Journal of Supercritical Fluids最新文献

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Enhanced separation of valuable compounds from Spirulina using supercritical carbon dioxide: Influence of pretreatments and co-solvent addition on composition and bioactivity of extracts

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-10 DOI: 10.1016/j.supflu.2025.106545

Stoja Milovanovic , Agnieszka Grzegorczyk , Łukasz Świątek , Katarzyna Tyśkiewicz , Marcin Konkol , Dusica Stojanovic

There is a lack of information on pretreatments that improve the separation of biologically valuable extracts from Spirulina using supercritical carbon dioxide (scCO₂). Therefore, this study was focused on testing microwave irradiation and rapid gas decompression pretreatments for the recovery of Spirulina extracts that express antioxidant, antimicrobial, and cytotoxic activity. Extractions from native and pretreated microalgae were performed using scCO₂ at 40 MPa and 40 °C, without or with ethanol as a co-solvent. Results revealed that the extraction process was positively influenced to some extent by the application of each pretreatment and co-solvent addition. Specifically, extraction yield was improved up to 8.7-fold, separation of γ-linolenic acid increased from 7.3% to 35.6 %, chlorophyll A content increased from 12.1 to 272.1 mg/g extract, and tocopherol amount rose from 1.3 to 24.7 mg α-TE/g dry biomass. On the other hand, separations performed with co-solvent decreased the content of carotenoids from 100.2 to 35.6 mg/g as well as the antioxidant activity of extracts and their cytotoxicity on human hypopharyngeal squamous cell carcinoma. Moreover, the addition of ethanol to scCO₂ had an adverse effect on the flavonoid content (which ranged from 45.8 to 82.4 mg RE/g) and the antimicrobial activity of extracts against 32 microbial strains. This exploratory study provides guidelines for the design, operation, and intensification of an environmentally friendly separation of added-value Spirulina extracts.

{"title":"Enhanced separation of valuable compounds from Spirulina using supercritical carbon dioxide: Influence of pretreatments and co-solvent addition on composition and bioactivity of extracts","authors":"Stoja Milovanovic , Agnieszka Grzegorczyk , Łukasz Świątek , Katarzyna Tyśkiewicz , Marcin Konkol , Dusica Stojanovic","doi":"10.1016/j.supflu.2025.106545","DOIUrl":"10.1016/j.supflu.2025.106545","url":null,"abstract":"<div><div>There is a lack of information on pretreatments that improve the separation of biologically valuable extracts from <em>Spirulina</em> using supercritical carbon dioxide (scCO<sub>2</sub>). Therefore, this study was focused on testing microwave irradiation and rapid gas decompression pretreatments for the recovery of <em>Spirulina</em> extracts that express antioxidant, antimicrobial, and cytotoxic activity. Extractions from native and pretreated microalgae were performed using scCO<sub>2</sub> at 40 MPa and 40 °C, without or with ethanol as a co-solvent. Results revealed that the extraction process was positively influenced to some extent by the application of each pretreatment and co-solvent addition. Specifically, extraction yield was improved up to 8.7-fold, separation of γ-linolenic acid increased from 7.3% to 35.6 %, chlorophyll A content increased from 12.1 to 272.1 mg/g extract, and tocopherol amount rose from 1.3 to 24.7 mg α-TE/g dry biomass. On the other hand, separations performed with co-solvent decreased the content of carotenoids from 100.2 to 35.6 mg/g as well as the antioxidant activity of extracts and their cytotoxicity on human hypopharyngeal squamous cell carcinoma. Moreover, the addition of ethanol to scCO<sub>2</sub> had an adverse effect on the flavonoid content (which ranged from 45.8 to 82.4 mg RE/g) and the antimicrobial activity of extracts against 32 microbial strains. This exploratory study provides guidelines for the design, operation, and intensification of an environmentally friendly separation of added-value <em>Spirulina</em> extracts.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"220 ","pages":"Article 106545"},"PeriodicalIF":3.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Measurement of phase transition, density and viscosity of supercritical carbon dioxide-Fischer-Tropsch wax mixtures

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-10 DOI: 10.1016/j.supflu.2025.106546

