Xiaojin Zhang, Xi Huang, Jing Li, Zhongping Tang, Jiangbing Wang
Aviation lubricating oil, as the “blood of machine operation”, plays an important role in the lubrication, cooling, cleaning, sealing, rust prevention, and other aspects of aero‐engines, thereby ensuring the safe and stable long‐term endurance of aero‐engines under high‐speed and high‐temperature conditions. The thermal oxidation of aviation lubricating oil leading to decay is the most important factor causing lubricating oil failure, which will seriously affect the performance of aero‐engines and endanger flight safety. Here, we comprehensively summarize the oxidation mechanism of aviation lubricating oil, factors affecting thermal oxidation of aviation lubricating oil, evaluation methods for thermal oxidation of aviation lubricating oil, and antioxidants that inhibit thermal oxidation of aviation lubricating oil. We hope that this review can enhance readers' understanding of the thermal oxidation of aviation lubricating oil, stimulate broader interest, and promote more exciting development in this promising field.
{"title":"Thermal oxidation of aviation lubricating oil: Mechanism, influencing factors, evaluation methods, and antioxidants","authors":"Xiaojin Zhang, Xi Huang, Jing Li, Zhongping Tang, Jiangbing Wang","doi":"10.1002/apj.3114","DOIUrl":"https://doi.org/10.1002/apj.3114","url":null,"abstract":"Aviation lubricating oil, as the “blood of machine operation”, plays an important role in the lubrication, cooling, cleaning, sealing, rust prevention, and other aspects of aero‐engines, thereby ensuring the safe and stable long‐term endurance of aero‐engines under high‐speed and high‐temperature conditions. The thermal oxidation of aviation lubricating oil leading to decay is the most important factor causing lubricating oil failure, which will seriously affect the performance of aero‐engines and endanger flight safety. Here, we comprehensively summarize the oxidation mechanism of aviation lubricating oil, factors affecting thermal oxidation of aviation lubricating oil, evaluation methods for thermal oxidation of aviation lubricating oil, and antioxidants that inhibit thermal oxidation of aviation lubricating oil. We hope that this review can enhance readers' understanding of the thermal oxidation of aviation lubricating oil, stimulate broader interest, and promote more exciting development in this promising field.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Layered oxides are considered to be potential cathodes for sodium‐ion batteries based on high theoretical capacity and ease of synthesis. However, the complex phase transition caused by interlayer sliding in layered oxides leads to poor cycling stability, which will hinder their further application. Here, we designed a newly O3‐type layered cathode NaNi0.3Co0.2Cu0.1Mn0.2Ti0.2O2 based on high‐entropy to achieve highly reversible phase transition behavior. It reveals 132 mAh g−1 at 0.2 C within 2–4 V increasing the energy density to 408 Wh kg−1 and it shows an outstanding rate capability of 90 mAh g−1 at 80 C (84.90% capacity retention after 1,500 cycles at 80 C). In‐situ XRD shows that reasonable design of high‐entropy components in layered material can achieve the purpose of delaying the occurrence of phase transition and DFT calculations show that the introduction of Co in transition metal layers can effectively improve the rate performance of the material. This work is of great significance in guiding the design and synthesis of highly stable layered cathode materials for sodium‐ion batteries.
