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Keywords = alpha olefin

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18 pages, 1899 KB  
Article
Performance Analysis of New Deuterium Tracer for Online Oil Consumption Measurements
by Francesco Marzemin, Martin Vareka, Kevin Gschiel, Bernhard Rossegger, Peter Grabner, Michael Engelmayer and Nicole Wermuth
Lubricants 2025, 13(8), 351; https://doi.org/10.3390/lubricants13080351 - 5 Aug 2025
Viewed by 663
Abstract
The accurate and precise measurement of lubricating oil consumption is critical for developing environmentally friendly internal combustion engines, particularly hydrogen-fueled internal combustion engines. The deuterium tracer method is based on the addition of poly-deuterated base oil tracers to fully formulated oils for precise, [...] Read more.
The accurate and precise measurement of lubricating oil consumption is critical for developing environmentally friendly internal combustion engines, particularly hydrogen-fueled internal combustion engines. The deuterium tracer method is based on the addition of poly-deuterated base oil tracers to fully formulated oils for precise, accurate, and fast lubricating oil consumption measurements. Previously performed measurements have shown that the use of poly-deuterated poly-alpha olefins has minimal impact on lubricating oil properties, except for a slight drop in oil viscosity. To further reduce the impact on lubricating oil characteristics, a new base oil for the synthesis of a poly-deuterated tracer is introduced, and its influence on the lubricating oil’s chemical, tribological, and rheological properties is analyzed. Furthermore, the influence of the tracer addition on the preignition tendencies of the fully formulated oil is also examined. Based on the analyses, no relevant changes in the lubricating oil properties, such as viscosity, density, and thermal degradation behavior, can be observed. Additionally, the deuterium tracer does not negatively influence combustion anomalies, thus reducing preignition tendencies. These results establish the method’s compatibility with new-generation engines, especially hydrogen-fueled internal combustion engines. Full article
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12 pages, 1944 KB  
Article
Perfluorotetradecanoic Acid as an Additive for Friction Reduction in Full-Film EHD Contacts: The Role of Functional Group, Base Oil Polarity, Additive Concentration and Contact Pressure
by Marko Polajnar, Tomaž Požar and Mitjan Kalin
Lubricants 2025, 13(6), 263; https://doi.org/10.3390/lubricants13060263 - 14 Jun 2025
Viewed by 2953
Abstract
Perfluorinated tetradecanoic acid was added as an additive to a base oil and tested under full film elastohydrodynamic (EHD) contact conditions between a steel ball and a steel disc. By varying key performance parameters, we aimed to assess the feasibility and limitations of [...] Read more.
Perfluorinated tetradecanoic acid was added as an additive to a base oil and tested under full film elastohydrodynamic (EHD) contact conditions between a steel ball and a steel disc. By varying key performance parameters, we aimed to assess the feasibility and limitations of perfluorinated carboxylic acids in reducing friction in lubricated contacts. The results demonstrate that the tested perfluorinated additive is effective in reducing friction when blended with a non-polar synthetic poly-alpha-olefin oil. However, no significant friction reduction was observed when the same additive was used in a slightly polar synthetic ester. The carboxylic acid functional group plays a crucial role in the observed friction-reducing effect. Adjusting the additive concentration further plays an important role in reducing friction. A concentration of at least 0.35 wt.% is required to achieve a notable friction reduction of approximately 10%. Increasing the concentration beyond this threshold continues to improve the friction-reducing effect. Conversely, increasing the contact pressure has a detrimental impact on friction reduction. The greatest reduction in friction—over 20% compared to the base oil—was achieved at the lowest contact pressure tested (0.69 GPa). Full article
(This article belongs to the Special Issue Novel Lubricant Additives in 2025)
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16 pages, 8324 KB  
Article
Tribological Behavior of Anodized Aluminum Oxide (AAO) Under the Addition of PAO6 Lubrication with Nano-Alumina
by Marina C. Vasco, Rodrigo L. Villanova and Giuseppe Pintaude
Lubricants 2025, 13(3), 97; https://doi.org/10.3390/lubricants13030097 - 21 Feb 2025
Viewed by 1356
Abstract
Anodizing can generate porous wear-resistant layers, which can act as reservoirs for gradually releasing lubricants. Studies on the formation of zinc dialkyl dithiophosphate (ZDDP) tribofilms in non-ferrous metals are relatively rare. Furthermore, adding nanoparticles can improve wear resistance in various applications. This investigation [...] Read more.
