Pub Date : 2024-10-28DOI: 10.1016/j.jcou.2024.102968
Mahtab Madani , Leonhard Schill , Blete Hulaj , Jakob Willner , Andreas Limbeck , Katharina Bica-Schröder , Rasmus Fehrmann , Anders Riisager
The continuous extraction of the rhodium inventory in supported liquid-phase (SLP) catalytic materials utilized in the hydroformylation (HyFo) of 1-butene was investigated by supercritical carbon dioxide (scCO2). Optimization of extraction efficiency involved varying parameters such as temperature (90 and 120 °C), pressure (10, 20 and 30 MPa), and the addition of methanol as a polar co-feed to the extraction medium (0–20 vol%). The results underscored the critical role of methanol in facilitating extraction, as experiments employing pure scCO2 yielded no rhodium recovery. Furthermore, extraction performance demonstrated sensitivity to temperature and pressure adjustments during the process. Notably, the use of 10 vol% methanol at 120 °C and 30 MPa achieved complete rhodium extraction from the grained SLP materials, which was identified as the optimum extraction condition. This study highlights the potential for scaling up in-situ rhodium extraction processes within HyFo production plants based on SLP catalysts, emphasizing significant implications for industrial applications.
{"title":"Extraction of rhodium from supported liquid-phase hydroformylation catalysts with supercritical carbon dioxide","authors":"Mahtab Madani , Leonhard Schill , Blete Hulaj , Jakob Willner , Andreas Limbeck , Katharina Bica-Schröder , Rasmus Fehrmann , Anders Riisager","doi":"10.1016/j.jcou.2024.102968","DOIUrl":"10.1016/j.jcou.2024.102968","url":null,"abstract":"<div><div>The continuous extraction of the rhodium inventory in supported liquid-phase (SLP) catalytic materials utilized in the hydroformylation (HyFo) of 1-butene was investigated by supercritical carbon dioxide (scCO<sub>2</sub>). Optimization of extraction efficiency involved varying parameters such as temperature (90 and 120 °C), pressure (10, 20 and 30 MPa), and the addition of methanol as a polar co-feed to the extraction medium (0–20 vol%). The results underscored the critical role of methanol in facilitating extraction, as experiments employing pure scCO<sub>2</sub> yielded no rhodium recovery. Furthermore, extraction performance demonstrated sensitivity to temperature and pressure adjustments during the process. Notably, the use of 10 vol% methanol at 120 °C and 30 MPa achieved complete rhodium extraction from the grained SLP materials, which was identified as the optimum extraction condition. This study highlights the potential for scaling up in-situ rhodium extraction processes within HyFo production plants based on SLP catalysts, emphasizing significant implications for industrial applications.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102968"},"PeriodicalIF":7.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-28DOI: 10.1016/j.jcou.2024.102964
Joonho Seo , Daeik Jang , Jin-Ho Bae , Naru Kim , Jihoon Park , Alam Cho , H.K. Lee
Reaction products and properties of carbonation-cured calcium sulfoaluminate (CSA) cements exposed to a sulfate attack were explored in an attempt to elucidate their durability aspects and potential opportunities for practical applications. CSA paste samples were either normally cured or carbonation-cured and subsequently immersed in a Na2SO4 solution. The test results indicated that carbonation curing hindered the delayed ettringite formation induced by a sulfate attack, especially in the carbonation-cured samples with an m-value of 0.5 or 1.0. In addition, these carbonation-cured samples exhibited less degrees of weight and mass loss compared to the normally cured samples. Given these test results, the carbonation-cured samples with an m-value of 0.5 – 1.0 were found to be the most durable against the Na2SO4 attack. The outcomes of this study can be viewed important as they provide a fundamental data source for developing guidelines on producing highly durable materials by combining mixture proportioning and carbonation curing when CSA cements are applied in areas particularly susceptible to sulfate attacks.
