Polyepoxysuccinic Acid Research Articles

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.

Time dependent anti-corrosion and anti-scaling efficiency of polyepoxysuccinic acid inhibitor in simulated hard water

In this study, the time-dependent performance of a phosphorus-free corrosion and scale inhibitor primarily composed of polyoxyuccinic acid (PESA) and zinc salts was investigated in a laboratory-simulated hard water environment. Long-term static scale inhibition tests and corrosion rotation coupon tests were conducted under two temperature conditions, 45 °C and 80 °C, following established literature standards. Changes in water quality, scale morphology, metal corrosion status, and electrochemical impedance were monitored using calcium ion concentration analysis, optical microscopy imaging, X-ray diffraction (XRD), and electrochemical testing. The study revealed a progressive decline in the corrosion and scale inhibition efficiency of the phosphorus-free inhibitor in simulated hard water with calcium carbonate hardness levels of 300, 400, and 500 mg/L over time. Moreover, higher water hardness accelerated corrosion onset, suggesting that calcium carbonate deposition promotes metal corrosion under the experimental conditions. Density functional theory (DFT) calculations indicated that PESA chemically adsorbs onto both metal and calcite surfaces, underscoring its dual role in corrosion and scale inhibition. These findings underscore the intrinsic corrosion and scale inhibition capabilities of PESA, complementing its synergistic film-forming properties with Zn2+.

Effect of environmentally friendly reverse osmosis scale inhibitors on inorganic calcium carbonate scale

A highly efficient and environmentally friendly composite scale inhibitor was developed using sodium carboxymethyl cellulose (CMC-Na) and polyepoxysuccinic acid (PESA). The PESA:CMC-Na=1:3 optimum ratio was observed with a maximum enhancement factor of 1.81. The film flux attenuation rate was reduced from 24.98 % to 6.2 % at optimal operational condition (concentration 80 mg/L, initial pH 7) for actual mine water treatment. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis results showed that the addition of the compound scale inhibitor transformed the calcium carbonate scale from calcite to vaterite with looser and more porous structure. The molecular dynamics simulation results demonstrate that composite scale inhibitor had a higher binding energy with calcite than that of PESA, CMC-Na, resulting in the restrained formation of calcite. This study provides a new technical idea for the application of scale inhibitor to improve the treatment efficiency of mine water by reverse osmosis.

Effects of biodegradable dispersants on the separation flotation of chalcopyrite and serpentine

The presence of serpentine slime coating on the chalcopyrite surfaces severely affects the chalcopyrite floatability. In this study, three biodegradable polymers, namely polyaspartic acid (PASP), polyepoxy succinic acid (PESA), and hydrolyzed polymaleic (HPMA) were used as dispersants to disperse the chalcopyrite and serpentine particles. The micro-flotation experiments demonstrated that the application of dispersants in the flotation effectively reduced the negative impact of serpentine over a wide pH range, restoring the recovery rate of chalcopyrite to about 85%. The XPS analysis revealed that the dispersants could be adsorbed onto the mineral surfaces through the binding of carboxyl groups with the magnesium or copper sites. As a result, the surface potentials of serpentine changed from positive to negative, while that of the chalcopyrite became even more negative, resulting in a strong electrostatic repulsion between them, which effectively eliminated the covering of the serpentine on the chalcopyrite surface. The AFM force measurements indicate a weak interaction of the polycarboxylic acids dispersants with the surface of chalcopyrite. Consequently, the adsorption of dispersants on the chalcopyrite surface has an insignificant impact on the subsequent adsorption of collectors, which is further supported by the adhesion force measurements between the air bubble and mineral surfaces. Therefore, the application of polycarboxylic acid dispersants in the flotation significantly enhanced the floatability of chalcopyrite in the presence of the serpentine fines.

