Pub Date : 2024-11-22DOI: 10.1016/j.ces.2024.120960
Jingyu Zhu, Conghui Gu, Mingpu Du, Kaiyuan Deng, Danila Pliutenko
This study experimentally investigated the transport characteristics of flaky, fibrous and streaky biomass particles in a fluidization tube. The movement and distribution of these non-spherical biomass particles in different sections of the fluidization tube were visualized and analyzed by using a Particle Tracking Velocimetry measuring approach. The method for calculating the solidity rate distribution of particles in the fluidization tube was also developed. Furthermore, the distribution patterns of non-spherical biomass particles with three different morphologies in the near-wall region of the fluidization tube were significantly analyzed. It could be observed that the area of the non-spherical biomass particles in the near-wall region exhibited an ’M’ shape. Three empirical formulas for predicting the maximum area of non-spherical biomass particle clusters in the fluidization tube were firstly proposed. Among the three prediction formulas, the correlation coefficients are 0.7142, 0.8797, and 0.9567, respectively
{"title":"Experimental study on the motion characteristics of non-spherical biomass particulate systems in a fluidization tube","authors":"Jingyu Zhu, Conghui Gu, Mingpu Du, Kaiyuan Deng, Danila Pliutenko","doi":"10.1016/j.ces.2024.120960","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120960","url":null,"abstract":"This study experimentally investigated the transport characteristics of flaky, fibrous and streaky biomass particles in a fluidization tube. The movement and distribution of these non-spherical biomass particles in different sections of the fluidization tube were visualized and analyzed by using a Particle Tracking Velocimetry measuring approach. The method for calculating the solidity rate distribution of particles in the fluidization tube was also developed. Furthermore, the distribution patterns of non-spherical biomass particles with three different morphologies in the near-wall region of the fluidization tube were significantly analyzed. It could be observed that the area of the non-spherical biomass particles in the near-wall region exhibited an ’M’ shape. Three empirical formulas for predicting the maximum area of non-spherical biomass particle clusters in the fluidization tube were firstly proposed. Among the three prediction formulas, the correlation coefficients are 0.7142, 0.8797, and 0.9567, respectively","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"6 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684957","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}
The pollution of aqueous solution with dyes poses great hazard to the environment and human health. Adsorption has been extensively adopted for decontaminating dyes from wastewater. A series of heterostructured microspheres (PSDVB-PHEA) with adjustable structure and composition were prepared by emulsion interfacial polymerization for removing malachite green (MG) and basic fuchsine (BF). The heterostructured microspheres show the maximum adsorption capacities of 122.84 mg·g−1 for MG and 84.25 mg·g−1 for BF. The optimum adsorption pH for MG and BF is 7. The adsorption kinetic and isotherm process follow pseudo-second-order and Langmuir model. The microspheres also exhibit good performance in the presence of Na(Ⅰ) and K(Ⅰ). Adsorption mechanism demonstrates the OH, C-O and C = O groups participate in the adsorption. The heterostructured microspheres show excellent reusability and maintain 92.0 % regeneration rate after ten cycles. This work provided a simple method for synthesizing efficient adsorbents to remove MG and BF from aqueous solution.
