Pub Date : 2025-02-20DOI: 10.1016/j.ces.2025.121365
Martín Obligado , Mark Terentyak , Alain Cartellier , Zhujun Huang , Marek C. Ruzicka , Sandra Orvalho
Bubble column reactors are widely used in chemical engineering. They often operate in the heterogeneous regime combining thus high gas concentrations and strong velocity fluctuations. Furthermore, processes are usually dynamic as the injected gas flowrate may be unsteady, they can suffer sudden change of operating parameters, etc…
We present experimental results for six different bubble columns (with 5 different column diameters) in both the homogeneous and the heterogeneous regime. We cover two different time-dependent situations. First, the startup of the bubble column is considered. This unsteady regime consists on injecting a fixed gas flowrate starting from zero. The time that bubbles require to reach the free surface and the duration of the unsteady regime are then analyzed. Later, we focus on the fluctuations of several quantities (void fraction, correlation times…) within stable operating conditions. Our results show that even within steady gas injection conditions, all studied parameters present significant fluctuations.
{"title":"Time-dependent hydrodynamics of bubble columns","authors":"Martín Obligado , Mark Terentyak , Alain Cartellier , Zhujun Huang , Marek C. Ruzicka , Sandra Orvalho","doi":"10.1016/j.ces.2025.121365","DOIUrl":"10.1016/j.ces.2025.121365","url":null,"abstract":"<div><div>Bubble column reactors are widely used in chemical engineering. They often operate in the heterogeneous regime combining thus high gas concentrations and strong velocity fluctuations. Furthermore, processes are usually dynamic as the injected gas flowrate may be unsteady, they can suffer sudden change of operating parameters, etc…</div><div>We present experimental results for six different bubble columns (with 5 different column diameters) in both the homogeneous and the heterogeneous regime. We cover two different time-dependent situations. First, the startup of the bubble column is considered. This unsteady regime consists on injecting a fixed gas flowrate starting from zero. The time that bubbles require to reach the free surface and the duration of the unsteady regime are then analyzed. Later, we focus on the fluctuations of several quantities (void fraction, correlation times…) within stable operating conditions. Our results show that even within steady gas injection conditions, all studied parameters present significant fluctuations.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121365"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-20DOI: 10.1016/j.ces.2025.121390
Siyuan Xie , Jianwei Wang , Kui Liu , Zhongyuan Guo , Xiaohan Fang , Chenyu Wen , Yufen Xie , Gang Qin , Jia Yang , Qiang Chen
To meet the demands of wearable electronics, flexible supercapacitors based on gel polymer electrolyte (GPE) have attracted significant interest. Herein, a physically cross-linked double network polyvinyl alcohol-sodium alginate-CoSO4 GPE was developed. The multivalence ion Co2+ was utilized as charge carrier for the first time, resulting in exceptional conductivity (3.7 S/m). On the other hand, Co2+ functioned as an ion crosslinker, constructing a double network structure, endowing the GPE with outstanding mechanical properties. Furtherly, polyaniline was in-situ synthesized on the GPE surface to fabricate an integrated supercapacitor. The integrated configuration provided a seamless electrode/electrolyte interface, significantly reducing interface resistance and improving specific capacitance (169 mF/cm2) and energy density (60 μWh/cm2). Notably, benefiting from this unique structure, the supercapacitor exhibited remarkable deformation adaptability and security without slippage and delamination among multilayers. This GPE and integrated supercapacitor offered a novel preparation strategy for wearable energy storage devices, demonstrating application potential in flexible electronics.