Andri Swanepoel , Philip W. Labuschagne , Cara E. Schwarz

Melting temperature, phase behaviour and densities of binary mixtures of CO₂ and three Fischer-Tropsch waxes with varying molecular weights were experimentally determined. The melting temperatures of the lower molecular weight waxes increased with CO₂ pressure, and pressure induced crystallisation of the lowest molecular weight wax occurred above 20 MPa. CO₂ solubility in the waxes decreased with increasing wax molecular weight. Trends in mixture densities with changes in temperature and pressure mimicked that of pure CO₂. The viscosity of the lowest molecular weight wax decreased with increased CO₂ concentration, and decreased with increases in temperature and pressure, with the impact of pressure minimised above the temperature inversion point. Solubility data were correlated with a modified Chrastil and the Mendez-Santiago & Teja models. The Chrastil model accurately predicted solubility of CO₂ in all three waxes to within 1 % of the measured values.

引用次数: 0

Phase equilibrium modeling for CCUS fluids using a modified association equation of state

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-07 DOI: 10.1016/j.supflu.2025.106543

Wei Xiong , Lie-Hui Zhang , Yu-Long Zhao , Shao-Mu Wen , Li-Li Liu , Zheng-Lin Cao , Yong-Chao Wang , Shan-Gui Luo , Xian-Yu Jiang

Accurate derivatives are required for simulating large-scale carbon dioxide (CO₂) geological storage using the Cubic-Plus-Association equation of state (CPA EoS). However, due to the mathematical implicitness of cross-association, calculating the correct derivatives of site fractions for cross-association mixtures is extremely difficult and computationally demanding. A general explicit formulation of cross-association for different bonding types is presented. The non-bonded fraction of cross-associating molecules is obtained from the non-bonded fraction of self-associating molecules without cross-association. This approach eliminates the circular iterative process and improves computational efficiency. The overall CPU time decreases by 70 % for flash calculations and compositional simulations. The modeling capability of CPA is extended to H₂O-CO₂-H₂S-N₂-O₂-Ar-SO₂-CH₄-C₂H₆-C₃H₈ mixtures. Results indicate that CPA can accurately predict the phase behavior of binary CO₂ capture, utilization, and storage (CCUS) mixtures. This study provides a modified CPA EoS, applicable to most of the currently treated CCUS fluids, and discusses its strengths and limitations.

{"title":"Phase equilibrium modeling for CCUS fluids using a modified association equation of state","authors":"Wei Xiong , Lie-Hui Zhang , Yu-Long Zhao , Shao-Mu Wen , Li-Li Liu , Zheng-Lin Cao , Yong-Chao Wang , Shan-Gui Luo , Xian-Yu Jiang","doi":"10.1016/j.supflu.2025.106543","DOIUrl":"10.1016/j.supflu.2025.106543","url":null,"abstract":"<div><div>Accurate derivatives are required for simulating large-scale carbon dioxide (CO<sub>2</sub>) geological storage using the Cubic-Plus-Association equation of state (CPA EoS). However, due to the mathematical implicitness of cross-association, calculating the correct derivatives of site fractions for cross-association mixtures is extremely difficult and computationally demanding. A general explicit formulation of cross-association for different bonding types is presented. The non-bonded fraction of cross-associating molecules is obtained from the non-bonded fraction of self-associating molecules without cross-association. This approach eliminates the circular iterative process and improves computational efficiency. The overall CPU time decreases by 70 % for flash calculations and compositional simulations. The modeling capability of CPA is extended to H<sub>2</sub>O-CO<sub>2</sub>-H<sub>2</sub>S-N<sub>2</sub>-O<sub>2</sub>-Ar-SO<sub>2</sub>-CH<sub>4</sub>-C<sub>2</sub>H<sub>6</sub>-C<sub>3</sub>H<sub>8</sub> mixtures. Results indicate that CPA can accurately predict the phase behavior of binary CO<sub>2</sub> capture, utilization, and storage (CCUS) mixtures. This study provides a modified CPA EoS, applicable to most of the currently treated CCUS fluids, and discusses its strengths and limitations.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106543"},"PeriodicalIF":3.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supercritical extraction of salicin, aspirin precursor, from the willow bark, laboratory optimization via response surface methodology and mathematical modeling

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-06 DOI: 10.1016/j.supflu.2025.106540

