CMD (2, 4, 6, 8, and 10, respectively). The adsorption configuration, radial distribution function, deformation energy, binding energy, and relative concentration distribution of water molecules near the surface of calcite were calculated. The results showed that the carboxyl functional groups in CMD were strongly electronegative and able to form strong chemisorption bonds with calcium ions on the calcite surface. This can change the regular arrangement of the surface and prevent the combination of carbonate particles and calcium ions to form calcite scale. Furthermore, as the DP increased, the binding energy and the peak value of the radial distribution function increased, indicating an increase in the probability and strength of adsorption of CMD on the calcite surface, which can further enhance the scale inhibition efficiency.

Impact of temperature and pH on calcite inhibition using innovative green scale inhibitors

This experimental study aimed at predicting firstly the critical mixing ratio of two incompatible aqueous phases of formation water and seawater by PHREEQC (pH-redox-equilibrium conditions) at temperatures of 40, 70, and 90 °C. Secondly, the performance of two green scale inhibitors (SI) of folic acid and inulin was experimentally studied through standard static jar tests in order to determine the optimum concentration and pH at which the calcite mitigation would be maximized. The optimum pH values of 4 and 6 were respectively found for folic acid and inulin, at three investigated temperatures. Interestingly, the inhibition efficiency of these SIs increased with temperature which is advantageous for the oil reservoirs. SEM (Scanning Electron Microscopy) and TGA (thermogravimetric analysis) analyses were also carried out to discern the SIs’ inhibition mechanisms and thermal performance. The SEM results showed that folic acid and inulin would inhibit precipitation under the crystal modification and threshold inhibition mechanisms, respectively. Furthermore, TGA analysis showed that these green SIs would sustain high temperatures, although their weight losses (heating rate of 10 °C /min and T < 100 °C) were almost 3.25 % and 9.15 % for folic acid and inulin, respectively.

Performance and mechanism study of PESA-IA as a green oilfield scale inhibitor: experimental and molecular dynamics simulation

Performance and mechanism study of PESA-IA as a green oilfield scale inhibitor: experimental and molecular dynamics simulation

Polyaspartic acid-capped (4-[(2-aminoethyl) amino]-4-oxobutanoic acid as an efficient and green gypsum scale inhibitor and its scale inhibition mechanism

Two new yet structurally similar scale inhibitors (PASP-AAB and PASP-AAA), have been successfully synthesized through ring-opening reaction of polysuccinimide (PSI) with inexpensive (4-[(2-aminoethyl) amino]-4-oxobutanoic acid or glycylglycine. Static antiscaling experiments imply they could dramatically improve the antiscaling efficiency of gypsum, better than that of PASP. Moreover, the slightly different nitrogen atom position on the side chain of PASP-AAB and PASP-AAA enables the former efficiently inhibit the gypsum scale at low concentration (2.0 mg/L). In addition, our results indicate the antiscaling performance of PASP-AAB (at 4.0 mg/L) could maintain the excellent efficiency (>99 %) against gypsum for at least 7 days, better than that of some reported polymer-, and phosphorus-based industrial antiscalants. The very efficient gypsum scale inhibition property of PASP-AAB makes it as one of the very effective green antiscalants reported in the literature by now. Detailed mechanism studies reveal that the better calcium scale inhibition performance of PASP-AAB should be attributed to the easier formation of seven-membered chelation ring of side chain with Ca2+. The unprecedented nitrogen substitution effect disclosed in this work provides a new perspective for understanding the structure-activity relationship of the grafting-modified polymeric inhibitor, meaningful for developing other novel green scale inhibitors.

Sustainable Synthesis of Carbon Quantum Dots with Tailored Surface Functional Groups from Pomelo Peel Waste for Inhibiting Scale

AbstractFruit Shatian pomelo peel is a common solid biological waste. This article reports the environmentally friendly synthesis of carbon quantum dots from Shatian pomelo peel waste by hydrothermal method. The synthesized carbon quantum dots (named PCA‐CQDs) were characterized by transmission electron microscope (TEM), Fourier transform infrared (FT‐IR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), ultraviolet‐visible spectroscopy (UV‐vis) and excitation‐dependent fluorescence emission spectroscopy. The resultant carbon quantum dots were spherical, and the average particle diameter was measured to be 5 nm. The surface of PCA‐CQDs has been successfully modified with functional oxygen‐containing functional groups such as hydroxyl and carboxyl groups. Therefore, PCA‐CQDs exhibit excellent water solubility and calcium ion chelating properties. Most importantly, PCA‐CQDs were used as a new type of green scale inhibitor for inhibiting the CaSO4 and CaCO3 scale for the first time, and the scale inhibition efficiency can reach more than 95 %. By observing the changes of the scale crystals in the SEM image, it is speculated that the mechanism of PCA‐CQDs inhibiting calcium scale may include chelation, dispersion and lattice distortion.

