Journal of Supercritical Fluids最新文献

Subcritical hydrolysis of defatted meal of crambe seed: A strategy for the full use of the matrix 苎麻籽脱脂粕的亚临界水解：充分利用基质的策略

IF 4.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-29 DOI: 10.1016/j.supflu.2025.106729

Djéssica Tatiane Raspe, Lúcio Cardozo-Filho, Camila da Silva

{"title":"Subcritical hydrolysis of defatted meal of crambe seed: A strategy for the full use of the matrix","authors":"Djéssica Tatiane Raspe, Lúcio Cardozo-Filho, Camila da Silva","doi":"10.1016/j.supflu.2025.106729","DOIUrl":"10.1016/j.supflu.2025.106729","url":null,"abstract":"<div><div>This work investigated the subcritical water hydrolysis (SWH) of defatted crambe seed meal to obtain total reducing sugars (RS), fermentable sugars (FS) and platform chemical products (PC). For this purpose, the experiments evaluated the effect of temperature (180, 200 and 220 °C) and pressure (5, 10 and 15 MPa) of the process conducted in semi-continuous mode. The results obtained indicate that the temperature of 180 ºC allowed the obtaining of RS and FS, while the higher PC contents are the result of the increase in this variable. Pressure influenced, in isolation, only the obtaining of FS, requiring synergy with temperature to obtain the other products. The dry hydrolysates presented xylose and glucose as predominant FS, and levulinic acid as PC. The FT-IR data demonstrated that the SWH process is efficient for the conversion of biomass into FS and PC, allowing the production of compounds with higher added value. The characterization of the residual biomass (RB) indicated the solubilization of phytochemicals into the hydrolysate, and the loss of its color suggests degradation due to the occurrence of the Maillard reaction of the residual constituents. Additionally, organic acids were identified by FT-IR and the characterization of RB demonstrated relative bioherbicidal potential, in addition to the possibility of thermochemical conversion for energy production, consolidating the concept of biorefinery to the matrix in question.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106729"},"PeriodicalIF":4.4,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144758074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determination of rate of diffusion of water into liquid carbon dioxide during CO2 storage 二氧化碳储存期间水向液态二氧化碳扩散速率的测定

IF 4.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-28 DOI: 10.1016/j.supflu.2025.106730

Hakduck Kim , Seungtaek Lee , Heechang Lim , Juhun Song

{"title":"Determination of rate of diffusion of water into liquid carbon dioxide during CO2 storage","authors":"Hakduck Kim , Seungtaek Lee , Heechang Lim , Juhun Song","doi":"10.1016/j.supflu.2025.106730","DOIUrl":"10.1016/j.supflu.2025.106730","url":null,"abstract":"<div><div>The disposal of liquid CO2 (LCO2) into the ocean has been recognized as a potential method for mitigating global warming. This approach requires a deep understanding of water solubility and the kinetics of water dissolution into LCO2. Therefore, it is essential to determine both the diffusion rate and the underlying diffusion mechanism of water into LCO2. In this study, the volume change of water dissolved in LCO<sub>2</sub> was visualized using the shadowgraph technique, from which the diffusion rate constant was derived. The diffusion coefficient of water in the LCO<sub>2</sub> system was determined using a steady state dissolution model of a water drop. The diffusion rate of water containing ionic solutes, such as potassium hydroxide (KOH), was further measured at different concentrations. The results showed that the square of the equivalent diameter decreased linearly with time for water without KOH. A linear relationship existed between the diffusion rate constant and water solubility in CO<sub>2</sub>. These findings indicate that the diffusion of water is the most important mechanism for the dissolution of water into LCO<sub>2</sub>. Increasing the ionic solute concentration decelerates water dissolution due to the discernible precipitation of salts such as bicarbonates or carbonates.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106730"},"PeriodicalIF":4.4,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chitosan aerogel beads production by supercritical gel drying, and their application to methylene blue adsorption 超临界凝胶干燥法制备壳聚糖气凝胶微珠及其在亚甲基蓝吸附中的应用

IF 4.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-28 DOI: 10.1016/j.supflu.2025.106731

