Pub Date : 2025-03-15DOI: 10.1016/j.supflu.2025.106595
William Gustavo Sganzerla , Barbara Pezzini Moreira , Daniel Lachos-Perez , Giovani L. Zabot , Luiz Eduardo Nochi Castro , Tânia Forster-Carneiro , Maurício Ariel Rostagno
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.
{"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}
Pub Date : 2025-03-12DOI: 10.1016/j.supflu.2025.106593
Linhu Li , Gaoyun Wang , Xujun Li , Shi Liu , Wen Cao
Supercritical water gasification (SCWG) is a promising method for treating hazardous oily sludge waste from petroleum industry. However, achieving complete gasification under mild conditions remains challenging, particularly for persistent intermediates such as toluene and naphthalene. Herein, molecular dynamics simulations are used to explore the impact of Na2CO3 on target product yields from toluene and naphthalene in SCWG. The findings reveal that Na2CO3 considerably enhances radical yields within the reaction system, especially OH radicals, leading to increased gas production (H2, CO, and CO2). Molecular dynamics and density functional theory calculations reveal that Na2CO3 accelerates the ring-opening process and reduces the energy barrier of toluene and naphthalene to 7.4379 ± 0.0001 kcal/mol and 53.5887 ± 0.0011 kcal/mol, respectively. This study highlights OH radicals as an effective active substance in SCWG aromatic conversion. Further catalyst optimization and system design are essential for a highly efficient and clean oily sludge treatment.
{"title":"Revealing the catalytic gasification mechanisms of toluene and naphthalene in supercritical water using ReaxFF-MD and DFT methods","authors":"Linhu Li , Gaoyun Wang , Xujun Li , Shi Liu , Wen Cao","doi":"10.1016/j.supflu.2025.106593","DOIUrl":"10.1016/j.supflu.2025.106593","url":null,"abstract":"<div><div>Supercritical water gasification (SCWG) is a promising method for treating hazardous oily sludge waste from petroleum industry. However, achieving complete gasification under mild conditions remains challenging, particularly for persistent intermediates such as toluene and naphthalene. Herein, molecular dynamics simulations are used to explore the impact of Na<sub>2</sub>CO<sub>3</sub> on target product yields from toluene and naphthalene in SCWG. The findings reveal that Na<sub>2</sub>CO<sub>3</sub> considerably enhances radical yields within the reaction system, especially OH radicals, leading to increased gas production (H<sub>2</sub>, CO, and CO<sub>2</sub>). Molecular dynamics and density functional theory calculations reveal that Na<sub>2</sub>CO<sub>3</sub> accelerates the ring-opening process and reduces the energy barrier of toluene and naphthalene to 7.4379 ± 0.0001 kcal/mol and 53.5887 ± 0.0011 kcal/mol, respectively. This study highlights OH radicals as an effective active substance in SCWG aromatic conversion. Further catalyst optimization and system design are essential for a highly efficient and clean oily sludge treatment.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106593"},"PeriodicalIF":3.4,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619214","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}
Mechanical subcooling is an effective method to improve the transcritical CO2 refrigeration system. To further improve its performance, a transcritical CO2 refrigeration system is investigated with vapor injection and mechanical subcooling (MVS) using R152a as an auxiliary circulating refrigerant. A comparative analysis with the basic vapor injection CO2 refrigeration system (BVS) and the mechanical subcooling CO2 refrigeration system (MSS) is conducted from the perspective of energy and exergy. The results indicate that there are optimal values for the compressor discharge pressure, subcooling degree, and relative intermediate pressure coefficient, which together can maximize the COP of MVS under various operating conditions. At an evaporation temperature of −15 °C and a gas cooler outlet temperature of 40 °C, MVS has a COP of 1.9, which is 17.8 % and 4.9 % higher compared to the BVS and MSS, respectively. The exergy efficiency is increased by 9.5 % and 6.6 %, respectively.