Mohammad Abohassan , Normurot Fayzullaev , Gaber Edris , Subasini Uthirapathy , Gaurav Sanghvi , Naga Bhushana Rao Vakada , Swati Sharma , Prashant Nakash , Yasser Fakri Mustafa , Maythum Ali Shallan

In this study, salicin, the key active ingredient in willow bark and a primary source of aspirin, was extracted using supercritical CO₂. Gas chromatography (GC) characterized the extract. Key operating factors, including pressure, temperature, particle size, and extraction time, were varied to optimize extraction yield, employing response surface methodology (RSM) with a central composite design (CCD) method. The maximum yield was 12.371 % (mass of extracted salicin / mass of dry willow bark) with a 56.75 % salicin recovery under the optimal condition, determined as 22 MPa pressure, 40 °C temperature, 0.45 mm particle size, and 100 minutes extraction time. Results showed that higher extraction time and pressure increased yield, while temperature and particle size reduced it. Extraction time had the most significant effect, while temperature was the least impactful. The Sovová and Tan and Liou models were applied, showing close agreement between predicted and experimental extraction curves.

{"title":"Supercritical extraction of salicin, aspirin precursor, from the willow bark, laboratory optimization via response surface methodology and mathematical modeling","authors":"Mohammad Abohassan , Normurot Fayzullaev , Gaber Edris , Subasini Uthirapathy , Gaurav Sanghvi , Naga Bhushana Rao Vakada , Swati Sharma , Prashant Nakash , Yasser Fakri Mustafa , Maythum Ali Shallan","doi":"10.1016/j.supflu.2025.106540","DOIUrl":"10.1016/j.supflu.2025.106540","url":null,"abstract":"<div><div>In this study, salicin, the key active ingredient in willow bark and a primary source of aspirin, was extracted using supercritical CO₂. Gas chromatography (GC) characterized the extract. Key operating factors, including pressure, temperature, particle size, and extraction time, were varied to optimize extraction yield, employing response surface methodology (RSM) with a central composite design (CCD) method. The maximum yield was 12.371 % (mass of extracted salicin / mass of dry willow bark) with a 56.75 % salicin recovery under the optimal condition, determined as 22 MPa pressure, 40 °C temperature, 0.45 mm particle size, and 100 minutes extraction time. Results showed that higher extraction time and pressure increased yield, while temperature and particle size reduced it. Extraction time had the most significant effect, while temperature was the least impactful. The Sovová and Tan and Liou models were applied, showing close agreement between predicted and experimental extraction curves.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106540"},"PeriodicalIF":3.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supercritical CO2 foaming and mechanical properties of thermoplastic polyurethane based on molecular structure

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-06 DOI: 10.1016/j.supflu.2025.106541

Chenyang Niu, Xiulu Gao, Yichong Chen, Weizhen Sun, Ling Zhao, Dongdong Hu

The molecular structures of thermoplastic polyurethane (TPU) affect its microphase separation and foaming behavior. Three aliphatic TPUs were studied to investigate the influence of their molecular structures on their crystallization behavior, shear rheological properties, mechanical properties, and foaming behavior. The experimental results indicated that the branched structure and hard segment content affected the crystallization behavior of TPU. Lower crystallinity decreased the foaming initiation temperature, whereas higher crystallinity enhanced the stability of cell structure. The branched structure and hard segment domains functioned as heterogeneous nucleation sites, leading to increased cell density and reduced cell size in microcellular TPU. Microcellular TPU with a high molecular weight and branched structure exhibited superior tensile strength and elongation at break, i.e., the tensile strength and elongation at break of TPU1 with a density of 0.25 g/cm³ reached 10.82 MPa and 373 %, respectively. This study demonstrated the regulation of microcellular TPU by analyzing its molecular structures.

