Preetom K. Roy, Sai Praneeth, Ahmed K. Sakr, Chandra M. Tummala, Mohammed Dardona, Timothy M. Dittrich
{"title":"Efficient two-step separation of vanadium, scandium, and heavy rare-earth elements from gallium and germanium in high-value fly ash: Coupling solid-phase and solvent extraction","authors":"Preetom K. Roy, Sai Praneeth, Ahmed K. Sakr, Chandra M. Tummala, Mohammed Dardona, Timothy M. Dittrich","doi":"10.1016/j.seppur.2025.133713","DOIUrl":"10.1016/j.seppur.2025.133713","url":null,"abstract":"<div><div>Geopolitical factors have significantly disrupted global supply chains for critical metals such as gallium, germanium, and rare-earth elements (REEs). This study examined 18 unconventional feedstock samples—including fly ash, raw coal, plasma slag, and gypsum fertilizer—to determine critical material content, estimate metal oxide equivalent values (MOEVs) with current market prices, and develop a system for extraction and separation. A recovery framework was developed to prioritize critical metal extraction with a particular focus on fly ash resulting from fuel blends containing 10–15 % petroleum coke (petcoke). Petcoke fly ash contains as high as 1.5 g of vanadium per kilogram of ash and has an estimated MOEV of ∼$80 per ton when only considering vanadium, gallium, germanium, and scandium. The recovery process involves three stages: (i) leaching metals using 6.0 M nitric acid, (ii) separating heavy rare-earth elements with a TODGA-organosilica packed-bed column, (iii) and extracting vanadium with D2EHPA solvent extraction. This method achieved > 30 % vanadium recovery using a 1:1 organic-to-aqueous ratio, 15 min reaction time, and a solvent mixture of 10 % D2EHPA in kerosene at pH 1.5 or higher. The TODGA-organosilica packed bed column strip solution contained > 75 % pure rare-earth elements (based on multivalent cation mass in solution), with more than 95 % of V, Ga, and Ge remaining in solution. Vanadium recovery via solvent extraction with D2EHPA started with an original leach solution of < 0.2 % vanadium, while the strip solution contained a concentrated vanadium and iron matrix (>34 % vanadium and 56 % iron). The findings demonstrate the potential of extracting vanadium, gallium, germanium, scandium and other critical metals from coal fly ash and industrial waste, offering a promising opportunity for resource recovery.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133713"},"PeriodicalIF":8.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joule-heating-assisted Janus MoS2-based evaporators for high-efficiency and all-weather solar desalination","authors":"Hejian Yin, Qingmiao Wang, Tianchen Wang, Huiling Zhang, Qian Wan, Feifei Jia, Shaoxian Song, Qing Ye","doi":"10.1016/j.seppur.2025.133725","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133725","url":null,"abstract":"Solar desalination offers a promising, environmentally sustainable solution to the growing global freshwater scarcity. However, ensuring consistent steam production throughout the day—especially during periods of limited sunlight, such as at night or on cloudy days—remains a significant challenge. This study introduces a novel MoS<sub>2</sub>-based evaporator that integrates photothermal and Joule heating effects, allowing it to dynamically adjust the surface temperature and evaporation rate based on varying light conditions. Under one sun’s intensity (1 kW m<sup>−2</sup>) and powered by a 5 V voltage, the evaporator achieves a surface temperature of 60 °C with an evaporation rate of 2.38 kg m<sup>-2</sup>h<sup>−1</sup>. Even in low-light conditions (dark), the evaporator maintains an evaporation rate of 1.07 kg m<sup>-2</sup>h<sup>−1</sup>. Additionally, the hydrophobic treatment applied to the surface of evaporators effectively prevents salt crystallization, improving the system’s operational stability and longevity. This innovative MoS<sub>2</sub>-based evaporator represents a significant step forward in all-weather seawater desalination, offering a reliable solution to the global freshwater crisis.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"138 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yi Wang, Huanhuan Guo, Xiaohan Xing, Can Wang, Xuefeng Zhang, Xiumin Li, Fengfeng Gao, Xiaogang Hao