研究人员探讨了硫酸盐侵蚀下碳化硫铝酸钙（CSA）水泥的反应产物和特性，试图阐明其耐久性方面的问题以及实际应用的潜在机会。CSA 浆料样品经过正常固化或碳化固化，然后浸入 Na2SO4 溶液中。测试结果表明，碳化固化阻碍了硫酸盐侵蚀引起的蚀变体延迟形成，尤其是在 m 值为 0.5 或 1.0 的碳化固化样品中。此外，与正常固化的样品相比，这些碳化固化样品的重量和质量损失程度较小。鉴于这些测试结果，我们发现 m 值为 0.5 - 1.0 的碳化固化样品最能抵御 Na2SO4 的侵蚀。这项研究的结果非常重要，因为它为制定指导方针提供了基础数据源，以便在特别容易受到硫酸盐侵蚀的地区应用 CSA 水泥时，通过将混合物配比和碳化固化相结合来生产高耐久性材料。
{"title":"Transformations in the reaction products and properties of carbonation-cured CSA cements exposed to a sulfate attack","authors":"Joonho Seo , Daeik Jang , Jin-Ho Bae , Naru Kim , Jihoon Park , Alam Cho , H.K. Lee","doi":"10.1016/j.jcou.2024.102964","DOIUrl":"10.1016/j.jcou.2024.102964","url":null,"abstract":"<div><div>Reaction products and properties of carbonation-cured calcium sulfoaluminate (CSA) cements exposed to a sulfate attack were explored in an attempt to elucidate their durability aspects and potential opportunities for practical applications. CSA paste samples were either normally cured or carbonation-cured and subsequently immersed in a Na<sub>2</sub>SO<sub>4</sub> solution. The test results indicated that carbonation curing hindered the delayed ettringite formation induced by a sulfate attack, especially in the carbonation-cured samples with an m-value of 0.5 or 1.0. In addition, these carbonation-cured samples exhibited less degrees of weight and mass loss compared to the normally cured samples. Given these test results, the carbonation-cured samples with an m-value of 0.5 – 1.0 were found to be the most durable against the Na<sub>2</sub>SO<sub>4</sub> attack. The outcomes of this study can be viewed important as they provide a fundamental data source for developing guidelines on producing highly durable materials by combining mixture proportioning and carbonation curing when CSA cements are applied in areas particularly susceptible to sulfate attacks.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102964"},"PeriodicalIF":7.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Normally, carbonation can cause the decalcification of C-(A)-S-H gel of alkali-activated cement and the degradation of mechanical properties. While, we propose another possibility to form CaCO3-based binder by carbonating the alkali-activated slag cement of high-dosage Ca(OH)2 (30 %) + slag (70 %) + NaHCO3 (5.11 % by weight of Ca(OH)2 and slag) (HCHSN) in this study. The results supported that the compressive strength and volume stability of HCHSN cement paste can be improved by the carbonation curing and the carbonated HCHSN cement paste could reach a maximum compressive strength of 32.4 MPa. According to the micro-analysis of XRD, TGA, FTIR, 1H NMR, BSE and SEM, the carbonated HCHSN cement paste was developed into a CaCO3-based binder with a CaCO3 content approaching 60 % (based on the mass of the samples heated to 800℃). NaHCO3 played a key role in the formation of the CaCO3-based binder, which not only accelerated the carbonation rate, but also promoted the carbonation of slag. The eco-efficiency assessment showed that compared to the production of 12.5 kg CO2 /MPa/t from carbonated ordinary Portland cement, the carbonated HCHSN cement paste only produced 3.5 kg CO2 /MPa/t, making it a very green CaCO3-based cementitious materials.