层状氧化物理论容量高且易于合成，因此被认为是钠离子电池的潜在阴极。然而，层状氧化物层间滑动引起的复杂相变导致其循环稳定性较差，这将阻碍其进一步应用。在此，我们设计了一种基于高熵的新型 O3 型层状阴极 NaNi0.3Co0.2Cu0.1Mn0.2Ti0.2O2，以实现高度可逆的相变行为。在 0.2 摄氏度、2-4 V 的条件下，它显示出 132 mAh g-1，能量密度增加到 408 Wh kg-1，并且在 80 摄氏度条件下显示出 90 mAh g-1 的出色速率能力（在 80 摄氏度条件下循环 1,500 次后，容量保持率为 84.90%）。原位 XRD 显示，在层状材料中合理设计高熵成分可以达到延迟相变发生的目的，DFT 计算显示，在过渡金属层中引入 Co 可以有效提高材料的速率性能。这项工作对设计和合成高稳定性的钠离子电池层状正极材料具有重要的指导意义。
{"title":"High‐entropy configuration strategy boosts excellent rate performance of layered oxide for sodium‐ion batteries","authors":"Qiuyun Cai, Xiangyu Liu, Haonan Hu, Pengfei Wang, Min Jia, Xiaoyu Zhang","doi":"10.1002/apj.3116","DOIUrl":"https://doi.org/10.1002/apj.3116","url":null,"abstract":"Layered oxides are considered to be potential cathodes for sodium‐ion batteries based on high theoretical capacity and ease of synthesis. However, the complex phase transition caused by interlayer sliding in layered oxides leads to poor cycling stability, which will hinder their further application. Here, we designed a newly O3‐type layered cathode NaNi<jats:sub>0.3</jats:sub>Co<jats:sub>0.2</jats:sub>Cu<jats:sub>0.1</jats:sub>Mn<jats:sub>0.2</jats:sub>Ti<jats:sub>0.2</jats:sub>O<jats:sub>2</jats:sub> based on high‐entropy to achieve highly reversible phase transition behavior. It reveals 132 mAh g<jats:sup>−1</jats:sup> at 0.2 C within 2–4 V increasing the energy density to 408 Wh kg<jats:sup>−1</jats:sup> and it shows an outstanding rate capability of 90 mAh g<jats:sup>−1</jats:sup> at 80 C (84.90% capacity retention after 1,500 cycles at 80 C). In‐situ XRD shows that reasonable design of high‐entropy components in layered material can achieve the purpose of delaying the occurrence of phase transition and DFT calculations show that the introduction of Co in transition metal layers can effectively improve the rate performance of the material. This work is of great significance in guiding the design and synthesis of highly stable layered cathode materials for sodium‐ion batteries.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sundus Azhar, Khuram Shahzad Ahmad, Isaac Abrahams, Wang Lin, Ram K. Gupta, Munirah D. Albaqami, Saikh Mohammad, Mahwash Mahar Gul
This study investigates the environmentally friendly synthesis of ZrO2‐NdO mixed nanomaterial using green reducing and capping agents derived from the plant Amaranthus viridis. X‐ray diffraction (XRD) analysis confirmed the successful synthesis of the mixed nanomaterial, revealing an optical band gap of 2.5 eV. The morphology was characterized by spherical‐shaped particles with an average size ranging from 66 to 77 nm. The synthesized ZrO2‐NdO mixed nanomaterial was evaluated for its potential application as an electrode material in energy devices, specifically for pseudocapacitors and water splitting studies. Electrochemical performance was assessed using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) techniques. Notably, a specific capacitance of 573.5 F/g was achieved through CV at a scan rate of 2 mV/s. Fabricated electrocatalyst was further analyzed for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and the results showed better over potential value of 164 mV for HER studies. The stability analysis further endorsed the large‐scale commercialization possibility of ZrO‐NdO‐based electrode material.
