{"title":"A flexible approach for accurate supercritical CO2 cycle performance modeling","authors":"Petros Chatzopoulos, Nikolaos Aretakis, Konstantinos Mathioudakis","doi":"10.1016/j.supflu.2025.106604","DOIUrl":"10.1016/j.supflu.2025.106604","url":null,"abstract":"<div><div>A rapid and efficient method for modeling supercritical CO<sub>2</sub> (scCO<sub>2</sub>) Brayton cycles is presented, enabling calculations for both design and off-design conditions. A library is developed within an object-oriented simulation environment, to perform the calculations, incorporating an existing open-source library for accurately computing the specific properties of CO<sub>2</sub> near its critical point. For turbomachinery, compressors and turbines, predefined performance maps and appropriate similitude models are utilized for cycle simulations. The recuperator performance representation is based on effectiveness and is scaled according to mass flow rate for off-design operation. A particular feature of the approach is the implementation of adaptive modeling, for producing models that accurately represent operating installations, marking the first application of such a technique in supercritical CO<sub>2</sub> cycle modeling in general. The process of model building is demonstrated through application to a recuperated single shaft closed cycle. The accuracy of computations is validated through comparisons to published results.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106604"},"PeriodicalIF":3.4,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734756","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}
Oxana N. Fedyaeva , Sergey A. Alekhin , Sergey V. Morozov , Anatoly A. Vostrikov
{"title":"Supercritical water co-oxidation of swine manure with methane and lignite in the flow mode","authors":"Oxana N. Fedyaeva , Sergey A. Alekhin , Sergey V. Morozov , Anatoly A. Vostrikov","doi":"10.1016/j.supflu.2025.106602","DOIUrl":"10.1016/j.supflu.2025.106602","url":null,"abstract":"<div><div>This paper presents the results of a comparative study of supercritical water (SCW) co-oxidation of swine manure (SM) with methane and lignite continuously fed into a flow reactor. The tests were carried out at a temperature gradient along the vertical axis of the reactor (390–600 °C), a pressure of 25 MPa, varying reactant flow rates and oxidation ratio (OR). An analysis of the time dependence of the reactor wall temperature and the power of the resistive heaters was carried out and has shown that, compared to the SCW oxidation of SM, its co-oxidation with methane and lignite led to a 1.5 and 1.8-fold reduction in the power of the heaters, respectively. The gas products were found to be CO<sub>2</sub>, N<sub>2</sub>, and traces of N<sub>2</sub>O. Saturated carboxylic acids C<sub>5</sub>–C<sub>16</sub>, N-bearing aromatics, phenols, chlorophenols, and polycyclic aromatic hydrocarbons (PAHs) were identified in the aqueous effluent by gas chromatography-mass spectrometry. The levels of phenols, chlorophenols, and PAHs in the effluent decreased with increasing OR and with the addition of NaOH. At OR ≥ 1.14, their contents were below the maximum permissible concentrations of these compounds in wastewater. Furthermore, the co-oxidation of SM and lignite increases the content of carboxylic acids, nitrate and sulfate ions in the effluent. The formation of mineral acids during the SCW oxidation of SM intensifies the corrosion of structural materials, resulting in increased contents of chromium, copper, and nickel in the effluent. The paper discusses the transformation mechanisms of organic and mineral components of SM and lignite, as well as ecological aspects of contaminants migration and the efficiency of their removal by SCW oxidation in the SCW/O<sub>2</sub> fluid.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106602"},"PeriodicalIF":3.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697279","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}
Dan Zhou , Wen Yu , Jianfei Sun , Jianlei Qi , Jianzhong Yin
