SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xinjiao Tian,Hao Wei,Wenying Wang,Yixiang Huang,Hongxiang Wang,Jiefeng Pan,Rui Wang,Zhenming Li
In the process of air filtration, filter materials may encounter oil-solid mixed particles from various sources such as industry and household, and the influence of filter material with different wettability on the filtration performance of oil-solid mixed particles has not been fully reported. The objective of this study was to prepare filter materials with varying wettability properties and investigate their filtration performance for oil-solid mixed particles with diverse oil contents. In this study, four filter materials were prepared using the impregnation method, exhibiting 0° (superoleophilic), 46° (oleophilic), 90° and 122° (oleophobic) oil contact angles. The oil-solid mixed particles with varying oil contents were loaded on the four different filter materials. The loading behavior of the filter materials was characterized from two aspects: macroscopic loading behavior (changes in pressure drop and DHC) and microscopic particle deposition behavior. The results demonstrated that, under the conditions of 25% and 50% oil content, the enhanced liquid bridge force between the oil-solid mixed particles on the oleophobic filter material facilitated the formation of a loose and porous cake layer structure compared with other filter materials, resulting in a lower growth rate of pressure drop and a higher dust holding capacity (DHC). However, in 75% and 100% oil content environments, the superoleophilic filter material owned a remarkably high affinity for oil particles compared with other filter materials, leading to the gradual formation of an oil film structure on the filter material, yielding lower the growth rate of pressure drop and higher DHC. These findings shed light on the mechanism of particle deposition under diverse filtration conditions and are applicable to the filtration of various oil-solid mixed particles over a wide range of oil contents.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jiesong Tan,Yiqing Zeng,Jiahao Chen,Yutang Kang,Jiangxiao Qiao,Feng Zhang,Feng Han,Zhaoxiang Zhong,Weihong Xing
Oily particulate matter (PM) filtration faces the problems of high pressure drop and difficult regeneration. Herein, vertical arrays of MnO 2 nanosheets was assembled on Zr doped TiO 2 (Zr-TiO 2 ) nanofibers to construct a core–shell structure MnO 2 @Zr-TiO 2 (CSMT-x) catalytic membranes for highly efficient oily PM filtration and decomposition. The confining effect of the ultrathin MnO 2 nanosheets enhances PM capture efficiency, and the increase of effective contact area between MnO 2 and oily PM accelerate the decomposition of oily PM. The optimized CSMT-3 catalytic membrane exhibited high gas permeability and redox capacity, outperforming the Zr-TiO 2 (Bare T) membrane with over 99.97 % PM filtration efficiency and a low pressure drop at the temperatures of 25–425 °C. The catalytic decomposition of PM prevented the accumulation of particles on the membrane surface, which inhibited the formation of cake layer. Therefore, the CSMT-3 membrane exhibited a slight increase in pressure drop (less than 120 Pa) even after 120 h long-term filtration. This work may contribute to the development of advanced multifunctional membranes for purification of oily PM.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2024
·
IF 3.5
Jingwei Zhang,Xiaohui Zhang,Jianhong Xu,Zhuo Chen
In this work, the liquid–liquid two-phase pressure drop and mass transfer characteristics in micro-packed beds with different shaped packing are investigated. The experimental results show that the liquid–liquid mass transfer performance of micro-packed bed is significantly affected by both apparent flow rates and phase ratio. By changing the characteristic size of the micro-packed bed, the experimental results show that the average volume mass transfer coefficient has no obvious correlation with the length of the bed, which indicates that the flow and dispersion behavior along the length of the micro-packed bed is basically stable. By considering dispersion strengthening, vortex strengthening and size effect, a semi-empirical model for predicting liquid–liquid mass transfer performance in a micro-packed bed is established for the first time. The model is in good agreement with the experimental results and has strong applicability to various shaped packings. In addition, by considering the contribution of inertia force, viscous force and interfacial tension to energy dissipation, a semi-empirical model of liquid–liquid two-phase pressure drop in a micro-packed bed is established. The pressure drop prediction model can also be applied to different shaped packings.