Synthesis and evaluation of a new scale inhibitor: the modified epoxysuccinic acid copolymer

Polyepoxysuccinic acid (PESA) scale inhibitor is widely recognized as a green and environmentally friendly scale inhibitor. However, its functional group type is single and cannot be used for a variety of scales. Based on this, a modified epoxy succinic acid quaternary polymer scale inhibitor PEAPS was prepared by introducing a variety of functional groups. The effects of scale inhibitor dosage, temperature, and solution pH on the scale inhibition performance of CaCO3, CaSO4, BaSO4, and SrSO4 were studied. At the same time, it is compared with the commonly used oilfield scale inhibitors Polyacrylic acid (PAA), PESA, and Ethylenediaminetetramethylenephosphonic acid (EDTMP). The results show that under the optimal synthesis conditions, the scale inhibition efficiency of PEAPS scale inhibitor on CaCO3 scale and CaSO4 reaches 100%, and the scale inhibition efficiency of BaSO4 and SrSO4 can reach at least 60%. Its comprehensive scale inhibition efficiency is better than other commonly used scale inhibitors under the same test conditions, and it has certain corrosion inhibition performance through static corrosion evaluation. The crystal parameters and micro-morphology of the four scales before and after the addition of scale inhibitor were analyzed using SEM and XRD. The results showed that after adding the PEAPS scale inhibitor, the crystal structure parameters of the CaCO3 scale and CaSO4 scale changed, and the micro-morphology of the four scale crystals also changed, to achieve the purpose of scale inhibition.

Designing a self-breathing electrode modulated by spatial hydrophobic microenvironments with stabilized H2O2 generation for wastewater treatment

A novel self-breathing air-diffusion rod graphite electrode (ADE-RG) engineered with spatial hydrophobic microenvironments was developed to enhance H2O2 production without external air aeration. The microenvironments, created through thermal shaking-induced turbulence and centrifugal effect, significantly improved the air-diffusion capability. This innovation led to the increase in H2O2 generation (3.36 times higher than that in the unmodified system) due to a locally enhanced electric field, increased oxygen transfer rate, and improved selectivity for two-electron transfer process. Furthermore, incorporating polyepoxysuccinic acid into the electrolyte not only prevents electrode scaling but also minimizes H2O2 decomposition, culminating in the H2O2 concentration of 50.64 ± 2.92 mg L−1 cm−2. Notably, the system performed prominently in treating industrial rifampicin wastewater, achieving a degradation efficiency of 95.29 ± 0.47%, even under high-loading conditions (initial COD was 22,898.50 ± 405.17 mg L−1). These results indicate the significant potential of the self-breathing ADE-RG system in broad-scale wastewater treatment applications.

Morphology transformation of Na2SO4 from prism into dendrite enhanced desalination efficiency in sandstone by biodegradable polycarboxylate modifiers

The salt decay on the surface of stone cultural relics is the greatest damage to its loaded information. Polycarboxylate modifiers can reduce salt crystallization pressure and/or change crystal habits, thereby becoming a new method for controlling salt crystallization damage in pores. However, the lack of precise regulation of crystal morphology by modifier and the unclear relationship between modifier and crystal transformation during salt growth hinder its practical application. Herein, diethylenetriamine pentamethylene phosphonic acid (DTPMP), phosphorus-free, green polyaspartic acid (PASP) and polyepoxysuccinic acid (PESA), as well as three composite modifiers composed of DTPMP and PESA (M-1:9, M-2:8, M-3:7) were systematically investigated. Video microscope, scanning electron microscope, and X-ray diffraction showed that the addition of these modifier could obviously transform the crystal morphology of sodium sulfate(thenardite) from prism into dendrite, which was related to the significant change in the intensity ratios of corresponding peaks on the different crystal planes. Molecular dynamics simulations were conducted to investigate the interactions of PASP and PESA on different surfaces of sodium sulfate, revealing that the crystal transformation of sodium sulfate was mainly influenced by the coordination/adsorption effect of the modifiers on the (010) plane. All modifiers were used for sandstone desalination, and the clean and desalted sandstones were analyzed for desalting efficiency, colorimetry and porosity, which showed that PESA, PASP and composite modifier M-3:7 all promoted the precipitation of sodium sulfate on the surface. Especially, composite modifier M-3:7 prefers to change the crystallization and morphology of sodium sulfate from prism into dendritic flower, which can be used to protect to sandstone cultural relics from salt damage.