{"title":"Synthesis of heterostructured microspheres for efficient removal of malachite green and basic fuchsine","authors":"Bingxiang Wang, Liping Luan, Ziwei Li, Jiaxuan Wang, Yongfeng Liu, Yuzhong Niu, Hou Chen","doi":"10.1016/j.ces.2024.120956","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120956","url":null,"abstract":"The pollution of aqueous solution with dyes poses great hazard to the environment and human health. Adsorption has been extensively adopted for decontaminating dyes from wastewater. A series of heterostructured microspheres (PSDVB-PHEA) with adjustable structure and composition were prepared by emulsion interfacial polymerization for removing malachite green (MG) and basic fuchsine (BF). The heterostructured microspheres show the maximum adsorption capacities of 122.84 mg·g<sup>−1</sup> for MG and 84.25 mg·g<sup>−1</sup> for BF. The optimum adsorption pH for MG and BF is 7. The adsorption kinetic and isotherm process follow pseudo-second-order and Langmuir model. The microspheres also exhibit good performance in the presence of Na(Ⅰ) and K(Ⅰ). Adsorption mechanism demonstrates the OH, C-O and C = O groups participate in the adsorption. The heterostructured microspheres show excellent reusability and maintain 92.0 % regeneration rate after ten cycles. This work provided a simple method for synthesizing efficient adsorbents to remove MG and BF from aqueous solution.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"81 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684959","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 : 2024-11-21DOI: 10.1016/j.ces.2024.120971
Shujuan Yang, Keyang Mai, Furui He, Haifang Liu, Qingmei Zhu, Yuhong Feng, Gaobo Yu, Jiacheng Li
Insufficient deposition of pesticide droplets is a major factor contributing to ineffective control of agriculture. Improving the deposition of colloidal particle as agricultural delivery system is very important. Herein, supra-amphiphilic soft template was programmed by recognizing host–guest molecules on emulsion droplet surface. The supra-amphiphilic interfacial system possessed self-regulated amphiphilicity by modulating aggregation/disaggregation of supra-amphiphiles responding to redox-stimulus to control interface flexibility/functionalization characteristics of supramolecular colloids. This interface adjustability of hierarchical colloids greatly facilitated their prediction, control of corresponding targeting interfacial interaction responses of leaves. Then hierarchical particles exhibited a topology, pliability that allowed them to adapt to the micro/nanostructures of leaf surfaces, thus facilitating easier passage into the targeted pathogens. In vitro plot experiments, the supra-amphiphilic colloid with flexibility performed greatest antifungal capabilities against Botrytis Cinerea, reaching up to 88.65%, even after multiple rain erosions. Modulating the interfacial interactions towards hierarchical targets technically inspired a new green, sustainable agricultural application.
{"title":"Redox-Animated Supra-Amphiphilic Host-Guest interfacial recognition for Reconfiguring Alginate-Derived hierarchical colloidal particles to enhance foliar pesticide deposition","authors":"Shujuan Yang, Keyang Mai, Furui He, Haifang Liu, Qingmei Zhu, Yuhong Feng, Gaobo Yu, Jiacheng Li","doi":"10.1016/j.ces.2024.120971","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120971","url":null,"abstract":"Insufficient deposition of pesticide droplets is a major factor contributing to ineffective control of agriculture. Improving the deposition of colloidal particle as agricultural delivery system is very important. Herein, supra-amphiphilic soft template was programmed by recognizing host–guest molecules on emulsion droplet surface. The supra-amphiphilic interfacial system possessed self-regulated amphiphilicity by modulating aggregation/disaggregation of supra-amphiphiles responding to redox-stimulus to control interface flexibility/functionalization characteristics of supramolecular colloids. This interface adjustability of hierarchical colloids greatly facilitated their prediction, control of corresponding targeting interfacial interaction responses of leaves. Then hierarchical particles exhibited a topology, pliability that allowed them to adapt to the micro/nanostructures of leaf surfaces, thus facilitating easier passage into the targeted pathogens. <em>In vitro</em> plot experiments, the supra-amphiphilic colloid with flexibility performed greatest antifungal capabilities against <em>Botrytis Cinerea</em>, reaching up to 88.65%, even after multiple rain erosions. Modulating the interfacial interactions towards hierarchical targets technically inspired a new green, sustainable agricultural application.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"19 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679011","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 : 2024-11-21DOI: 10.1016/j.ces.2024.120958
Jingfeng He, Lingtao Zhu, Shulian Guo, Bin Yang
In this work, coal-series kaolin (CK) was first calcined and acid-modified as raw material, and then it was prepared into a magnetic adsorbent by sol–gel method for removing Congo red. After calcination and sulfamic acid modification treatment, the specific surface area and pore volume of acid-modified calcined coal-series kaolin (ACCK) increased by 11.43 and 15.53 times, respectively. CuFe2O4 was effectively loaded on the surface of ACCK to realize for the preparation of magnetic adsorbent. The Congo red sorption by the magnetic sorbent was physical heat-absorbing reaction, mainly originating from hydrogen bonding and electrostatic attraction. Under the optimal operating conditions, the magnetic sorbent efficiently removed Congo red from dye solution, in which the sorption amount and removal rate of Congo red were 59.11 mg/g and 88.66 %, respectively. The magnetic adsorbent was able to remove Congo red efficiently after four cycles of sorption/desorption.