Anodizing can generate porous wear-resistant layers, which can act as reservoirs for gradually releasing lubricants. Studies on the formation of zinc dialkyl dithiophosphate (ZDDP) tribofilms in non-ferrous metals are relatively rare. Furthermore, adding nanoparticles can improve wear resistance in various applications. This investigation aims to correlate several anodized surfaces using H2SO4 (5 or 10%wt. concentration and 45 or 60 min exposition) to tribological outputs, contributing to understanding the friction behavior of non-metallic layers. Three steps were applied on anodized Alumold 500 alloy. Firstly, the scratching test, to select the layers with higher critical loads. The greatest scratch resistance was obtained with the highest H3/E2 value and thickest layer. Secondly, lubricated tests with only poly-alpha-olefin oils (PAO6) were performed in a reciprocating test rig using an alumina ball as the counterpart. From that, only the best AAO condition was selected. Finally, three more lubricant compositions were tested, as follows: adding ZDDP to PAO6, alumina nanoparticles (~100 nm) to PAO6, and ZDDP + nanoparticles. The addition of nano-alumina to the PAO6 resulted in the maintenance of COF values with only PAO6 (~0.1), when the most significant drop in the surface roughness was observed along with the tests. Full article
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11 pages, 1914 KB  
Article
α-Olefin Oligomerization Mediated by Group 4 Metallocene Catalysts: An Extreme Manifestation of the Multisite Nature of Methylaluminoxane
by Francesco Zaccaria, Antonio Vittoria, Giuseppe Antinucci, Roberta Cipullo and Vincenzo Busico
Polymers 2025, 17(1), 46; https://doi.org/10.3390/polym17010046 - 28 Dec 2024
Cited by 2 | Viewed by 1721
Abstract
Group 4 metallocenes are competent catalysts for the oligomerization of higher α-olefins. Among the many chemical and physical variables of importance in the process, one is the choice of cocatalyst (activator). The impact of various activators on the performance of a representative catalyst, [...] Read more.
Group 4 metallocenes are competent catalysts for the oligomerization of higher α-olefins. Among the many chemical and physical variables of importance in the process, one is the choice of cocatalyst (activator). The impact of various activators on the performance of a representative catalyst, (nBuCp)2ZrCl2, in the oligomerization of 1-octene was thoroughly investigated; in particular, the molecular weight distribution (MWD) of the oligomers was determined by means of high-resolution high performance liquid chromatography (HR-HPLC). Unexpectedly, a bimodal MWD was highlighted when the precatalyst was activated with methylaluminoxane (MAO), whereas a single Schulz–Flory (SF) MWD was observed with borate salts. The presence of Al centers with different Lewis acidity in the complex and ill-defined structure of MAO is well known, and the broadening effects on the MWD of olefin polymerization products made with metallocene/MAO catalyst systems have been reported before. However, to the best of our knowledge, clear HR-HPLC evidence of two active species resulting from activation with MAO of one single zirconocene precursor, yielding two discrete SF product distributions, is unprecedented. By varying the polarity of the reaction medium, we managed to modulate the MWD of the oligomers from bimodal to monomodal, even with MAO, thus demonstrating that ion pairing effects are behind these unusual findings. Full article
(This article belongs to the Section Polymer Chemistry)
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18 pages, 13047 KB  
Article
Utilizing Headspace–Gas Chromatography–Ion Mobility Spectroscopy Technology to Establish the Volatile Chemical Component Fingerprint Profiles of Schisandra chinensis Processed by Different Preparation Methods and to Perform Differential Analysis of Their Components
by Yiping Yan, Bowei Sun, Mengqi Wang, Yanli Wang, Yiming Yang, Baoxiang Zhang, Yining Sun, Pengqiang Yuan, Jinli Wen, Yanli He, Weiyu Cao, Wenpeng Lu and Peilei Xu
Molecules 2024, 29(24), 5883; https://doi.org/10.3390/molecules29245883 - 13 Dec 2024
Viewed by 1101
Abstract
In order to characterize the volatile chemical components of Schisandra chinensis processed by different Traditional Chinese Medicine Processing methods and establish fingerprint profiles, headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS) technology was employed to detect, identify, and analyze Schisandra chinensis processed by five different methods. [...] Read more.