{"title":"Lithium-selective extraction utilizing lithium-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane within the ship lock-type ion selective permeability system","authors":"Yi Wang, Huanhuan Guo, Xiaohan Xing, Can Wang, Xuefeng Zhang, Xiumin Li, Fengfeng Gao, Xiaogang Hao","doi":"10.1016/j.seppur.2025.133730","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133730","url":null,"abstract":"A lithium aluminum iron layered double hydroxides/multiwalled carbon nanotubes/quaternized chitosan (LiAlFe-LDHs/MWCNTs/QCS) composite membrane with lithium-ion vacancies (Li<sup>+</sup>-trap) was fabricated through vacuum filtration method and pre-desorption process. The Li<sup>+</sup>-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane had been developed for the selective extraction of Li<sup>+</sup> within the ship lock-type ion selective permeability (SL-ISP) system. In the Li<sup>+</sup>-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane, the Li<sup>+</sup>-trap within LiAlFe-LDHs was pivotal for achieving selective Li<sup>+</sup> extraction. This selectivity was realized through the cyclic intercalation of Li<sup>+</sup> into the Li<sup>+</sup>-trap sites within the interlayer structure of LiAlFe-LDHs, a process that also facilitates the permeation of Cl<sup>-</sup>. The interference of impurity ions was further eliminated by the SL-ISP system, thus facilitating the selective extraction of Li<sup>+</sup>. Upon investigation, the Li<sup>+</sup>-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane was found to achieve a Li<sup>+</sup> flux of 0.055 mol·m<sup>−2</sup>·h<sup>−1</sup> and a separation factor of 8.3 at an equimolar concentration (<em>C</em><sub>Mg, Li</sub> = 0.05 M) within the SL-ISP system. Additionally, the Li<sup>+</sup>-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane demonstrated excellent separation performance in simulated brine, with a calculated Li<sup>+</sup> permeation flux of 0.053 mol·m<sup>−2</sup>·h<sup>−1</sup>. The separation factors of Li<sup>+</sup>/Mg<sup>2+</sup>, Li<sup>+</sup>/K<sup>+</sup>, Li<sup>+</sup>/Na<sup>+</sup> and Li<sup>+</sup>/Ca<sup>2+</sup> reached values of 91.84, 69.75, 81.51 and 17.99, respectively. Therefore, the Li<sup>+</sup>-trap LiAlFe-LDHs/MWCNTs/QCS composite membrane could be effectively applied in the SL-ISP system for the selective extraction of Li<sup>+</sup>.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"18 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144133519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Xiao , Pengrui Jin , Yue Wang , Riri Liu , Lei Jiang , Qin Chen , Chen Zhao , Kai Sheng , Zhao Yang , Shushan Yuan , Bart Van der Bruggen
{"title":"Partially carbonized watermelon flesh-based 3D evaporator enhanced by side heat absorption for efficient seawater desalination","authors":"Xin Xiao , Pengrui Jin , Yue Wang , Riri Liu , Lei Jiang , Qin Chen , Chen Zhao , Kai Sheng , Zhao Yang , Shushan Yuan , Bart Van der Bruggen","doi":"10.1016/j.seppur.2025.133724","DOIUrl":"10.1016/j.seppur.2025.133724","url":null,"abstract":"<div><div>Three-dimensional (3D) carbon materials have shown great potential in solar interface evaporation devices, but salt deposition and low evaporation efficiency significantly hinder their continuous operation under seawater conditions. This work presents an all-in-one and sustainable all-biomass evaporator with unique structural advantages, in which the space between the watermelon fibers acts as micro/nanopores water transport channels, while carbonized nanosheets formed onto the outer surface transform absorbed sunlight to heat. As a result, the biomass foam evaporator achieved an excellent evaporation rate of up to 2.35 kg·m<sup>−2</sup>·h<sup>−1</sup> in pure water and 2.0 kg·m<sup>−2</sup>·h<sup>−1</sup> in 3.5 wt% NaCl solution under 1 sun irradiation, and similarly exhibited a high efficiency and stable operation and superior anti-salt performance in 25 wt% NaCl solution, as well as a remarkable wastewater purification performance. This is attributed to the fast water replenishment facilitated by multi-layered porous structures and hydrophilic groups, efficient thermal management provided by the<!--> <!-->three-dimensional cylindrical shape, and the<!--> <!-->capture of environmental energy from the<!--> <!-->cold side surface of the<!--> <!-->3D evaporator. This research not only highlights the potential of incompletely carbonized watermelon as a low-cost biomass material for seawater desalination during solar steam generation but also provides insights for improving the water transport properties of 3D biochar evaporators.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133724"},"PeriodicalIF":8.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144133520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francis Adu-Boahene, Ramatisa Ladeia Ramos, Andrea I. Schäfer