{"title":"An effective strategy for coal-series kaolin utilization: Preparation of magnetic adsorbent for Congo red adsorption","authors":"Jingfeng He, Lingtao Zhu, Shulian Guo, Bin Yang","doi":"10.1016/j.ces.2024.120958","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120958","url":null,"abstract":"In this work, coal-series kaolin (CK) was first calcined and acid-modified as raw material, and then it was prepared into a magnetic adsorbent by sol–gel method for removing Congo red. After calcination and sulfamic acid modification treatment, the specific surface area and pore volume of acid-modified calcined coal-series kaolin (ACCK) increased by 11.43 and 15.53 times, respectively. CuFe<sub>2</sub>O<sub>4</sub> was effectively loaded on the surface of ACCK to realize for the preparation of magnetic adsorbent. The Congo red sorption by the magnetic sorbent was physical heat-absorbing reaction, mainly originating from hydrogen bonding and electrostatic attraction. Under the optimal operating conditions, the magnetic sorbent efficiently removed Congo red from dye solution, in which the sorption amount and removal rate of Congo red were 59.11 mg/g and 88.66 %, respectively. The magnetic adsorbent was able to remove Congo red efficiently after four cycles of sorption/desorption.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"35 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679012","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 : 2024-11-20DOI: 10.1016/j.ces.2024.120967
Kun Li, Yanlei Wang, Hongyan He
Ammonia synthesis depends on N2 critically, a principal raw material whose solubility influences the reaction kinetics and product selectivity. Ionic liquids (ILs) possess the advantage of structure tunability to modulate N2 solubility. In practical applications, ILs are commonly mixed with other solvents to achieve a balance between reaction and transport processes. Herein, the dissolution and diffusion behaviors of N2 in mixed systems are analyzed microscopically through molecular dynamics simulations. It reveals that introducing a small quantity of trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)-trifluorophosphate into tetrahydrofuran enhances the solubility and diffusion coefficients of N2 significantly. The transition point is governed by the fraction of nanocavity, which exhibits distinct expansion, saturation, and compression zones. Furthermore, the response trend of N2 solubility in mixed systems to temperature changes varies with molar concentrations, reflecting differences in solvation enthalpy changes. These findings provide theoretical insights for the design of mixed solvents with high N2 dissolution and diffusion capabilities.
{"title":"Unveiling molecular mechanisms of enhanced N2 solvation and diffusion in ionic liquid mixtures","authors":"Kun Li, Yanlei Wang, Hongyan He","doi":"10.1016/j.ces.2024.120967","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120967","url":null,"abstract":"Ammonia synthesis depends on N<sub>2</sub> critically, a principal raw material whose solubility influences the reaction kinetics and product selectivity. Ionic liquids (ILs) possess the advantage of structure tunability to modulate N<sub>2</sub> solubility. In practical applications, ILs are commonly mixed with other solvents to achieve a balance between reaction and transport processes. Herein, the dissolution and diffusion behaviors of N<sub>2</sub> in mixed systems are analyzed microscopically through molecular dynamics simulations. It reveals that introducing a small quantity of trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)-trifluorophosphate into tetrahydrofuran enhances the solubility and diffusion coefficients of N<sub>2</sub> significantly. The transition point is governed by the fraction of nanocavity, which exhibits distinct expansion, saturation, and compression zones. Furthermore, the response trend of N<sub>2</sub> solubility in mixed systems to temperature changes varies with molar concentrations, reflecting differences in solvation enthalpy changes. These findings provide theoretical insights for the design of mixed solvents with high N<sub>2</sub> dissolution and diffusion capabilities.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"57 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679019","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 : 2024-11-20DOI: 10.1016/j.ces.2024.120932
Tianyang Liu, Junli Wang, Xuanbing Wang, Jinlong Wei, Xiaoning Tong, Shengyou Su, Ju Zhang, Yuantao Yang, Ruidong Xu, Linjing Yang
The traditional Pb-Ag anodes used in zinc electrowinning exhibit high overpotential for oxygen evolution reaction (OER) and poor mechanical strength, leading to high energy consumption. To overcome the shortcomings, Ti/SnO2-Sb2O4/PbO2-La-doped MnCo2O4.5 composite anode was prepared by this work. It demonstrated enhanced electrochemical performance, requiring 565 mV to reach the benchmark current density of 50 mA cm−2, and the Tafel slop of 179.79 mV dec–1 in the acidic media containing 50 g L–1 Zn2+ and 150 g L–1 H2SO4. According to the results of XPS, the content of Mn4+ and Co3+ increased, which was beneficial to promote the OER catalytic activity of the electrode. The current efficiency was improved by 1.7 % compared with traditional Pb-0.76 % Ag anode, resulting in a significant reduction in energy consumption of 477.46 kW∙h for producing one ton of zinc. Moreover, the Ti/SnO2-Sb2O4/PbO2-La-doped MnCo2O4.5 anode showed excellent corrosion resistance, and the accelerated service time was extended to 50 h at 2 A cm−2. The service life of the electrode was extended thanks to the introduction of the intermediate layer and La-doped MnCo2O4.5 powder. Therefore, this work provided a novel strategy to prepare the anodes with enhanced electrochemical performance applied in zinc electrowinning and other aspects.