{"title":"Supercritical CO2 foaming and mechanical properties of thermoplastic polyurethane based on molecular structure","authors":"Chenyang Niu, Xiulu Gao, Yichong Chen, Weizhen Sun, Ling Zhao, Dongdong Hu","doi":"10.1016/j.supflu.2025.106541","DOIUrl":"10.1016/j.supflu.2025.106541","url":null,"abstract":"<div><div>The molecular structures of thermoplastic polyurethane (TPU) affect its microphase separation and foaming behavior. Three aliphatic TPUs were studied to investigate the influence of their molecular structures on their crystallization behavior, shear rheological properties, mechanical properties, and foaming behavior. The experimental results indicated that the branched structure and hard segment content affected the crystallization behavior of TPU. Lower crystallinity decreased the foaming initiation temperature, whereas higher crystallinity enhanced the stability of cell structure. The branched structure and hard segment domains functioned as heterogeneous nucleation sites, leading to increased cell density and reduced cell size in microcellular TPU. Microcellular TPU with a high molecular weight and branched structure exhibited superior tensile strength and elongation at break, i.e., the tensile strength and elongation at break of TPU1 with a density of 0.25 g/cm<sup>3</sup> reached 10.82 MPa and 373 %, respectively. This study demonstrated the regulation of microcellular TPU by analyzing its molecular structures.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106541"},"PeriodicalIF":3.4,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143228086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supercritical CO2 assisted extraction, purification and modelling of free fatty acids from the crude mixture – A case study of tallow hydrolysis

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-04 DOI: 10.1016/j.supflu.2025.106542

EK Anagha , R. Sariga , K. ShyamSundar , Rames C. Panda , M. Helen Kalavathy , S.N. Naik

Background

Tallow, a by-product of the leather-industry, is widely used in pharmaceuticals and oleochemical applications as a source/precursor of glycerol, obtained by aqueous-hydrolysis under high-pressure-temperature from a hydrolyzing-tower. Though standard procedures of extracting glycerol from the bottom-product are well established, the purification of fatty-acids (FA) from the top crude-mixture needs attention

Method

This paper identifies and separates individual fatty-acids from the Twitchell-process using the supercritical-fluid-extraction (SFE). Solubilities (Soave-Redlich-Kwong) and phase-diagrams are obtained using Matlab & Aspen, respectively. The characteristics of the product are analyzed by mass-spectroscopy which reveals that the FA-components present in the crude-mixture in the ratio of 4.3:32.2:43.0:20.4 for C-14, C16, C16 = 2, and C18 components respectively are more efficiently extracted by the solvent of SFE compared to CH₃OH solvent

Findings

It has been found from the analysis and characterization that the rate of extraction is improved by 2–3 times in case of saturated while it’s about 9 times in-case-of unsaturated FA compared to the nominal method of extraction. Addition of ionic-liquid (IL) with SFE-solvent improved the solubility to 92 %. A model is formulated to validate the findings. It is suggested that the pure components extracted by SFE assisted by IL can be used for the preparation of oleochemicals in further downstream-processing.

{"title":"Supercritical CO2 assisted extraction, purification and modelling of free fatty acids from the crude mixture – A case study of tallow hydrolysis","authors":"EK Anagha , R. Sariga , K. ShyamSundar , Rames C. Panda , M. Helen Kalavathy , S.N. Naik","doi":"10.1016/j.supflu.2025.106542","DOIUrl":"10.1016/j.supflu.2025.106542","url":null,"abstract":"<div><h3>Background</h3><div>Tallow, a by-product of the leather-industry, is widely used in pharmaceuticals and oleochemical applications as a source/precursor of glycerol, obtained by aqueous-hydrolysis under high-pressure-temperature from a hydrolyzing-tower. Though standard procedures of extracting glycerol from the bottom-product are well established, the purification of fatty-acids (FA) from the top crude-mixture needs attention</div></div><div><h3>Method</h3><div>This paper identifies and separates individual fatty-acids from the Twitchell-process using the supercritical-fluid-extraction (SFE). Solubilities (Soave-Redlich-Kwong) and phase-diagrams are obtained using Matlab & Aspen, respectively. The characteristics of the product are analyzed by mass-spectroscopy which reveals that the FA-components present in the crude-mixture in the ratio of 4.3:32.2:43.0:20.4 for C-14, C16, C16 = 2, and C18 components respectively are more efficiently extracted by the solvent of SFE compared to CH<sub>3</sub>OH solvent</div></div><div><h3>Findings</h3><div>It has been found from the analysis and characterization that the rate of extraction is improved by 2–3 times in case of saturated while it’s about 9 times in-case-of unsaturated FA compared to the nominal method of extraction. Addition of ionic-liquid (IL) with SFE-solvent improved the solubility to 92 %. A model is formulated to validate the findings. It is suggested that the pure components extracted by SFE assisted by IL can be used for the preparation of oleochemicals in further downstream-processing.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106542"},"PeriodicalIF":3.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of pressure and monomer concentration on ring-opening enzymatic polymerization of globalide in pressurized propane

