{"title":"Prediction of CO2 solubility in polar aprotic solvents using the PC-SAFT equation of state","authors":"Lisi Niu , Irwanjot Kaur , Anupam Yadav , Fadhil Faez Sead , Reza Shahriari","doi":"10.1016/j.supflu.2025.106575","DOIUrl":"10.1016/j.supflu.2025.106575","url":null,"abstract":"<div><div>In this work, the PC-SAFT equation of state (EoS) is used to predict the solubility of CO<sub>2</sub> in polar aprotic solvents (PASs). The PAS molecules are modeled as pseudo–associating molecules to mimic the polar interaction. Four scenarios are considered to study the CO<sub>2</sub> solubility in PASs. In scenario I, the CO<sub>2</sub> and PAS molecules are considered inert molecules (non-associating), in scenario II, the CO<sub>2</sub> molecules are modeled as inert, in scenario III the PAS molecules are considered inert, and in scenario IV all components are modeled as associating molecules. In scenario IV, the cross-association between PAS and CO<sub>2</sub> molecules is considered. The vapor-liquid equilibrium (VLE) of binary systems is predicted without using any additional adjustable parameters. The ARD values of scenarios I to III for all binary systems are almost the same. The average ARD values of scenarios I to III, and IV are about 22.3 %, and 11.6 %, respectively. The results show that by considering the cross-association between CO<sub>2</sub> and PAS the model performance improves dramatically. Therefore, considering non-auto associative molecules as associative ones is a trick that improves the model prediction capability.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106575"},"PeriodicalIF":3.4,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551783","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}
{"title":"Investigation of SO2-induced corrosion of X65 steel in gaseous, liquid, and supercritical CO2 environments through experimental and thermodynamic approaches","authors":"Xiu Jiang, Xiaoliang Song, Chao Yu, Hui Xie, Dingrong Qu, Jing Hua","doi":"10.1016/j.supflu.2025.106574","DOIUrl":"10.1016/j.supflu.2025.106574","url":null,"abstract":"<div><div>Laboratory experiments and thermodynamic simulations were performed at 25 °C (8 MPa) and 35 °C (4, 8 MPa) to investigate the effects of SO<sub>2</sub> on the corrosion of X65 steel and water chemistry during liquid, gaseous, and supercritical CO<sub>2</sub> transportation. Results indicated that less than 100 ppm SO<sub>2</sub> significantly influenced corrosion processes. In the water-saturated CO<sub>2</sub> environment, higher SO<sub>2</sub> concentrations led to elevated general corrosion rates. Interestingly, in the CO<sub>2</sub>-saturated water environment, the general corrosion rate decreased at 35°C, 4 and 8 MPa, whereas it increased with rising SO<sub>2</sub> levels at 25°C, 8 MPa. SO<sub>2</sub> worsened water chemistry by reducing the contents of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup>, but enhancing the contents of H<sup>+</sup>, SO<sub>3</sub><sup>2-</sup> and HSO<sub>3</sub><sup>-</sup>in the CO<sub>2</sub>-saturated water phase at each CO<sub>2</sub> phase state. In the gaseous and supercritical CO<sub>2</sub>-saturated water environment, a thin or absent corrosion product was observed, with the adsorption of SO<sub>2</sub> and its derivatives being the dominant factor. In the liquid CO<sub>2</sub>-saturated water environment, the corrosion product competed with SO<sub>2</sub>, HSO<sub>3</sub><sup>-</sup>, and SO<sub>3</sub><sup>2-</sup> for adsorption sites, accelerating the corrosion rate.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106574"},"PeriodicalIF":3.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527035","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}
{"title":"Preparation of ultrathin two-dimensional nanosheet Ni/TiO2-SC catalyst and their catalytic performance in the liquid-phase hydrogenation of maleic anhydride","authors":"Yin Zhang, Wei Wei, Chengliang Wang, Di Zhang, Haitao Li, Dongjie Zhang, Yue Zhang","doi":"10.1016/j.supflu.2025.106573","DOIUrl":"10.1016/j.supflu.2025.106573","url":null,"abstract":"<div><div>An ultrathin two-dimensional (2D) nanosheet Ni/TiO<sub>2</sub>-SC catalyst was synthesised through supercritical ethanol stripping, using Ni-Ti-layered double hydroxide (NiTi-LDH) as the precursor. Characterisation of the catalysts was conducted using XRD, N<sub>2</sub> physical adsorption–desorption, SEM, HR–TEM, AFM, H<sub>2</sub>–TPD, XPS, and EPR to evaluate their catalytic activity for the liquid-phase hydrogenation of maleic anhydride (MA). The catalytic performance of Ni/TiO<sub>2</sub>-SC was compared with that of the Ni/TiO<sub>2</sub> catalyst without supercritical stripping. Results indicated that the Ni/TiO<sub>2</sub>-SC catalysts featured a two-dimensional nanosheet structure with enhanced active metal dispersion and a high density of oxygen vacancies (OV) on the surface, showing superior C<img>C hydrogenation and C<img>O hydrogenolysis activities.