Alessandra Zanotti, Lucia Baldino, Giuseppina Iervolino, Stefano Cardea, Ernesto Reverchon

{"title":"Chitosan aerogel beads production by supercritical gel drying, and their application to methylene blue adsorption","authors":"Alessandra Zanotti, Lucia Baldino, Giuseppina Iervolino, Stefano Cardea, Ernesto Reverchon","doi":"10.1016/j.supflu.2025.106731","DOIUrl":"10.1016/j.supflu.2025.106731","url":null,"abstract":"<div><div>Water contamination from synthetic dyes is an urgent issue often addressed by means of adsorption, which is an easy, cost-effective, and flexible unit operation employed for contaminants removal. In this work, chitosan-based highly porous adsorbents were produced through supercritical drying, featuring a regular, nanostructured, and fiber-like morphology. Methylene blue withdrawal was assessed, exploring the effect of pH, temperature, and adsorbent dosage. The optimal operating conditions were at pH= 8 and T = 25 °C, resulting in an estimated saturation capacity of 196.538 mg/g. Adopting the multi-step strategy, it was possible to reach a value of adsorption efficiency of 88.0 ± 1.1 %. Lastly, chitosan aerogels are recyclable: they retain 88.0 ± 3.2 % of the initial adsorption capacity after five adsorption cycles. Kinetic analysis proved that most of dye withdrawal takes place in the first 10 min, accessing a fast and effective process. Overall, this research aims at proving the effectiveness of nanostructured devices for water remediation, moving a step further the full exploitation of aerogels into industrial scenarios.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106731"},"PeriodicalIF":4.4,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144738603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Supercritical CO2 extraction of aspen bark (Populus tremula L.): Influence of operating conditions on yield, vitamin-E content and extract characterization 超临界CO2提取白杨树皮：操作条件对收率、维生素e含量及提取物性质的影响

IF 4.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-26 DOI: 10.1016/j.supflu.2025.106727

L.Yu. Yarullin , S.A. Kovalenko , Ya.Yu. Korepanova , V.F. Khairutdinov , I.M. Abdulagatov

{"title":"Supercritical CO2 extraction of aspen bark (Populus tremula L.): Influence of operating conditions on yield, vitamin-E content and extract characterization","authors":"L.Yu. Yarullin , S.A. Kovalenko , Ya.Yu. Korepanova , V.F. Khairutdinov , I.M. Abdulagatov","doi":"10.1016/j.supflu.2025.106727","DOIUrl":"10.1016/j.supflu.2025.106727","url":null,"abstract":"<div><div>Aspen bark (<em>Populus tremula L</em>.) is known as a plant that consists of a medicinal compound (vitamin- E). Supercritical carbon dioxide extraction (SC CO<sub>2</sub>) is one of the most efficient methods of extracting interesting compounds from plants. By altering pressure and temperature (operating conditions of the supercritical fluid process), the specific compound can be extracted. Based on the method of supercritical fluid extraction (SFE) technology using carbon dioxide, extracts of <em>Populus tremula L</em>. were obtained at a temperature of 313.15 K and pressures of (15, 20, 30) MPa. For a comparison of quantitative indicators of vitamin -E content and antioxidant properties, an extract of <em>Populus tremula L</em>. was obtained using a conventional method. The GC/MS analysis revealed the presence of vitamin- E in all three CO₂ extracts. The quantification of vitamin E was analyzed with gas chromatography (GC-MS). The vitamin -E yield was obtained at the highest condition of 30 MPa at 313.15 K with a yield of 8.5 %.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106727"},"PeriodicalIF":4.4,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144723358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Oxidation behavior of 316L stainless steel in supercritical water 316L不锈钢在超临界水中的氧化行为

IF 4.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-23 DOI: 10.1016/j.supflu.2025.106728