{"title":"Tough and safe integrated supercapacitor based on physically crosslinked double network gel polymer electrolyte with dual-role Co2+","authors":"Siyuan Xie , Jianwei Wang , Kui Liu , Zhongyuan Guo , Xiaohan Fang , Chenyu Wen , Yufen Xie , Gang Qin , Jia Yang , Qiang Chen","doi":"10.1016/j.ces.2025.121390","DOIUrl":"10.1016/j.ces.2025.121390","url":null,"abstract":"<div><div>To meet the demands of wearable electronics, flexible supercapacitors based on gel polymer electrolyte (GPE) have attracted significant interest. Herein, a physically cross-linked double network polyvinyl alcohol-sodium alginate-CoSO<sub>4</sub> GPE was developed. The multivalence ion Co<sup>2+</sup> was utilized as charge carrier for the first time, resulting in exceptional conductivity (3.7 S/m). On the other hand, Co<sup>2+</sup> functioned as an ion crosslinker, constructing a double network structure, endowing the GPE with outstanding mechanical properties. Furtherly, polyaniline was in-situ synthesized on the GPE surface to fabricate an integrated supercapacitor. The integrated configuration provided a seamless electrode/electrolyte interface, significantly reducing interface resistance and improving specific capacitance (169 mF/cm<sup>2</sup>) and energy density (60 μWh/cm<sup>2</sup>). Notably, benefiting from this unique structure, the supercapacitor exhibited remarkable deformation adaptability and security without slippage and delamination among multilayers. This GPE and integrated supercapacitor offered a novel preparation strategy for wearable energy storage devices, demonstrating application potential in flexible electronics.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121390"},"PeriodicalIF":4.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-19DOI: 10.1016/j.ces.2025.121387
Nastaran Samani , Roger Khalil , Liang Wang , Morten Seljeskog , Marianne S. Eikeland
This work explores the entrained flow gasification of sewage sludge digestate (SSD) and its mixtures with wood powder (WP) through experimental and modeling approaches. Key parameters including reactor temperature, pressure, steam-to-biomass ratio (S/B), and air excess ratio (λ) were investigated to assess their impact on gasification performance. Results showed that blending SSD with WP significantly improved gasification efficiency, leading to higher hydrogen (H2) and carbon monoxide (CO) yields. Complete carbon conversion was achieved at temperatures above 1100 °C with a 50/50 SSD/WP mixture, highlighting the effectiveness of WP addition. Cold gas efficiency (CGE) exceeded 100 % for mixed feedstocks at optimal conditions, demonstrating improved syngas quality. SEM-EDS analysis indicated better properties and nutrient retention potential of residues derived from gasification of blended feedstocks. Computational Particle Fluid Dynamics (CPFD) simulations, validated against experimental data, provided deeper insights into gasification, confirming enhanced syngas production and reactor performance with SSD/WP mixtures. These findings underline the potential of SSD and WP co-gasification for sustainable waste management and energy recovery.
{"title":"Entrained flow gasification of sewage sludge digestate: Experimental and simulation study","authors":"Nastaran Samani , Roger Khalil , Liang Wang , Morten Seljeskog , Marianne S. Eikeland","doi":"10.1016/j.ces.2025.121387","DOIUrl":"10.1016/j.ces.2025.121387","url":null,"abstract":"<div><div>This work explores the entrained flow gasification of sewage sludge digestate (SSD) and its mixtures with wood powder (WP) through experimental and modeling approaches. Key parameters including reactor temperature, pressure, steam-to-biomass ratio (S/B), and air excess ratio (λ) were investigated to assess their impact on gasification performance. Results showed that blending SSD with WP significantly improved gasification efficiency, leading to higher hydrogen (H<sub>2</sub>) and carbon monoxide (CO) yields. Complete carbon conversion was achieved at temperatures above 1100 °C with a 50/50 SSD/WP mixture, highlighting the effectiveness of WP addition. Cold gas efficiency (CGE) exceeded 100 % for mixed feedstocks at optimal conditions, demonstrating improved syngas quality. SEM-EDS analysis indicated better properties and nutrient retention potential of residues derived from gasification of blended feedstocks. Computational Particle Fluid Dynamics (CPFD) simulations, validated against experimental data, provided deeper insights into gasification, confirming enhanced syngas production and reactor performance with SSD/WP mixtures. These findings underline the potential of SSD and WP co-gasification for sustainable waste management and energy recovery.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121387"},"PeriodicalIF":4.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451905","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 : 2025-02-19DOI: 10.1016/j.ces.2025.121404
Ishioma Laurene Egun , Yang Hou , Zhengfei Chen
Zinc Supercapatteries (ZnSCs) are promising, low-cost and environmentally friendly electrochemical energy storage devices, with biomass-derived carbon showing promising results as its positrode active material. However, achieving sustainable biomass-derived carbon via a simple, single-stage and low-temperature process with properties for optimum electrochemical performance is still a challenge. In this study, we show that ultramicroporous and self-doped carbon which are critical electrode properties can be obtained from wet waste coffee grounds via a single-stage thermal process termed molten base carbonization and activation. The process integrates carbonization, in-situ activation and self-doping in one thermal step, driven by the catalytic reactivity of intercalated potassium ion within various components. Temperature control during the process resulted to changes in the microstructure, hierarchical porosity, oxygen and nitrogen functionalities affecting electrochemical performance. The carbon obtained at 700 °C (CGZ-700) as positive electrode active material in Zinc supercapattery achieved specific capacity of 361 mAh g−1, specific capacitance of 204F g−1 at 0.1 A g−1, alongside a specific energy and power of 91.99 Wh kg−1 and 89.99 W kg−1. At 1.0 A g−1, it achieved a coulombic efficiency of 99.8 % and 78 % capacity retention after 10,000 cycles. This study offers a facile, low temperature single-stage thermal conversion process for low-cost waste biomass, advancing the application of waste-derived carbon in ZnSCs and sustainable energy storage devices.