Study on the scale-forming mechanism of magnesium phosphate by polyepoxysuccinic acid based on solution conductivity method

PurposeThis study aims to investigate the influence of polyepoxysuccinic acid sodium (PESA), a green antiscalant, on the nucleation, crystallization and precipitation of magnesium phosphate.Design/methodology/approachThe conductivity method was used to investigate the maximum relative supersaturation of magnesium phosphate across various PESA dosages. Subsequently, a magnesium phosphate scale was prepared using the static scale inhibition method (GB/T16632-1996) and then analyzed via scanning electron microscopy.FindingsThe findings showed that PESA extends the induction period of magnesium phosphate crystallization, reduces crystal growth rate and elevates the solution’s relative supersaturation. Notably, PESA exerts a low dosage effect on inhibition of the magnesium phosphate scale, with the optimal dosage identified at 10 mL. Scanning electron microscopy revealed that PESA dispenses a dispersing effect on the magnesium phosphate scale, generating numerous concave, convex and deeper pores on the scale particles’ surface, and thereby significantly enhancing the surface area, especially when using an antiscalant with variable dosages.Originality/valueThis study sheds new light on the impact of PESA, a green antiscalant, on the crystallization and precipitation of magnesium phosphate, thus paving the way for the development of enhanced and eco-friendly scale inhibition strategies in future applications.

How accompanying ions affect soil heavy metal removal by polyepoxysuccinic acid during washing?

Soil washing with green eluent is an efficient technique to remediate heavy metal contaminated farmland. In addition to eluent, less is known about the roles of accompanying ions on heavy metal removal. We investigated the effects of accompanying ions including Fe3+, Mn2+, Ca2+, Mg2+, Al3+, Si4+ and PO43− on the desorption of Pb2+ and Cd2+ in paddy and arid soils using ethylenediaminetetraacetic acid and polyepoxysuccinic acid as eluents. The release rates of target and accompanying ions showed significant fast and slow reaction stages based on corresponding analysis and kinetic models. In fast reaction stage, Pb2+ and Cd2+ performed geochemical analogy with Ca2+, Mg2+ and PO43−. The release curves of these ions were fitted well with Elovich model, indicating that they released from oxysalt surface into solution via ion exchange, and dissolution of Fe/Mn/Al/Si (hydr)oxides through H+- and ligand-promoted dissolution. In slow reaction stage, Pb2+ and Cd2+ were related to Fe3+, Mn2+, Al3+ and Si4+, which were controlled by intraparticle diffusion process. H+ slowly diffused into interlayer of phyllosilicates to displace target and accompanying ions by ion exchange. Therefore, this research filled the gap of accompanying ions driving the release behavior of heavy metal ions during leaching.

Novel Polyepoxysuccinic Acid-Grafted Polyacrylamide as a Green Corrosion Inhibitor for Carbon Steel in Acidic Solution.

Utilizing green corrosion inhibitors has been classified among the most efficient and economical mitigation practices against metallic degradation and failure. This study aims to integrate the features of green and complementary properties of polyepoxysuccinic acid (PESA) and polyacrylamide (PAM) for steel corrosion inhibition. A novel PESA-grafted-PAM (PESAPAM) has been first-ever synthesized in this research study and deployed as a corrosion inhibitor for C-steel in 1.0 M HCl solution. Eco-toxicity prediction confirmed the environmentally friendly properties acquired by the synthesized inhibitor. Electrochemical, kinetics, and surface microscopic studies were carried out to gain a holistic view of C-steel corrosion behavior with the PESAPAM. Furthermore, the performance of PESAPAM was compared with that of the pure PESA under the same testing conditions. Results revealed predominant inhibitive properties of PESAPAM with an inhibition efficiency (IE) reaching 90% at 500 mg·L-1 at 25 °C. Grafting PAM onto the PESA chain showed an overall performance improvement of 109% from IE% of 43 to 90%. Electrochemical measurements revealed a charge transfer-controlled corrosion mechanism and the formation of a thick double layer on the steel surface. The potentiodynamic study classified PESAPAM as a mixed-type inhibitor. Furthermore, the investigation of C-steel corrosion kinetics with the presence of PESAPAM predicted an activation energy of 85 kJ·mol-1, correlated with a physical adsorption behavior. Finally, performed scanning electron microscopy and energy-dispersive X-ray analyses confirmed the adsorption of PESA and PESAPAM, with superior coverage of PESAPAM onto the steel surface.