{"title":"The formation of CaCO3-based binder by carbonating high-dosage Ca(OH)2 + slag + NaHCO3 (HCHSN) cement paste","authors":"Yilin Zhao, Zanqun Liu, Jiahui Zhu, Yu Cui, Babar Iqbal","doi":"10.1016/j.jcou.2024.102967","DOIUrl":"10.1016/j.jcou.2024.102967","url":null,"abstract":"<div><div>Normally, carbonation can cause the decalcification of C-(A)-S-H gel of alkali-activated cement and the degradation of mechanical properties. While, we propose another possibility to form CaCO<sub>3</sub>-based binder by carbonating the alkali-activated slag cement of high-dosage Ca(OH)<sub>2</sub> (30 %) + slag (70 %) + NaHCO<sub>3</sub> (5.11 % by weight of Ca(OH)<sub>2</sub> and slag) (HCHSN) in this study. The results supported that the compressive strength and volume stability of HCHSN cement paste can be improved by the carbonation curing and the carbonated HCHSN cement paste could reach a maximum compressive strength of 32.4 MPa. According to the micro-analysis of XRD, TGA, FTIR, <sup>1</sup>H NMR, BSE and SEM, the carbonated HCHSN cement paste was developed into a CaCO<sub>3</sub>-based binder with a CaCO<sub>3</sub> content approaching 60 % (based on the mass of the samples heated to 800℃). NaHCO<sub>3</sub> played a key role in the formation of the CaCO<sub>3</sub>-based binder, which not only accelerated the carbonation rate, but also promoted the carbonation of slag. The eco-efficiency assessment showed that compared to the production of 12.5 kg CO<sub>2</sub> /MPa/t from carbonated ordinary Portland cement, the carbonated HCHSN cement paste only produced 3.5 kg CO<sub>2</sub> /MPa/t, making it a very green CaCO<sub>3</sub>-based cementitious materials.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102967"},"PeriodicalIF":7.2,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1016/j.jcou.2024.102963
Friso G. Versteeg, Frederique A. Versteeg, Francesco Picchioni
Polymerization reactions often leave unreacted monomers in the polymer. These unreacted monomers can emit vapors at ambient temperatures that cause unpleasant odors, pose both environmental and safety risks, and negatively impacts polymer properties. Therefore, a purification step is necessary after polymerization to remove these residual monomers. High temperature devolatilization is the currently applied technique of removing these monomers, however this treatment can also negatively impact the properties of the polymer. In this study the possibility of using supercritical CO2 (scCO2) as an extraction medium of these residual monomers, which are considered as Volatile Organic Compounds (VOCs), has been investigated experimentally. Polymer samples of either PS or PMMA with 4–7 wt% of residual monomers were extracted continuously with scCO2 at temperatures ranging from 50 to 90 °C and pressures of 100–400 bar. The measured extraction efficiencies, based on 1H NMR analysis, were 99+% and was reached between 4 and 16 h depending on the experimental conditions. In general, higher temperatures and higher pressures lead to enhanced extraction rates and thus higher efficiencies at shorter process times. The experimental results were successfully modelled with an empirical extraction simulation model as originally proposed by Sovová.
{"title":"Monomer extraction from polymers using supercritical CO2","authors":"Friso G. Versteeg, Frederique A. Versteeg, Francesco Picchioni","doi":"10.1016/j.jcou.2024.102963","DOIUrl":"10.1016/j.jcou.2024.102963","url":null,"abstract":"<div><div>Polymerization reactions often leave unreacted monomers in the polymer. These unreacted monomers can emit vapors at ambient temperatures that cause unpleasant odors, pose both environmental and safety risks, and negatively impacts polymer properties. Therefore, a purification step is necessary after polymerization to remove these residual monomers. High temperature devolatilization is the currently applied technique of removing these monomers, however this treatment can also negatively impact the properties of the polymer. In this study the possibility of using supercritical CO<sub>2</sub> (scCO<sub>2</sub>) as an extraction medium of these residual monomers, which are considered as Volatile Organic Compounds (VOCs), has been investigated experimentally. Polymer samples of either PS or PMMA with 4–7 wt% of residual monomers were extracted continuously with scCO<sub>2</sub> at temperatures ranging from 50 to 90 °C and pressures of 100–400 bar. The measured extraction efficiencies, based on <sup>1</sup>H NMR analysis, were 99+% and was reached between 4 and 16 h depending on the experimental conditions. In general, higher temperatures and higher pressures lead to enhanced extraction rates and thus higher efficiencies at shorter process times. The experimental results were successfully modelled with an empirical extraction simulation model as originally proposed by Sovová.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102963"},"PeriodicalIF":7.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-21DOI: 10.1016/j.jcou.2024.102941
Yang Jeong Park , Sungroh Yoon , Sung Eun Jerng
Metal-organic frameworks (MOFs) are attractive materials with easily tunable porous structures. Their selective carbon dioxide (CO2) capture ability can be varied by altering the functionality of the organic ligands. However, rule-based approaches to tuning and developing MOFs with high CO2 capture and conversion abilities are hindered by the numerous possible combinations of metal ions and organic linkers. Recently, machine learning (ML) has been applied to unravel key descriptors in predicting the performance of MOFs. This review summarizes recent advancements in ML models for MOFs in CO2 capture and utilization, including high-throughput screening, neural network interatomic potential, and generative models. The development of sophisticated ML models for designing high-performance MOFs will play a critical role in addressing climate change in the future. Finally, the main challenges and limitations of current approaches in designing high-performance MOFs are discussed.