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106573"},"PeriodicalIF":3.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527034","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}
Kriptsan Abdon Poletto Diel , Leandro Martins Siqueira , Pablo Pitol Silveira , Júlia Maier Labes , Mariana Koetz , Lucas Cardoso Marinho , Eduardo Cassel , Rubem Mário Figueiró Vargas , Gilsane Lino von Poser
{"title":"Sustainable extraction of bioactive compounds from Vismia guianensis based on the principles of green chemistry","authors":"Kriptsan Abdon Poletto Diel , Leandro Martins Siqueira , Pablo Pitol Silveira , Júlia Maier Labes , Mariana Koetz , Lucas Cardoso Marinho , Eduardo Cassel , Rubem Mário Figueiró Vargas , Gilsane Lino von Poser","doi":"10.1016/j.supflu.2025.106562","DOIUrl":"10.1016/j.supflu.2025.106562","url":null,"abstract":"<div><div><em>Vismia guianensis</em> (Aubl.) Choisy (Hypericaceae), a medicinal plant prevalent in the Amazon Forest region, presents anthraquinones as the main compounds. This study aims to compare the chemical composition of extracts obtained using organic solvents and supercritical CO<sub>2</sub> (scCO<sub>2</sub>) under varying conditions. Additionally, mathematical models were applied to predict extraction kinetics. The results indicated that the extracts contained vismiaquinone A and physcion, among other minor anthraquinones, with scCO<sub>2</sub> proving to be more efficient in extracting both compounds. Notably, scCO<sub>2</sub> exhibited a higher selectivity for vismiaquinone A, yielding remarkably greater amounts. The mathematical modeling confirmed the consistency between the response surface method and the experimental data. In addition to demonstrating the effectiveness of an environmentally friendly extraction method, this research aims to add value to a medicinal plant widely used in Brazil, yet underexplored for its pharmacological and economic potential.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106562"},"PeriodicalIF":3.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551826","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}
{"title":"CO2 trapping mechanism in deep saline aquifers under the control of composite geological factors: A numerical case study in China","authors":"Xiaoyuan Li , Gaofan Yue","doi":"10.1016/j.supflu.2025.106547","DOIUrl":"10.1016/j.supflu.2025.106547","url":null,"abstract":"<div><div>The increasingly intensifying global climatic change necessitates carbon capture and storage. Reservoir physical properties including porosity, permeability, temperature, and pressure directly control the spatial migration, storage forms, and storage capacity of CO<sub>2</sub> in saline aquifers. Based on China’s first CCS demonstration project in saline aquifers, this study constructed a water-CO<sub>2</sub>-thermal-chemical coupling model for long-term CCS in reservoirs. The results indicate that the deep saline aquifers in the Ordos Basin are favorable for CO<sub>2</sub> mineral trapping, with a mineralization storage amount reaching up to 64.02 % of the total injection amount at 1000 years. Temperature is identified as the most significant factor influencing safe CO<sub>2</sub> mineral trapping under CO<sub>2</sub> injection. The study not only provides valuable insights into the mechanisms of CO<sub>2</sub> trapping but also lays a foundation for optimizing the design of ongoing CCS projects and evaluating site suitability for future projects, facilitating progress toward China's carbon neutrality target.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106547"},"PeriodicalIF":3.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ji Sun Lim , Seung Eun Lee , Bonggeun Shong , Young-Kwon Park , Hong-shik Lee