Mitigation of Mineral Deposition in Carbonate and Sandstone Rocks Using Green Scale Inhibitors.

Waterflooding is potentially a viable approach to enhance oil recovery, though its efficacy can profoundly be compromised due to formation damage as a result of inorganic scale deposition. In this study, a series of high-temperature core flooding experiments were conducted to evaluate two green scale inhibitors (SIs) of folic acid and inulin as alternative inhibitors to mitigate mineral deposition. The co-injection of two incompatible brines (with and without SIs) for two flow rates of 0.5 and 3 mL/min into two core samples of dolomite and sandstone was experimentally investigated. The results showed that folic acid would inhibit scale formation as much as 45-49%, at the lower flow rate, compared to inulin with an efficiency of 29-39%, at the higher flow rate. Moreover, computed tomography imaging technique showed that scale formation and fine migration would be dominant mechanisms for formation damage in dolomite and sandstone rocks, respectively. The theoretical study based on surface energy also confirmed the experimental results in terms of the work of adhesion which showed that folic acid would mitigate the calcite deposition on rock surfaces approximately 55%. Finally, a phosphonate-based commercial SI was compared with the green SIs which reaffirmed their potencies.

Abatement of scale precipitation in oilfields using green scale inhibitors

Scale formation in upstream oil operations may cause lower production rate, higher operational costs and detrimental environmental impacts when hazardous chemical inhibitors should be used to combat scaling. Green scale inhibitors (SI) are also gaining increased attention but their utilization is still a matter of much debate with many open questions to be addressed. In this study, green SIs, i.e., folic acid and inulin were investigated from experimental and theoretical perspectives. In the experimental part, two brines were mixed incompatibly through standard high-temperature static tests i) to examine the performance of green SIs and also ii) to discern their optimum concentrations and pH. Furthermore, SEM (Scanning Electron Microscopy) and EDX (Energy Dispersive X-ray) analyses were carried out to identify mechanisms under which the mitigation of scale precipitation would take place. The results revealed that folic acid and inulin could optimally be applied with concentrations of 450 mg/L (pH = 4) and 600 mg/L (pH = 6), respectively. SEM analyses also showed that the dominant inhibition mechanism for folic acid was crystal modification whereas it was threshold inhibition for inulin. Moreover, based on the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, the work of cohesion was calculated which confirmed that folic acid and inulin retarded calcite from getting precipitated almost %65 and 54%, respectively. Finally, the performance of a commercial phosphonated SI was also investigated for the sake of comparison with the green SIs which confirmed their comparable efficacy. • Assessment of two green scale inhibitors for utilization at reservoir conditions. • Experimentally optimization of concentration and pH of green scale inhibitors. • Utilization of surface energy theory to calculate the inhibition efficiency. • Comparable efficacy of green scale inhibitors with respect that of commercial one.

A sustainable approach to synthesize phosphonated chitosan using ball milling and its application for oilfield scale management

For many years, the petroleum industry has strived to develop green organophosphorus-based scale inhibitors. The high biodegradability of chitosan encouraged us to synthesize phosphonated chitosan (PCH) under mechanochemical conditions as a green oilfield scale inhibitor.

Evaluating the Effectiveness of Red Onion Skin Extract Derivatives as Oilfield Scale Inhibitors

With growing awareness of the environmental impact of some conventional production chemicals and concerns about the depletion of non-renewable natural resources, increased efforts are being made to use renewable and non-toxic materials in the oilfield. In this study, a potential green scale inhibitor was developed from the skin of red onions and evaluated for calcium sulphate, calcium carbonate and barium scale inhibition. Based on the different extraction processes utilized, two products were obtained and characterized using FTIR and SEM and evaluated using a static jar test procedure. The FTIR results confirmed the bands that make up the major constituents (quercetin) and other important compounds, which supports the present study. Laboratory evaluation show that ROSE can efficiently inhibit calcium sulphate scale and barium sulphate scales with a good inhibition rate of greater than 75% at an optimum dosage. Effect of temperature and dosage on inhibition performance revealed that ROSE is stable at higher temperatures and can effectively inhibit calcium and barium sulphate scales at nearly the same rate without degradation but requires additional dosage to produce same result for calcium carbonate scale. Also, the effect of time reveals that scale inhibitor performs a continuous CaSO4 and CaCO3 inhibition. Not only does ROSE perform excellently in the laboratory condition as a green scale inhibitor, but it also show a relatively close performance rate when compared to an existing commercial inhibitor which indicate that ROSE has a high potential for use in the oil industry.