锌电积中使用的传统铅-银阳极具有较高的氧进化反应（OER）过电位和较差的机械强度，导致能耗较高。为了克服这些缺点，本研究制备了 Ti/SnO2-Sb2O4/PbO2-La 掺杂 MnCo2O4.5 复合阳极。在含有 50 g L-1 Zn2+ 和 150 g L-1 H2SO4 的酸性介质中，它的电化学性能得到了增强，达到 50 mA cm-2 的基准电流密度需要 565 mV，Tafel slop 为 179.79 mV dec-1。根据 XPS 的结果，Mn4+ 和 Co3+ 的含量增加，有利于提高电极的 OER 催化活性。与传统的 Pb-0.76% Ag 阳极相比，电流效率提高了 1.7%，从而显著降低了生产一吨锌的能耗 477.46 kW∙h。此外，Ti/SnO2-Sb2O4/PbO2-La 掺杂的 MnCo2O4.5 阳极表现出优异的耐腐蚀性，在 2 A cm-2 的条件下，加速服务时间延长至 50 h。中间层和掺 La 的 MnCo2O4.5 粉末的引入延长了电极的使用寿命。因此，这项研究为制备具有更强电化学性能的阳极提供了一种新的策略，该阳极可应用于锌电积等方面。
{"title":"La-doped MnCo2O4.5 modified Ti/SnO2-Sb2O4/PbO2 anode for enhancing the electrochemical performance in zinc electrowinning","authors":"Tianyang Liu, Junli Wang, Xuanbing Wang, Jinlong Wei, Xiaoning Tong, Shengyou Su, Ju Zhang, Yuantao Yang, Ruidong Xu, Linjing Yang","doi":"10.1016/j.ces.2024.120932","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120932","url":null,"abstract":"The traditional Pb-Ag anodes used in zinc electrowinning exhibit high overpotential for oxygen evolution reaction (OER) and poor mechanical strength, leading to high energy consumption. To overcome the shortcomings, Ti/SnO<sub>2</sub>-Sb<sub>2</sub>O<sub>4</sub>/PbO<sub>2</sub>-La-doped MnCo<sub>2</sub>O<sub>4.5</sub> composite anode was prepared by this work. It demonstrated enhanced electrochemical performance, requiring 565 mV to reach the benchmark current density of 50 mA cm<sup>−2</sup>, and the Tafel slop of 179.79 mV dec<sup>–1</sup> in the acidic media containing 50 g L<sup>–1</sup> Zn<sup>2+</sup> and 150 g L<sup>–1</sup> H<sub>2</sub>SO<sub>4</sub>. According to the results of XPS, the content of Mn<sup>4+</sup> and Co<sup>3+</sup> increased, which was beneficial to promote the OER catalytic activity of the electrode. The current efficiency was improved by 1.7 % compared with traditional Pb-0.76 % Ag anode, resulting in a significant reduction in energy consumption of 477.46 kW∙h for producing one ton of zinc. Moreover, the Ti/SnO<sub>2</sub>-Sb<sub>2</sub>O<sub>4</sub>/PbO<sub>2</sub>-La-doped MnCo<sub>2</sub>O<sub>4.5</sub> anode showed excellent corrosion resistance, and the accelerated service time was extended to 50 h at 2 A cm<sup>−2</sup>. The service life of the electrode was extended thanks to the introduction of the intermediate layer and La-doped MnCo<sub>2</sub>O<sub>4.5</sub> powder. Therefore, this work provided a novel strategy to prepare the anodes with enhanced electrochemical performance applied in zinc electrowinning and other aspects.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"19 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673696","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 : 2024-11-20DOI: 10.1016/j.ces.2024.120965
Dongbo Xu, Xiaoying Gao, Zijin Gui, Yingtao Duan, Yihuan Li, Xinhuo Meng, Na Gao, Weidong Shi
The water oxidation kinetics on the surface of bismuth vanadate (BiVO4) photoanode is slow and the surface charge recombination is serious which hindering the photoelectrochemical (PEC) water splitting process. To enhance the PEC performance of BiVO4 and expedite the water oxidation process, in this work, a straightforward electrostatic adsorption and pyrolysis methods were devised to convert bimetallic Ni-Fe-zeolitic imidazolate frameworks (Ni-Fe-ZIF) molecular sieve into NiFeOx oxygen evolution co-catalyst and modified on BiVO4 photoanode surface (NiFeOx/BiVO4). The optimized NiFeOx/BiVO4 photoanode showed a high optical photocurrent density of 3.57 mA/cm2 at 1.23 V compared with reversible hydrogen electrode under AM 1.5G illumination with 4.4 times compared to the pure BiVO4 photoanode. The NiFeOx/BiVO4 composites photoanodes also exhibited the higher charge transfer efficiency of more than 77.8 % than the pure BiVO4 photoanode, indicating that the NiFeOx has excellent co-catalytic properties during PEC process. The improvement of photoelectric conversion efficiency can be attributed to the presence of NiFeOx layer with oxygen vacancies and more metal active sites on the BiVO4 surface which promoted the separation and transport of photoelectron-hole pairs and the surface oxygen evolution kinetics, thus significantly improving the photocurrent density.