{"title":"Valorization of cocoa bean shell residue from supercritical fluid extraction through hydrothermal carbonization for porous material production","authors":"Ji Sun Lim , Seung Eun Lee , Bonggeun Shong , Young-Kwon Park , Hong-shik Lee","doi":"10.1016/j.supflu.2025.106550","DOIUrl":"10.1016/j.supflu.2025.106550","url":null,"abstract":"<div><div>This study investigated the potential for high-value utilization of cocoa shell (CS) residues derived from supercritical fluid extraction (SFE) by converting them into hydrochar through hydrothermal carbonization (HTC) and activation (A-HTC). Hydrochar produced from residues extracted with water as a co-solvent exhibited the highest carbon content (78.7 %) after HTC and activation, highlighting the critical role of the co-solvent in optimizing dehydrogenation and dehydration reactions. Structural analysis revealed that residues rich in water-soluble components formed smaller pores, whereas lipid-rich residues formed larger pores. Activated hydrochar obtained from water-extracted residues demonstrated the largest surface area (315 m²/g) and pore diameter (7.10 nm), indicating mesoporous properties suitable for adsorption applications. The Van Krevelen diagram confirmed that HTC hydrochar stability improved through condensation and aromatization processes. By integrating SFE with HTC, this study presents a systematic approach for converting by-products into high-value hydrochar, offering a sustainable solution for resource recycling and utilization.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106550"},"PeriodicalIF":3.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479863","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}
Jiwan Seo , Jaesung Lee , Sangwoo Lee , Jaeho Lee , Kyu Hong Kim
{"title":"Enhanced density modeling of hydrocarbon fuels at near supercritical gas-liquid boundary and high-pressure liquid region using a new volume-translated three-parameter cubic equation of state","authors":"Jiwan Seo , Jaesung Lee , Sangwoo Lee , Jaeho Lee , Kyu Hong Kim","doi":"10.1016/j.supflu.2025.106548","DOIUrl":"10.1016/j.supflu.2025.106548","url":null,"abstract":"<div><div>Recently, understanding the Equation of State (EoS) has become increasingly critical for high-fidelity numerical simulations of hydrocarbon-fueled cooling channel and internal combustion engine. However, selecting an appropriate EoS that balances a straightforward algorithm with high predictive accuracy for density across various fluids remains challenging. In this work, integrating and applying simple modifications to the Redlich-Kwong-Peng-Robinson (RKPR) EoS, the generalized Redlich-Kwong (gRK) attraction term, and the Volume-Translation (VT) method present to achieve improvements in three key areas: (1) extending EoS applicability from low to high critical compressibility factor, (2) enhancing density prediction near the supercritical gas-liquid boundary, and (3) improving density prediction within the high-pressure liquid region. To evaluate the performance of the newly developed Volume-Translated Redlich-Kwong Peng-Robinson (VTRKPR) EoS, density of fluids (exo-THDCPD, n-decane, n-dodecane) over a wide range of pressures and temperatures is calculated using various EoSs and the NIST database with the SUPERTRAPP and REFPROP programs. Results confirm that the VTRKPR EoS provides superior density predictions compared to other EoSs.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"220 ","pages":"Article 106548"},"PeriodicalIF":3.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444283","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}
{"title":"Apparent molar volumes of isoprene and limonene in dense-phase CO2","authors":"Safeer S. Nanji, Robert A. Marriott","doi":"10.1016/j.supflu.2025.106544","DOIUrl":"10.1016/j.supflu.2025.106544","url":null,"abstract":"<div><div>Apparent molar volumes were calculated from measured density differences <em>(δΔρ =</em> 0.01 – 2.90 kg m<sup>−3</sup>, depending on compressibility) for subsaturated isoprene and limonene in CO<sub>2</sub> from <em>T</em> = 298 – 313 K and <em>p</em> = 8 – 13 MPa and used to fit a fluctuation solution theory equation with RMSD values of 58.5 and 177.8 cm<sup>3</sup> mol<sup>−1</sup>, respectively. Apparent molar volume minima at supercritical temperatures were correlated to a compressibility Widom line. Literature vapour-liquid-equilibrium and solubility data were compared to values calculated using fluctuation solution theory equations. The fluctuation solution theory fit to apparent molar volumes calculated literature bubble points (AARD = 0.0031 – 0.0371) and solubility data (AARD 0.6991). Krichevskii parameters for each solute were compared to literature for other similar solutes. Fluctuation solution theory was deemed a good model to calculate the properties of dilute terpenes in CO<sub>2</sub>, especially in the near-critical region.