{"title":"Energy and exergy analysis of a transcritical CO2 refrigeration system integrated with vapor injection and mechanical subcooling","authors":"Zeye Zheng, Dewei Lv, Qichao Yang, Guangbin Liu, Yuanyang Zhao, Liansheng Li","doi":"10.1016/j.supflu.2025.106592","DOIUrl":"10.1016/j.supflu.2025.106592","url":null,"abstract":"<div><div>Mechanical subcooling is an effective method to improve the transcritical CO<sub>2</sub> refrigeration system. To further improve its performance, a transcritical CO<sub>2</sub> refrigeration system is investigated with vapor injection and mechanical subcooling (MVS) using R152a as an auxiliary circulating refrigerant. A comparative analysis with the basic vapor injection CO<sub>2</sub> refrigeration system (BVS) and the mechanical subcooling CO<sub>2</sub> refrigeration system (MSS) is conducted from the perspective of energy and exergy. The results indicate that there are optimal values for the compressor discharge pressure, subcooling degree, and relative intermediate pressure coefficient, which together can maximize the COP of MVS under various operating conditions. At an evaporation temperature of −15 °C and a gas cooler outlet temperature of 40 °C, MVS has a COP of 1.9, which is 17.8 % and 4.9 % higher compared to the BVS and MSS, respectively. The exergy efficiency is increased by 9.5 % and 6.6 %, respectively.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106592"},"PeriodicalIF":3.4,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610839","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}
Pub Date : 2025-03-08DOI: 10.1016/j.supflu.2025.106576
Zhaolan Li , Qihui Hu , Yuxing Li , Buze Yin , Liesibieke Talafubieke , Xuefeng Zhao , Lan Meng , Jianlu Zhu , Wuchang Wang
Releasing supercritical and dense-phase CO2 from pipelines entails significant phase transitions and swift depressurization. This leads to significant temperature drops and reverse thrust forces, posing risks to pipeline integrity and support structures. This study investigates stress distribution across pipeline sections during vertical and horizontal releases of supercritical and dense-phase CO2, aiming to quantify external thrust generated during discharge. Experiments were conducted at pressures ranging from 7.5 MPa to 10.0 MPa and temperatures between 25 °C and 40 °C. Maximum stress distribution across pipeline sections was measured, and a practical formula was developed to estimate external thrust during CO2 discharge. The effects of impurities like N2 and CH4 on pipeline vibrations and stresses were also examined. Results indicate that maximum stress concentration occurs near the initial support point, mainly due to the excessive strength of a singular support structure. During CO2 release, the pipeline system undergoes significant vibrations, leading to excessive longitudinal and hoop stresses. Impurities such as N2 and CH4 further exacerbate flow non-uniformity and vibration intensity. Notably, dense-phase CO2 discharge generates higher maximum stress under identical conditions than supercritical CO2 discharge. The reverse thrust formula demonstrates reasonable applicability under supercritical conditions. The findings emphasize the importance of considering phase behavior and impurity effects in pipeline safety assessments.
{"title":"Experimental investigation on the stress of supercritical and dense-phase CO2 pipeline system in the venting process","authors":"Zhaolan Li , Qihui Hu , Yuxing Li , Buze Yin , Liesibieke Talafubieke , Xuefeng Zhao , Lan Meng , Jianlu Zhu , Wuchang Wang","doi":"10.1016/j.supflu.2025.106576","DOIUrl":"10.1016/j.supflu.2025.106576","url":null,"abstract":"<div><div>Releasing supercritical and dense-phase CO<sub>2</sub> from pipelines entails significant phase transitions and swift depressurization. This leads to significant temperature drops and reverse thrust forces, posing risks to pipeline integrity and support structures. This study investigates stress distribution across pipeline sections during vertical and horizontal releases of supercritical and dense-phase CO<sub>2</sub>, aiming to quantify external thrust generated during discharge. Experiments were conducted at pressures ranging from 7.5 MPa to 10.0 MPa and temperatures between 25 °C and 40 °C. Maximum stress distribution across pipeline sections was measured, and a practical formula was developed to estimate external thrust during CO<sub>2</sub> discharge. The effects of impurities like N<sub>2</sub> and CH<sub>4</sub> on pipeline vibrations and stresses were also examined. Results indicate that maximum stress concentration occurs near the initial support point, mainly due to the excessive strength of a singular support structure. During CO<sub>2</sub> release, the pipeline system undergoes significant vibrations, leading to excessive longitudinal and hoop stresses. Impurities such as N<sub>2</sub> and CH<sub>4</sub> further exacerbate flow non-uniformity and vibration intensity. Notably, dense-phase CO<sub>2</sub> discharge generates higher maximum stress under identical conditions than supercritical CO<sub>2</sub> discharge. The reverse thrust formula demonstrates reasonable applicability under supercritical conditions. The findings emphasize the importance of considering phase behavior and impurity effects in pipeline safety assessments.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106576"},"PeriodicalIF":3.4,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619215","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}
Pub Date : 2025-03-06DOI: 10.1016/j.supflu.2025.106586
Lei Chen , Meng Zhu , Haoran Qing , Lingang Zhou , Can Wang , Jing Zhou , Kai Xu , Jun Xu , Long Jiang , Sheng Su , Song Hu , Jun Xiang
Supercritical carbon dioxide is a promising working fluid for power generation due to its superior heat transfer properties. To investigate its heat transfer behavior under in a vertical tube under operating conditions, an combined experimental and numerical study was conducted. Parameters range from (15−27) MPa of pressure, (763–2774) kg/(m2s) of mass flux, (207−424) kW/m2 of heat flux. Results show that pressure and mass flux effects on heat transfer coefficients are consistent under uniform heating conditions. However, under high heat flux conditions, the non-uniform distribution of fluid density along the flow direction reduces turbulence production, leading to a lower heat transfer coefficient. Moreover, a new heat transfer correlation was proposed. The predictive and experimental values demonstrated a high correlation, with 79.30 % of data points falling within a 10 % error range and 100 % within a 20 % error range.
