Pub Date : 2025-06-06DOI: 10.1016/j.ctta.2025.100198
Danielle Schweke, Daniel Rabin, Eli Brosh
Standard metal-oxygen or metal-hydrogen phase diagrams neglect the presence of water vapor. However, water vapor present in the environment often destabilizes the oxide or hydride phase, leading to the stabilization of hydroxide, oxy-hydroxide or hydrate phases. Appropriate phase diagrams are required to properly describe and predict the chemistry of a metal and its oxide or hydride in realistic conditions.
In the present work, M-O-H phase stability diagrams were computed for uranium, lanthanum and cerium (U, La and Ce), based on previously compiled as well as newly assessed thermodynamic data, in CALPHAD (CALculations of PHAse Diagrams) formalism. We show how the ternary phase diagrams relate to diverse experimental observations on the behavior of these elements in environments containing hydrogen or water vapor.
The phase diagrams allow the identification of common trends as well as differences between the systems studied. For example, all the elements form hydride phases but minor concentrations of oxygen or water are sufficient to destabilize the hydride. The oxide phases have a wide range of stability, but the oxide may react in the presence of water vapor to form a hydroxide (in the case of La) or hydrates (in the case of U). The range of stability of the hydroxide and hydrate phases increases as the temperature is lowered.
{"title":"Phase stability of Ce, La and U oxides in the presence of hydrogen and water: Thermodynamic modeling and experimental insights","authors":"Danielle Schweke, Daniel Rabin, Eli Brosh","doi":"10.1016/j.ctta.2025.100198","DOIUrl":"10.1016/j.ctta.2025.100198","url":null,"abstract":"<div><div>Standard metal-oxygen or metal-hydrogen phase diagrams neglect the presence of water vapor. However, water vapor present in the environment often destabilizes the oxide or hydride phase, leading to the stabilization of hydroxide, oxy-hydroxide or hydrate phases. Appropriate phase diagrams are required to properly describe and predict the chemistry of a metal and its oxide or hydride in realistic conditions.</div><div>In the present work, M-O-H phase stability diagrams were computed for uranium, lanthanum and cerium (U, La and Ce), based on previously compiled as well as newly assessed thermodynamic data, in CALPHAD (CALculations of PHAse Diagrams) formalism. We show how the ternary phase diagrams relate to diverse experimental observations on the behavior of these elements in environments containing hydrogen or water vapor.</div><div>The phase diagrams allow the identification of common trends as well as differences between the systems studied. For example, all the elements form hydride phases but minor concentrations of oxygen or water are sufficient to destabilize the hydride. The oxide phases have a wide range of stability, but the oxide may react in the presence of water vapor to form a hydroxide (in the case of La) or hydrates (in the case of U). The range of stability of the hydroxide and hydrate phases increases as the temperature is lowered.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"19 ","pages":"Article 100198"},"PeriodicalIF":0.0,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144270333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores the thermodynamic behavior and adsorption mechanism of Sclerocarya birrea leaf extract as a sustainable corrosion inhibitor for mild steel in simulated seawater (3.5 % NaCl). Corrosion inhibition efficiency and corrosion rate were assessed using the weight-loss method over a temperature range of 303–323 K. Thermodynamic parameters such as activation energy (Ea), enthalpy (ΔH°), entropy (ΔS°), and Gibbs free energy (ΔG°) were calculated to evaluate the adsorption nature and spontaneity of the inhibition process. Adsorption isotherms (Langmuir, Temkin, and Freundlich) were applied to model the inhibitor-metal surface interactions. The results show that increasing extract concentration enhanced inhibition efficiency, while increasing the temperature reduced it, indicating a temperature-sensitive physisorption process. Inhibited samples exhibited Ea values below 80 kJ/mol and positive ΔH° values, confirming endothermic adsorption. ΔG° values ranged from -6.653 to -21.765 kJ/mol, consistent with spontaneous physical adsorption. Among the isotherm models evaluated, the Temkin isotherm best described the adsorption behavior (R² = 0.932 at 303 K). These findings demonstrate that Sclerocarya birrea extract offers a viable, eco-friendly approach to corrosion mitigation through thermodynamically favorable physisorption.