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"221 ","pages":"Article 106544"},"PeriodicalIF":3.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jean Maurício Leão Pinheiro , Ana Paula de Souza e Silva , Kelly Roberta Pinheiro Pantoja , Marcos Antônio Ribeiro Cardoso , Fernando de Freitas Maues de Azevedo , Leonardo Victor Gomes de Melo , Gabriela Izane de Almeida Campos , Rafael Vitti Mota , Rayssa de Sousa Mouzinho , Raul Nunes de Carvalho Junior
{"title":"Supercritical extraction of butter from agroindustrial cocoa residue from the Amazon","authors":"Jean Maurício Leão Pinheiro , Ana Paula de Souza e Silva , Kelly Roberta Pinheiro Pantoja , Marcos Antônio Ribeiro Cardoso , Fernando de Freitas Maues de Azevedo , Leonardo Victor Gomes de Melo , Gabriela Izane de Almeida Campos , Rafael Vitti Mota , Rayssa de Sousa Mouzinho , Raul Nunes de Carvalho Junior","doi":"10.1016/j.supflu.2025.106560","DOIUrl":"10.1016/j.supflu.2025.106560","url":null,"abstract":"<div><div>Cocoa bean husk (CBH), an agro-industrial by-product of Amazonian cocoa, was valorized using supercritical CO₂ extraction, yielding 31.49 % cocoa butter. The defatted CBH powder showed high phenolic content (23.90 mg GAE/g) and strong antioxidant activity (77.71 μmol TE/g), highlighting its bioactive potential. Supercritical Fluid Chromatography (SFC) revealed that theobromine was mostly retained in the defatted fraction (10.95 mg/g), while the fatty acid profile of the cocoa butter indicated high levels of oleic (38.15 %) and stearic acids (24.65 %). The findings support supercritical CO₂ as a sustainable method to enhance the economic value of CBH, promoting its application in functional foods and industry.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106560"},"PeriodicalIF":3.4,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578991","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}
Z. Alexander , T. Krause , N. Ly , U. Hegde , M. Hicks , M. Ihme
{"title":"Observations and analysis of near-critical fuel injection","authors":"Z. Alexander , T. Krause , N. Ly , U. Hegde , M. Hicks , M. Ihme","doi":"10.1016/j.supflu.2025.106549","DOIUrl":"10.1016/j.supflu.2025.106549","url":null,"abstract":"<div><div>Results from a study of n-heptane jets injected into a nitrogen environment under supercritical pressures with respect to n-heptane are presented. The temperature of the injected jet varies from supercritical to subcritical values (with respect to the n-heptane critical temperature) while the ambient environment is maintained at temperatures above the critical temperature of n-heptane. Three types of jets are observed and described: (1) subcritical, where the liquid/gas interface persists until complete evaporation of the liquid phase (2) supercritical, where there is no sharp interface between the injected jet and the ambient gas, and (3) transcritical, where distinct liquid/gas phase interface exists at injection but disappears before complete evaporation of the liquid. The subcritical and transcritical jets exhibit Rayleigh-Plateau instability where the jet breaks up into droplets. For subcritical jets, the droplets maintain their sharp interface whereas for the transcritical case the droplets transition from evaporative mixing to diffusive mixing with the surrounding fluid. The experiments are conducted under microgravity conditions at the Zero-Gravity Facility at NASA Glenn Research Center to minimize effects of buoyancy. To interpret these observations, the evolution of a transitioning droplet is modeled with a Regularized Interface Method that can describe both subcritical and supercritical processes as well as transcritical dynamics. Model predictions of critical transition are compared with experimental results and show good agreement.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"220 ","pages":"Article 106549"},"PeriodicalIF":3.4,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454911","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}