{"title":"Optimizing surface properties and porosity of carbonized waste coffee grounds via molten base activation for enhanced zinc supercapattery performance","authors":"Ishioma Laurene Egun , Yang Hou , Zhengfei Chen","doi":"10.1016/j.ces.2025.121404","DOIUrl":"10.1016/j.ces.2025.121404","url":null,"abstract":"<div><div>Zinc Supercapatteries (ZnSCs) are promising, low-cost and environmentally friendly electrochemical energy storage devices, with biomass-derived carbon showing promising results as its positrode active material. However, achieving sustainable biomass-derived carbon via a simple, single-stage and low-temperature process with properties for optimum electrochemical performance is still a challenge. In this study, we show that ultramicroporous and self-doped carbon which are critical electrode properties can be obtained from wet waste coffee grounds via a single-stage thermal process termed molten base carbonization and activation. The process integrates carbonization, in-situ activation and self-doping in one thermal step, driven by the catalytic reactivity of intercalated potassium ion within various components. Temperature control during the process resulted to changes in the microstructure, hierarchical porosity, oxygen and nitrogen functionalities affecting electrochemical performance. The carbon obtained at 700 °C (CGZ-700) as positive electrode active material in Zinc supercapattery achieved specific capacity of 361 mAh g<sup>−1</sup>, specific capacitance of 204F g<sup>−1</sup> at 0.1 A g<sup>−1</sup>, alongside a specific energy and power of 91.99 Wh kg<sup>−1</sup> and 89.99 W kg<sup>−1</sup>. At 1.0 A g<sup>−1</sup>, it achieved a coulombic efficiency of 99.8 % and 78 % capacity retention after 10,000 cycles. This study offers a facile, low temperature single-stage thermal conversion process for low-cost waste biomass, advancing the application of waste-derived carbon in ZnSCs and sustainable energy storage devices.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121404"},"PeriodicalIF":4.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-19DOI: 10.1016/j.ces.2025.121370
Guibin Gu , Xiangtong Meng , Yuanyang Xie , Wenlei Wang , Jianli Wang , Chang Liu , Jiawei Li , Jieshan Qiu
Developing facile synthesis methods for porous carbon and tuning its pores are crucial for high-performance supercapacitors. Herein, a soft-template synthesis method for porous carbon is reported using thermosetting phenolic resin as template. The ratio of coal pitch to phenolic resin plays a vital role in tuning the distribution of micro/mesopores in the derived porous carbon. The obtained porous carbon (SHC3) exhibits a high specific surface area of 2424 m2 g-1 compared to pure coal pitch-based sample (2186 m2 g-1). As supercapacitor electrode, the SHC3 exhibits excellent double-layer capacitance properties, delivering a high specific capacitance of 324.6 F g−1@1 A g-1. Significantly, the specific capacitance remains 256.3 F g−1 even at 10 A g-1. The SHC3//SHC3 symmetric supercapacitor displays an excellent cycling stability of 96.6 % capacitance retention after 10,000 cycles at 5 A g-1. This work provides a straightforward approach to preparing porous carbon materials for supercapacitors using low-value carbon resources.