{"title":"Thermodynamics and adsorption behaviour of Sclerocarya birrea leaf extract as a potential green corrosion inhibitor for mild steel in a simulated seawater (3.5 % NaCl) environment","authors":"Phenyo Shathani, Enoch Nifise Ogunmuyiwa, Oluseyi Philip Oladijo, Babatunde Abiodun Obadele","doi":"10.1016/j.ctta.2025.100197","DOIUrl":"10.1016/j.ctta.2025.100197","url":null,"abstract":"<div><div>This study explores the thermodynamic behavior and adsorption mechanism of <em>Sclerocarya birrea</em> leaf extract as a sustainable corrosion inhibitor for mild steel in simulated seawater (3.5 % NaCl). Corrosion inhibition efficiency and corrosion rate were assessed using the weight-loss method over a temperature range of 303–323 K. Thermodynamic parameters such as activation energy (Ea), enthalpy (ΔH°), entropy (ΔS°), and Gibbs free energy (ΔG°) were calculated to evaluate the adsorption nature and spontaneity of the inhibition process. Adsorption isotherms (Langmuir, Temkin, and Freundlich) were applied to model the inhibitor-metal surface interactions. The results show that increasing extract concentration enhanced inhibition efficiency, while increasing the temperature reduced it, indicating a temperature-sensitive physisorption process. Inhibited samples exhibited Ea values below 80 kJ/mol and positive ΔH° values, confirming endothermic adsorption. ΔG° values ranged from -6.653 to -21.765 kJ/mol, consistent with spontaneous physical adsorption. Among the isotherm models evaluated, the Temkin isotherm best described the adsorption behavior (R² = 0.932 at 303 K). These findings demonstrate that <em>Sclerocarya birrea</em> extract offers a viable, eco-friendly approach to corrosion mitigation through thermodynamically favorable physisorption.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"19 ","pages":"Article 100197"},"PeriodicalIF":0.0,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Corrigendum to “Thermo-acoustical investigation of monosodium glutamate food preservative in an aqueous solution of poly-ethylene glycols (400 and 600) by using ultrasonic technique’ [Chemical Thermodynamics and Thermal Analysis Volume 13, March 2024, 100127]","authors":"Ansari Ammara Firdaus , Nabaparna Chakraborty , K.C. Juglan","doi":"10.1016/j.ctta.2025.100194","DOIUrl":"10.1016/j.ctta.2025.100194","url":null,"abstract":"","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"18 ","pages":"Article 100194"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144229760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-24DOI: 10.1016/j.ctta.2025.100196
Sunil Nath
Recently, in a series of three papers, Tolley, Woodfield, and Hansen analyzed six types of spontaneous ideal processes where and for which and are also zero. But this leads to a conundrum because it does not answer the question why the process occurs spontaneously, and where the entropic increase originated from. The papers resolve an apparent contradiction in classical thermodynamics that was recognized by Max Planck in his famous Treatise on Thermodynamics a century ago. Planck realized the need for inclusion of the distribution of matter in a more complete development of thermodynamics. However no such development was forthcoming. The conundrum is resolved by Hansen and colleagues by the novel proposal of a probability distribution of particles, and an entropy change associated with this distribution, . Equations for have been worked out for the six types of processes considered. Applications of their fundamental work to efficient energy conversion in real chemical and biological systems—that presents new challenges and conundrums—and intersects with the author’s own research are discussed, and some suggestions for future work are offered.