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-03 DOI: 10.1016/j.supflu.2024.106508

Maria N.H. Cupaja , Camila Guindani , Frederico W. Tavares , Papa M. Ndiaye

Propane is considered an alternative in enzymatic polyester synthesis due to its favorable enzymatic interactions and mild operating pressures. In this study, enzymatic polymerizations were carried out by ring-opening polymerization of the monomer globalide at 65 °C, using pressurized propane as solvent. Mass ratios of propane:globalide of 1:2, 1:1, and 2:1 were evaluated, as well as pressure conditions of 30, 70, 110, and 150 bar. The enzyme concentration was kept at 5 % relative to globalide mass, with a fixed reaction time of two hours. Results showed monomer conversions up to 93 % and molecular weights ranging from 17.5 kDa to 125.9 kDa, surpassing those with pressurized CO₂. Working pressure had an effect in monomer conversion, suggesting that both the increase in propane viscosity as well as the confinement of the system (compressibility) play important roles in the reaction, but depending on the working pressure, one of the effects will be dominant.

引用次数: 0

Applications of ionic liquids in improving CO2 miscibility in crude oil for enhanced oil recovery and CO2 sequestration applications

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-02-02 DOI: 10.1016/j.supflu.2025.106539

Mohammed A. Al-Hakami , Ahmed Farid Ibrahim , Khaled Z. Abdelgawad

Innovation and sustainability are critical for maximizing reserves in the petroleum industry, especially in deep heavy oil reservoirs where traditional thermal EOR techniques often underperform. CO₂-flooding offers a promising alternative, with its effectiveness dependent on achieving minimum miscibility pressure (MMP). Reducing MMP offers higher recovery factors while avoiding issues due to formation fracturing at high injection pressures. This study evaluates ionic liquids (ILs), 1-methyl-3-octylimidazolium chloride ([MOIM]Cl) and 1-decyl-3-methylimidazolium chloride ([DMIM]Cl), for lowering MMP in CO₂-crude oil systems. Results showed [MOIM]Cl and [DMIM]Cl reduced MMP by 17 % and 13.5 %, outperforming n-butanol and non-ionic surfactants, which achieved 6 % and 9 % reductions, respectively. For extra heavy oil, [MOIM]Cl reduced MMP by 15.5 %. The ILs also lowered first contact miscibility pressure across crude oils with asphaltene content ranging from 6.4 to 36 wt%. These findings highlight ILs' potential to improve CO₂ miscibility in heavy oil reservoirs, providing a sustainable solution for enhanced oil recovery.

{"title":"Applications of ionic liquids in improving CO2 miscibility in crude oil for enhanced oil recovery and CO2 sequestration applications","authors":"Mohammed A. Al-Hakami , Ahmed Farid Ibrahim , Khaled Z. Abdelgawad","doi":"10.1016/j.supflu.2025.106539","DOIUrl":"10.1016/j.supflu.2025.106539","url":null,"abstract":"<div><div>Innovation and sustainability are critical for maximizing reserves in the petroleum industry, especially in deep heavy oil reservoirs where traditional thermal EOR techniques often underperform. CO<sub>2</sub>-flooding offers a promising alternative, with its effectiveness dependent on achieving minimum miscibility pressure (MMP). Reducing MMP offers higher recovery factors while avoiding issues due to formation fracturing at high injection pressures. This study evaluates ionic liquids (ILs), 1-methyl-3-octylimidazolium chloride ([MOIM]Cl) and 1-decyl-3-methylimidazolium chloride ([DMIM]Cl), for lowering MMP in CO<sub>2</sub>-crude oil systems. Results showed [MOIM]Cl and [DMIM]Cl reduced MMP by 17 % and 13.5 %, outperforming n-butanol and non-ionic surfactants, which achieved 6 % and 9 % reductions, respectively. For extra heavy oil, [MOIM]Cl reduced MMP by 15.5 %. The ILs also lowered first contact miscibility pressure across crude oils with asphaltene content ranging from 6.4 to 36 wt%. These findings highlight ILs' potential to improve CO<sub>2</sub> miscibility in heavy oil reservoirs, providing a sustainable solution for enhanced oil recovery.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106539"},"PeriodicalIF":3.4,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-pressure phase behavior of the carbon dioxide-trifluoropropylisobutyl polyhedral oligomeric silsesquioxane binary system