Wenxin Ren , Lu Ren , Mengmeng Liang , Jianxing Zhou , Xiaohui Zhang , Z. Li

{"title":"Oxidation behavior of 316L stainless steel in supercritical water","authors":"Wenxin Ren , Lu Ren , Mengmeng Liang , Jianxing Zhou , Xiaohui Zhang , Z. Li","doi":"10.1016/j.supflu.2025.106728","DOIUrl":"10.1016/j.supflu.2025.106728","url":null,"abstract":"<div><div>Supercritical water oxidation technology has been extensively employed in organics treatment, significantly enhancing energy utilization and recovery efficiency. However, due to its extreme corrosiveness, supercritical water systems impose stringent requirements on the material properties. This study investigates the oxidation behavior of 316 L stainless steel in supercritical water at 798 K and 24 MPa for 200 h. Results indicate that the average weight gain of the specimens was 1.73 g/m<sup>2</sup> after 200 h. A discrete monolayer oxide film forms on its surface, accompanied by noticeable pitting corrosion. The oxide layer is primarily composed of Fe oxides, with some Cr oxides present. A significant amount of oxides is also found around the pits, which is mainly composed of Fe and Ni oxides, and the presence of NiFe<sub>2</sub>O<sub>4</sub> spinel is detected as well. This study further explores the oxidation mechanism of 316L stainless steel in supercritical water, to provide novel perspectives and insights into the selection of materials for supercritical water systems, thereby extending the service life of the equipment.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106728"},"PeriodicalIF":4.4,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A supercritical carbon dioxide dyeing strategy for polyester/cotton blended fabrics with excellent dyeing performance 涤纶/棉混纺织物超临界二氧化碳染色工艺研究

IF 3.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-23 DOI: 10.1016/j.supflu.2025.106726

Hongjuan Zhao , Yu Wang , Qian Zhao , Xiaoqing Xiong

{"title":"A supercritical carbon dioxide dyeing strategy for polyester/cotton blended fabrics with excellent dyeing performance","authors":"Hongjuan Zhao , Yu Wang , Qian Zhao , Xiaoqing Xiong","doi":"10.1016/j.supflu.2025.106726","DOIUrl":"10.1016/j.supflu.2025.106726","url":null,"abstract":"<div><div>Supercritical carbon dioxide dyeing technique offers a promising solution to the challenges of environmental issues in dyeing polyester/cotton blended fabrics, but they have yet to achieve excellent dyeing performance. In this study, a novel dyeing strategy for polyester/cotton blended fabrics was developed by optimizing the action mode of dye molecules on fiber substrates in supercritical carbon dioxide, thereby addressing the problem of poor dyeing performances associated with supercritical carbon dioxide dyeing techniques. The dyed polyester/cotton blended fabrics exhibit deep and uniform coloring (RUI values ranging from 0.021 to 0.056), excellent washing and rubbing fastness (average grades of 4–5), and a wide range of color options. In addition, this dyeing strategy retains excellent environmental performance of supercritical carbon dioxide dyeing technique, with a theoretical energy consumption of only 5 MJ per kilogram of dyed fabrics and an E factor as low as 0.057. Its environmental performance significantly outperforms existing dyeing techniques, such as two-step dyeing, one-step exhaust dyeing, one-step pad dyeing, and D5 dyeing, offering a viable and eco-friendly alternative for the industrial dyeing of T/C blended fabrics.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106726"},"PeriodicalIF":3.4,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An in silico environmental risk assessment of palm oil transesterification in supercritical ethanol as a tool to enhance sustainable biofuel production 棕榈油在超临界乙醇中酯交换反应的环境风险计算机模拟评估：提高可持续生物燃料生产的工具

IF 3.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-21 DOI: 10.1016/j.supflu.2025.106724

Laura Pedraza-Casanova , Paula Romero-Ramirez , Hamilton Carrillo , Bernay Cifuentes , Jose L. Guerrero , Jesús Alberto García-Núñez