In order to characterize the volatile chemical components of Schisandra chinensis processed by different Traditional Chinese Medicine Processing methods and establish fingerprint profiles, headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS) technology was employed to detect, identify, and analyze Schisandra chinensis processed by five different methods. Fingerprint profiles of volatile chemical components of Schisandra chinensis processed by different methods were established; a total of 85 different volatile organic compounds (VOCs) were detected in the experiment, including esters, alcohols, ketones, aldehydes, terpenes, olefinic compounds, nitrogen compounds, lactones, pyrazines, sulfur compounds, thiophenes, acid, and thiazoles. Principal component analysis (PCA), Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA), and Pearson correlation analysis methods were used to cluster and analyze the detected chemical substances and their contents. The analysis results showed significant differences in the volatile chemical components of Schisandra chinensis processed by different methods; the Variable Importance in Projection (VIP) values of the OPLS-DA model and the P values obtained from one-way ANOVA were used to score and screen the detected volatile chemical substances, resulting in the identification of five significant chemical substances with the highest VIP values: Alpha-Farnesene, Methyl acetate,1-octene, Ethyl butanoate, and citral. These substances will serve as marker compounds for the identification of Schisandra chinensis processed by different methods in the future. Full article
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14 pages, 3871 KB  
Article
Effects and Mechanisms of Dilute-Foam Dispersion System on Enhanced Oil Recovery from Pore-Scale to Core-Scale
by Xiuyu Wang, Rui Shen, Yuanyuan Gao, Shengchun Xiong and Chuanfeng Zhao
Energies 2024, 17(16), 4050; https://doi.org/10.3390/en17164050 - 15 Aug 2024
Viewed by 1322
Abstract
The dilute-foam dispersion system improves oil recovery by reducing interfacial tension between oil and water, altering wettability, and diverting displaced fluids by plugging larger pores. An optimized foaming system is obtained by formability evaluation experiments, in which the half-life for drainage and foaming [...] Read more.
The dilute-foam dispersion system improves oil recovery by reducing interfacial tension between oil and water, altering wettability, and diverting displaced fluids by plugging larger pores. An optimized foaming system is obtained by formability evaluation experiments, in which the half-life for drainage and foaming volume by different types and concentrations of surfactants are analyzed, followed by the addition of partially hydrolyzed polyacrylamide (HPAM) with varied concentrations to enhance the foam stability. Using COMSOL Multiphysics 5.6 software, the Jamin effect and plugging mechanism of the water–gas dispersion system in narrow pore throats were simulated. This dispersion system is applied to assist CO2 huff-n-puff in a low-permeability core, combined with the online NMR method, to investigate its effects on enhanced oil recovery from the pore scale. Core-flooding experiments with double-pipe parallel cores are then performed to check the effect and mechanism of this dilute-foam dispersion system (DFDS) on enhanced oil recovery from the core scale. Results show that foam generated by combining 0.6% alpha-olefin sulfonate (AOS) foaming agent with 0.3% HPAM foam stabilizer exhibits the strongest foamability and the best foam stability. The recovery factor of the DFDS-assisted CO2 huff-n-puff method is improved by 6.13% over CO2 huff-n-puff, with smaller pores increased by 30.48%. After applying DFDS, the minimum pore radius for oil utilization is changed from 0.04 µm to 0.029 µm. The calculation method for the effective working distance of CO2 huff-n-puff for core samples is proposed in this study, and it is increased from 1.7 cm to 2.05 cm for the 5 cm long core by applying DFDS. Double-pipe parallel core-flooding experiments show that this dispersion system can increase the total recovery factor by 17.4%. The DFDS effectively blocks high-permeability layers, adjusts the liquid intake profile, and improves recovery efficiency in heterogeneous reservoirs. Full article
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19 pages, 5769 KB  
Article
An Experimental Investigation of Surfactant-Stabilized CO2 Foam Flooding in Carbonate Cores in Reservoir Conditions
by Madiyar Koyanbayev, Randy Doyle Hazlett, Lei Wang and Muhammad Rehan Hashmet
Energies 2024, 17(13), 3353; https://doi.org/10.3390/en17133353 - 8 Jul 2024
Cited by 6 | Viewed by 2720
Abstract
Carbon dioxide (CO2) injection for enhanced oil recovery (EOR) has attracted great attention due to its potential to increase ultimate recovery from mature oil reservoirs. Despite the reported efficiency of CO2 in enhancing oil recovery, the high mobility of CO [...] Read more.