金属有机框架（MOFs）是一种极具吸引力的材料，具有易于调整的多孔结构。通过改变有机配体的功能，可以改变其选择性二氧化碳（CO2）捕获能力。然而，由于金属离子和有机连接体的可能组合较多，基于规则的方法难以调整和开发具有较高二氧化碳捕获和转化能力的 MOFs。最近，机器学习（ML）已被用于揭示预测 MOF 性能的关键描述符。本综述总结了在二氧化碳捕获和利用中使用 MOFs 的 ML 模型的最新进展，包括高通量筛选、神经网络原子间势能和生成模型。开发用于设计高性能 MOFs 的复杂 ML 模型将在未来应对气候变化方面发挥关键作用。最后，讨论了当前设计高性能 MOFs 方法所面临的主要挑战和局限性。
{"title":"Machine learning of metal-organic framework design for carbon dioxide capture and utilization","authors":"Yang Jeong Park , Sungroh Yoon , Sung Eun Jerng","doi":"10.1016/j.jcou.2024.102941","DOIUrl":"10.1016/j.jcou.2024.102941","url":null,"abstract":"<div><div>Metal-organic frameworks (MOFs) are attractive materials with easily tunable porous structures. Their selective carbon dioxide (CO<sub>2</sub>) capture ability can be varied by altering the functionality of the organic ligands. However, rule-based approaches to tuning and developing MOFs with high CO<sub>2</sub> capture and conversion abilities are hindered by the numerous possible combinations of metal ions and organic linkers. Recently, machine learning (ML) has been applied to unravel key descriptors in predicting the performance of MOFs. This review summarizes recent advancements in ML models for MOFs in CO<sub>2</sub> capture and utilization, including high-throughput screening, neural network interatomic potential, and generative models. The development of sophisticated ML models for designing high-performance MOFs will play a critical role in addressing climate change in the future. Finally, the main challenges and limitations of current approaches in designing high-performance MOFs are discussed.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102941"},"PeriodicalIF":7.2,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.jcou.2024.102965
Christian Di Stasi, Jaime López-de los Ríos, Alejandro Ayala-Cortés, Daniel Torres, José Luis Pinilla, Isabel Suelves
Carbon nanofibers (CNFs) modified with CeO2 were employed as support for the synthesis of Ni catalysts for the CO2 methanation reaction. Two different preparation methods were investigated: incipient wetness impregnation and mechanochemical synthesis. The catalysts were tested at atmospheric pressure under a wide range of temperatures (200 – 600 °C) using a stoichiometric ratio of undiluted H2/CO2 and a flow to weight ratio of 600 NL h−1 gNi−1. The results showed that the Ni-CeO2/CNF catalyst prepared by mechanochemical synthesis showed higher CO2 conversion and CH4 selectivity at low temperatures than the one prepared via traditional method. This was attributed to smaller Ni crystallites and to the higher quantity of Ce3+ sites exposed by the milling process. Stress test carried out at 450 °C showed that the activity and the reaction mechanism remained stable for at least 50 h.