{"title":"An in silico environmental risk assessment of palm oil transesterification in supercritical ethanol as a tool to enhance sustainable biofuel production","authors":"Laura Pedraza-Casanova , Paula Romero-Ramirez , Hamilton Carrillo , Bernay Cifuentes , Jose L. Guerrero , Jesús Alberto García-Núñez","doi":"10.1016/j.supflu.2025.106724","DOIUrl":"10.1016/j.supflu.2025.106724","url":null,"abstract":"<div><div>An <em>in silico</em> methodology was employed to assess the ecotoxicity of biofuels produced through the supercritical transesterification of palm oil with ethanol. The study correlated operating conditions (temperature and pressure) with variations in the composition of the resulting mixtures and their impact on key ecotoxicological factors, including molecular weight distribution, bioaccumulation factor (BCF), biodegradability, soil sorption coefficient (Log Koc), and octanol-air partition coefficient (Log Koa). Four biofuel samples were analyzed under distinct conditions: S1 (350 °C, 10.3 MPa), S2 (450 °C, 10.3 MPa), S3 (350 °C, 17.2 MPa), and S4 (450 °C, 17.2 MPa). Higher temperatures promoted thermal decomposition and polymerization, forming high-molecular-weight compounds, while increased pressure amplified this effect (up to 300 g·mol⁻¹ in S4). Ecotoxicological assessments revealed that S2 and S3 exhibited lower bioaccumulation potential (Log Kow < 3.5 in over 50 % of compounds) and high biodegradability, with more than 90 % degrading rapidly (BIOWIN 3 > 2.75). In contrast, S1 and S4 contained a higher proportion of compounds with elevated bioaccumulation potential and reduced biodegradability. Compared to commercial diesel (B8 blend), biofuels demonstrated a lower proportion of compounds with high soil adsorption potential (Log Koc > 4.5), reducing their environmental impact. Therefore, samples S2 and S3 stand out for their lower ecotoxicity and balanced composition of fatty acid ethyl esters (FAEE), which are less toxic than the fatty acid methyl esters (FAME) found in B8. This study emphasizes the significance of <em>in silico</em> evaluations in selecting emerging biofuels and mitigating their environmental impact.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106724"},"PeriodicalIF":3.4,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of solvent and pyrolysis upgrade on the products of liquefaction of Saccharina latissima 溶剂和热解升级对糖精液化产物的影响

IF 3.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-14 DOI: 10.1016/j.supflu.2025.106723

Mayokun Oke, Fernando Resende

{"title":"Effect of solvent and pyrolysis upgrade on the products of liquefaction of Saccharina latissima","authors":"Mayokun Oke, Fernando Resende","doi":"10.1016/j.supflu.2025.106723","DOIUrl":"10.1016/j.supflu.2025.106723","url":null,"abstract":"<div><div>In this work, we report results for thermal liquefaction of the brown macroalga <em>S. latissima</em> with HZSM-5 catalyst in three solvent schemes (water-only, water-methanol as co-solvents, and methanol-only). We investigate the effects of these schemes on product yields and biocrude composition. We conducted the experiments in a batch reactor at 330 °C (sub-critical water with supercritical methanol) and 1 hr residence time. The highest biocrude yield (28 wt%) was observed in the catalytic run with methanol-only solvent, but the absence of water in this run meant that no water-soluble products (WSP) were obtained. The impact of the HZSM-5 catalyst in hydrothermal liquefaction appears to be solvent-dependent, with significant impact in the presence of water, but marginal changes for methanol. Methanol as a solvent or co-solvent led to significant fractions of fatty acids and esters in the biocrude (43.9 % - 69.1 %), which suggests a path for the production of sustainable aviation fuels (SAF). Methanol decomposition under liquefaction conditions led to the production of aliphatic chain alcohols, with selectivities ranging from 1.0 % (20 % methanol) to 6.1 % (100 % methanol). The highest yield of hydrocarbons (0.8 wt%) was obtained in the presence of HZSM-5 with 20 % methanol as a co-solvent. We further subjected the biocrude produced to upgrading via catalytic fast pyrolysis in HZSM-5. The upgrade at the biocrude-to-catalyst ratio 1:5 produced mostly aromatic hydrocarbons, but at a low yield of 4.1 wt%. These findings are promising to support the utilization of <em>S</em>. <em>latissima</em> as a potential resource to produce transportation drop-in fuels.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"226 ","pages":"Article 106723"},"PeriodicalIF":3.4,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermophysical characterization of Brazil nut oil in pressurized solvents: Density modeling and barocaloric effect for sustainable process development 巴西坚果油在加压溶剂中的热物理特性：可持续工艺开发的密度建模和气压效应