{"title":"Enhancement of BiVO4 photoanode surface oxygen evolution kinetics via Ni-Fe-ZIF derived bimetallic NiFeOx co-catalyst for water oxidation","authors":"Dongbo Xu, Xiaoying Gao, Zijin Gui, Yingtao Duan, Yihuan Li, Xinhuo Meng, Na Gao, Weidong Shi","doi":"10.1016/j.ces.2024.120965","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120965","url":null,"abstract":"The water oxidation kinetics on the surface of bismuth vanadate (BiVO<sub>4</sub>) photoanode is slow and the surface charge recombination is serious which hindering the photoelectrochemical (PEC) water splitting process. To enhance the PEC performance of BiVO<sub>4</sub> and expedite the water oxidation process, in this work, a straightforward electrostatic adsorption and pyrolysis methods were devised to convert bimetallic Ni-Fe-zeolitic imidazolate frameworks (Ni-Fe-ZIF) molecular sieve into NiFeO<sub>x</sub> oxygen evolution co-catalyst and modified on BiVO<sub>4</sub> photoanode surface (NiFeO<sub>x</sub>/BiVO<sub>4</sub>). The optimized NiFeO<sub>x</sub>/BiVO<sub>4</sub> photoanode showed a high optical photocurrent density of 3.57 mA/cm<sup>2</sup> at 1.23 V compared with reversible hydrogen electrode under AM 1.5G illumination with 4.4 times compared to the pure BiVO<sub>4</sub> photoanode. The NiFeO<sub>x</sub>/BiVO<sub>4</sub> composites photoanodes also exhibited the higher charge transfer efficiency of more than 77.8 % than the pure BiVO<sub>4</sub> photoanode, indicating that the NiFeO<sub>x</sub> has excellent co-catalytic properties during PEC process. The improvement of photoelectric conversion efficiency can be attributed to the presence of NiFeO<sub>x</sub> layer with oxygen vacancies and more metal active sites on the BiVO<sub>4</sub> surface which promoted the separation and transport of photoelectron-hole pairs and the surface oxygen evolution kinetics, thus significantly improving the photocurrent density.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"23 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678737","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 : 2024-11-20DOI: 10.1016/j.ces.2024.120966
Zhipeng Yang, Siru Lu, Tianyu Wu, Hong Yao, Changan Zhou, Chao Wang, Kui Ma, Lei Song, Hairong Yue
Acid sites and redox sites with high thermal stability are crucial for the NH3-SCR catalyst for diesel vehicles. The surface acidity of FeTi catalysts is improved by modified with the solid acid of PO43- or WO3. The acid-modified FeTi catalysts show superior NH3-SCR activity hydrothermal stability with a wide temperature window. The introduction of acid groups not only provides a large number of Brønsted acid sites but also promotes high dispersion of the active species of redox sites due to the formation of the structure P-O-Fe/W-O-Fe. The P-O-Fe/W-O-Fe structure can also improve the redox properties of the FeTi catalysts and inhibit the phase transformation of the TiO2 support during high-temperature hydrothermal process. The reaction kinetics indicate that the reaction rate is primarily related to the concentration of NO. The mechanistic study indicates that the catalytic reaction is primarily governed by the Eley-Rideal mechanism.