{"title":"Mechanism analysis of convective heat transfer of supercritical CO2 in heated vertical-flow tube","authors":"Lei Chen , Meng Zhu , Haoran Qing , Lingang Zhou , Can Wang , Jing Zhou , Kai Xu , Jun Xu , Long Jiang , Sheng Su , Song Hu , Jun Xiang","doi":"10.1016/j.supflu.2025.106586","DOIUrl":"10.1016/j.supflu.2025.106586","url":null,"abstract":"<div><div>Supercritical carbon dioxide is a promising working fluid for power generation due to its superior heat transfer properties. To investigate its heat transfer behavior under in a vertical tube under operating conditions, an combined experimental and numerical study was conducted. Parameters range from (15−27) MPa of pressure, (763–2774) kg/(m<sup>2</sup>s) of mass flux, (207−424) kW/m<sup>2</sup> of heat flux. Results show that pressure and mass flux effects on heat transfer coefficients are consistent under uniform heating conditions. However, under high heat flux conditions, the non-uniform distribution of fluid density along the flow direction reduces turbulence production, leading to a lower heat transfer coefficient. Moreover, a new heat transfer correlation was proposed. The predictive and experimental values demonstrated a high correlation, with 79.30 % of data points falling within a 10 % error range and 100 % within a 20 % error range.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106586"},"PeriodicalIF":3.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619213","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}
Pub Date : 2025-03-06DOI: 10.1016/j.supflu.2025.106589
Hiroaki Matsukawa, Katsuto Otake
Phthalate plasticizers, which are widely used as general-purpose plasticizers for polyvinyl chloride (PVC), have been identified as harmful to human health. This has created a pressing need to separate these substances from PVC products. In addition, the potential contamination of trioctyl trimellitate (TOTM), an alternative to phthalate plasticizers, with dioctyl phthalate (DOP) cannot be overlooked. Supercritical carbon dioxide (scCO2) has been proposed as a solvent for extracting and separating these compounds; therefore, understanding the phase behavior of these systems is critical for optimizing the process design. This study investigated the phase behavior of CO2/DOP and CO2/TOTM binary systems using a synthetic method combined with a laser displacement technique to measure the movement of the piston in a high-pressure vessel. The phase boundaries were determined over temperature and CO2 mole fraction ranges of (313–373) K and (0.2–0.9), respectively. The vapor–liquid equilibria of the two experimentally obtained binary systems were correlated using the Sanchez-Lacombe equation of state. The one- and two-parameter mixing rules were tested, with better correlation over a wide composition range achieved using the two-parameter mixing rule. The results of this study imply that while separating DOP and TOTM using scCO2 may be challenging, scCO2 shows great potential as an extraction solvent for both plasticizers.