{"title":"A thermodynamic conundrum through the ages","authors":"Sunil Nath","doi":"10.1016/j.ctta.2025.100196","DOIUrl":"10.1016/j.ctta.2025.100196","url":null,"abstract":"<div><div>Recently, in a series of three papers, Tolley, Woodfield, and Hansen analyzed six types of <em>spontaneous</em> ideal processes where <span><math><mrow><mi>Q</mi><mo>=</mo><mi>W</mi><mo>=</mo><mn>0</mn></mrow></math></span> and for which <span><math><mrow><mstyle><mi>Δ</mi></mstyle><mi>U</mi></mrow></math></span> and <span><math><mrow><mstyle><mi>Δ</mi></mstyle><mi>S</mi></mrow></math></span> are also zero. But this leads to a conundrum because it does not answer the question why the process occurs spontaneously, and where the entropic increase originated from. The papers resolve an apparent contradiction in classical thermodynamics that was recognized by Max Planck in his famous <em>Treatise on Thermodynamics</em> a century ago. Planck realized the need for inclusion of the distribution of matter in a more complete development of thermodynamics. However no such development was forthcoming. The conundrum is resolved by Hansen and colleagues by the novel proposal of a probability distribution of particles, and an entropy change associated with this distribution, <span><math><mrow><mstyle><mi>Δ</mi></mstyle><msub><mi>S</mi><mi>D</mi></msub></mrow></math></span>. Equations for <span><math><mrow><mstyle><mi>Δ</mi></mstyle><msub><mi>S</mi><mi>D</mi></msub></mrow></math></span> have been worked out for the six types of processes considered. Applications of their fundamental work to efficient energy conversion in real chemical and biological systems—that presents new challenges and conundrums—and intersects with the author’s own research are discussed, and some suggestions for future work are offered.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"19 ","pages":"Article 100196"},"PeriodicalIF":0.0,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-05-20DOI: 10.1016/j.ctta.2025.100195
Ayoub Lahmidi, Sanaa Rabii, Soumia Chliyah, Samir Chtita, M’hammed El Kouali, Abdelkbir Errougui
Potassium carbonate is widely used in various industries such as soap, glass production, and chemical processes due to its effectiveness in neutralizing acids as a strong base. Furthermore, computer simulations play a crucial role in understanding the structural and dynamic properties of electrolytic systems. In this work, the hydration structure and the dynamic and dielectric properties of K2CO3 ion pairs in aqueous medium were studied using molecular dynamics simulations. We employed the CHARMM36.FF force field combined with the TIP3P water model to simulate our system. The radial distribution function (RDF) was calculated to analyze the structural behavior of various ion pairs, while the dynamic and dielectric properties of this electrolytic system were assessed by simulating the self-diffusion coefficient and dielectric constant at temperatures ranging from 278.15 to 373.15 K. The obtained simulation results showed that temperature exerts disruptive effects due to thermal agitation, leading to an increase in kinetic energy. This increase promotes structural modifications in the distribution of hydrogen bonds and causes apparent changes in the transport and dielectric behaviors of this electrolytic system. Additionally, we compared and validated our structural results with Fourier-transform infrared (FTIR) spectroscopy data across the various vibrational modes of the K2CO3(aq) binary system at a concentration of 1.07 mol.kg-1 and T = 298.15 K.
{"title":"Molecular simulations and FTIR spectroscopic studies on the hydration, dynamics, and dielectric properties of the aqueous potassium carbonate system at various temperatures from 278.15 K to 373.15 K","authors":"Ayoub Lahmidi, Sanaa Rabii, Soumia Chliyah, Samir Chtita, M’hammed El Kouali, Abdelkbir Errougui","doi":"10.1016/j.ctta.2025.100195","DOIUrl":"10.1016/j.ctta.2025.100195","url":null,"abstract":"<div><div>Potassium carbonate is widely used in various industries such as soap, glass production, and chemical processes due to its effectiveness in neutralizing acids as a strong base. Furthermore, computer simulations play a crucial role in understanding the structural and dynamic properties of electrolytic systems. In this work, the hydration structure and the dynamic and dielectric properties of K<sub>2</sub>CO<sub>3</sub> ion pairs in aqueous medium were studied using molecular dynamics simulations. We employed the CHARMM36.FF force field combined with the TIP3P water model to simulate our system. The radial distribution function (RDF) was calculated to analyze the structural behavior of various ion pairs, while the dynamic and dielectric properties of this electrolytic system were assessed by simulating the self-diffusion coefficient and dielectric constant at temperatures ranging from 278.15 to 373.15 K. The obtained simulation results showed that temperature exerts disruptive effects due to thermal agitation, leading to an increase in kinetic energy. This increase promotes structural modifications in the distribution of hydrogen bonds and causes apparent changes in the transport and dielectric behaviors of this electrolytic system. Additionally, we compared and validated our structural results with Fourier-transform infrared (FTIR) spectroscopy data across the various vibrational modes of the K<sub>2</sub>CO<sub>3</sub>(aq) binary system at a concentration of 1.07 mol.kg<sup>-1</sup> and <em>T</em> = 298.15 K.