Carbon dioxide (CO2) injection for enhanced oil recovery (EOR) has attracted great attention due to its potential to increase ultimate recovery from mature oil reservoirs. Despite the reported efficiency of CO2 in enhancing oil recovery, the high mobility of CO2 in porous media is one of the major issues faced during CO2 EOR projects. Foam injection is a proven approach to overcome CO2 mobility problems such as early gas breakthrough and low sweep efficiency. In this experimental study, we investigated the foam performance of a commercial anionic surfactant, alpha olefin sulfonate (AOS), in carbonate core samples for gas mobility control and oil recovery. Bulk foam screening tests demonstrated that varying surfactant concentrations above a threshold value had an insignificant effect on foam volume and half-life. Moreover, foam stability and capacity decreased with increasing temperature, while variations in salinity over the tested range had a negligible influence on foam properties. The pressure drop across a brine-saturated core sample increased with an increasing concentration of surfactant in the injected brine during foam flooding experiments. Co-injection of CO2 and AOS solution at an optimum concentration and gas fractional flow enhanced oil recovery by 6–10% of the original oil in place (OOIP). Full article
(This article belongs to the Topic Enhanced Oil Recovery Technologies, 3rd Edition)
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19 pages, 7477 KB  
Article
Effect of Asphaltenes and Asphaltene Dispersants on Wax Precipitation and Treatment
by Oualid M’barki, John Clements and Quoc P. Nguyen
Colloids Interfaces 2024, 8(3), 30; https://doi.org/10.3390/colloids8030030 - 14 May 2024
Cited by 3 | Viewed by 2612
Abstract
A detailed understanding of the interactions between wax and asphaltenes with other components of crude oils and the effect of treatments with paraffin inhibitors (PIs) and asphaltene dispersants (ADs), with a focus on identifying specific structure-activity relationships, is necessary to develop effective flow [...] Read more.
A detailed understanding of the interactions between wax and asphaltenes with other components of crude oils and the effect of treatments with paraffin inhibitors (PIs) and asphaltene dispersants (ADs), with a focus on identifying specific structure-activity relationships, is necessary to develop effective flow assurance strategies. The morphological and rheological consequences of treating wax and asphaltenes in oils of differing composition with a series of ADs having structural features in common with an alpha olefin-maleic anhydride (AO-MA) comb-like copolymer PI were assessed alone and in combination with said PI. Of the four ADs studied, two were identified as being effective dispersants of asphaltenes in heptane-induced instability tests and in a West Texas (WT) crude. The degree to which a low concentration of asphaltenes stabilizes wax in the absence of treatment additives is lessened in oils having greater aromatic fractions. This is because these stabilizing interactions are replaced by more energetically favorable aromatic–asphaltene interactions, increasing oil viscosity. Treatment with AD alone also reduces the extent of wax–asphaltene interactions, increasing oil viscosity. In concert with the PI, treatment with the AD having greater structural similarity with the PI appears to improve wax solubility in both the presence and absence of asphaltenes. However, the viscosity of the treated oils is greater than that of the oil treated with PI alone, while treatment with AD having lesser structural similarity with the PI does not adversely affect oil viscosity. These data suggest that rather than treating both wax and asphaltenes, AD may poison the function of the PI. These data illuminate the pitfalls of designing flow assurance additives to interact with both wax and asphaltenes and developing treatment plans. Full article
(This article belongs to the Special Issue Crude Oil Recovery)
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20 pages, 5974 KB  
Article
Structure–Performance Relationship of Coal-Based Lubricating Base Oils and Sensitivities to Typical Additives
by Junyi Liu, Zhaojun Zhang, Xia Zhou, Wenjing Hu, Renmin Pan and Jiusheng Li
Lubricants 2024, 12(5), 156; https://doi.org/10.3390/lubricants12050156 - 30 Apr 2024
Cited by 3 | Viewed by 2302
Abstract
The relationship between the structure characteristics and performances of coal-based hydrogenation isomeric (CTL) base oil and metallocene-catalyzed coal-based poly-alpha-olefin (mPAO) base oil is clarified in this paper. CTL and mPAO were compared with typical petroleum-based and natural gas-based commercial API III and IV [...] Read more.