{"title":"Phenolic resin-templating synthesis of coal pitch-based porous carbon electrodes for high-performance double-layer supercapacitors","authors":"Guibin Gu , Xiangtong Meng , Yuanyang Xie , Wenlei Wang , Jianli Wang , Chang Liu , Jiawei Li , Jieshan Qiu","doi":"10.1016/j.ces.2025.121370","DOIUrl":"10.1016/j.ces.2025.121370","url":null,"abstract":"<div><div>Developing facile synthesis methods for porous carbon and tuning its pores are crucial for high-performance supercapacitors. Herein, a soft-template synthesis method for porous carbon is reported using thermosetting phenolic resin as template. The ratio of coal pitch to phenolic resin plays a vital role in tuning the distribution of micro/mesopores in the derived porous carbon. The obtained porous carbon (SHC<sub>3</sub>) exhibits a high specific surface area of 2424 m<sup>2</sup> g<sup>-1</sup> compared to pure coal pitch-based sample (2186 m<sup>2</sup> g<sup>-1</sup>). As supercapacitor electrode, the SHC<sub>3</sub> exhibits excellent double-layer capacitance properties, delivering a high specific capacitance of 324.6 F g<sup>−1</sup>@1 A g<sup>-1</sup>. Significantly, the specific capacitance remains 256.3 F g<sup>−1</sup> even at 10 A g<sup>-1</sup>. The SHC<sub>3</sub>//SHC<sub>3</sub> symmetric supercapacitor displays an excellent cycling stability of 96.6 % capacitance retention after 10,000 cycles at 5 A g<sup>-1</sup>. This work provides a straightforward approach to preparing porous carbon materials for supercapacitors using low-value carbon resources.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121370"},"PeriodicalIF":4.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient fluid blending in small-volume flow channels with high throughput is essential for the preparation of nanoliposomes. However, designing micromixer channel structures that optimize mixing efficiency while minimizing pressure drop remains a significant challenge. To address this, we developed a micromixer based on Cantor fractal theory, incorporating cantilevered baffles on both the side and bottom surfaces. The configuration was optimized using grey relational analysis. This micromixer achieved a mixing efficiency of 0.9960 and a Poiseuille number of 647.92, demonstrating superior mixing performance and operational safety. Laser engraving was utilized to fabricate the complex flow channel structure, producing nanoliposomes with a mean particle size of 128 nm and a polydispersity index of 0.23. Furthermore, our findings reveal that the channel’s depth-to-width ratio significantly impacts both mixing efficiency and power consumption, underscoring its reliability and scalability for high-flow-rate applications.
{"title":"Grey Relationship optimization based structural design Inspired by Cantor fractals for micromixers in nanoliposome preparation","authors":"Wei Zhou, Wenqiang Zhang, Chao Liang, Xue Deng, Wentao Xu","doi":"10.1016/j.ces.2025.121403","DOIUrl":"https://doi.org/10.1016/j.ces.2025.121403","url":null,"abstract":"Efficient fluid blending in small-volume flow channels with high throughput is essential for the preparation of nanoliposomes. However, designing micromixer channel structures that optimize mixing efficiency while minimizing pressure drop remains a significant challenge. To address this, we developed a micromixer based on Cantor fractal theory, incorporating cantilevered baffles on both the side and bottom surfaces. The configuration was optimized using grey relational analysis. This micromixer achieved a mixing efficiency of 0.9960 and a Poiseuille number of 647.92, demonstrating superior mixing performance and operational safety. Laser engraving was utilized to fabricate the complex flow channel structure, producing nanoliposomes with a mean particle size of 128 nm and a polydispersity index of 0.23. Furthermore, our findings reveal that the channel’s depth-to-width ratio significantly impacts both mixing efficiency and power consumption, underscoring its reliability and scalability for high-flow-rate applications.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"50 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-19DOI: 10.1016/j.ces.2025.121380
Qingjin Zhang, Zeshi Chen, Han Gao, Liangliang Fu, Guangwen Xu, Dingrong Bai
The gas–solid flow structure in dense fluidized beds has been understood to be a bubble-emulsion two-phase flow characteristically dominated by bubble dynamics. Recent studies have suggested that bed temperature significantly affects this flow, but a clear understanding remains elusive. To address the issue, we investigate the impact of temperature on the gas–solid flow structure in bubbling fluidized beds by analyzing pressure fluctuation signals at various axial positions from ambient to 1500 °C. The results reveal that depending on bed temperature, two distinct flow structures can be observed in fluidized beds: a bubble-dominated flow structure below approximately 1200 °C, characterized by noticeable axial variations in the standard deviation and dominant frequency of pressure fluctuations resulting from bubble formation, coalescence, growth, and breakup along the axial direction; a homogeneous and stable bed structure above 1200 °C, featured by axially constant standard deviation and dominant frequency attributed to uniformly distributed small bubbles within constantly agglomerating and dispersing particles.