用 CeO2 修饰的碳纳米纤维 (CNF) 作为支撑物，用于合成二氧化碳甲烷化反应的镍催化剂。研究了两种不同的制备方法：初湿浸渍法和机械化学合成法。使用未稀释的 H2/CO2 的化学计量比和 600 NL h-1 gNi-1 的流量重量比，在常压和较宽的温度范围（200 - 600 °C）下对催化剂进行了测试。结果表明，与传统方法相比，机械化学合成法制备的 Ni-CeO2/CNF 催化剂在低温下具有更高的 CO2 转化率和 CH4 选择性。这归因于较小的 Ni 结晶和研磨过程中暴露出的较多 Ce3+ 位点。在 450 °C 下进行的应力测试表明，活性和反应机理在至少 50 小时内保持稳定。
{"title":"Activity enhancement of carbon nanofiber-based catalysts for CO2 methanation by mechanochemical synthesis","authors":"Christian Di Stasi, Jaime López-de los Ríos, Alejandro Ayala-Cortés, Daniel Torres, José Luis Pinilla, Isabel Suelves","doi":"10.1016/j.jcou.2024.102965","DOIUrl":"10.1016/j.jcou.2024.102965","url":null,"abstract":"<div><div>Carbon nanofibers (CNFs) modified with CeO<sub>2</sub> were employed as support for the synthesis of Ni catalysts for the CO<sub>2</sub> methanation reaction. Two different preparation methods were investigated: incipient wetness impregnation and mechanochemical synthesis. The catalysts were tested at atmospheric pressure under a wide range of temperatures (200 – 600 °C) using a stoichiometric ratio of undiluted H<sub>2</sub>/CO<sub>2</sub> and a flow to weight ratio of 600 NL h<sup>−1</sup> g<sub>Ni</sub><sup>−1</sup>. The results showed that the Ni-CeO<sub>2</sub>/CNF catalyst prepared by mechanochemical synthesis showed higher CO<sub>2</sub> conversion and CH<sub>4</sub> selectivity at low temperatures than the one prepared via traditional method. This was attributed to smaller Ni crystallites and to the higher quantity of Ce<sup>3+</sup> sites exposed by the milling process. Stress test carried out at 450 °C showed that the activity and the reaction mechanism remained stable for at least 50 h.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102965"},"PeriodicalIF":7.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.jcou.2024.102961
T.N. van Schagen, D.W.F. Brilman
A highly integrated, natural convection-driven, condensing methanol reactor with the catalyst bed, heat integration section and liquid product separation in a single pressure vessel without moving parts is successfully tested. Space-time yields of up to are demonstrated, comparable to other CO2-to-methanol processes. The internal recycle by natural convection is successfully achieved as well as significant heat integration. A further reduction of heat losses to the environment is needed for autothermal operation. The dynamic characteristics of the process, with fast start-up times, a high turn-down ratio add to the potential to deal with intermittent feed supply. Overall the LOGIC 2.0 reactor concept is a promising process configuration for green methanol production.
{"title":"Characterization of a highly integrated, natural convection-driven, condensing methanol reactor","authors":"T.N. van Schagen, D.W.F. Brilman","doi":"10.1016/j.jcou.2024.102961","DOIUrl":"10.1016/j.jcou.2024.102961","url":null,"abstract":"<div><div>A highly integrated, natural convection-driven, condensing methanol reactor with the catalyst bed, heat integration section and liquid product separation in a single pressure vessel without moving parts is successfully tested. Space-time yields of up to <span><math><mrow><mn>600</mn><mspace></mspace><msub><mrow><mi>kg</mi></mrow><mrow><mi>MeOH</mi></mrow></msub><mspace></mspace><msubsup><mrow><mi>m</mi></mrow><mrow><mi>cat.</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msubsup><mspace></mspace><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> are demonstrated, comparable to other CO<sub>2</sub>-to-methanol processes. The internal recycle by natural convection is successfully achieved as well as significant heat integration. A further reduction of heat losses to the environment is needed for autothermal operation. The dynamic characteristics of the process, with fast start-up times, a high turn-down ratio add to the potential to deal with intermittent feed supply. Overall the LOGIC 2.0 reactor concept is a promising process configuration for green methanol production.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102961"},"PeriodicalIF":7.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1016/j.jcou.2024.102962
Francesco Nocito , Nicoletta Ditaranto , Angela Dibenedetto
The Carbon Capture and Utilization (CCU) option can be an efficient solution for CO2 emission mitigation. To this end, we have investigated the carbon dioxide methanation at low temperatures. Highly active, selective, stable, low-cost catalysts are required for energy and carbon balance benefits. Supported nickel-based catalysts result as the most studied and promising candidates showing a good compromise between performance and low preparation costs. The catalyst design role is key to obtaining the best performance, requiring many experiments and optimisation procedures. Herein, the enhanced Montmorillonite MK10-supported Ni(0)Ce(III) catalyst, prepared by consecutive hydrothermal and electrostatic adsorption methods followed by reduction under hydrogen flow, was used in batch CO2 methanation, exhibiting 76 % of CO2 conversion with 100 % CH4 selectivity after 3 h. The catalytic system reveals very high robustness preserving the same activity and selectivity for at least 5 reaction cycles if compared with γ-Al2O3-supported Ni(0)Ce(III) catalyst, the latter showing the same activity but only in the first cycle. EDX, XPS, SEM, TPD, TPR, and BET characterisation techniques were used to elucidate and evaluate the potential synergistic effect of the active metal centre-promoter-support interfaces, highlighting their role in the activity and robustness of the catalyst, comparing the same effect using different alumina and silicate solid supports. The effects of the reaction conditions on the methane yield and selectivity were also evaluated.