Preparation and application of new polycarboxylic acid for scale inhibition

In oilfield, scaling caused by water injection is becoming increasingly serious by blocking the gathering and transmission pipelines of the oilfield and resulting in a decline in oilfield production and a great loss of production. Oil and gas leakage caused by pipeline scaling, corrosion and perforation has caused irreversible damage to the surrounding environment. In this paper, citric acid and sodium pyrophosphate are used as the main agents, and hydrolytic polymaleic anhydride, polyaspartic sodium and polyepoxysuccinic acid are respectively compounded to establish polycarboxylic acid scale inhibitor. The scale inhibition experiments of CaCO3, CaSO4 and BaSO4 were carried out to obtain a new type of highly effective polycarboxylic acid scale inhibitor formula. For CaCO3, the best formula is 200 ppm citric acid + 30 ppm hydrolyzed polymaleic anhydride. For CaSO4, the best formula is 100 ppm citric acid + 5 ppm sodium polyaspartate.

Geometrical and Electronic Analysis of Polyepoxysuccinic Acid (PESA) for Iron Sulfide Scale Inhibition in Oil Wells.

Scale formation causes major losses in oil wells, related to production and equipment damages. Thus, it is important to develop effective materials to prevent scale formation and inhibit any additional formation. One known environmentally friendly material with promising performance for scale inhibition is polyepoxysuccinic acid (PESA). However, the performance and further development of any scale treatment chemical is highly affected by its electronic structure and behavior. Thus, this paper aims to obtain insights into the kinetics and thermodynamics of the chemical reactions during scale inhibition by investigating the geometrical and electronic structure of PESA. Density Functional Theory (B3LYP/6-31 g (d)-lanl2dz) was used to study the structure of PESA, considering different forms of PESA and their corresponding binding affinities and chemical behaviors. The scale is represented as FeII ions, and PESA is modeled as (n = 1, and 2). Three conditions of PESA were considered: the standard form, the form with a modified electron donating group (R- = CH3-), and ammonium salt of PESA (M+ = NH4+). The results showed that PESA has a high binding affinity to FeII, comparable to known chelating agents, with the highest binding affinity for ammonium salt of PESA with the CH3- donating group (-1530 kJ/mol). The molecular orbitals (MO), electron affinity (EA), and charge analysis further explained the findings. The HOMO-LUMO gap and EA results revealed the high reactivity and thermodynamic stability of all forms of PESA. In addition, the ammonium salt form of PESA with the electron donating group performs better, as it has a greater overall negative charge in the compounds. Furthermore, the NH4+ cationic group tends to lower the value of the HOMO orbital, which increases the inhibition performance of PESA.

Synthesis and evaluation of amino acid modified polyepoxysuccinic acid as inhibitor of calcium carbonate scale

Abstract Amino acid (AA) was used as a green grafting agent to functionalize polyepoxysuccinic acid (PESA), and three AA-modified PESA (AA-PESA) CaCO3 scale inhibitors were obtained to change the structural singleness of PESA and further improve its comprehensive properties. The structures of AA-PESA were characterized by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance hydrogen (1HNMR) spectroscopy. The molecular weights of AA-PESA were analyzed by gel permeation chromatography (GPC). The synthesis technology of AA-PESA was optimized by single-factor and orthogonal experiments. The CaCO3 scale inhibition performance of AA-PESA was studied by the static scale-inhibition method, and the scale inhibition mechanism was analyzed. Results showed that AA-PESAs had the same synthesis process: n(PESA):n(AA) = 1:0.625, reaction temperature of 95 °C, and reaction time of 2 h. In the water system with pH 7.0–8.5, agent concentration of 8–10 mg/L, action period of 10–14 h, ambient temperature <80 °C, and ρ(Ca2+) < 250 mg/L, the inhibition rate of the three AA-PESAs on CaCO3 could reach 100%, and GIN was preferred for the graft modification of PESA. FTIR, X-ray diffraction (XRD), and scanning electron microscopy (SEM) results showed that the addition of AA-PESA could control the nucleation sites of CaCO3 crystals, had important influence on the growth of calcite (104) crystal planes, and had a good inhibitory effect on the CaCO3 scale.