研究领域:
化学工程
·
传质与流体力学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Min Meng,Qiang Yang
Medium coalescence technology is a research hotspot for the separation of oil-in-water emulsions. However, the coalescence mechanism is still unclear, making it challenging to effectively improve the separation performance. Herein, the microscopic mechanism of medium coalescence was revealed. We found that the effective collision positions under the action of the flow field include the exposed granule surface, adherent droplet surface, and three-phase contact line. Furthermore, a numerical model of the microscopic process of water-in-oil emulsion permeation through a granular bed was established. The effects of different parameters (including the number of medium layers, Reynolds number, and inlet concentration) on the microscopic process of capturing dispersed-phase droplets in the bed and the pressure drop in the coalescence area were studied. The numerical results show that the droplets form the bridging structure between the granules. On the one hand, the bridging structure promotes the capture of the droplets by the bed; on the other hand, it causes pressure-drop fluctuations in the coalescence area and asymmetric distribution of the velocity field.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2021
·
IF 3.739
Chengwei Xu,Yan Yu,Xiaodong Si
The surface wettability of fibers in coalescing filter has a critical effect on filter’s performance. In this study, we employed common glass fiber filters as model and prepared superoleophilic and superoleophobic surface filters via a facile dip-coating method. The superoleophilic treatment shows a considerable reduction in pressure drop. The wet pressure drop at saturation decrease from 12.91 kPa to 8.56 kPa after superoleophilic coating. The filtration efficiency of fine particles (<100 nm) increase owing to coating treatment. The combinations of superoleophilic and superoleophobic filter and drainage strategy were also evaluated. The results show that the combination has no advantage due to emergency turn of wettability. The drainage layer with appropriate rank could enhance the drainage rate at unsaturation stage. However, the drainage strategy is never a good idea to improving coalescence performance because it brings the extra pressure drop.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Haiqiang Zhang,Yue Pan,Chengzhong Deng,Zhuolun Niu,Ruoyu You,Chun Chen
Improving aircraft environmental control systems could reduce the risk of airborne infectious disease transmission in aircraft cabins. The high-efficiency particulate air (HEPA) filters used in the existing systems exhibit high pressure drop, which results in high consumption of energy and fuel. Nanofiber air filters fabricated by electrospinning can reduce pressure drop, but their performance in aircraft cabins is unknown. Therefore, this study experimentally investigated the interpersonal particle transport in an aircraft cabin mockup with nanofiber air filters. First, a full-scale, fully occupied, 7-row, single-aisle aircraft cabin mockup was constructed. Nanofiber filtration units were fabricated using the electrospinning technique. Under the well-sealed laboratory testing conditions, both the small-scale nanofiber and HEPA filter media exhibited a particle removal efficiency of around 99 %. The performance of nanofiber and HEPA filtration units installed in the environmental control system of the mockup was then measured. Finally, the interpersonal particle transport in the cabin was measured. The results show that the particle removal efficiency of the nanofiber filtration units installed in the environmental control system ranged from 64 to 72 % when the particle size was 0.3–0.4 μm, which primarily reflected the large air leakages associated with the filter installation. At the filter media level, the pressure drop across the nanofiber units in the mockup was 61–67 % lower than that across the HEPA units under the same airflow rate, which however may not necessarily translate into lower pressure drop for actual filters in aircraft due to the potentially different design in terms of media face area. The average normalized particle concentration in the breathing zones of fellow passengers in the cabin mockup with the nanofiber filtration units was by 0.23, 0.29, and 0.32, respectively, when the index passenger was seated at the window, middle, and aisle.
研究领域:
环境科学
·
公共卫生
·
航空航天工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 24
·2311129
·
IF 27.4
Zhiqiang Zhou,Tianle You,Zhengyuan Pan,Di Wang,Hao Wang,Lingyun Wang,Guilong Xu,Yun Liang,Jian Hu,Min Tang
Air pollution threats to human health have increased awareness of the role of filter units in air cleaning applications. As an ideal energy-saving strategy for air filters, the slip effect on nanofiber surfaces can potentially overcome the trade-off between filtration efficiency and pressure drop. However, the potential of the slip effect in nanofibrous structures is significantly limited by the tight nanofiber stacks. In this study, trichome-like biomimetic (TLB) air filters with 3D-templated silicone nanofilaments (average diameter: ≈74 nm) are prepared based on an in situ chemical vapor deposition (CVD) method inspired by plant purification. Theoretical modeling and experimental results indicate that TLB air filters make significant use of the slip effect to overcome the efficiency-resistance tradeoff. The selectable filter class (up to U15, ≈99.9995%) allows TLB air filters to meet various requirements, and their integral filtration performance surpasses that of most commodity air filters, including melt-blown cloth, ePTFE membranes, electrospun mats, and glass fiber paper. The proposed strategy directly transforms commercial filter media and filters into TLB air filters using a bottom-up, one-step approach. As a proof-of-concept, reusable N95 respirators and air purifiers equipped with TLB air filters are fabricated, overcoming the limitations of existing filter designs and fabrication methods.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2024
·
IF 3.5
Shuangfei Zhao,Xin Hu,Huiyue Wang,Yihuan Liu,Zheng Fang,Kai Guo,Ning Zhu
The scale-up of microreactor-based flow chemical process represents a grand challenge in chemical engineering. The small characteristic size (<1000 μm) of a typical microreactor leads to not only microscale effect (process intensification) but also low throughput. Here, we report macro-microreactor to achieve scale-up of liquid–liquid chemical operation with process intensification. By incorporating the designed internals based on computational fluid dynamics, the characteristic size of the macro-microreactor is expanded into 3000–4000 μm. The optimized design of macro-microreactor with helical-shaped internal exhibits both similar or even stronger microscale effect and high throughput in contrast to the typical microreactor. For the liquid–liquid chemical process, seven times higher mass transfer coefficient and about half reduction of the pressure drop are realized. These macro-microreactors would find further applications in industrial chemical manufacturing.