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"19 ","pages":"Article 100195"},"PeriodicalIF":0.0,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144155178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study looks into the potential of pig fur biowaste as a biomass source for renewable energy production using detailed characterisation, pyrolysis analysis, and kinetic studies. The effect of pyrolysis factors such as temperature and heating rate on bio-oil, biochar, and syngas production was investigated in a fixed bed reactor with readily available pig fur. The prepared materials were pyrolysed at 50 °C intervals between 300 and 600 °C. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and proximate and ultimate analyses were all used to characterize pig fur biowaste. Proximate and ultimate analyses show that pig fur biowaste has a low moisture content of 7.97 % and a high volatile matter content of 73.10 %, indicating its suitability for efficient thermochemical processes. The ultimate analysis reveals a significant carbon content of 48.31 %, as well as relatively low nitrogen and sulfur levels, indicating that emissions during combustion are manageable. FTIR of the raw biomass identifies key functional groups such as alkanes, alkenes, and alcohols, while FTIR of the bio-oil highlights alcohols, alkanes, and aldehydes. Bio-oil has significantly higher heating values (HHV) of 22.31 MJ/kg, lower heating values (LHV) of 18.71 MJ/kg, and properties suitable for heavy oil applications, such as a density of 0.965 g/ml and kinematic viscosity of 6.4 cSt. Gas chromatography-mass spectrometry analysis of the bio-oil identifies several valuable compounds, including 24.9 % citral and 38.86 % 2,6-octadienal, indicating potential applications in the chemical, pharmaceutical, and biodiesel industries. Pyrolysis yields show that bio-oil production peaks at 450 °C, while bio-char decreases and syngas increases with higher temperatures. TGA identifies three degradation stages: dehydration, devolatilization, and char formation, with different temperatures influencing yield and degradation rates. Activation energy values from the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods range from 120.316 to 184.299 kJ/mol, indicating that biomass conversion requires moderate energy. This comprehensive analysis emphasises the viability of pig fur biowaste as a renewable energy resource, as well as its potential for pyrolysis to produce valuable bio-oil and biochar.
{"title":"Production of bio-oil, physico-chemical and thermal analysis of degradation of pig fur biowaste","authors":"J.L. Chukwuneke , O.C. Uyeri , H.O. Orugba , H.C. Olisakwe , V.I. Okoro , J.C. Okeke , I.C. Egbuna","doi":"10.1016/j.ctta.2025.100193","DOIUrl":"10.1016/j.ctta.2025.100193","url":null,"abstract":"<div><div>This study looks into the potential of pig fur biowaste as a biomass source for renewable energy production using detailed characterisation, pyrolysis analysis, and kinetic studies. The effect of pyrolysis factors such as temperature and heating rate on bio-oil, biochar, and syngas production was investigated in a fixed bed reactor with readily available pig fur. The prepared materials were pyrolysed at 50 °C intervals between 300 and 600 °C. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and proximate and ultimate analyses were all used to characterize pig fur biowaste. Proximate and ultimate analyses show that pig fur biowaste has a low moisture content of 7.97 % and a high volatile matter content of 73.10 %, indicating its suitability for efficient thermochemical processes. The ultimate analysis reveals a significant carbon content of 48.31 %, as well as relatively low nitrogen and sulfur levels, indicating that emissions during combustion are manageable. FTIR of the raw biomass identifies key functional groups such as alkanes, alkenes, and alcohols, while FTIR of the bio-oil highlights alcohols, alkanes, and aldehydes. Bio-oil has significantly higher heating values (HHV) of 22.31 MJ/kg, lower heating values (LHV) of 18.71 MJ/kg, and properties suitable for heavy oil applications, such as a density of 0.965 g/ml and kinematic viscosity of 6.4 cSt. Gas chromatography-mass spectrometry analysis of the bio-oil identifies several valuable compounds, including 24.9 % citral and 38.86 % 2,6-octadienal, indicating potential applications in the chemical, pharmaceutical, and biodiesel industries. Pyrolysis yields show that bio-oil production peaks at 450 °C, while bio-char decreases and syngas increases with higher temperatures. TGA identifies three degradation stages: dehydration, devolatilization, and char formation, with different temperatures influencing yield and degradation rates. Activation energy values from the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods range from 120.316 to 184.299 kJ/mol, indicating that biomass conversion requires moderate energy. This comprehensive analysis emphasises the viability of pig fur biowaste as a renewable energy resource, as well as its potential for pyrolysis to produce valuable bio-oil and biochar.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"19 ","pages":"Article 100193"},"PeriodicalIF":0.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this work is to show the impacts of thermos-diffusion on unsteady MHD free convection mass and heat flow past an accelerating vertical porous plate in the existence of radiation. This analysis is carried out by numerically solving the dimensionless equations by the use of the finite difference approach (FDM). Graphs are used in order to facilitate the discussion and analysis of the influence that a variety of physical characteristics have on momentum, energy, and concentration. In addition, the numerical values for the local Skin friction, the Nusselt number, and the Sherwood number are detailed and analyzed. The concentration profile for So rises with time. The Sherwood quantity falls for So, while it enhances considerably for Sc and Kr.Additional domains that provide opportunities to investigate practical uses, such as energy systems, industrial cooling, and biological fluid flows.