{"title":"Enhancements of activity and hydrothermal stability of FeTi catalyst from solid acid sites for selective catalytic reduction of NOx","authors":"Zhipeng Yang, Siru Lu, Tianyu Wu, Hong Yao, Changan Zhou, Chao Wang, Kui Ma, Lei Song, Hairong Yue","doi":"10.1016/j.ces.2024.120966","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120966","url":null,"abstract":"Acid sites and redox sites with high thermal stability are crucial for the NH<sub>3</sub>-SCR catalyst for diesel vehicles. The surface acidity of FeTi catalysts is improved by modified with the solid acid of PO<sub>4</sub><sup>3-</sup> or WO<sub>3</sub>. The acid-modified FeTi catalysts show superior NH<sub>3</sub>-SCR activity hydrothermal stability with a wide temperature window. The introduction of acid groups not only provides a large number of Brønsted acid sites but also promotes high dispersion of the active species of redox sites due to the formation of the structure P-O-Fe/W-O-Fe. The P-O-Fe/W-O-Fe structure can also improve the redox properties of the FeTi catalysts and inhibit the phase transformation of the TiO<sub>2</sub> support during high-temperature hydrothermal process. The reaction kinetics indicate that the reaction rate is primarily related to the concentration of NO. The mechanistic study indicates that the catalytic reaction is primarily governed by the Eley-Rideal mechanism.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"34 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679013","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 : 2024-11-20DOI: 10.1016/j.ces.2024.120969
Yao Yang, Yawei Shi, Yu Qi, Chaoqun Yao
The concentration fields during the bubble formation stages and the regular flowing stages were measured and discussed in three microchannels. It was shown that mass transfer coefficients during the bubble formation stage were 2–3 times larger than that during the regular flow stage. The influence of the disturbance induced by the bubble formation could extend to certain distances, which decreased with the increase in the channel size. During regular flow stage, three mass transfer regimes were observed, which was shown to be dependent on the circulation patterns inside the liquid slug. The channel size significantly influences the occurrence of these regimes. From the analysis of the evolution characteristics, a simple map based the Fo number was proposed for the distinguish of these regimes. The values of the mass transfer coefficient are compared to two models derived from the penetration theory. The validity of the models and scope of application are discussed and proposed.