The relationship between the structure characteristics and performances of coal-based hydrogenation isomeric (CTL) base oil and metallocene-catalyzed coal-based poly-alpha-olefin (mPAO) base oil is clarified in this paper. CTL and mPAO were compared with typical petroleum-based and natural gas-based commercial API III and IV base oils. Pressurized differential scanning calorimetry (PDSC), the rotary bomb oxidation test (RBOT), and a four-ball friction tester were used to evaluate the oxidation stability and lubrication performance of base oils under different working conditions. The sensitivity of different base oils to typical antioxidants and extreme-pressure antiwear agents was compared. In particular, the composition and structure of CTL base oil are clearly different from GTL and mineral base oil. The coal-based CTL and mPAO base oils exhibit commendable viscosity–temperature properties, coupled with low-temperature fluidity, fire safety, and minimal evaporation loss. The lubricating properties, oxidation stability, and sensitivity to extreme-pressure antiwear agents of CTL are close to those of similar base oils. However, the sensitivity of CTL to typical antioxidants is relatively poor. In addition, compared with commercial PAO base oil, mPAO has a lower isomerization degree and fewer isomerization types. The oxidation stability and sensitivity to typical antioxidants of mPAO base oil are comparable with those of commercial PAO base oil, while its lubrication performance and sensitivity to typical extreme-pressure antiwear agents are significantly better than those of commercial PAO base oil. Full article
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16 pages, 6946 KB  
Article
Enhancing Catalytic Efficiency in Long-Chain Linear α-Olefin Epoxidation: A Study of CaSnO3-Based Catalysts
by Min Zhang, Hongwei Xiang and Xiaodong Wen
Catalysts 2024, 14(1), 70; https://doi.org/10.3390/catal14010070 - 17 Jan 2024
Cited by 2 | Viewed by 2264
Abstract
This investigation explores the synthesis of advanced catalysts for epoxidizing long-chain linear α-olefins, a pivotal process in the chemical industry for generating critical intermediates. Employing a hydrothermal technique, we developed four distinct catalysts (CS-1–4), methodically modulating the Ca/Sn ratio to elucidate its impact [...] Read more.