{"title":"Thermodiffusion and radiation impacts on heat and mass transfer casson fluid flow with porous medium with chemical reaction","authors":"Vasa Vijaya Kumar , MN Raja Shekar , Shankar Goud Bejawada","doi":"10.1016/j.ctta.2025.100192","DOIUrl":"10.1016/j.ctta.2025.100192","url":null,"abstract":"<div><div>The purpose of this work is to show the impacts of thermos-diffusion on unsteady MHD free convection mass and heat flow past an accelerating vertical porous plate in the existence of radiation. This analysis is carried out by numerically solving the dimensionless equations by the use of the finite difference approach (FDM). Graphs are used in order to facilitate the discussion and analysis of the influence that a variety of physical characteristics have on momentum, energy, and concentration. In addition, the numerical values for the local Skin friction, the Nusselt number, and the Sherwood number are detailed and analyzed. The concentration profile for <em>So</em> rises with time. The Sherwood quantity falls for <em>So</em>, while it enhances considerably for <em>Sc</em> and <em>Kr</em>.Additional domains that provide opportunities to investigate practical uses, such as energy systems, industrial cooling, and biological fluid flows.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"18 ","pages":"Article 100192"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-11DOI: 10.1016/j.ctta.2025.100191
Shekhar Jyoti Dutta , Dhrubajyoti Neog
The proposed work aims to conduct a comparative study regarding the feasibility of chemical EOR in producing heavy crude oil with respect to part of a porous medium in the upper Assam basin, India. The current study incorporated two crude oil samples, CSG1 and CSG2, belonging to the upper Assam oil field, having an °API of around 23° and 19° and viscosities of 25.785 mPa.s. at 64.94 °C and 42.9 mPa.s. at 40 °C, respectively. In the current work, alkaline (A) solutions were first synthesized with different concentrations of sodium carbonate (Na2CO3) with 0.5 % weight in volume (w/v) of sodium hydroxide (NaOH) and measured for surface tension (ST), interfacial tension (IFT), and contact angle (CA). The subsequent analysis included the formulation of alkaline surfactant (AS) solutions. Na2CO3 and NaOH were used to prepare the alkaline solution in distilled water (DW), while sodium lauryl sulfate (SLS) was used to prepare the surfactant solutions. The AS solutions were then analyzed for estimation of ST, IFT, and CA by varying the % (w/v) concentration of SLS while maintaining the composition of the alkaline part at 0.5 % (w/v) Na2CO3 with 0.5 % (w/v) NaOH. This followed the formulation of alkaline surfactant polymer (ASP) solutions. For that, alkaline and surfactant components remained the same, but for polymers, this study used Xanthan gum with different concentrations. The current study used the drop shape analyser method for the determination of ST, IFT, and CA (for wettability). Based on the interaction of crude oil with differently concentrated A, AS, and ASP solutions and with the porous media, the findings on the feasibility of heavy crude oil recovery were analyzed. The current work finally concludes that AS solutions are more effective in enhancing heavy oil recovery than alkaline and ASP flooding, as they are capable of lowering the IFT and CA more than alkaline and ASP flooding.