{"title":"Synthesis of ZrO2‐NdO‐based mixed nanomaterial using green capping agent and its functionalization as electrode material for energy devices: Pseudo capacitors and water splitting","authors":"Sundus Azhar, Khuram Shahzad Ahmad, Isaac Abrahams, Wang Lin, Ram K. Gupta, Munirah D. Albaqami, Saikh Mohammad, Mahwash Mahar Gul","doi":"10.1002/apj.3119","DOIUrl":"https://doi.org/10.1002/apj.3119","url":null,"abstract":"This study investigates the environmentally friendly synthesis of ZrO<jats:sub>2</jats:sub>‐NdO mixed nanomaterial using green reducing and capping agents derived from the plant <jats:styled-content style=\"fixed-case\"><jats:italic>Amaranthus viridis</jats:italic></jats:styled-content>. X‐ray diffraction (XRD) analysis confirmed the successful synthesis of the mixed nanomaterial, revealing an optical band gap of 2.5 eV. The morphology was characterized by spherical‐shaped particles with an average size ranging from 66 to 77 nm. The synthesized ZrO<jats:sub>2</jats:sub>‐NdO mixed nanomaterial was evaluated for its potential application as an electrode material in energy devices, specifically for pseudocapacitors and water splitting studies. Electrochemical performance was assessed using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) techniques. Notably, a specific capacitance of 573.5 F/g was achieved through CV at a scan rate of 2 mV/s. Fabricated electrocatalyst was further analyzed for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), and the results showed better over potential value of 164 mV for HER studies. The stability analysis further endorsed the large‐scale commercialization possibility of ZrO‐NdO‐based electrode material.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To improve the utilization rate of herbicides and reduce their environmental residues, it is urgent to develop a simple and low‐cost method to prepare slow‐release pesticides. In this study, a biochar (280CPFe) with a high surface area and rich oxygen‐containing functional groups was synthesized by low temperature (280°C) boiling strategy, which was used as a carrier to prepare pH‐responsive slow‐release herbicide. The obtained biochar has a high adsorption capacity of 153.59 mg·g−1 for quinclorac (QNC). The release rates of QNC‐280CPFe are 21%, 56%, and 90% at the initial pH of 3, 5, and 11, respectively. The controlled release behavior of QNC‐280CPFe is related to its adsorption mechanism, in which the pore filling and functional group adsorption are mainly responsible for the adsorption of QNC on 280CPFe. Compared with QNC alone, QNC‐280CPFe slow‐release herbicide has a good control effect on Barnyard grass but does not affect the normal growth of rice. Therefore, this study provides a simple, low‐cost cost, and environmentally friendly biochar carrier for preparing slow‐release herbicide, improving its utilization rate and reducing its environmental pollution risk.
{"title":"Synthesis of oxygen‐rich functional groups biochar for high‐efficiency adsorption of herbicide and as a potential carrier for pH‐responsive slow release","authors":"Yufeng Chen, Fangge Zhu, Sijie Jiang, Guorong Shi, Mei'e Zhong","doi":"10.1002/apj.3113","DOIUrl":"https://doi.org/10.1002/apj.3113","url":null,"abstract":"To improve the utilization rate of herbicides and reduce their environmental residues, it is urgent to develop a simple and low‐cost method to prepare slow‐release pesticides. In this study, a biochar (280CPFe) with a high surface area and rich oxygen‐containing functional groups was synthesized by low temperature (280°C) boiling strategy, which was used as a carrier to prepare pH‐responsive slow‐release herbicide. The obtained biochar has a high adsorption capacity of 153.59 mg·g<jats:sup>−1</jats:sup> for quinclorac (QNC). The release rates of QNC‐280CPFe are 21%, 56%, and 90% at the initial pH of 3, 5, and 11, respectively. The controlled release behavior of QNC‐280CPFe is related to its adsorption mechanism, in which the pore filling and functional group adsorption are mainly responsible for the adsorption of QNC on 280CPFe. Compared with QNC alone, QNC‐280CPFe slow‐release herbicide has a good control effect on Barnyard grass but does not affect the normal growth of rice. Therefore, this study provides a simple, low‐cost cost, and environmentally friendly biochar carrier for preparing slow‐release herbicide, improving its utilization rate and reducing its environmental pollution risk.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a novel air‐cooled supercapacitor thermal management system (STMS) based on the corner deflectors and the inclined inlet and outlet was proposed. The temperature and velocity fields were simulated and analyzed by CFD. Moreover, the heat dissipation effect of different STMSs was analyzed against each other. The results showed that the STMS proposed had a better heat dissipation effect when the inclined angle of inlet and outlet was appropriate, in which the maximum temperature (Tmax) and the maximum temperature difference (ΔTmax) of the module could be reduced by 10.3% and 34.6%. And it is shown that the structure with inclined inlet and outlet plays an important role for the heat dissipation capability of the STMS proposed. And it has experimentally proven its heat dissipation ability. Consequently, the impacts of inclined angle (α), monomer spacing (dc), and the distance between monomer and module shell (dx, dy, and dz) on the heat dissipation effect were deeply analyzed. For the STMS arranged in four rows and three columns, it had a better heat dissipation effect when inclined angle was in the range of 40° to 50°. The results showed that the structural parameters had a large influence on the Tmax and ΔTmax. Besides, it had shown that the temperature curves of the Tmax and ΔTmax had a main trend of “decreasing and then increasing” when the monomer spacing as well as the distance between monomer and module shell are taken from 1 mm to 5 mm. It implies that a small spacing (1 mm to 2 mm) will hinder the air circulation and reduce heat dissipation, and a large spacing (3 mm to 5 mm) will reduce the average flow rate of air and reduce the efficiency of heat transfer.