{"title":"Phase behavior of carbon dioxide/dioctyl phthalate and trioctyl trimellitate systems","authors":"Hiroaki Matsukawa, Katsuto Otake","doi":"10.1016/j.supflu.2025.106589","DOIUrl":"10.1016/j.supflu.2025.106589","url":null,"abstract":"<div><div>Phthalate plasticizers, which are widely used as general-purpose plasticizers for polyvinyl chloride (PVC), have been identified as harmful to human health. This has created a pressing need to separate these substances from PVC products. In addition, the potential contamination of trioctyl trimellitate (TOTM), an alternative to phthalate plasticizers, with dioctyl phthalate (DOP) cannot be overlooked. Supercritical carbon dioxide (scCO<sub>2</sub>) has been proposed as a solvent for extracting and separating these compounds; therefore, understanding the phase behavior of these systems is critical for optimizing the process design. This study investigated the phase behavior of CO<sub>2</sub>/DOP and CO<sub>2</sub>/TOTM binary systems using a synthetic method combined with a laser displacement technique to measure the movement of the piston in a high-pressure vessel. The phase boundaries were determined over temperature and CO<sub>2</sub> mole fraction ranges of (313–373) K and (0.2–0.9), respectively. The vapor–liquid equilibria of the two experimentally obtained binary systems were correlated using the Sanchez-Lacombe equation of state. The one- and two-parameter mixing rules were tested, with better correlation over a wide composition range achieved using the two-parameter mixing rule. The results of this study imply that while separating DOP and TOTM using scCO<sub>2</sub> may be challenging, scCO<sub>2</sub> shows great potential as an extraction solvent for both plasticizers.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106589"},"PeriodicalIF":3.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580098","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}
Pub Date : 2025-03-06DOI: 10.1016/j.supflu.2025.106588
Arash Pakravesh , Amir H. Mohammadi , Dominique Richon
Hydrogen, recognized as a future fuel, is considered one of the most sustainable energy sources. Accurate prediction of its thermophysical properties, particularly at high pressures, is essential for the design and development of industrial applications. Equations of state (EoSs), as practical tools for thermodynamic modeling, provide a reliable means of predicting hydrogen's thermodynamic properties. However, due to the variety of available EoSs comparing their performance in predicting the thermodynamic behavior of supercritical hydrogen can help optimize their application in real systems. This study assessed the accuracy of the PR, SRK, Quantum-corrected PR (QPR), three versions of the PρT-SAFT, and five versions of the PC-SAFT EoSs in predicting the thermodynamic properties of supercritical hydrogen under a vast range of pressures (10–2000 MPa) and temperatures (100–1000 K), including volumetric properties, caloric properties, and the Joule-Thomson effect. Additionally, the accuracy of SAFT type EoSs in reproducing hydrogen’s critical point was evaluated, revealing that the rescaled versions of PρT-SAFT EoS yield the most precise predictions of hydrogen's thermodynamic properties. Additionally, a comparison of SAFT and QPR type EoSs for predicting hydrogen's saturated thermodynamic properties shows that QPR performs best. Lastly, the ability of all eleven EoSs to accurately describe the thermodynamic properties of supercritical hydrogen in a limited range of pressures (10–100 MPa) and temperatures (100–400 K), which are more relevant to industrial applications, were investigated and compared with molecular dynamics simulation results. In these regions, the EoSs show promising results, with SRK and PρT-SAFT delivering the best performance.
{"title":"Modeling of supercritical hydrogen thermodynamic properties using cubic and SAFT type equations of state","authors":"Arash Pakravesh , Amir H. Mohammadi , Dominique Richon","doi":"10.1016/j.supflu.2025.106588","DOIUrl":"10.1016/j.supflu.2025.106588","url":null,"abstract":"<div><div>Hydrogen, recognized as a future fuel, is considered one of the most sustainable energy sources. Accurate prediction of its thermophysical properties, particularly at high pressures, is essential for the design and development of industrial applications. Equations of state (EoSs), as practical tools for thermodynamic modeling, provide a reliable means of predicting hydrogen's thermodynamic properties. However, due to the variety of available EoSs comparing their performance in predicting the thermodynamic behavior of supercritical hydrogen can help optimize their application in real systems. This study assessed the accuracy of the PR, SRK, Quantum-corrected PR (QPR), three versions of the PρT-SAFT, and five versions of the PC-SAFT EoSs in predicting the thermodynamic properties of supercritical hydrogen under a vast range of pressures (10–2000 MPa) and temperatures (100–1000 K), including volumetric properties, caloric properties, and the Joule-Thomson effect. Additionally, the accuracy of SAFT type EoSs in reproducing hydrogen’s critical point was evaluated, revealing that the rescaled versions of PρT-SAFT EoS yield the most precise predictions of hydrogen's thermodynamic properties. Additionally, a comparison of SAFT and QPR type EoSs for predicting hydrogen's saturated thermodynamic properties shows that QPR performs best. Lastly, the ability of all eleven EoSs to accurately describe the thermodynamic properties of supercritical hydrogen in a limited range of pressures (10–100 MPa) and temperatures (100–400 K), which are more relevant to industrial applications, were investigated and compared with molecular dynamics simulation results. In these regions, the EoSs show promising results, with SRK and PρT-SAFT delivering the best performance.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106588"},"PeriodicalIF":3.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628974","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}
Pub Date : 2025-03-06DOI: 10.1016/j.supflu.2025.106587
Jiacheng Zhu, Jin Wen, Chao Jia, Meifang Zhu
In this study, the dissolution behavior of the carbon dioxide-polyethylene system is investigated under various conditions using molecular dynamics (MD) simulations. In addition, the dispersion behavior of polyethylene particles in the solvent is examined across different processes using computational fluid dynamics (CFD) simulations. The results indicate that optimal dissolution is achieved by incorporating carbon dioxide, ethanol, acetone, and toluene at molar ratio of 90:3:3:4 under pressure of 30 MPa and temperature of 440 K. The dissolution mechanism is primarily attributed to the strong hydrogen bonding interactions between ethanol and acetone. In terms of agitation, effective dispersion during particle mixing can be achieved by reducing the installation distance to 5 cm, decreasing relative distance to 3 cm, increasing agitation speed to 10 rad s−1, and installing eight baffles in the vessel. These multiscale simulation findings provide key insights for the solution preparation of the flash pressure release spinning.