拟议的工作旨在对印度上阿萨姆盆地部分多孔介质中重质原油的化学 EOR 生产可行性进行比较研究。本次研究采用了属于上阿萨姆油田的 CSG1 和 CSG2 两种原油样本，其 °API 分别约为 23° 和 19°，在 64.94 °C 时的粘度分别为 25.785 mPa.s.，在 40 °C 时的粘度分别为 42.9 mPa.s.。在本次研究中，首先用不同浓度的碳酸钠（Na2CO3）和 0.5%体积重量比（w/v）的氢氧化钠（NaOH）合成了碱性（A）溶液，并测量了表面张力（ST）、界面张力（IFT）和接触角（CA）。随后的分析包括碱性表面活性剂（AS）溶液的配制。用 Na2CO3 和 NaOH 配制蒸馏水（DW）中的碱性溶液，用十二烷基硫酸钠（SLS）配制表面活性剂溶液。然后，通过改变 SLS 的百分比（w/v）浓度，同时保持碱性部分的成分为 0.5 %（w/v）Na2CO3 和 0.5 %（w/v）NaOH，对 AS 溶液进行分析，以估算 ST、IFT 和 CA。这样就配制出了碱性表面活性剂聚合物（ASP）溶液。为此，碱性和表面活性剂成分保持不变，但在聚合物方面，本研究使用了不同浓度的黄原胶。本研究使用液滴形状分析仪法测定 ST、IFT 和 CA（润湿性）。根据原油与不同浓度的 A、AS 和 ASP 溶液以及多孔介质之间的相互作用，分析了重质原油回收的可行性。目前的研究最终得出结论，AS 溶液在提高重油采收率方面比碱性和 ASP 淹没更有效，因为它们比碱性和 ASP 淹没更能降低 IFT 和 CA。
{"title":"Sustaining heavy crude oil production with chemical EOR: A comparative study","authors":"Shekhar Jyoti Dutta , Dhrubajyoti Neog","doi":"10.1016/j.ctta.2025.100191","DOIUrl":"10.1016/j.ctta.2025.100191","url":null,"abstract":"<div><div>The proposed work aims to conduct a comparative study regarding the feasibility of chemical EOR in producing heavy crude oil with respect to part of a porous medium in the upper Assam basin, India. The current study incorporated two crude oil samples, CSG1 and CSG2, belonging to the upper Assam oil field, having an °API of around 23° and 19° and viscosities of 25.785 mPa.s. at 64.94 °C and 42.9 mPa.s. at 40 °C, respectively. In the current work, alkaline (A) solutions were first synthesized with different concentrations of sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) with 0.5 % weight in volume (w/v) of sodium hydroxide (NaOH) and measured for surface tension (ST), interfacial tension (IFT), and contact angle (CA). The subsequent analysis included the formulation of alkaline surfactant (AS) solutions. Na<sub>2</sub>CO<sub>3</sub> and NaOH were used to prepare the alkaline solution in distilled water (DW), while sodium lauryl sulfate (SLS) was used to prepare the surfactant solutions. The AS solutions were then analyzed for estimation of ST, IFT, and CA by varying the % (w/v) concentration of SLS while maintaining the composition of the alkaline part at 0.5 % (w/v) Na<sub>2</sub>CO<sub>3</sub> with 0.5 % (w/v) NaOH. This followed the formulation of alkaline surfactant polymer (ASP) solutions. For that, alkaline and surfactant components remained the same, but for polymers, this study used Xanthan gum with different concentrations. The current study used the drop shape analyser method for the determination of ST, IFT, and CA (for wettability). Based on the interaction of crude oil with differently concentrated A, AS, and ASP solutions and with the porous media, the findings on the feasibility of heavy crude oil recovery were analyzed. The current work finally concludes that AS solutions are more effective in enhancing heavy oil recovery than alkaline and ASP flooding, as they are capable of lowering the IFT and CA more than alkaline and ASP flooding.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"18 ","pages":"Article 100191"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to understand the molecular interactions between glucose and antidiabetic human mixtard insulin and metformin, the present study reports measured density, ultrasonic velocity, refractive index, viscosity and surface tension of glucose + aqueous-{1 %, 3 %, 5 % and 7 % v/w human mixtard insulin and 7 % v/w human mixtard insulin + 0.05 mol·kg-1metformin} at different temperatures. Apparent molar volume () and apparent molar isentropic compressibility () of glucose were calculated from density and ultrasonic velocity. Concentration dependence of apparent molar properties was studied and respective partial molar volume () and compressibility () were determined using Masson's and Gucker's relation respectively. Standard transfer volumes and compressibilities ( and) of studied solutions were calculated. Transfer properties like viscosity of studied solutions have been measured and viscosity B-coefficients at different temperatures were determined. In addition to this, surface tension and refractive index measurements were carried out. The measured and derived properties have been evaluated in terms of hydration behavior of glucose and molecular interactions of glucose with insulin and metformin. The results of volumetric and acoustic properties indicated the significant effect of HMI and slight effect of metformin on the hydration of glucose at different temperatures. The viscosity study confirms structure making nature of glucose for aqueous-HMI and aqueous-HMI-Met solutions.