碳捕集与利用（CCU）方案是减少二氧化碳排放的有效解决方案。为此，我们研究了二氧化碳在低温下的甲烷化。为了获得能源和碳平衡效益，需要高活性、高选择性、稳定、低成本的催化剂。负载型镍基催化剂是研究最多、最有前景的候选催化剂，在性能和低制备成本之间表现出良好的折衷。催化剂设计是获得最佳性能的关键，需要进行大量实验和优化程序。在此，通过连续水热法和静电吸附法制备的增强型蒙脱石 MK10 支承 Ni(0)Ce(III)催化剂，随后在氢气流下进行还原，被用于批量 CO2 甲烷化，3 小时后 CO2 转化率达到 76%，CH4 选择性达到 100%。与 γ-Al2O3 支持的 Ni(0)Ce(III)催化剂相比，该催化体系具有很高的稳定性，至少在 5 个反应循环中保持了相同的活性和选择性。使用 EDX、XPS、SEM、TPD、TPR 和 BET 表征技术阐明并评估了活性金属中心-促进剂-支撑界面的潜在协同效应，强调了它们在催化剂活性和稳健性方面的作用，并比较了使用不同氧化铝和硅酸盐固体支撑的相同效果。此外，还评估了反应条件对甲烷产率和选择性的影响。
{"title":"Highly dispersed Ni-Ce catalyst over clay montmorillonite K10 in low-temperature CO2 methanation","authors":"Francesco Nocito , Nicoletta Ditaranto , Angela Dibenedetto","doi":"10.1016/j.jcou.2024.102962","DOIUrl":"10.1016/j.jcou.2024.102962","url":null,"abstract":"<div><div>The Carbon Capture and Utilization (CCU) option can be an efficient solution for CO<sub>2</sub> emission mitigation. To this end, we have investigated the carbon dioxide methanation at low temperatures. Highly active, selective, stable, low-cost catalysts are required for energy and carbon balance benefits. Supported nickel-based catalysts result as the most studied and promising candidates showing a good compromise between performance and low preparation costs. The catalyst design role is key to obtaining the best performance, requiring many experiments and optimisation procedures. Herein, the enhanced Montmorillonite MK10-supported Ni(0)Ce(III) catalyst, prepared by consecutive hydrothermal and electrostatic adsorption methods followed by reduction under hydrogen flow, was used in batch CO<sub>2</sub> methanation, exhibiting 76 % of CO<sub>2</sub> conversion with 100 % CH<sub>4</sub> selectivity after 3 h. The catalytic system reveals very high robustness preserving the same activity and selectivity for at least 5 reaction cycles if compared with γ-Al<sub>2</sub>O<sub>3</sub>-supported Ni(0)Ce(III) catalyst, the latter showing the same activity but only in the first cycle. EDX, XPS, SEM, TPD, TPR, and BET characterisation techniques were used to elucidate and evaluate the potential synergistic effect of the active metal centre-promoter-support interfaces, highlighting their role in the activity and robustness of the catalyst, comparing the same effect using different alumina and silicate solid supports. The effects of the reaction conditions on the methane yield and selectivity were also evaluated.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102962"},"PeriodicalIF":7.2,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1016/j.jcou.2024.102950
Emmanuel Dan , Alan J. McCue , Davide Dionisi , Claudia Fernández Martín
This study reveals the impact of the activation with microwave and conventional heating sources on textural properties and CO2 uptake of a mixed plastic-based char. Two mixed plastic-based adsorbents, one activated using microwaves and the other using conventional heating, were produced at optimum activation conditions, and subsequently compared. The findings show that both heating sources produced microporous adsorbents, but activation heating sources influenced their physicochemical properties and CO2 uptake. The microwave-produced activated carbon (AC) displayed superior BET surface area, total, micro- and ultra-micropore volumes compared to the conventionally produced AC. The microwave-produced AC possessed CO2 adsorption capacities of 1.66 and 2.37 mmol/g under dynamic and equilibrium conditions, respectively, at 25 °C and 1 bar. These capacities represent an 8 and 30 % higher uptake, respectively, compared to the 1.53 and 1.66 mmol/g displayed by the conventionally prepared AC under the same adsorption conditions. Both samples displayed stable and excellent CO2 recyclability over 10 