{"title":"Design and optimization of air‐cooled supercapacitor thermal management system based on the corner deflectors and the inclined inlet and outlet","authors":"Chaoying Xu, Guofu Li, Dianbo Ruan","doi":"10.1002/apj.3104","DOIUrl":"https://doi.org/10.1002/apj.3104","url":null,"abstract":"In this paper, a novel air‐cooled supercapacitor thermal management system (STMS) based on the corner deflectors and the inclined inlet and outlet was proposed. The temperature and velocity fields were simulated and analyzed by CFD. Moreover, the heat dissipation effect of different STMSs was analyzed against each other. The results showed that the STMS proposed had a better heat dissipation effect when the inclined angle of inlet and outlet was appropriate, in which the maximum temperature (<jats:italic>T</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub>) and the maximum temperature difference (<jats:italic>ΔT</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub>) of the module could be reduced by 10.3% and 34.6%. And it is shown that the structure with inclined inlet and outlet plays an important role for the heat dissipation capability of the STMS proposed. And it has experimentally proven its heat dissipation ability. Consequently, the impacts of inclined angle (<jats:italic>α</jats:italic>), monomer spacing (<jats:italic>d</jats:italic><jats:sub><jats:italic>c</jats:italic></jats:sub>), and the distance between monomer and module shell (<jats:italic>d</jats:italic><jats:sub><jats:italic>x</jats:italic></jats:sub>, <jats:italic>d</jats:italic><jats:sub><jats:italic>y</jats:italic></jats:sub>, and <jats:italic>d</jats:italic><jats:sub><jats:italic>z</jats:italic></jats:sub>) on the heat dissipation effect were deeply analyzed. For the STMS arranged in four rows and three columns, it had a better heat dissipation effect when inclined angle was in the range of 40° to 50°. The results showed that the structural parameters had a large influence on the <jats:italic>T</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub> and <jats:italic>ΔT</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub>. Besides, it had shown that the temperature curves of the <jats:italic>T</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub> and <jats:italic>ΔT</jats:italic><jats:sub><jats:italic>max</jats:italic></jats:sub> had a main trend of “decreasing and then increasing” when the monomer spacing as well as the distance between monomer and module shell are taken from 1 mm to 5 mm. It implies that a small spacing (1 mm to 2 mm) will hinder the air circulation and reduce heat dissipation, and a large spacing (3 mm to 5 mm) will reduce the average flow rate of air and reduce the efficiency of heat transfer.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ailian Chang, Le Huang, Benqing Huang, Kambiz Vafai
A series of interactive experiments are conducted to analyze the drag reduction technology with a rotating disk apparatus that combines microgroove structure and drag‐reducing additives including polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and sodium salicylate (NaSal). By varying the disk type, concentration of drag‐reducing additives, temperature, and Reynolds number (Re), the corresponding drag reduction rates are obtained effectively. The experimental results indicate that adding CTAC strengthens the heat degradation and shear resistance of PEO; while PEO can enhance the ability of CTAC to form micellar structures and balance energy distribution at low concentrations. Moreover, the synergistic effect of these two additives presents a better drag reduction performance with a maximum drag reduction rate of 24.1%; while the microgroove structure enhances the effect of active drag reduction. Therefore, the combination of active and passive drag reduction technology broadens the application of energy saving and consumption reduction in hydraulic rotating machinery.