This investigation explores the synthesis of advanced catalysts for epoxidizing long-chain linear α-olefins, a pivotal process in the chemical industry for generating critical intermediates. Employing a hydrothermal technique, we developed four distinct catalysts (CS-1–4), methodically modulating the Ca/Sn ratio to elucidate its impact on the catalysts’ physicochemical properties. Our research uncovered that an escalated Ca/Sn ratio induces a morphological shift from octagonal to cubic structures, concomitant with a diminution in particle size and an enhancement in specific surface area. Significantly, the CS-3 catalyst outperformed others in 1-octene epoxidation, an efficacy attributed to its augmented surface alkalinity and proliferation of medium-strength alkaline sites, likely emanating from increased surface oxygen defects. Subsequent hydrogen reduction of CS-3 further amplified these oxygen defects, yielding a 10% uptick in catalytic activity. This correlation underscores the potential of oxygen defect manipulation in optimizing catalytic efficiency. Our findings contribute a novel perspective to the development of robust, high-performance catalysts for α-olefin epoxidation, seamlessly aligning with the principles of sustainable chemistry. Full article
(This article belongs to the Special Issue Advanced Research of Perovskite Materials as Catalysts)
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15 pages, 2370 KB  
Article
Investigation of Crystallization, Morphology, and Mechanical Properties of Polypropylene/Polypropylene-Polyethylene Block Copolymer Blends
by Wenjun Shao, Li-Zhi Liu, Ying Wang, Yuanxia Wang, Ying Shi and Lixin Song
Polymers 2023, 15(24), 4680; https://doi.org/10.3390/polym15244680 - 12 Dec 2023
Cited by 9 | Viewed by 3770
Abstract
Polyethylene (PE)-based elastomers are the ideal choice for enhancing the compatibility of polypropylene/polyethylene (PP/PE) blends and improving the mechanical properties of PP-based materials. However, the issue of blend systems lies in the interplay between the crystallization processes. Therefore, we investigated the crystallization behavior [...] Read more.
Polyethylene (PE)-based elastomers are the ideal choice for enhancing the compatibility of polypropylene/polyethylene (PP/PE) blends and improving the mechanical properties of PP-based materials. However, the issue of blend systems lies in the interplay between the crystallization processes. Therefore, we investigated the crystallization behavior during the cooling process of a new generation of PP/PE block copolymers (PP-b-PE) and random polypropylene (PPR, a copolymer of propylene and a small amount of ethylene or an alpha-olefin) blends using in-situ X-ray diffraction/scattering and differential scanning calorimetry (DSC) techniques. We also conducted mechanical performance tests on PPR/PP-b-PE blends at room temperature and low temperature (−5 °C). The results indicate that during the cooling process, the PP phase of PP-b-PE will follow the PPR to crystallize in advance and form a eutectic mixture, thereby enhancing the compatibility of PP/PE. Moreover, the PPR/PP-b-PE blend will form stable β-(300) crystals with excellent mechanical properties. Due to the improved compatibility of PP/PE with PP-b-PE, PE crystals are dispersed within PP crystals, providing bonding that improves the toughness of PPR under the low stiffness failure conditions of PPR/PP-b-PE blends, thereby enhancing their impact performance at low and room temperatures. This research has great significance for both recycling waste plastics and enhancing the low-temperature toughness of PPR. Full article
(This article belongs to the Special Issue Advances and Applications of Block Copolymers II)
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13 pages, 3850 KB  
Article
Experimental Study on SiO2 Nanoparticles-Assisted Alpha-Olefin Sulfonate Sodium (AOS) and Hydrolyzed Polyacrylamide (HPAM) Synergistically Enhanced Oil Recovery
by Jiani Hu, Meilong Fu, Yuxia Zhou, Fei Wu and Minxuan Li
Energies 2023, 16(22), 7523; https://doi.org/10.3390/en16227523 - 10 Nov 2023
Cited by 5 | Viewed by 1903
Abstract
The purpose of this study is to investigate the use of SiO2 nanoparticles in assisting with surfactants and polymers for tertiary oil recovery, with the aim of enhancing oil recovery. The article characterizes the performance of SiO2 nanoparticles, including particle size, [...] Read more.