{"title":"The scaling-up effect on the concentration field and mass transfer of gas–liquid Taylor flow in micro/mini-channel reactors","authors":"Yao Yang, Yawei Shi, Yu Qi, Chaoqun Yao","doi":"10.1016/j.ces.2024.120969","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120969","url":null,"abstract":"The concentration fields during the bubble formation stages and the regular flowing stages were measured and discussed in three microchannels. It was shown that mass transfer coefficients during the bubble formation stage were 2–3 times larger than that during the regular flow stage. The influence of the disturbance induced by the bubble formation could extend to certain distances, which decreased with the increase in the channel size. During regular flow stage, three mass transfer regimes were observed, which was shown to be dependent on the circulation patterns inside the liquid slug. The channel size significantly influences the occurrence of these regimes. From the analysis of the evolution characteristics, a simple map based the <em>Fo</em> number was proposed for the distinguish of these regimes. The values of the mass transfer coefficient are compared to two models derived from the penetration theory. The validity of the models and scope of application are discussed and proposed.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"60 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678708","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}
The corona discharge in electrostatic precipitator (ESP) can contribute to homogenous Hg0 oxidation, thus favoring the simultaneous removal of mercury by the existing air pollution control devices in coal-fired power plant. A multi-field model consisting of reaction kinetics and dynamics was established to simulate the Hg0 oxidation performance in ESPs. The HCl dissociation products (i.e., Cl and Cl2) were responsible for the oxidation of Hg0 to HgCl2 and HgCl, in which the Hg0 oxidation efficiency (EHg) was increased from 13.3 % to 52.6 % with the increase of HCl concentration from 1 to 4 ppm. The increase of O2 concentration from 2 % to 8 % resulted in 2.1 % reduction of EHg, which was primary attributed to the inhibition of HCl dissociation process to form Cl-containing species. As the H2O content increased from 3 % to 12 %, EHg rose from 25.9 % to 29.1 %, due to H2O dissociation products (i.e., H and OH) enhancing the formation of Cl-containing species from HCl dissociation. The voltage fluctuations demonstrated dual effects on EHg: increasing from 35 kV to 40 kV reduced efficiency from 27.3 % to 26.4 %, attributed to diminished Cl-containing species, whereas further increasing to 50 kV enhanced efficiency to 32.1 % due to increased production of O-containing substances. A higher flow rate facilitated the escape of reactive chemical species from ESPs. The EHg decreased from 36.3 % to 17.5 % when the flow velocity increased from 0.1 to 0.25 m/s. These results clarified the key factors for affecting Hg0 oxidation within an ESP, which provides the fundamental to simultaneously control Hg0 emission from coal-fired power plants.
{"title":"Numerical simulation of homogeneous elemental mercury oxidation within an electrostatic precipitator","authors":"Guohai Huang, Hongxiao Zu, Zequn Yang, Wenqi Qu, Chenghang Zheng, Jianping Yang, Hailong Li","doi":"10.1016/j.ces.2024.120968","DOIUrl":"https://doi.org/10.1016/j.ces.2024.120968","url":null,"abstract":"The corona discharge in electrostatic precipitator (ESP) can contribute to homogenous Hg<sup>0</sup> oxidation, thus favoring the simultaneous removal of mercury by the existing air pollution control devices in coal-fired power plant. A multi-field model consisting of reaction kinetics and dynamics was established to simulate the Hg<sup>0</sup> oxidation performance in ESPs. The HCl dissociation products (i.e., Cl and Cl<sub>2</sub>) were responsible for the oxidation of Hg<sup>0</sup> to HgCl<sub>2</sub> and HgCl, in which the Hg<sup>0</sup> oxidation efficiency (<em>E</em><sub>Hg</sub>) was increased from 13.3 % to 52.6 % with the increase of HCl concentration from 1 to 4 ppm. The increase of O<sub>2</sub> concentration from 2 % to 8 % resulted in 2.1 % reduction of <em>E</em><sub>Hg</sub>, which was primary attributed to the inhibition of HCl dissociation process to form Cl-containing species. As the H<sub>2</sub>O content increased from 3 % to 12 %, <em>E</em><sub>Hg</sub> rose from 25.9 % to 29.1 %, due to H<sub>2</sub>O dissociation products (i.e., H and OH) enhancing the formation of Cl-containing species from HCl dissociation. The voltage fluctuations demonstrated dual effects on <em>E</em><sub>Hg</sub>: increasing from 35 kV to 40 kV reduced efficiency from 27.3 % to 26.4 %, attributed to diminished Cl-containing species, whereas further increasing to 50 kV enhanced efficiency to 32.1 % due to increased production of O-containing substances. A higher flow rate facilitated the escape of reactive chemical species from ESPs. The <em>E</em><sub>Hg</sub> decreased from 36.3 % to 17.5 % when the flow velocity increased from 0.1 to 0.25 m/s. These results clarified the key factors for affecting Hg<sup>0</sup> oxidation within an ESP, which provides the fundamental to simultaneously control Hg<sup>0</sup> emission from coal-fired power plants.","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":"1 1","pages":""},"PeriodicalIF":4.7,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679017","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}
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