{"title":"Interactive experimental study on microgroove structure and drag‐reducing additives in rotating disk apparatus","authors":"Ailian Chang, Le Huang, Benqing Huang, Kambiz Vafai","doi":"10.1002/apj.3112","DOIUrl":"https://doi.org/10.1002/apj.3112","url":null,"abstract":"A series of interactive experiments are conducted to analyze the drag reduction technology with a rotating disk apparatus that combines microgroove structure and drag‐reducing additives including polyethylene oxide (PEO), cetyltrimethyl ammonium chloride (CTAC), and sodium salicylate (NaSal). By varying the disk type, concentration of drag‐reducing additives, temperature, and Reynolds number (<jats:italic>Re</jats:italic>), the corresponding drag reduction rates are obtained effectively. The experimental results indicate that adding CTAC strengthens the heat degradation and shear resistance of PEO; while PEO can enhance the ability of CTAC to form micellar structures and balance energy distribution at low concentrations. Moreover, the synergistic effect of these two additives presents a better drag reduction performance with a maximum drag reduction rate of 24.1%; while the microgroove structure enhances the effect of active drag reduction. Therefore, the combination of active and passive drag reduction technology broadens the application of energy saving and consumption reduction in hydraulic rotating machinery.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The attrition behavior of HZSM-5 zeolite catalyst particles at room temperature was investigated in a laboratory-scale fluidized bed. The effects of three fluidization conditions on particle attrition were investigated, and a new attrition model was proposed. The results demonstrate that the attrition rate is inversely proportional to the initial particle size and proportional to the apparent gas velocity. After increasing to 80 μm and .3 m/s respectively, they are no longer the main factor affecting attrition. The effect of bed pressure on attrition rate is nonlinear, and the lowest attrition rate is obtained when the diameter-height ratio is 1:1. Unsteady attrition stage can be divided into initial stage and deceleration stage. Surface delamination dominates particle attrition throughout the whole process, and bulk fracture is the dominant mechanism only in the deceleration stage. Based on the Gwyn equation, a new attrition model in the form of cubic polynomial is established with the ratio of total attrition rate to unstable attrition rate P as a parameter. The model has high accuracy and repeatability and is suitable for various fluidization conditions. It can effectively describe the attrition process and change rule of particles and reasonably predict the fluidization attrition rate of particles.
在实验室规模的流化床中研究了室温下 HZSM-5 沸石催化剂颗粒的损耗行为。研究了三种流化条件对颗粒损耗的影响，并提出了一个新的损耗模型。结果表明，磨损率与初始粒度成反比，与表观气体速度成正比。分别增加到 80 μm 和 .3 m/s 后，它们不再是影响磨损的主要因素。床层压力对磨损率的影响是非线性的，当直径-高度比为 1:1 时，磨损率最低。非稳定磨损阶段可分为初始阶段和减速阶段。在整个过程中，表面分层是颗粒损耗的主要机制，只有在减速阶段，块体断裂才是主要机制。以 Gwyn 方程为基础，以总损耗率与不稳定损耗率之比 P 为参数，建立了立方多项式形式的新损耗模型。该模型具有较高的精度和可重复性，适用于各种流化条件。它能有效地描述颗粒的损耗过程和变化规律，合理地预测颗粒的流化损耗率。
{"title":"Analysis of HZSM-5 molecular sieve particles attrition behavior under fluidized conditions","authors":"Zhiwei Huang, Feng Gao, Yang Miao","doi":"10.1002/apj.3111","DOIUrl":"https://doi.org/10.1002/apj.3111","url":null,"abstract":"The attrition behavior of HZSM-5 zeolite catalyst particles at room temperature was investigated in a laboratory-scale fluidized bed. The effects of three fluidization conditions on particle attrition were investigated, and a new attrition model was proposed. The results demonstrate that the attrition rate is inversely proportional to the initial particle size and proportional to the apparent gas velocity. After increasing to 80 μm and .3 m/s respectively, they are no longer the main factor affecting attrition. The effect of bed pressure on attrition rate is nonlinear, and the lowest attrition rate is obtained when the diameter-height ratio is 1:1. Unsteady attrition stage can be divided into initial stage and deceleration stage. Surface delamination dominates particle attrition throughout the whole process, and bulk fracture is the dominant mechanism only in the deceleration stage. Based on the Gwyn equation, a new attrition model in the form of cubic polynomial is established with the ratio of total attrition rate to unstable attrition rate P as a parameter. The model has high accuracy and repeatability and is suitable for various fluidization conditions. It can effectively describe the attrition process and change rule of particles and reasonably predict the fluidization attrition rate of particles.