adsorption-desorption cycles, with desorption efficiencies ranging from 93.46 % to 96.72 % (microwave- and conventionally- produced ACs respectively). The Avrami model most accurately described the experimental CO2 adsorption data under dynamic conditions, while the Sip model gave the best fit for equilibrium conditions. These findings apply to both types of ACs at various temperatures, irrespective of the heating source. Overall microwave heating is more efficient than conventional heating, requiring 300°C lower temperature, 115 minutes shorter time, 0.79 kWh less energy, and less KOH. It improves CO2 uptake and reduces production costs by 80 %, offering a sustainable alternative for CO2 adsorbent production.
本研究揭示了微波活化和传统加热源对混合塑料基炭的质地特性和二氧化碳吸收的影响。研究人员在最佳活化条件下制备了两种混合塑料吸附剂，一种使用微波活化，另一种使用传统加热，并进行了比较。研究结果表明，两种加热源都能产生微孔吸附剂，但活化加热源会影响吸附剂的理化性质和二氧化碳吸收量。与传统的活性炭相比，微波生产的活性炭（AC）在 BET 表面积、总孔、微孔和超微孔体积方面都更胜一筹。在 25 °C 和 1 bar 的动态和平衡条件下，微波生产的活性炭的二氧化碳吸附容量分别为 1.66 和 2.37 mmol/g。在相同的吸附条件下，传统制备的 AC 的吸附能力分别为 1.53 和 1.66 mmol/g，而这些吸附能力分别比传统制备的 AC 高出 8% 和 30%。在 10 次吸附-解吸循环中，两种样品都显示出稳定而出色的二氧化碳可回收性，解吸效率从 93.46% 到 96.72%（分别为微波制备的 AC 和传统制备的 AC）。Avrami 模型最准确地描述了动态条件下的二氧化碳吸附实验数据，而 Sip 模型则最适合平衡条件。这些发现适用于不同温度下的两种交流电，与加热源无关。总体而言，微波加热比传统加热更有效，所需的温度低 300°C，时间短 115 分钟，能耗低 0.79 千瓦时，KOH 用量少。它提高了二氧化碳的吸收率，并将生产成本降低了 80%，为二氧化碳吸附剂的生产提供了一种可持续的替代方法。
{"title":"The role of the activation heating source on the carbon capture performance of two new adsorbents produced from household-mixed-plastic waste","authors":"Emmanuel Dan , Alan J. McCue , Davide Dionisi , Claudia Fernández Martín","doi":"10.1016/j.jcou.2024.102950","DOIUrl":"10.1016/j.jcou.2024.102950","url":null,"abstract":"<div><div>This study reveals the impact of the activation with microwave and conventional heating sources on textural properties and CO<sub>2</sub> uptake of a mixed plastic-based char. Two mixed plastic-based adsorbents, one activated using microwaves and the other using conventional heating, were produced at optimum activation conditions, and subsequently compared. The findings show that both heating sources produced microporous adsorbents, but activation heating sources influenced their physicochemical properties and CO<sub>2</sub> uptake. The microwave-produced activated carbon (AC) displayed superior BET surface area, total, micro- and ultra-micropore volumes compared to the conventionally produced AC. The microwave-produced AC possessed CO<sub>2</sub> adsorption capacities of 1.66 and 2.37 mmol/g under dynamic and equilibrium conditions, respectively, at 25 °C and 1 bar. These capacities represent an 8 and 30 % higher uptake, respectively, compared to the 1.53 and 1.66 mmol/g displayed by the conventionally prepared AC under the same adsorption conditions. Both samples displayed stable and excellent CO<sub>2</sub> recyclability over 10 adsorption-desorption cycles, with desorption efficiencies ranging from 93.46 % to 96.72 % (microwave- and conventionally- produced ACs respectively). The Avrami model most accurately described the experimental CO<sub>2</sub> adsorption data under dynamic conditions, while the Sip model gave the best fit for equilibrium conditions. These findings apply to both types of ACs at various temperatures, irrespective of the heating source. Overall microwave heating is more efficient than conventional heating, requiring 300°C lower temperature, 115 minutes shorter time, 0.79 kWh less energy, and less KOH. It improves CO<sub>2</sub> uptake and reduces production costs by 80 %, offering a sustainable alternative for CO<sub>2</sub> adsorbent production.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102950"},"PeriodicalIF":7.2,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-14DOI: 10.1016/j.jcou.2024.102956