{"title":"Advances and applications of supercritical carbon dioxide microemulsions with or without ionic liquids","authors":"Dan Zhou , Wen Yu , Jianfei Sun , Jianlei Qi , Jianzhong Yin","doi":"10.1016/j.supflu.2025.106603","DOIUrl":"10.1016/j.supflu.2025.106603","url":null,"abstract":"<div><div>Supercritical carbon dioxide (scCO<sub>2</sub>) has gained prominence in green chemistry due to its eco-friendly nature and unique properties, including low viscosity, nearly zero surface tension, and tunable characteristics. However, its nonpolar nature limits applications to nonpolar systems. The development of scCO<sub>2</sub> microemulsions with polar cores, especially those incorporating ionic liquids, addresses this limitation and expands its use across diverse fields such as cleaning, personal care, food, pharmaceuticals, materials science, and oil and gas recovery, while reducing environmental impact. Despite progress, challenges remain in understanding the thermodynamic phase behavior, nanostructure formation, and molecular dynamics of these systems. Additionally, their potential in catalysis, metal-organic frameworks (MOFs) synthesis, and polymer foaming is underexplored. This review systematically examines advancements in scCO<sub>2</sub> microemulsions, bridging fundamental research with applications, and highlights their promise for driving innovation in sustainable industrial processes and advancing green chemical solutions.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106603"},"PeriodicalIF":3.4,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747174","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":"A machine learning-based platform for dye solubility in supercritical carbon dioxide: Classification optimization and predictive analysis","authors":"Rongzhen Wang, Tong Feng, Haixin Sun, Lin Li, Kunpeng Yu, Jianzhong Yin","doi":"10.1016/j.supflu.2025.106601","DOIUrl":"10.1016/j.supflu.2025.106601","url":null,"abstract":"<div><div>This study addresses the critical need for the accurate prediction of dye solubility in supercritical carbon dioxide (scCO<sub>2</sub>) to optimize the dyeing process. An open-access dye solubility database was developed that includes 2991 experimental data points for 90 dyes. Machine learning models, namely the multilayer perceptron (MLP), wavelet neural network (WNN), recurrent neural network (RNN), and long short-term memory (LSTM) models, were trained to predict dye solubility. Initial mixed-data training showed limited performance, while classification based on molecular structures by separating anthraquinone dyes, azo dyes and other dyes into distinct datasets, greatly improved the prediction accuracy. For example, WNN achieved an R<sup>2</sup> value of 0.998 for anthraquinone dyes, while MLP and RNN showed better performance for azo and other dye categories. This classification strategy not only improves model performance, but also verifies the critical role of molecular structure in predicting dye solubility, offering a reliable approach for the development of accurate prediction models.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106601"},"PeriodicalIF":3.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698030","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}
Yanhui Li , Limei Xing , Shaoming Ding , Zhouyang Bai , Wang Zhu , Qibo Wang , Donghai Xu , Kai Wang
{"title":"Hydrothermal corrosion of inconel 625 in high-chlorine, high-alkalinity supercritical water oxidation environments: A new mechanism","authors":"Yanhui Li , Limei Xing , Shaoming Ding , Zhouyang Bai , Wang Zhu , Qibo Wang , Donghai Xu , Kai Wang","doi":"10.1016/j.supflu.2025.106600","DOIUrl":"10.1016/j.supflu.2025.106600","url":null,"abstract":"<div><div>This study investigates the hydrothermal corrosion behavior of Inconel 625 in high-chlorine, high-alkalinity supercritical water oxidation (SCWO) environments. A significant reduction in corrosion rate was observed between 450°C and 500°C due to a transition from electrochemical to chemical corrosion mechanisms. The transition temperature increased from approximately 420°C to 450–500°C at 25 MPa, attributed to molten NaOH stabilizing ion transport. At 600°C, interactions between molten NaOH and oxide films cause melting and sintering, leading to oxide film resolidification but raising concerns about mechanical instability. Under oxygen-rich conditions, chromium from the protective inner oxide layer oxidizes to soluble Cr⁶⁺, depleting the inner layer and accelerating outer layer growth, with a significant increase in the outer-to-inner layer thickness ratio compared to near-pure supercritical water (SCW). The study highlights the synergistic effects of alkalinity, oxygen, and chlorine, provides new insights into corrosion mechanisms, and offers guidance for mitigation strategies in SCWO systems.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106600"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677699","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}