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nianci Liu, Te Li, Zhuorui Zhang, Ling Su, Guiquan Jiang
In this study, we synthesized eight palladium-based catalysts using two carriers, ZrO2 and MCM-41. These catalysts were used for the degradation of condensed tannins extracted from larch bark. The average polymerization degree and degradation rate of the products were used as indicators to evaluate the efficiency of degradation. The effects of different Pd:Cu loading ratios under the same carrier conditions and the effects of different carriers under the same Pd:Cu loading ratio were investigated. The results revealed that when the carrier was kept constant, the Pd:Cu ratio of 1:1 exhibited the highest efficiency in degrading condensed tannins. Moreover, when the Pd:Cu loading ratio was the same, the degradation efficiency was higher when ZrO2 was used as the carrier. Based on these findings, the catalyst (Pd1-Cu1)5/ZrO2 (where “1” are the molar ratios of Pd to Cu added during the preparation of the catalyst and where ‘5’ is the mass percentage of Pd/Cu metal to total catalyst, i.e., 5 wt%), with ZrO2 as the carrier and a Pd:Cu ratio of 1:1, demonstrated the highest degradation efficiency, with a degradation rate of 73.89%. This catalyst successfully reduced the average polymerization degree of condensed tannins from 9.5 to 2.48.
{"title":"Preparation of palladium-based catalysts and use for depolymerization of larch bark tannins","authors":"Nianci Liu, Te Li, Zhuorui Zhang, Ling Su, Guiquan Jiang","doi":"10.1002/apj.3088","DOIUrl":"https://doi.org/10.1002/apj.3088","url":null,"abstract":"In this study, we synthesized eight palladium-based catalysts using two carriers, ZrO<sub>2</sub> and MCM-41. These catalysts were used for the degradation of condensed tannins extracted from larch bark. The average polymerization degree and degradation rate of the products were used as indicators to evaluate the efficiency of degradation. The effects of different Pd:Cu loading ratios under the same carrier conditions and the effects of different carriers under the same Pd:Cu loading ratio were investigated. The results revealed that when the carrier was kept constant, the Pd:Cu ratio of 1:1 exhibited the highest efficiency in degrading condensed tannins. Moreover, when the Pd:Cu loading ratio was the same, the degradation efficiency was higher when ZrO<sub>2</sub> was used as the carrier. Based on these findings, the catalyst (Pd<sub>1</sub>-Cu<sub>1</sub>)<sub>5</sub>/ZrO<sub>2</sub> (where “1” are the molar ratios of Pd to Cu added during the preparation of the catalyst and where ‘5’ is the mass percentage of Pd/Cu metal to total catalyst, i.e., 5 wt%), with ZrO<sub>2</sub> as the carrier and a Pd:Cu ratio of 1:1, demonstrated the highest degradation efficiency, with a degradation rate of 73.89%. This catalyst successfully reduced the average polymerization degree of condensed tannins from 9.5 to 2.48.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to improve the catalytic activity and hydrothermal stability of Cu‐SSZ‐39 zeolite by coupling it with cerium zirconium oxides (CeZrOx), which possesses excellent oxidizing ability, and a hybrid catalyst CeZrOx/Cu‐SSZ‐39 was prepared. It is found that it exhibited enhanced low‐temperature activity, high‐temperature activity, and a wider effective temperature range compared to Cu‐SSZ‐39. Characterization results showed that the CeZrOx/Cu‐SSZ‐39 catalyst had a higher concentration of active Cu2+ ion species and improved redox properties, which could potentially promote the NH3‐SCR reaction. Additionally, the CeZrOx/Cu‐SSZ‐39 