Search Results (5)

To alleviate CaF₂ scaling on reverse osmosis membranes, polyepoxysuccinic acid (PESA) was modified with 2,5-dihydroxyterephthalic acid (DHTA) to obtain DHTA-PESA. Its structure and thermal stability were confirmed through characterization. Scale inhibition performance was evaluated using static and dynamic experiments. Results showed that in static tests, at a dosage of 200 mg/L, DHTA-PESA achieved a CaF₂ scale inhibition rate of nearly 100%, demonstrating Ca²⁺ chelation ability and the capacity to prolong crystallization induction time. In dynamic experiments, indicating superior CaF₂ dispersion performance and effective mitigation of membrane fouling. X-ray diffraction and scanning electron microscopy analysis revealed that DHTA-PESA induces irregular growth of CaF₂ crystals, disrupting their formation and altering crystal morphology. The primary scale inhibition mechanisms include dispersion, lattice distortion, and chelation. Full article

Water-based drilling fluids (WBDFs) cannot be effectively applied in long horizontal wells, such as shale gas wells, due to their high coefficient of friction (COF) and filtration loss that can strongly limit the efficient and environmentally friendly development of oil and gas resources. The objective of this study is the formulation of a WBDF characterized by ultra-low friction and ultra-low filtration properties, with a high-concentration polyepoxysuccinic acid (PESA) solution being utilized in the continuous phase. The research aims at the exploration of the feasibility of the method, the validation of the results, and the elucidation of the underlying mechanisms. The experimental results confirmed that the proposed WBDFs have excellent rheological properties, a COF of 0.016 and an API filtration of 0.4 mL. Microscopic analysis confirmed a direct and positive correlation between the macroscopic properties of the drilling fluids and their adsorption behavior at high PESA concentrations. This approach can be used to redesign traditional WBDFs and provide new possibilities to realize super performance in WBDFs that can be used to replace oil-based drilling fluids. Full article

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 Fe^II 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 Fe^II, 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. Full article

Poly acrylic acid (PAA) and polyepoxysuccinic acid (PESA) were investigated as scale inhibitors. The static experiments certified that PAA was superior to PESA for the inhibition of calcium carbonate in the low molecular weight range. The X-ray diffraction patterns suggest that the effect of PAA on the calcite (1 0 4) and (1 1 0) crystal plane was more obvious. Scanning electron microscopy was used to study the surface morphology of the depositions, which indicated that the addition of scale inhibitors could disturb the normal growth of CaCO₃ scale. The transmittance ratio of ferric oxide demonstrated that PAA had a better dispersion performance than PESA. The molecular dynamics simulation and quantum calculation were selected to theoretically explore the mechanism and structure of scale inhibitors, indicating that the interaction of PAA with (1 0 4) and (1 1 0) calcite crystal surfaces was stronger than PESA. In addition, the results indicated that the PAA with negative charge more easily adsorbed free Ca²⁺ in the aqueous phase. Based on these observations, PAA exhibited better scale inhibition and dispersion effects than PESA in the case of low molecular weight. Full article

A novel corrosion and scale inhibitor (TPP) containing tobacco stem extract (TSE), polyepoxysuccinic acid (PESA), and polyaspartic acid (PASP) was obtained by the optimal proportion of the orthogonal test. The anticorrosion effect of TPP for carbon steel was researched by static weight-loss method, on-line simulated dynamic test, electrochemical measurement, and scanning electron microscopy (SEM). The results showed that TPP could protect carbon steel efficiently with a maximal corrosion inhibition rate of 85.7% and it was a mixed-type corrosion inhibitor, mainly exhibiting cathode suppression capacity. Simultaneously, the results of calcium carbonate deposition experiment indicated that the scale inhibition rate of TPP was up to 100%. Full article