The purpose of this study is to investigate the use of SiO2 nanoparticles in assisting with surfactants and polymers for tertiary oil recovery, with the aim of enhancing oil recovery. The article characterizes the performance of SiO2 nanoparticles, including particle size, dispersion stability, and zeta potential, evaluates the synergistic effects of nanoparticles with alpha-olefin sulfonate sodium (AOS) surfactants and hydrolyzed polyacrylamide (HPAM) on reducing interfacial tension and altering wettability, and conducts core flooding experiments in rock cores with varying permeabilities. The findings demonstrate that the particle size decreased from 191 nm to 125 nm upon the addition of SiO2 nanoparticles to AOS surfactant, but increased to 389 nm upon the addition of SiO2 nanoparticles to HPAM. The dispersibility experiment showed that the SiO2 nanoparticle solution did not precipitate over 10 days. After adding 0.05% SiO2 nanoparticles to AOS surfactant, the zeta potential was −40.2 mV, while adding 0.05% SiO2 nanoparticles to 0.1% HPAM resulted in a decrease in the zeta potential to −25.03. The addition of SiO2 nanoparticles to AOS surfactant further reduced the IFT value to 0.19 mN/m, altering the rock wettability from oil-wet to strongly water-wet, with the contact angle decreasing from 110° to 18°. In low-permeability rock core oil displacement experiments, the use of AOS surfactants and HPAM for enhanced oil recovery increased the recovery rate by 24.5% over water flooding. The recovery rate increased by 21.6% over water flooding in low-permeability rock core experiments after SiO2 nanoparticles were added and surfactants and polymers were utilized for oil displacement. This is because the nanoparticles blocked small pore throats, resulting in increased resistance and hindered free fluid flow. The main causes of this plugging are mutual interference and mechanical entrapment, which cause the pressure differential to rise quickly. In high-permeability rock core oil displacement experiments, the use of AOS surfactants and HPAM for oil recovery increased the recovery rate by 34.6% over water flooding. Additionally, the recovery rate increased by 39.4% over water flooding with the addition of SiO2 nanoparticles and the use of AOS surfactants and HPAM for oil displacement. Because SiO2 nanoparticles create wedge-shaped structures inside highly permeable rock cores, they create structural separation pressure, which drives crude oil forward and aids in diffusion. This results in a comparatively small increase in pressure differential. Simultaneously, the nanoparticles change the rock surfaces’ wettability, which lowers the amount of crude oil that adsorbs and improves oil recovery. Full article
(This article belongs to the Topic Enhanced Oil Recovery Technologies, 2nd Volume)
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10 pages, 718 KB  
Article
Investigation of Vegetable Oils and Their Derivatives for the Synthesis of Extreme Pressure Additives
by Gábor Zoltán Nagy and Roland Nagy
Materials 2023, 16(19), 6570; https://doi.org/10.3390/ma16196570 - 6 Oct 2023
Cited by 1 | Viewed by 1738
Abstract
The harmful effects of wear can be reduced through proper lubrication of the frictional parts. When exposed to excessive loads, the lubricant film is displaced from the surfaces, and even the adhesive lubricant layer may rupture. Additives known as Extreme Pressure (EP) are [...] Read more.
The harmful effects of wear can be reduced through proper lubrication of the frictional parts. When exposed to excessive loads, the lubricant film is displaced from the surfaces, and even the adhesive lubricant layer may rupture. Additives known as Extreme Pressure (EP) are frequently incorporated into lubricants to minimise wear and avert seizures under high temperature and pressure. Mechanistically, these additives generate a film on the surface through chemisorption. These additives are extensively applied in various lubricants, with the largest quantities being employed in metalworking fluids and lubricating greases. Sulfurized vegetable oils and their derivates can be used as EP additives for lubricants. To conduct the investigations, sulfurized additives were synthesized using different vegetable-based oils and fatty acid esters, and alpha-olefins. In this study, the Four-ball test results were compared to gain a more accurate comprehension of how various raw-material-based additives influence wear and friction. The goal was to select raw materials that could be used with favorable results for the production of EP additives. The objective was to achieve a minimum Four-ball weld load parameter of 2000 N. The experiments revealed that the functional impacts of the synthesized samples are dependent on the type of raw materials employed. Based on the experimental data and the stated criteria, the examined raw materials were found to be suitable for the synthesis of EP additives. Full article
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16 pages, 7836 KB  
Article
Research and Evaluation of Foam-Drainage Corrosion-Inhibition Hydrate Anti-Aggregation Integrated Agent
by Weijun Ni, Guohao Yang, Jie Dong, Yansong Pan, Gang Chen and Xuefan Gu
Processes 2023, 11(9), 2745; https://doi.org/10.3390/pr11092745 - 14 Sep 2023
Cited by 3 | Viewed by 1501
Abstract
In natural gas exploitation, foam drainage, corrosion inhibition and hydrate inhibition of wellbore fluid are conventional operations. However, there is often a problem where multiple chemical agents cannot be effectively used together and can only be used separately, resulting in complex production processes. [...] Read more.