catalyst had increased chemisorbed oxygen species on its surface, facilitating the oxidation of NO to NO2 and enhancing the rate of the SCR reaction. Moreover, even after undergoing hydrothermal aging treatment, the CeZrOx/Cu‐SSZ‐39 catalyst exhibited superior catalytic activity and improved hydrothermal stability, surpassing the performance of Cu‐SSZ‐39. It is found the CeZrOx coupling allowed the hybrid catalyst to maintain a better specific surface area and pore structure during hydrothermal aging, resulting in reduced activity loss. Therefore, the addition of CeZrOx enhanced the NH3‐SCR activity of Cu‐SSZ‐39 zeolite, leading to improved catalytic activity and hydrothermal stability. CeZrOx/Cu‐SSZ‐39 catalyst has shown promising aspect for reducing NOx emissions from diesel vehicle exhaust.
{"title":"Enhancement of nitric oxide reduction via CeZrOx/Cu‐SSZ‐39 hybrid catalyst: Improving activity and hydrothermal stability","authors":"Yunhui Li, Kunting Li, Xingdong Zhu, Xinyan Zhang, Xin Zhang","doi":"10.1002/apj.3109","DOIUrl":"https://doi.org/10.1002/apj.3109","url":null,"abstract":"This study aimed to improve the catalytic activity and hydrothermal stability of Cu‐SSZ‐39 zeolite by coupling it with cerium zirconium oxides (CeZrO<jats:sub>x</jats:sub>), which possesses excellent oxidizing ability, and a hybrid catalyst CeZrO<jats:sub>x</jats:sub>/Cu‐SSZ‐39 was prepared. It is found that it exhibited enhanced low‐temperature activity, high‐temperature activity, and a wider effective temperature range compared to Cu‐SSZ‐39. Characterization results showed that the CeZrO<jats:sub>x</jats:sub>/Cu‐SSZ‐39 catalyst had a higher concentration of active Cu<jats:sup>2+</jats:sup> ion species and improved redox properties, which could potentially promote the NH<jats:sub>3</jats:sub>‐SCR reaction. Additionally, the CeZrO<jats:sub>x</jats:sub>/Cu‐SSZ‐39 catalyst had increased chemisorbed oxygen species on its surface, facilitating the oxidation of NO to NO<jats:sub>2</jats:sub> and enhancing the rate of the SCR reaction. Moreover, even after undergoing hydrothermal aging treatment, the CeZrO<jats:sub>x</jats:sub>/Cu‐SSZ‐39 catalyst exhibited superior catalytic activity and improved hydrothermal stability, surpassing the performance of Cu‐SSZ‐39. It is found the CeZrO<jats:sub>x</jats:sub> coupling allowed the hybrid catalyst to maintain a better specific surface area and pore structure during hydrothermal aging, resulting in reduced activity loss. Therefore, the addition of CeZrO<jats:sub>x</jats:sub> enhanced the NH<jats:sub>3</jats:sub>‐SCR activity of Cu‐SSZ‐39 zeolite, leading to improved catalytic activity and hydrothermal stability. CeZrO<jats:sub>x</jats:sub>/Cu‐SSZ‐39 catalyst has shown promising aspect for reducing NOx emissions from diesel vehicle exhaust.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Because of the increasingly deteriorating quality of petroleum coke raw materials, abnormal furnace conditions, such as “firing and blasting”, frequently arise during the calcination of petroleum coke with a high powder/coke ratio in a vertical shaft calciner. This poses an urgent technical challenge that needs to be addressed. In iron and steel metallurgy, the burden distribution system is an important way to regulate blast furnace conditions and improve the permeability of a particle packed bed. In this work, advanced burden distribution concepts were introduced into the calcination process of petroleum coke in a vertical shaft calciner. Experimental devices were established to determine the resistance characteristics of a petroleum coke particle packed bed, along with a cold physical model of a 1/8 scale vertical shaft calciner. The influence of particle size and burden distribution methods on the resistance characteristics and particle motion behavior of the petroleum coke particle packed bed was systematically studied. The research findings indicate that both particle size and burden distribution methods significantly impact the resistance characteristics of petroleum coke particle packed beds. The smaller the particle size, the poorer the permeability of the bed. The layered burden