Suelly R. Hollas , Bárbara Moreira , Milena Garcia , Michel Corrente , Leoni Brondani , Roger Wagner , Flávio D. Mayer , Fernanda de Castilhos , Ederson R. Abaide
{"title":"Integrated process of extraction and reaction of rice bran oil to produce biodiesel","authors":"Suelly R. Hollas , Bárbara Moreira , Milena Garcia , Michel Corrente , Leoni Brondani , Roger Wagner , Flávio D. Mayer , Fernanda de Castilhos , Ederson R. Abaide","doi":"10.1016/j.supflu.2025.106598","DOIUrl":"10.1016/j.supflu.2025.106598","url":null,"abstract":"<div><div>The production of fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE) from rice bran (RB) by integrated extraction and reaction process with pressurized ethanol and dimethyl carbonate (DMC) as solvents was evaluated in this research. The first step was pressurized liquid extraction (PLE) in a semi-continuous mode (120 and 150 °C, with a solvent flow rate of 4 and 8 mL min<sup>−1</sup>) and sequentially the solvent and oil were directed to a continuous reaction unit (250 °C and 300 °C) under subcritical and supercritical conditions. Soxhlet extraction was performed for comparative purposes with the PLE. The use of DMC in PLE resulted in a high oil yield (20.08 ± 0.20 % (w/w)), and lipids presented oleic and linoleic acids as the major fatty acids in their composition, with high content of free fatty acids. In the sequential reaction, DMC at 250 °C provided the highest FAME yield (96.97 wt% in 20 min).</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106598"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677701","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}
Taja Žitek Makoter , Vesna Postružnik , Anastasia Kyriakoudi , Elli Pantazi , Natasa Kalogiouri , Ioannis Mourtzinos , Željko Knez , Maša Knez Marevci
{"title":"Comparison of conventional and supercritical isolation methods from bee pollen and their effects on the concentrations of bioactive compounds","authors":"Taja Žitek Makoter , Vesna Postružnik , Anastasia Kyriakoudi , Elli Pantazi , Natasa Kalogiouri , Ioannis Mourtzinos , Željko Knez , Maša Knez Marevci","doi":"10.1016/j.supflu.2025.106599","DOIUrl":"10.1016/j.supflu.2025.106599","url":null,"abstract":"<div><div>The present work represents a profound investigation of material pretreatment, comparison of different isolation methods (conventional and supercritical), and characterization of phenolic compounds and amino acids from bee pollen. The determination of amino acids was carried out after developing a novel hydrophilic interaction chromatography combined with quadrupole time-of-flight tandem mass spectrometric method (HILIC-QTOF-MS/MS) with limits of detection over the range 1 mg/kg −5 mg/kg and recoveries over the range 87.6 % - 97.1 %. The optimal conditions for the isolation of amino acids are in the range of temperatures between 25°C to 55°C and at pressures between 300 bar and 350 bar. It can be concluded that the extraction temperature and the pressure affect antioxidant activity. The favored conditions are lower temperatures and higher pressures.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106599"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677700","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}
Clarinda Costa , Liliana Grenho , Teresa Casimiro , Pedro Sousa Gomes , Maria Helena Fernandes , M. Luisa Corvo , Ana Aguiar-Ricardo
{"title":"Optimization of quercetin - liposomal dry powders for pulmonary delivery using supercritical CO₂-assisted spray drying","authors":"Clarinda Costa , Liliana Grenho , Teresa Casimiro , Pedro Sousa Gomes , Maria Helena Fernandes , M. Luisa Corvo , Ana Aguiar-Ricardo","doi":"10.1016/j.supflu.2025.106591","DOIUrl":"10.1016/j.supflu.2025.106591","url":null,"abstract":"<div><div>Quercetin exhibits anti-inflammatory and antioxidant properties. Incorporating quercetin into liposomes can overcome its limited water solubility and poor oral bioavailability, making it a promising candidate for treating inflammatory diseases. For pulmonary administration, supercritical CO<sub>2</sub>-assisted spray drying can be used to convert liposomal