Study on the remediation of heavy metal contaminated soils by citric acid and polyepoxysuccinic acid complex leaching

ABSTRACT Soil leaching remediation has attracted extensive attention because of its good removal effect, short operation period and stable removal effect of heavy metals. The key to reduce the harm of heavy metal contaminated soil to the environment and human health is to use appropriate leachate to repair heavy metal contaminated soil. In this study, citric acid (CA), iron nitrate (Fe(NO3)3) and polyepoxysuccinic acid (PESA) with different concentrations were used as research reagents to explore the best combination of leaching effects of heavy metals (Cu, Zn, Pb, Cd) in contaminated soil. The effects of concentration of eluent, liquid to solid ratio and leaching time on leaching efficiency of heavy metals and the changes of soil physical and chemical properties before and after leaching were studied. The results showed that 0.5 mol/L CA and 0.05 mol/L PESA were combined according to the volume ratio of 7:3, and the leaching effect was the best when the liquid–solid ratio was 15 and the leaching time was 240 min. Under the optimal leaching condition, the four heavy metals in the soil had significant removal effects, and the removal rates were, respectively, 86.06% Cu, Zn 74.55%, Pb 67.88% and Cd 91.63%. The X-ray spectrum and Fourier infrared spectrum analysis of soil before and after leaching showed that CA-PESA combined leaching had little effect on soil structure change. This study provided theoretical support for the development and application of suitable leaching agents for the remediation of heavy metal-contaminated soil.

Synthesis and evaluation of scale inhibitor with high-temperature resistance and low corrosion capability for geothermal exploitation

Scale and corrosion issues of well pipelines become more prominent in geothermal exploitation at temperatures exceeding 100 °C. Effective scale and corrosion inhibitors are the keys to addressing the concerns. In this study, maleic anhydride (MA), acrylic acid (AA), 2-acrylamide-2-methylpropane sulfonic acid (AMPS), sodium hypophosphite, and sodium dodecyl sulfate (SDS) were utilized to synthesize a multi-polymer scale inhibitor PZGS with high-temperature resistance and low corrosion capability for geothermal exploitation. The functional groups and molecular weight of PZGS were analyzed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The scale inhibitor contains carboxylic acid groups, amide groups, phosphonic acid groups, and sulfonic acid groups. These groups ensure the capability of PZGS to chelate Ca2+, thus promoting the lattice distortion of calcium carbonate scale and improving its scale inhibition performance and temperature resistance. The number average molecular weight and the weight average molecular weight of PZGS are 5446 g/mol and 7139 g/mol respectively. The scale inhibition rate of 480 mg/L PZGS could reach 95% at 150 °C which is better than common scale inhibitors such as nitrogen trimethyl triphosphonic acid (ATMPA) and diethylenetriamine pentamethylene phosphonic acid (DTPMPA), whose inhibition rates are just 62% and 60% at 150 °C respectively. With the increase of the concentration, the formation of aragonite and vaterite gradually increased while calcite decreased because of the chelation and lattice distortion of polycarboxylic acid groups, phosphonic acid, sulfonic acid, and other groups from PZGS over the calcium carbonate scale. The compound formula “240 mg/L PZGS plus 200 mg/L polyepoxysuccinic acid (PESA)" performed the best effectiveness in its anti-scale and low corrosion capability. Its scale inhibition rate on the calcium carbonate scale was 94.1% at 150 °C, and the corrosion rate of the KLF carbon steel corrosion test piece was only 0.35 g/(m2·h) due to the PESA film coverage. Compared with 0.94 g/(m2·h) from brine solution and 0.91 g/(m2·h) from 240 mg/L PZGS, the corrosion rate of the compound formula was reduced by 63.2% and 61.7% in simulated geothermal water respectively. The findings of this study can provide effective guidelines for the development of scale and corrosion inhibitors for geothermal exploitation.

A novel module for scale inhibitors detection in RO process: Membrane modification and enrichment mechanism

Inventing a method for accurately determining trace scale inhibitor in reverse osmosis (RO) concentrate is of great value for improving RO operation efficiency. In this regard, a module for detecting scale inhibitor polyepoxysuccinic acid (PESA) based on membrane enrichment was designed and a novel polythersulfone (PES) membrane modified by cationic polyacrylamide (CPAM) and pinacyanol chloride (PC) was developed. CPAM adsorption reduced the electronegativity of PES substrate and formed a prefiltering layer, which increased the rejection rate of PESA from 85% to 95%. Meanwhile, PC could complex with PESA to increase the PESA particle size and further improved the detection accuracy. The electrostatic force between the modified layer and PESA revealed that the electronics of CPAM and the complexity of PC can parallel promote the enrichment of PESA. Further, the extensive comparative study between membrane detection and conventional PC detection was performed. The PES-(CPAM/PC) membrane detection showed high sensitivity and the minimum detection concentration was 0.1 mg/L. Compared with PC detection, PES-(CPAM/PC) membrane detection improved durability by 33%. Simultaneously, the change rate of detection results in ionic interference is reduced by 15%. Finally, the practicability of the new module was verified by the PESA concentration detection in four RO concentrate. The enrichment detection method and mechanism provided in this study can provide technical guidance for scale inhibitor monitoring in water treatment.