distribution, symmetrical burden distribution, and dual‐particle mixed conventional burden distribution all contribute to improving the permeability of the petroleum coke particle packed bed in the vertical shaft calciner. Furthermore, employing symmetrical burden distribution in Bed‐3, which is packed with petroleum coke particles of diameters −3.2 + 2.5 mm and −1.0 + 0.8 mm, results in the smallest unit pressure drop, at only 1.7% of that of the conventional burden distribution of unscreened raw materials. This is the most effective means of improving the permeability of the bed. During the discharging process, particle size and symmetrical burden distribution have no significant impact on the motion characteristics of petroleum coke particles in the vertical shaft calciner. In general, in the calciner area, particles primarily move in a plug flow pattern and gradually transform into funnel flow in the cooling water jacket area. These research results provide the theoretical basis for addressing the technical challenges associated with powder coke calcination in vertical shaft calciners through reasonable burden distribution methods for fine and coarse particles.
{"title":"Resistance characteristics and particle movement behavior of a petroleum coke particle packed bed in a vertical shaft calciner under different burden distribution methods","authors":"Jindi Huang, Hui Lu, Jing Li, Youming Yang","doi":"10.1002/apj.3105","DOIUrl":"https://doi.org/10.1002/apj.3105","url":null,"abstract":"Because of the increasingly deteriorating quality of petroleum coke raw materials, abnormal furnace conditions, such as “firing and blasting”, frequently arise during the calcination of petroleum coke with a high powder/coke ratio in a vertical shaft calciner. This poses an urgent technical challenge that needs to be addressed. In iron and steel metallurgy, the burden distribution system is an important way to regulate blast furnace conditions and improve the permeability of a particle packed bed. In this work, advanced burden distribution concepts were introduced into the calcination process of petroleum coke in a vertical shaft calciner. Experimental devices were established to determine the resistance characteristics of a petroleum coke particle packed bed, along with a cold physical model of a 1/8 scale vertical shaft calciner. The influence of particle size and burden distribution methods on the resistance characteristics and particle motion behavior of the petroleum coke particle packed bed was systematically studied. The research findings indicate that both particle size and burden distribution methods significantly impact the resistance characteristics of petroleum coke particle packed beds. The smaller the particle size, the poorer the permeability of the bed. The layered burden distribution, symmetrical burden distribution, and dual‐particle mixed conventional burden distribution all contribute to improving the permeability of the petroleum coke particle packed bed in the vertical shaft calciner. Furthermore, employing symmetrical burden distribution in Bed‐3, which is packed with petroleum coke particles of diameters −3.2 + 2.5 mm and −1.0 + 0.8 mm, results in the smallest unit pressure drop, at only 1.7% of that of the conventional burden distribution of unscreened raw materials. This is the most effective means of improving the permeability of the bed. During the discharging process, particle size and symmetrical burden distribution have no significant impact on the motion characteristics of petroleum coke particles in the vertical shaft calciner. In general, in the calciner area, particles primarily move in a plug flow pattern and gradually transform into funnel flow in the cooling water jacket area. These research results provide the theoretical basis for addressing the technical challenges associated with powder coke calcination in vertical shaft calciners through reasonable burden distribution methods for fine and coarse particles.","PeriodicalId":8852,"journal":{"name":"Asia-Pacific Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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