{"title":"Multiscale simulation of polyethylene dissolution and dispersion for flash pressure release spinning solutions","authors":"Jiacheng Zhu, Jin Wen, Chao Jia, Meifang Zhu","doi":"10.1016/j.supflu.2025.106587","DOIUrl":"10.1016/j.supflu.2025.106587","url":null,"abstract":"<div><div>In this study, the dissolution behavior of the carbon dioxide-polyethylene system is investigated under various conditions using molecular dynamics (MD) simulations. In addition, the dispersion behavior of polyethylene particles in the solvent is examined across different processes using computational fluid dynamics (CFD) simulations. The results indicate that optimal dissolution is achieved by incorporating carbon dioxide, ethanol, acetone, and toluene at molar ratio of 90:3:3:4 under pressure of 30 MPa and temperature of 440 K. The dissolution mechanism is primarily attributed to the strong hydrogen bonding interactions between ethanol and acetone. In terms of agitation, effective dispersion during particle mixing can be achieved by reducing the installation distance to 5 cm, decreasing relative distance to 3 cm, increasing agitation speed to 10 rad s<sup>−1</sup>, and installing eight baffles in the vessel. These multiscale simulation findings provide key insights for the solution preparation of the flash pressure release spinning.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106587"},"PeriodicalIF":3.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580099","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}
Given that casing materials in CO2 enhanced oil recovery (EOR) and sequestration processes are exposed to corrosive environments formed by supercritical CO2 and Cl–-containing water, with the crevice sensitivity yet to be fully understood, this study investigated the crevice corrosion susceptibility of L80-13Cr in Cl–-containing supercritical CO2 water-rich phases using high-pressure autoclave immersion tests. The potential impact of SO2 impurities in the injected carbon dioxide was also considered. The results revealed that L80-13Cr was at risk of crevice corrosion, which was further promoted by lower pH levels and the presence of SO2. The severity of corrosion within the crevice was associated with the concentration of cathodic depolarizers in the bulk solution and the stability of the passive film. These findings underscored the necessity of studying crevice corrosion susceptibility and accounting for the influence of impurities in the carbon source under CO2-EOR and sequestration conditions.
{"title":"Crevice corrosion mechanism of L80-13Cr in Cl- containing supercritical CO2 water-rich phase considering the influence of SO2","authors":"Yu Yuan , Chen Li , Yongyang Zhao , Fengyu Zhang , Yong Xiang","doi":"10.1016/j.supflu.2025.106577","DOIUrl":"10.1016/j.supflu.2025.106577","url":null,"abstract":"<div><div>Given that casing materials in CO<sub>2</sub> enhanced oil recovery (EOR) and sequestration processes are exposed to corrosive environments formed by supercritical CO<sub>2</sub> and Cl<sup>–</sup>-containing water, with the crevice sensitivity yet to be fully understood, this study investigated the crevice corrosion susceptibility of L80-13Cr in Cl<sup>–</sup>-containing supercritical CO<sub>2</sub> water-rich phases using high-pressure autoclave immersion tests. The potential impact of SO<sub>2</sub> impurities in the injected carbon dioxide was also considered. The results revealed that L80-13Cr was at risk of crevice corrosion, which was further promoted by lower pH levels and the presence of SO<sub>2</sub>. The severity of corrosion within the crevice was associated with the concentration of cathodic depolarizers in the bulk solution and the stability of the passive film. These findings underscored the necessity of studying crevice corrosion susceptibility and accounting for the influence of impurities in the carbon source under CO<sub>2</sub>-EOR and sequestration conditions.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"222 ","pages":"Article 106577"},"PeriodicalIF":3.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578990","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}
In this work, the PC-SAFT equation of state (EoS) is used to predict the solubility of CO2 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 CO2 solubility in PASs. In scenario I, the CO2 and PAS molecules are considered inert molecules (non-associating), in scenario II, the CO2 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 CO2 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 CO2 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.
{"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}
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