Study on the Corrosion and Scale Inhibition Mechanism of the Thiourea-Modified Polyepoxysuccinic Acid (CNS-PESA)

In this paper, thiourea-modified polyepoxysuccinic acid (CNS-PESA) was synthesized and used as a corrosion and scale inhibitor for the circulating cooling water system of the factory. Polyepoxysuccinic acid (PESA) has been widely used in industrial water treatment due to its good corrosion inhibition and scale inhibition performance. It also acts as a reliable material for dispersion of iron oxide, good biodegradation efficiency, and phosphorus-free content. The scale inhibition performance for calcium carbonate and calcium phosphate scale with corrosion inhibition performance using different inhibitor concentrations, temperatures, pH, and calcium ion concentration on scale inhibition efficiency were studied. The scanning electron microscope (SEM) analysis on the scale and corrosion of carbon steel with two methods as GB/T 18175-2000 “Measurement of inhibitors in water treatment: rotation coupon method” and electrochemical method for CNS-PESA and PESA were utilized. Compared to using CNS-PESA and PESA for calcium carbonate and calcium phosphate, the scale inhibition rates were increased by 6% and 18.7%, and the corrosion inhibition rate increased by 22.4%. The scale inhibition efficiency of CNS-PESA is best when the calcium ion concentration is less than or equal to 350 mg/L. Moreover, the thiourea-modified polyepoxysuccinic acid (CNS-PESA) was phosphorus-free corrosion and scale inhibitor and minimizes environmental pollution problems.

Flotation separation of bastnaesite from fluorite with an eco-friendly depressant polyepoxysuccinic acid and its depression mechanism

In this work, an eco-friendly depressant polyepoxysuccinic acid (PESA) was introduced for the flotation separation of bastnaesite from fluorite using octyl hydroxamic acid (OHA) as the collector. The depression effect and mechanism of PESA on the fluorite and bastnaesite were investigated by micro-flotation tests, contact angle, adsorption experiments, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The flotation results showed that the recovery of fluorite decreased by 89.71% when 4 mg/L PESA was added to the flotation system, while the bastnaesite recovery only exhibited a slight reduction of 2.88% under these conditions. Wettability results suggested that the PESA in the presence of OHA could make the fluorite surface hydrophilic, whereas it had a negligible impact on the hydrophobicity of the bastnaesite surface. The addition of PESA could impede the OHA adsorption on fluorite surface, which was revealed by adsorption tests and FT-IR, and the XPS analysis confirmed that the chemisorption of PESA on the Ca sites of fluorite occurred. For bastnaesite, the adsorption of OHA still could be detected, making the bastnaesite well floatable. Therefore, the efficient separation of bastnaesite from fluorite could be achieved with the PESA as a selective depressant.

Research on the preparation of a scale inhibitor PESA-ESA-AMPS based on polyepoxysuccinic acid

Research on the preparation of a scale inhibitor PESA-ESA-AMPS based on polyepoxysuccinic acid

Investigation of barium sulfate scale inhibitor to improve the squeeze performance in South China Sea Oilfield

In this study, the scale inhibitor PEPB (mixture of polyepoxysuccinic acid (PESA) and 2-phosphonobutane-1, 2, 4-tricarboxylic acid (PBTCA)) was selected to investigate the squeeze performance to solve the barium sulfate scaling problem in South China Sea Oilfield. The squeeze performance of scale inhibitor PEPB was evaluated using static inhibition efficiency test and static adsorption experiment. In addition, the adsorption/desorption characteristics of the inhibitor was investigated by core flooding experiment. The results of static inhibition efficiency tests show that the scale inhibition efficiency of the inhibitor PEPB is greater than 90% at a low concentration of 5 mg/L. The static adsorption capacity of the inhibitor PEPB increases by 171% when the pH value varied from 12.7 to 4.0. In addition, the desorption results evaluated by core flooding experiments show that PEPB has a better desorption performance at low pH value of 4.0. This study provides an effective guidance for optimizing scale inhibitor adsorption performance to extend squeeze lifetime in South China Sea Oilfield.