{"title":"Power distribution in the single-pass multi-stage electrodialysis (SPM-ED) for brackish water desalination","authors":"Francis Adu-Boahene, Ramatisa Ladeia Ramos, Andrea I. Schäfer","doi":"10.1016/j.seppur.2025.133719","DOIUrl":"https://doi.org/10.1016/j.seppur.2025.133719","url":null,"abstract":"Electrodialysis (ED) is able to produce drinking water from brackish sources through selective ion removal. ED can operate at different electrical potentials when configured in a single-pass multi-stage (SPM-ED) arrangement. This degree of freedom leaves doubts about how to distribute power among the stacks for better performance in salt removal and potential improvements in the system’s energy management. The limiting current density (LCD) is crucial in practical ED applications, as operating just below the LCD allows for the maximum ionic separation rate without violating electro-neutrality. This investigated the performance of a double stack SPM-ED system for brackish water desalination at varying salinities (0.58–15 g/L NaCl) and flow rates (73–100 L/h) under two distinct power distribution settings (LCD and 80 % LCD).The results indicated that increasing the salinity of the feed solution (0.58–15 g/L NaCl) and the fluid flow rate (73–100 L/h) raised the LCD for both the first and second stacks operating independently, with the second stack being more affected by the operational conditions due to its configuration. When both stacks operated together, they achieved higher salt removal. Hydraulic residence time and boundary layer thickness were identified as limiting factors affecting desalination as flow rates increased. Operating Stack 1 at 80 % LCD and Stack 2 at LCD maintained moderate SEC and higher current efficiency (CE) across all varying salinities. The findings suggest that employing staging in single-pass ED systems with different power distribution settings (80 % LCD for the first stack) can lead to enhanced salt removal, minimum specific energy consumption (SEC), and optimal current efficiency compared to operating at the LCD point.","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"10 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of ceramic hollow-fiber nanofiltration membranes containing a functionalized MoS2 nanomaterial for semiconductor wastewater treatment","authors":"Hyeyool Kim, Soyoun Kim, Chanhyuk Park","doi":"10.1016/j.seppur.2025.133702","DOIUrl":"10.1016/j.seppur.2025.133702","url":null,"abstract":"<div><div>In recent years, the rapid growth of the semiconductor industry has raised concerns about its environmental impact, particularly the wastewater generated from manufacturing processes such as wet chemical etching or cleaning. These processes typically produce effluent containing contaminants such as highly alkaline silica, ammonium phosphate, and various inorganic compounds. To address this issue, the present study developed ceramic nanofiltration (NF) membranes incorporating a molybdenum disulfide (MoS<sub>2</sub>) nanomaterial and evaluated their separation efficiency. Because of its stability and anti-fouling properties in water, MoS<sub>2</sub> was coated onto a ceramic hollow fiber ultrafiltration (UF) membrane substrate using pressure-assisted deposition. The physical and chemical properties of the fabricated ceramic NF membrane, indicating its pore size, surface charge, and hydrophilicity, were assessed and its removal efficiency for divalent ions, including magnesium sulfate (MgSO<sub>4</sub>) and calcium chloride (CaCl<sub>2</sub>), was compared to that of a pristine UF membrane and other commercially available polymeric NF membranes. This study demonstrates the potential of MoS<sub>2</sub>-coated ceramic NF membranes for the effective treatment of semiconductor wastewater by effectively removing the low-molecular-weight contaminants produced by high-integration semiconductor manufacturing and lithium-ion battery recycling processes.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133702"},"PeriodicalIF":8.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chuan Zhou , Junwei Sun , Chao Zheng , Cheng-an Tao , Li Li , Shupei Bai , Gang Fu , Xiaobing Yang , Sida Zhang , Song He