{"title":"Analysis of molecular interactions in glucose-aqueous-human mixtard insulin/metformin solutions by volumetric, acoustic properties","authors":"S.D. Deosarkar , H.N. Pawar , R.V. Dudhate , B.R. Bhosale , A.D. Arsule , T.M. Kalyankar","doi":"10.1016/j.ctta.2025.100190","DOIUrl":"10.1016/j.ctta.2025.100190","url":null,"abstract":"<div><div>In order to understand the molecular interactions between glucose and antidiabetic human mixtard insulin and metformin, the present study reports measured density, ultrasonic velocity, refractive index, viscosity and surface tension of glucose + aqueous-{1 %, 3 %, 5 % and 7 % v/w human mixtard insulin and 7 % v/w human mixtard insulin + 0.05 mol·kg<sup>-1</sup>metformin} at different temperatures. Apparent molar volume (<span><math><msub><mi>V</mi><mrow><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow></msub></math></span>) and apparent molar isentropic compressibility (<span><math><msub><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow></msub></math></span>) of glucose were calculated from density and ultrasonic velocity. Concentration dependence of apparent molar properties was studied and respective partial molar volume (<span><math><mrow><mi>V</mi><msub><mrow><msubsup><mrow></mrow><mn>2</mn><mi>o</mi></msubsup></mrow><mrow><mo>,</mo><mi>ϕ</mi></mrow></msub></mrow></math></span>) and compressibility (<span><math><msubsup><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow><mn>0</mn></msubsup></math></span>) were determined using Masson's and Gucker's relation respectively. Standard transfer volumes and compressibilities (<span><math><mrow><msub><mstyle><mi>Δ</mi></mstyle><mi>t</mi></msub><mi>V</mi><msub><mrow><msubsup><mrow></mrow><mn>2</mn><mi>o</mi></msubsup></mrow><mrow><mo>,</mo><mi>ϕ</mi></mrow></msub></mrow></math></span> and<span><math><mrow><msub><mstyle><mi>Δ</mi></mstyle><mi>t</mi></msub><msubsup><mi>κ</mi><mrow><mi>S</mi><mo>,</mo><mn>2</mn><mo>,</mo><mi>ϕ</mi></mrow><mn>0</mn></msubsup></mrow></math></span>) of studied solutions were calculated. Transfer properties like viscosity of studied solutions have been measured and viscosity <em>B</em>-coefficients at different temperatures were determined. In addition to this, surface tension and refractive index measurements were carried out. The measured and derived properties have been evaluated in terms of hydration behavior of glucose and molecular interactions of glucose with insulin and metformin. The results of volumetric and acoustic properties indicated the significant effect of HMI and slight effect of metformin on the hydration of glucose at different temperatures. The viscosity study confirms structure making nature of glucose for aqueous-HMI and aqueous-HMI-Met solutions.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"18 ","pages":"Article 100190"},"PeriodicalIF":0.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-28DOI: 10.1016/j.ctta.2025.100189
Sunita Devi , Nabaparna Chakraborty , K.C. Juglan
This study evaluates the volumetric characteristics of potassium sorbate, an antimicrobial agent, along with the antioxidant salts sodium and magnesium ascorbate in aqueous solutions across four temperatures (288.15, 298.15, 308.15, and 318.15 K) and concentrations (0.0, 0.1, 0.4, and 0.7 mol.kg-1) at 0.1 MPa. Density and ultrasonic velocity were measured using the Anton Paar DSA 5000 M to calculate key thermodynamic parameters, including apparent molar volume, partial molar volume, and partial molar volume of transfer. Additionally, the apparent molar isentropic compression (), partial molar isentropic compression (), and their transfer values () were computed to explore solute compressibility in the mixtures. The coefficients of thermal expansion, alongside pair and triplet interaction terms, provide insights into the interactions dynamics within the combinations. Furthermore, the temperature dependence of partial molar expansibility, helps determine whether the ternary system functions as a structure-maker or structure-breaker. These findings have significant implications for chemical engineering, materials science, and pharmaceutical applications.