{"title":"Effect of temperature on gas-solid flow structure in bubbling fluidized beds","authors":"Qingjin Zhang, Zeshi Chen, Han Gao, Liangliang Fu, Guangwen Xu, Dingrong Bai","doi":"10.1016/j.ces.2025.121380","DOIUrl":"https://doi.org/10.1016/j.ces.2025.121380","url":null,"abstract":"The gas–solid flow structure in dense fluidized beds has been understood to be a bubble-emulsion two-phase flow characteristically dominated by bubble dynamics. Recent studies have suggested that bed temperature significantly affects this flow, but a clear understanding remains elusive. To address the issue, we investigate the impact of temperature on the gas–solid flow structure in bubbling fluidized beds by analyzing pressure fluctuation signals at various axial positions from ambient to 1500 °C. The results reveal that depending on bed temperature, two distinct flow structures can be observed in fluidized beds: a bubble-dominated flow structure below approximately 1200 °C, characterized by noticeable axial variations in the standard deviation and dominant frequency of pressure fluctuations resulting from bubble formation, coalescence, growth, and breakup along the axial direction; a homogeneous and stable bed structure above 1200 °C, featured by axially constant standard deviation and dominant frequency attributed to uniformly distributed small bubbles within constantly agglomerating and dispersing particles.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"17 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-18DOI: 10.1016/j.ces.2025.121393
Shangchen Cai , Qiao Yang , Jing Li , Changan Zhou , Lei Song , Chao Wang , Lirong Zheng , Kui Ma , Hairong Yue
Catalytic hydrogenation of CO2 to chemicals and alternative fuels such as methanol is an attractive approach for CO2 utilization and hydrogen storage. Copper silicate is considered as efficient for hydrogenation of C-O/C=O bonds due to the synergistic effect from its unique dual-sites of Cu0-Cu+. However, it still confronts great obstacles of poor CO2 conversion and methanol selectivity. Herein, we introduce carbon nanotubes (CNTs) to electronically interact with Cu0-Cu+ sites, achieving CO2 conversion of ∼ 25 % with methanol selectivity up to 80 %, which breaks the equilibrium selectivity (∼51 %) on this condition. Intrinsically, CNTs could not alter the *HOCO and *CO intermediates pathway of hydrogenation over Cu0-Cu+ sites, but accelerate H2 dissociation on Cuδ+ (0 < δ < 1) originated from Cu0-C interaction at their interface. This leads to a local concentration enrichment of active H to boost deep hydrogenation to methanol. These findings open a new avenue for designing highly efficient and selective catalytic hydrogenation systems.