Tianhua Li , Huanda Zheng , Jie Song , Laijiu Zheng , Tao Cai , Fuer Zheng , Dawei Gao
In light of the global emphasis on sustainable development, the utilization of environmentally friendly supercritical CO2 dyeing technology represents a significant avenue for the textile industry to align itself with this trend. Nevertheless, the use of supercritical CO2 presents a challenge in achieving a complete color gamut of polyester substrates, and there is a dearth of relevant literature. To meet the basic requirements for the number of colors in polyester substrates in supercritical CO2, we investigated different ratios of Disperse Red 60, Disperse Yellow 54, and Disperse Blue 56 at a total dye concentration of 3 %. The influence of dye ratio on the color parameter values in the color gamut space of polyester knitted shoe materials, polyester zippers, and polyester buttons was analyzed. The study found that in the CIELAB color gamut, the color parameter value of dyed polyester substrate changes with variations in dye proportions. Furthermore, the color displayed by the polyester substrate appears in the red, orange, yellow, green, cyan, blue, and purple regions of the CIE 1931 chromaticity diagram, indicating that the design of the three dye ratios meets the basic requirements of the color and light diversity of the polyester substrate. The K/S value deviation values of knitted shoe materials and zippers remained stable within 0.2, demonstrating excellent dyeing uniformity. The experimental data provide a reference for the color gamut expansion of polyester substrates in supercritical CO2.
{"title":"Color gamut extension of polyester-based materials in supercritical CO2 and its application","authors":"Tianhua Li , Huanda Zheng , Jie Song , Laijiu Zheng , Tao Cai , Fuer Zheng , Dawei Gao","doi":"10.1016/j.jcou.2024.102956","DOIUrl":"10.1016/j.jcou.2024.102956","url":null,"abstract":"<div><div>In light of the global emphasis on sustainable development, the utilization of environmentally friendly supercritical CO<sub>2</sub> dyeing technology represents a significant avenue for the textile industry to align itself with this trend. Nevertheless, the use of supercritical CO<sub>2</sub> presents a challenge in achieving a complete color gamut of polyester substrates, and there is a dearth of relevant literature. To meet the basic requirements for the number of colors in polyester substrates in supercritical CO<sub>2</sub>, we investigated different ratios of Disperse Red 60, Disperse Yellow 54, and Disperse Blue 56 at a total dye concentration of 3 %. The influence of dye ratio on the color parameter values in the color gamut space of polyester knitted shoe materials, polyester zippers, and polyester buttons was analyzed. The study found that in the CIELAB color gamut, the color parameter value of dyed polyester substrate changes with variations in dye proportions. Furthermore, the color displayed by the polyester substrate appears in the red, orange, yellow, green, cyan, blue, and purple regions of the CIE 1931 chromaticity diagram, indicating that the design of the three dye ratios meets the basic requirements of the color and light diversity of the polyester substrate. The K/S value deviation values of knitted shoe materials and zippers remained stable within 0.2, demonstrating excellent dyeing uniformity. The experimental data provide a reference for the color gamut expansion of polyester substrates in supercritical CO<sub>2</sub>.</div></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":"89 ","pages":"Article 102956"},"PeriodicalIF":7.2,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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