In natural gas exploitation, foam drainage, corrosion inhibition and hydrate inhibition of wellbore fluid are conventional operations. However, there is often a problem where multiple chemical agents cannot be effectively used together and can only be used separately, resulting in complex production processes. In this study, the final integrated formulation was determined: 0.1% sodium alpha-olefin sulfonate (AOST) + 0.3% dodecyl dimethyl betaine (BS-12) + 0.3% sodium lignosulfonate + 0.5% hydrazine hydrate. The minimum tension of the integrated agent could be reduced to 23.5 mN/m. The initial foaming height of the integrated agent was 21.5 cm at 65 °C, the liquid-carrying capacity was 143 mL, and the liquid-carrying rate reached 71.5%. The maximum corrosion depth also decreased from 11.52 µm without the addition of hydrazine hydrate, gradually decreasing to 5.24 µm as the concentration of hydrazine hydrate increased. After adding an integrated agent, the growth rate of hydrates was slow and aggregation did not easily occur, and the formation temperature was also more demanding. Therefore, the integrated agent has a inhibitory effect on the formation of hydrates and has a good anti-aggregation effect. From the observation of the microstructure, the emulsion is an oil-in-water type, and the integrated agent adsorbs at the oil–water interface, preventing the dispersed water droplets in the oil phase from coalescing in one place. The oil-in-water type emulsion is more likely to improve the performance of the natural gas hydrate anti-aggregation agent. Full article
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15 pages, 2423 KB  
Article
Effect of Protease Combined with Heat Treatment on the Volatile Composition and Aroma Quality in Liqueur Wine
by Wen Li, Zhen Zhang, Yuanyuan Zhao, Wei Li, Li Wang, Qi Shang, Jianming Du and Lina Jin
Molecules 2023, 28(13), 5129; https://doi.org/10.3390/molecules28135129 - 30 Jun 2023
Cited by 7 | Viewed by 1821
Abstract
The aim of this paper was to compare the effects of two clarification methods, protease combined with heat treatment and bentonite, on the aroma quality of liqueur wines, and to identify and analyze the overall differences between the basic components and volatile aroma [...] Read more.
The aim of this paper was to compare the effects of two clarification methods, protease combined with heat treatment and bentonite, on the aroma quality of liqueur wines, and to identify and analyze the overall differences between the basic components and volatile aroma compounds of liqueur wines after the two treatments by chemical analysis, headspace–solid-phase microextraction–gas chromatography/mass spectrometry (HS-SPME-GC/MS), and orthogonal partial least squares discriminant analysis (OPLS-DA). The results showed that total acidity, volatile acidity and pH in liqueur wines after protease combined with heat treatment were not significantly different from those of the blank control, and the ability to remove proteins was equal to that of the bentonite treatment. A total of 58 volatile aroma compounds were detected by HS-SPME-GC/MS. Compared with the blank control group (44 species, total 108.705 mg/L), 52 (83.233 mg/L) and 50 (120.655 mg/L) aroma compounds were detected in the bentonite and protease combined with heat treatments, respectively. Compared with the control and bentonite treatment, the protease combined with heat treatment significantly increased the total content of aromatic compounds in liqueur wines, and the types and contents of olefins, furans and phenols were higher. Among them, the compounds with major contributions in the protease combined with heat treatment were ionone, β-damascenone, 3-methyl-1-butanol, alpha-terpineol and limonene, which helped increase the content of terpenoids and enhance the floral and fruit aroma of the wine. Meanwhile, linalool, diethyl succinate, 2-methyl-3-heptanone, butanal diethyl acetal, hexanal and n-octanol were six compounds with high content of aromatic compounds unique to liqueur wines after protease combined with heat treatment. The sensory evaluation results were consistent with the results of aromatic compound detection, and the overall quality was better. The results may provide a reference for further exploration of protease-based clarifiers suitable for liqueur wines. Full article
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