Structure-property Relationship of Flavonoids as Potential Green Inhibitors for Oilfield Scales: A Mini-review

Scale deposits are a significant flow assurance issue in oil and gas operation with huge financial consequences. Not only does scaling drastically impair well performance, but it also has the potential to permanently destroy formation and equipment. Scale inhibitors are commonly used to prevent the accumulation of scales. A good scale inhibitor should be stable at the minimum effective inhibitor concentration under imposed operating conditions without interfering with or being affected by other chemical additives. However, most conventional scale inhibitors that possess these attributes, do not meet environmental restrictions which make them unfavorable for continuous application, prompting the industry to focus more on developing eco-friendly substitutes. This paper reviews the various types of scale inhibitors and general scale inhibition mechanism, summarizes scale concepts and ultimately, assesses the potential of flavonoids from natural plants as potential green scale inhibitors.

Green and High Effective Scale Inhibitor Based on Ring-Opening Graft Modification of Polyaspartic Acid

Polyaspartic acid (PASP)-based green scale inhibitor has great potential application in water treatment. Here, we first synthesized PASP in ionic liquid. Then, an effective PASP-based green scale inhibitor was synthesized by ring-opening graft modification of PASP with both aspartic acid (ASP) and monoethanolamine (MEA). Its chemical composition was characterized by gel chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and 1H nuclear magnetic resonance (1H NMR). Scale inhibition efficiency was measured by static scale inhibition tests. The results showed that the new PASP-based scale inhibitor has high scale inhibition to both CaCO3 and Ca3(PO4)2. When the concentration was increased to 2 mg/L, the inhibition efficiency of the new PASP-based scale inhibitor was 99% for CaCO3, while when the concentration was raised to only 4 mg/L, its inhibition efficiency increased to 100% for Ca3(PO4)2. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the changes of crystal structure for CaCO3 and Ca3(PO4)2 after adding the new PASP-based scale inhibitor. The crystal size of CaCO3 and Ca3(PO4)2 became smaller and the crystal form became amorphous after adding the modified PASPs compared with adding pure PASP. Moreover, the modified PASP showed good biodegradation performance.

Synthesis and Study of Modified Polyaspartic Acid Coupled Phosphonate and Sulfonate Moieties As Green Oilfield Scale Inhibitors

The petroleum industry has strived for several years to explore environmentally friendly scale inhibitors with no acute environmental impact. Well-known industrial biodegradable polyaspartic acid is widely used as a potent scale inhibitor (SI) against various inorganic scales in industrial circulating cooling water and topside petroleum applications. However, polyaspartic acid showed weak thermal stability at the petroleum reservoir temperatures. Here, we attempt to develop a new class of polyaspartic acid for squeeze treatment applications under harsh conditions. In this project, a series of modified polyaspartic acid, including pendant anionic functional moieties (phosphonate and sulfonate) were synthesized and investigated as new SIs to inhibit the calcium carbonate (calcite, CaCO3) and barium sulfate (barite, BaSO4) scales under oilfield conditions. These classes were synthesized via aminolysis of polysuccinimide with nucleophilic amine reagents under alkaline conditions. The products are polyaspartic acid-capped aminomethylene phosphonic acid (SI-2), polyaspartic acid-capped bisphosphonic acid (SI-3), polyaspartic acid-capped aminomethanesulfonic acid (SI-4), and polyaspartic acid-capped aminoethanesulfonic acid (SI-5), as well as in-house synthesized polyaspartic acid (SI-1). The scale inhibition activities of these compounds against carbonate and sulfate scales were determined using the dynamic scale loop test at 100 °C and 80 bar. Furthermore, the long-term thermal aging and calcium tolerance experiments were also investigated. It was found that polyaspartic-acid-capped aminomethylene phosphonic acid (SI-2) gave outstanding calcite scale inhibition performance and showed excellent thermal stability at 130 °C for 7 days compared to SI-1 and other modified SIs (SI-3-SI-5). This phosphonated polymer also exhibited superior calcium tolerance performance with Ca2+ ions up to 100 ppm, and moderate performance in the range of 1000–10 000 ppm calcium ions. This project highlights the success of designing and developing a new environmentally friendly calcite SI-based polyaspartic acid under harsh oilfield conditions.