{"title":"A high-performance core-sheath C@CuSiO3 nanocatalyst for CO2 hydrogenation to methanol achieved by Cu-C interaction","authors":"Shangchen Cai , Qiao Yang , Jing Li , Changan Zhou , Lei Song , Chao Wang , Lirong Zheng , Kui Ma , Hairong Yue","doi":"10.1016/j.ces.2025.121393","DOIUrl":"10.1016/j.ces.2025.121393","url":null,"abstract":"<div><div>Catalytic hydrogenation of CO<sub>2</sub> to chemicals and alternative fuels such as methanol is an attractive approach for CO<sub>2</sub> utilization and hydrogen storage. Copper silicate is considered as efficient for hydrogenation of C-O/C=O bonds due to the synergistic effect from its unique dual-sites of Cu<sup>0</sup>-Cu<sup>+</sup>. However, it still confronts great obstacles of poor CO<sub>2</sub> conversion and methanol selectivity. Herein, we introduce carbon nanotubes (CNTs) to electronically interact with Cu<sup>0</sup>-Cu<sup>+</sup> sites, achieving CO<sub>2</sub> conversion of ∼ 25 % with methanol selectivity up to 80 %, which breaks the equilibrium selectivity (∼51 %) on this condition. Intrinsically, CNTs could not alter the *HOCO and *CO intermediates pathway of hydrogenation over Cu<sup>0</sup>-Cu<sup>+</sup> sites, but accelerate H<sub>2</sub> dissociation on Cu<sup>δ+</sup> (0 < δ < 1) originated from Cu<sup>0</sup>-C interaction at their interface. This leads to a local concentration enrichment of active H to boost deep hydrogenation to methanol. These findings open a new avenue for designing highly efficient and selective catalytic hydrogenation systems.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121393"},"PeriodicalIF":4.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143435716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-18DOI: 10.1016/j.ces.2025.121391
Pietro Giustacori, Elisabetta Brunazzi
The Reverse Jet Scrubber (RJS) is a versatile pollution control device that efficiently removes particulates and contaminant gases from industrial gas streams. It operates with either a liquid solution or finely suspended solids, handling high-flow gas streams with varying particle concentrations. Despite its promise, knowledge of RJS design and performance remains scarce, and design criteria are proprietary to the companies marketing the technology. This paper presents an experimental setup designed to characterize the device. In this investigation, gas pressure drop measurements across the liquid jet were used as a metric to define the operating parameters of the RJS. Additionally, absorption tests with two volatile organic compounds measured the mass transfer capabilities, with efficiency and overall mass transfer coefficient quantified at various gas and liquid flow rates. These results provide a valuable preliminary experimental data set necessary for the future development and validation of mechanistic design models for mass transfer.
{"title":"Characterization of a Reverse Jet Scrubber for gas/liquid absorption","authors":"Pietro Giustacori, Elisabetta Brunazzi","doi":"10.1016/j.ces.2025.121391","DOIUrl":"10.1016/j.ces.2025.121391","url":null,"abstract":"<div><div>The Reverse Jet Scrubber (RJS) is a versatile pollution control device that efficiently removes particulates and contaminant gases from industrial gas streams. It operates with either a liquid solution or finely suspended solids, handling high-flow gas streams with varying particle concentrations. Despite its promise, knowledge of RJS design and performance remains scarce, and design criteria are proprietary to the companies marketing the technology. This paper presents an experimental setup designed to characterize the device. In this investigation, gas pressure drop measurements across the liquid jet were used as a metric to define the operating parameters of the RJS. Additionally, absorption tests with two volatile organic compounds measured the mass transfer capabilities, with efficiency and overall mass transfer coefficient quantified at various gas and liquid flow rates. These results provide a valuable preliminary experimental data set necessary for the future development and validation of mechanistic design models for mass transfer.</div></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"308 ","pages":"Article 121391"},"PeriodicalIF":4.1,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-18DOI: 10.1016/j.ces.2025.121385
Halvard Thon, Galina Simonsen, Paul Roger Leinan
Efficient phase separation is one of the most crucial factor when it comes to operation of a direct contact thermal storage (DCTS) concept. In DCTS, energy is stored as latent heat or cold using a phase change material (PCM), which is in direct contact with a fluid used to deliver this energy, namely a heat transfer fluid (HTF). Droplet flow of the HTF through the PCM provides excellent heat transfer, although it also produces an emulsion at the contact interface between the two fluids. Extensive emulsification of the PCM is recognized as a limiting factor for DCTS, as it leads to PCM being transported from the storage vessel to the rest of the system, where it may crystallize and cause blockages. Investigation of enhanced separation of emulsions consisting of de-ionized water and methyl palmitate PCM (oil phase) by addition of surfactants was performed in an experimental DCTS device. A selection of 8 different surfactants based on an initial small scale screening was evaluated in terms of their ability to enhance phase separation. A near two-fold increase in the coalescence rate was achieved compared to a reference system without surfactants. Investigation of the effects of different surfactants on the dynamic interfacial tension and viscoelastic properties of the interfaces between oil and water phases were performed to identify key parameters critical for the process of coalescence. The results showed that chemical destabilization of emulsions facilitated by surfactants in a DCTS system is an applicable method to address the issue of extensive emulsification. Emulsion cascade collapse in a DCTS, a phenomenon scarcely reported in water-in-oil emulsions, is also observed and presented in the current study.
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