IF 3.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-01 DOI: 10.1016/j.supflu.2025.106711

Irede Dalmolin , Camila da Silva , Fernando Augusto Pedersen Voll , Gustavo Rodrigues Borges , Flavio Clareth Colman , Lúcio Cardozo-Filho , Cláudio Dariva

{"title":"Thermophysical characterization of Brazil nut oil in pressurized solvents: Density modeling and barocaloric effect for sustainable process development","authors":"Irede Dalmolin , Camila da Silva , Fernando Augusto Pedersen Voll , Gustavo Rodrigues Borges , Flavio Clareth Colman , Lúcio Cardozo-Filho , Cláudio Dariva","doi":"10.1016/j.supflu.2025.106711","DOIUrl":"10.1016/j.supflu.2025.106711","url":null,"abstract":"<div><div>In this work, we present a comprehensive thermophysical characterization of Brazil nut oil, emphasizing its potential for sustainable applications involving pressurized fluids. Density measurements were conducted for the binary systems of Brazil nut oil + n-propane and Brazil nut oil + ethanol using a vibrating tube densimeter. The measurements were taken at elevated pressures, varying temperatures, and different mass ratios. Systems with ethanol showed higher absolute densities, and increasing the oil mass fraction led to a consistent rise in system density. The experimental data were accurately described using the Peng–Robinson equation of state with volume translation, reinforcing their applicability in designing and optimizing high-pressure extraction processes. Beyond density modeling, Brazil nut oil was found to exhibit a large barocaloric effect, with an isothermal entropy-driven temperature change (ΔT<sub>s</sub>) of approximately (12 at 323) K and 174 MPa and a merit index of 65 K·GPa⁻¹ . This remarkable barocaloric behavior reveals this natural oil's previously unexplored thermophysical feature. The combined analysis of high-pressure density behavior and barocaloric response highlights the dual potential of Brazil nut oil as a feedstock for green extraction technologies using pressurized solvents such as n-propane and ethanol and as a promising candidate for solid-state refrigeration systems. These findings offer novel insights into the valorization of Brazil nut oil and support its integration into environmentally conscious process development within the scope of biorefinery and clean technology platforms.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"225 ","pages":"Article 106711"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144578108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of acid-catalytic effect of hot compressed water–methanol mixture using dehydration of tertiary alcohol as a probe reaction 以叔醇脱水为探针反应考察热压缩水-甲醇混合物的酸催化效果

IF 3.4 3区工程技术

Journal of Supercritical Fluids Pub Date : 2025-07-01 DOI: 10.1016/j.supflu.2025.106706

Shotaro Seki, Yoshito Oshima, Makoto Akizuki

{"title":"Investigation of acid-catalytic effect of hot compressed water–methanol mixture using dehydration of tertiary alcohol as a probe reaction","authors":"Shotaro Seki, Yoshito Oshima, Makoto Akizuki","doi":"10.1016/j.supflu.2025.106706","DOIUrl":"10.1016/j.supflu.2025.106706","url":null,"abstract":"<div><div>The acid-catalytic effect of a hot compressed water–methanol mixture was investigated by analyzing the reaction kinetics of α-cumyl alcohol at 250 <span><math><mi>℃</mi></math></span> and 30 MPa, with methanol mole fractions ranging from 0 to 0.4. By varying the HCl concentration to control proton content and measuring the corresponding reaction rate, the proton concentration associated with the dissociation of water and/or methanol in the absence of HCl was determined. The acid-catalytic effect of the reaction medium was evaluated using the stoichiometric autoprotolysis constant, because it can be used to calculate the amount of protons generated through solvent dissociation. This parameter reflects not only the polarity of the solvent but also its acidic and basic properties. The acid-catalytic effect attributable to autoprotolysis gradually diminished as the methanol content increased. However, the highest reaction rate of α-cumyl alcohol was observed when the methanol mole fraction was 0.2. This is because, while the autoprotolysis was suppressed with increasing methanol content, the rate constants increased with the methanol mole fraction and became nearly constant when it exceeded 0.2.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"225 ","pages":"Article 106706"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144577677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0