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-01-29 DOI: 10.1016/j.supflu.2025.106538

Alican Ertas, Cerag Dilek

The solubility of a bifunctional polyhedral oligomeric silsesquioxane, trifluoropropylisobutyl (TFIB) POSS, in supercritical carbon dioxide (scCO₂) was investigated. In the temperature and pressure ranges of 308 K to 323 K and 8.8 MPa to 14.5 MPa, respectively, TFIB POSS is soluble in scCO₂ up to 2.0 × 10⁻² by weight fraction corresponding to 1.0 × 10⁻³ by mole fraction, which is between the solubility of its monofunctional counterparts, octaisobutyl POSS and octatrifluoropropyl POSS. The study includes the modeling of the TFIB POSS-CO₂ binary system phase equilibrium with the density-based semi-empirical equations and Peng Robinson+COSMO segment activity coefficient (PR+COSMOSAC) equation of state (EOS). The prediction of the equation of state has been improved for the cage-structured molecule by introducing new electrostatic and dispersion contributions. While the density-based relations provide better fits to the solubility isotherms, the main advantage of the EOS is its applicability for a priori phase equilibrium predictions for the CO₂-POSS systems in the absence of the solute critical properties.

{"title":"High-pressure phase behavior of the carbon dioxide-trifluoropropylisobutyl polyhedral oligomeric silsesquioxane binary system","authors":"Alican Ertas, Cerag Dilek","doi":"10.1016/j.supflu.2025.106538","DOIUrl":"10.1016/j.supflu.2025.106538","url":null,"abstract":"<div><div>The solubility of a bifunctional polyhedral oligomeric silsesquioxane, trifluoropropylisobutyl (TFIB) POSS, in supercritical carbon dioxide (scCO<sub>2</sub>) was investigated. In the temperature and pressure ranges of 308 K to 323 K and 8.8 MPa to 14.5 MPa, respectively, TFIB POSS is soluble in scCO<sub>2</sub> up to 2.0 × 10<sup>−2</sup> by weight fraction corresponding to 1.0 × 10<sup>−3</sup> by mole fraction, which is between the solubility of its monofunctional counterparts, octaisobutyl POSS and octatrifluoropropyl POSS. The study includes the modeling of the TFIB POSS-CO<sub>2</sub> binary system phase equilibrium with the density-based semi-empirical equations and Peng Robinson+COSMO segment activity coefficient (PR+COSMOSAC) equation of state (EOS). The prediction of the equation of state has been improved for the cage-structured molecule by introducing new electrostatic and dispersion contributions. While the density-based relations provide better fits to the solubility isotherms, the main advantage of the EOS is its applicability for a priori phase equilibrium predictions for the CO<sub>2</sub>-POSS systems in the absence of the solute critical properties.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106538"},"PeriodicalIF":3.4,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143228559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of fin for rectangular microchannel printed circuit heat exchanger using supercritical CO2 as working fluid

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids

Pub Date : 2025-01-28 DOI: 10.1016/j.supflu.2025.106537

Yan Ren , Le Zeng , Shaogeng Zhong , Weidong Wu , Yingying Yang , Qiguo Yang

To improve the performance of printed circuit heat exchanger (PCHE) in the supercritical carbon dioxide (SCO₂) Brayton cycle system, the mathematic-physical model of the heat exchange unit was established, based on a new-type rectangular microchannel PCHE (RM-PCHE) manufacturing by total-etching technology in this study. And the influence mechanism and laws on the flow and heat transfer of the different fin distributions and shapes were numerically investigate. Results showed average simulation deviations of 0.9 % for outlet temperature and 13.3 % for heat transfer quantity, meeting accuracy requirement. Uniform fin distribution at 10 mm intervals significantly reduced pressure drop and improved comprehensive heat transfer performance by 14.8 %. When elliptical and airfoil fins were selected for the hot-side and cold-side channels, the flow characteristic significantly improved and the heat transfer process became more stable, improving the single-side performance by 15.9 % and 12.3 %, respectively.

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