{"title":"Monolithic UiO-66-OH metal-organic gels integrating LiCl for record capture and selective separation of NH3","authors":"Chuan Zhou , Junwei Sun , Chao Zheng , Cheng-an Tao , Li Li , Shupei Bai , Gang Fu , Xiaobing Yang , Sida Zhang , Song He","doi":"10.1016/j.seppur.2025.133720","DOIUrl":"10.1016/j.seppur.2025.133720","url":null,"abstract":"<div><div>For ammonia (NH<sub>3</sub>), a kind of momentous pollutant and chemical raw material, thus, developing advanced materials with outstanding NH<sub>3</sub> capture, storage, regeneration and separation performance are of great significance. Herein, we report the ultra-high adsorption of NH<sub>3</sub> up to 61.6 mmol/g at 298 K and 6 bar in a granular [email protected] metal–organic gel by anchoring LiCl in their nanopores. Notably, the record ideal adsorbed solution theory selectivity for NH<sub>3</sub>/N<sub>2</sub> (3.77*10<sup>5</sup>) and NH<sub>3</sub>/H<sub>2</sub> (1.27*10<sup>7</sup>) and outstanding practical selectivity for NH<sub>3</sub>/N<sub>2</sub> and NH<sub>3</sub>/H<sub>2</sub>O can be also obtained at 298 K. Spectral measurements and theoretical calculations reveal that this record capture and selectivity performance can be attributed to the weak chemisorption of NH<sub>3</sub> coordination to the highly dispersed Li<sup>+</sup> as well as hydrogen bonding interaction between NH<sub>3</sub> and Cl<sup>-</sup> within the nanopores of the MOF.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133720"},"PeriodicalIF":8.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced electrochlorination of ammonium to N2 mediated by pH self-buffering effect in the cathodic coagulation and anodic oxidation synergistic system","authors":"Xuanzhen Ren, Shuzhen Li, Xiangru Ren, Yifan Li, Qipeng Yang, Pei Dong, Bo Jiang","doi":"10.1016/j.seppur.2025.133679","DOIUrl":"10.1016/j.seppur.2025.133679","url":null,"abstract":"<div><div>Electrochlorination of NH<sub>4</sub><sup>+</sup> to N<sub>2</sub> has been widely used for wastewater treatment, but it suffers from inefficiency because of the solution acidification caused by the protons releasing from NH<sub>4</sub><sup>+</sup>-N oxidation. This study developed an electrochemical NH<sub>4</sub><sup>+</sup>-N oxidation system employing Al cathode paired with an IrO<sub>2</sub>-RuO<sub>2</sub>/Ti anode, where the acidification effect could be effectively spontaneously alleviated by the hydroxyl-aluminum species produced during the reaction. The solution pH maintained 5.1 and gradually increased to 7 after 120 min. In contrast, the solution pH dropped below 3 when SS or Ni foam was used as the cathode. The NH<sub>4</sub><sup>+</sup>-N oxidation system with Al cathode showed NH<sub>4</sub><sup>+</sup>-N oxidation efficiency of 99% at a current density of 20 mA cm<sup>−2</sup> and Cl<sup>-</sup> concentration of 30 mM, which outperformed the systems with Ni foam (20 %) and SS cathode (67 %). Additionally, the NH<sub>4</sub><sup>+</sup>-N oxidation system with Al cathode had appreciable resistance to organic pollutants, achieving 90 % COD removal efficiency while maintaining high NH<sub>4</sub><sup>+</sup>-N oxidation efficiency (88 %), which was much higher than SS (23 %) and Ni foam cathode (13.7 %). The NH<sub>4</sub><sup>+</sup>-N oxidation efficiency decreased 12 % by the addition of TBA to remove the Cl<sup>•</sup> and OH<sup>•</sup>. This result indicates that the free chlorine was the primary oxidizing species for NH<sub>4</sub><sup>+</sup>-N oxidation and could be well utilized to oxidize NH<sub>4</sub><sup>+</sup> to N<sub>2</sub> at nearly neutral pH spontaneously regulated by cathode coagulation reactions. This study offers a promising method for NH<sub>4</sub><sup>+</sup>-N wastewater treatment and promotes the industrial application.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133679"},"PeriodicalIF":8.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maryam Tavakolmoghadam , Astrid Ræbild Kjul , Carsten Kallesøe , Martin Bonderup Østergaard , Hicham Johra , Jan Dimon Bendtsen , Morten Lykkegaard Christensen , Mads Koustrup Jørgensen