suspensions into dry powder formulations suitable for inhalation. However, the extraction power of scCO<sub>2</sub> can pose challenges on retaining the incorporation efficiency (<em>IE</em>) of this flavonoid in the lipid bilayer. This study focuses on optimizing quercetin’s <em>IE</em> after drying using different liposomal lipid compositions with varying surface charges. The <em>IE</em> of quercetin into positively charged liposomes was 57 %. Additionally, the resulting powders had a mass median aerodynamic diameter of 1.7 µm and a fine particle fraction (particle size < 5 µm) of 63 %, indicating their suitability for inhalation. Cytotoxicity assays also revealed that both reconstituted liposomes and dry powder formulations were non-toxic to areolar fibroblast cells.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106591"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682990","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}
Chenchen Zhao , Yue Wang , Liu Yang , Bin Zhao , Qian Li , Weihua Cai
{"title":"Numerical study on flow and heat transfer characteristics of supercritical methane in microchannels with airfoil fins","authors":"Chenchen Zhao , Yue Wang , Liu Yang , Bin Zhao , Qian Li , Weihua Cai","doi":"10.1016/j.supflu.2025.106596","DOIUrl":"10.1016/j.supflu.2025.106596","url":null,"abstract":"<div><div>In order to study the thermal and flow properties of interstage coolers in the liquefaction of methane process, numerical analyses were carried out on methane flow within a printed circuit heat exchanger (PCHE) with airfoil fins. A geometry model was developed in this research to include staggered microchannels with airfoil fins. The SST <em>k-ω</em> turbulence model was utilized in the analysis of how various operating parameters, including inlet flux, outlet pressure and inlet temperature, impact flow and thermal characteristics. It was found that higher inlet temperatures result in improved thermal feature but are also associated with increased resistance. Conversely, higher outlet pressure conditions led to better overall flow and thermal feature. Furthermore, the impact of airfoil fins on flow characteristics was studied, considering factors such as secondary flow intensity and entropy generation. Correlations for Fanning frictional factor and Nusselt number were developed with a margin of error within ± 3.5 %. These research findings are intended to benefit the design and optimization of PCHEs featuring airfoil fins microchannels for applications.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106596"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143677702","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}
William Gustavo Sganzerla , Barbara Pezzini Moreira , Daniel Lachos-Perez , Giovani L. Zabot , Luiz Eduardo Nochi Castro , Tânia Forster-Carneiro , Maurício Ariel Rostagno
{"title":"Techno-economic analysis of amino acids production with subcritical water technology","authors":"William Gustavo Sganzerla , Barbara Pezzini Moreira , Daniel Lachos-Perez , Giovani L. Zabot , Luiz Eduardo Nochi Castro , Tânia Forster-Carneiro , Maurício Ariel Rostagno","doi":"10.1016/j.supflu.2025.106595","DOIUrl":"10.1016/j.supflu.2025.106595","url":null,"abstract":"<div><div>This study conducted a techno-economic assessment of amino acid production from brewers’ spent grains (BSG) using semi-continuous subcritical water hydrolysis. The process was operated at a pressure of 15 MPa, with a water flow rate of 5 mL/min, a solvent-to-feed ratio of 20 g water/g BSG, and at various temperatures (80 °C to 180 °C). The experimental results demonstrated that the amino acid yield of the single subcritical reactor (10.20 mg/g BSG) was higher compared to the two-sequential reactors (4.72 mg/g BSG). The hydrolysate obtained experimentally was composed mainly of tryptophan (215 µg/mL), valine (64 µg/mL), and aspartic acid (123 µg/mL). The economic analysis revealed that the manufacturing cost of amino acids ranged from 33.66 USD/kg to 49.42 USD/kg. The implementation cost of downstream processing represents the most significant fixed capital investment, as complex unit operations are required to isolate and purify amino acids.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106595"},"PeriodicalIF":3.4,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642771","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}