本研究在四种温度（288.15、298.15、308.15和318.15 K）和0.1 MPa下浓度（0.0、0.1、0.4和0.7 mol.kg-1）的水溶液中，评估了抗氧化剂山梨酸钾以及抗坏血酸钠和抗坏血酸镁的体积特性。利用Anton Paar DSA 5000 M测量密度和超声速度，计算关键热力学参数，包括表观摩尔体积（vφ）、部分摩尔体积（Vϕ）和部分摩尔传递体积（ΔVϕ0）。此外，计算表观摩尔等熵压缩（Kϕ，s），部分摩尔等熵压缩（Kϕ， 50）及其传递值（ΔKϕ， 50），以探索混合物中的溶质可压缩性。热膨胀系数，以及对和三重态相互作用项，提供了对组合内相互作用动力学的见解。此外，部分摩尔膨胀率的温度依赖性（∂Eϕ0/∂T）P有助于确定三元体系的功能是作为结构制造者还是结构破坏者。这些发现对化学工程、材料科学和制药应用具有重要意义。
{"title":"Acoustic and volumetric analysis of potassium sorbate interactions with sodium/magnesium ascorbate in aqueous solutions at different temperatures","authors":"Sunita Devi , Nabaparna Chakraborty , K.C. Juglan","doi":"10.1016/j.ctta.2025.100189","DOIUrl":"10.1016/j.ctta.2025.100189","url":null,"abstract":"<div><div>This study evaluates the volumetric characteristics of potassium sorbate, an antimicrobial agent, along with the antioxidant salts sodium and magnesium ascorbate in aqueous solutions across four temperatures (288.15, 298.15, 308.15, and 318.15 K) and concentrations (0.0, 0.1, 0.4, and 0.7 mol.kg<sup>-1</sup>) at 0.1 MPa. Density and ultrasonic velocity were measured using the Anton Paar DSA 5000 M to calculate key thermodynamic parameters, including apparent molar volume<span><math><mrow><mspace></mspace><mo>(</mo><msub><mi>V</mi><mi>ϕ</mi></msub><mo>)</mo></mrow></math></span>, partial molar volume<span><math><mrow><mspace></mspace><mo>(</mo><msubsup><mi>V</mi><mi>ϕ</mi><mn>0</mn></msubsup><mo>)</mo></mrow></math></span>, and partial molar volume of transfer<span><math><mrow><mspace></mspace><mo>(</mo><mrow><mstyle><mi>Δ</mi></mstyle><msubsup><mi>V</mi><mi>ϕ</mi><mn>0</mn></msubsup></mrow><mo>)</mo></mrow></math></span>. Additionally, the apparent molar isentropic compression (<span><math><msub><mi>K</mi><mrow><mi>ϕ</mi><mo>,</mo><mi>s</mi></mrow></msub></math></span>), partial molar isentropic compression (<span><math><msubsup><mi>K</mi><mrow><mi>ϕ</mi><mo>,</mo><mi>s</mi></mrow><mn>0</mn></msubsup></math></span>), and their transfer values (<span><math><mrow><mstyle><mi>Δ</mi></mstyle><msubsup><mi>K</mi><mrow><mi>ϕ</mi><mo>,</mo><mi>s</mi></mrow><mn>0</mn></msubsup></mrow></math></span>) were computed to explore solute compressibility in the mixtures. The coefficients of thermal expansion, alongside pair and triplet interaction terms, provide insights into the interactions dynamics within the combinations. Furthermore, the temperature dependence of partial molar expansibility<span><math><mrow><mo>,</mo><mspace></mspace><msub><mrow><mo>(</mo><mi>∂</mi><msubsup><mi>E</mi><mi>ϕ</mi><mn>0</mn></msubsup><mo>/</mo><mi>∂</mi><mi>T</mi><mo>)</mo></mrow><mrow><mi>P</mi><mspace></mspace></mrow></msub></mrow></math></span>, helps determine whether the ternary system functions as a structure-maker or structure-breaker. These findings have significant implications for chemical engineering, materials science, and pharmaceutical applications.</div></div>","PeriodicalId":9781,"journal":{"name":"Chemical Thermodynamics and Thermal Analysis","volume":"18 ","pages":"Article 100189"},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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