{"title":"Compressibility characterization of organic and inorganic fouling by the 3ω method","authors":"Maryam Tavakolmoghadam , Astrid Ræbild Kjul , Carsten Kallesøe , Martin Bonderup Østergaard , Hicham Johra , Jan Dimon Bendtsen , Morten Lykkegaard Christensen , Mads Koustrup Jørgensen","doi":"10.1016/j.seppur.2025.133722","DOIUrl":"10.1016/j.seppur.2025.133722","url":null,"abstract":"<div><div>Membrane fouling is a major problem that reduces the sustainability and efficiency of separation processes. In this study, an online fouling monitoring technique using the 3ω method was investigated to distinguish between different compositions and compactness of fouling layers based on their distinct thermal properties. Dead-end filtration of kaolin or humic acid suspensions were performed to represent both an inorganic and organic fouling while the 3ω signals were measured during the fouling layer build-up. The formation of an inorganic fouling layer reduced the 3ω signal due to its higher thermal conductivity compared to water. Limited compaction of the kaolin fouling layer was observed by elevating the pressure. In the organic fouling layer on the other hand, the 3ω signal showed higher values than for water, due to the insulating effect of organic materials. It was also possible to detect the compaction of the fouling layer, which was in good agreement with measurements of specific cake resistance and water content. The 3ω method can potentially characterize fouling layers in a non-destructive way at a distance ranging from micrometers to a few millimeters from the surface of the membrane, thus providing operators with insights for tailored fouling mitigation strategies.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133722"},"PeriodicalIF":8.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Junjie Yuan , Wenchuan Niu , Qi An , Gaofeng Deng , Zhichao Wang , Jubao Gao
{"title":"Photothermal nanotube enhanced thermomorphic absorbents for efficient low-temperature CO2 release","authors":"Junjie Yuan , Wenchuan Niu , Qi An , Gaofeng Deng , Zhichao Wang , Jubao Gao","doi":"10.1016/j.seppur.2025.133704","DOIUrl":"10.1016/j.seppur.2025.133704","url":null,"abstract":"<div><div>Aqueous amines have been identified as effective agents for CO<sub>2</sub> capture. However, their significant energy consumption during the regeneration process presents a major challenge, impeding further progress. This study presents a thermomorphic absorbent capable of regenerating at low temperatures. At a temperature of 323 K, the absorbent achieves a regeneration efficiency of 86.73 % in a water bath. Building on this capability, the desorption efficiency was further improved by incorporating photothermal nanotubes into the solution, replacing steam with photothermal energy for CO<sub>2</sub> desorption. This modification resulted in desorption efficiency comparable to that of the water bath at the same temperature. Furthermore, the absorption performance of the thermomorphic absorbent was evaluated, revealing a maximum upper-layer absorption capacity of 0.03885 g/g solvent and a lower-layer capacity of 0.08945 g/g solvent. The incorporation of carboxylated multi-walled carbon nanotubes not only acted as photothermal materials during desorption but also increased the solution absorption capacity by 25.93 % and sustained high absorption rates over time. Additionally, the presence of nanotubes boosted the solvent’s cycling capacity by 86.44 % compared to its absence. Fourier transform infrared testing and liquid nuclear magnetic resonance carbon spectroscopy of the thermomorphic absorbents indicated the formation of HCO<sub>3</sub><sup>–</sup>, an unstable compound prone to decomposition, which facilitates low-temperature CO<sub>2</sub> desorption. The regeneration energy consumption of the thermomorphic absorbent was evaluated to be 1.10 GJ/ton CO<sub>2</sub>, representing a 72.43 % reduction in energy consumption compared to 30 % MEA. This finding underscores the potential of the thermomorphic absorbent as a promising candidate for CO<sub>2</sub> capture.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"374 ","pages":"Article 133704"},"PeriodicalIF":8.1,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}