研究领域:
化学工程
·
化工设备设计
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Qinglin Yin,Hongji Chen,Shihao Ding,Qi He,Xiahui Gui,Yaowen Xing
Fluidized bed flotation involves three phases of gas, liquid and solid, which can be used for the separation of coarse minerals. In this study, a two-dimensional gas–liquid-solid fluidized bed was developed to explore the fluidization characteristics of fluidized bed flotation. The effects of water velocity, air velocity, frother dosage and particle size (Q l , Q g , ρ n , D p ) on the average pressure drop (–ΔP) and standard deviation (σ ΔP ) were investigated. As the water velocity increases, the pressure drop initially increases, subsequently decreases and eventually remains constant. Increasing the air velocity will enhance the resistance of the bed to the water flow, resulting in a reduction in the water velocity required by peak pressure drop. Furthermore, the pressure drop is observed to decrease due to an increase in air velocity after reaching complete fluidization. Increasing the particle size has the opposite effect, while variations in frother dosage only influence the peak pressure drop. According to the bubble behavior, the influence of different conditions on the pressure drop fluctuation was analyzed. Increasing the water velocity, the frother dosage and the particle size contribute to a reduction in pressure drop fluctuation, whereas an increase in air velocity has the opposite effect. When the water velocity exceeds 1.2 L/min and the frother dosage exceeds 80 g/t, the pressure drop fluctuation is basically unchanged. Finally, the response surface methodology was used to analyze the interaction among the variables, and a mathematical model of the correlation coefficient was established to predict effects.
研究领域:
矿物加工工程
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2019
·Vol. 7
·期 2
·1901808
·
IF 4.713
Jialin Liu,Hua Zhou,Xiaolin Wu,Hongxia Wang,Zhongli Ji,Yanning Xing,Jinjie Lu,Xin Wei,Tong Lin
In this paper, a novel, simple, but efficient method is reported to lower pressure drop and meanwhile maintain high filtration efficiency of superoleophobic filters for oil aerosol filtration. By close attachment of a thin oil-guiding fibrous layer to the front surface of a superoleophobic filter, the pressure drop at pseudostatic state can be reduced by 20%. Such a remarkable reduction in filtration resistance is originated from the capillary effect of the oil-guiding fabric, and pore size within the guiding fabric also played a role. This novel material may be useful for the development of high efficiency, low energy-consumption coalescing filters for various applications.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Aoze Miao,Mingjie Wei,Fang Xu,Yong Wang
There has been an argument on the influence of membrane hydrophilicity on permeability between experimental and simulation works. Theoretical work finds that the membranes have a characteristic called a threshold pressure drop (Δ P T ). Strongly hydrophobic membranes exhibit extremely high Δ P T , making membranes less wettable and consequently less permeable. In order to experimentally investigate the influence of wetting states of membranes, determined by membrane hydrophilicity, on permeability, we prepared a series of membranes with progressively changing hydrophilicities by atomic layer deposition (ALD) of TiO 2 on polytetrafluoroethylene membranes while keeping the pore size unchanged. In addition, adding ethanol into the water and raising the operating pressure drops are also selected to improve the wetting degrees. The experimental results verify the presence of Δ P T for all membranes and the hydrophobic membranes having higher Δ P T . Since the hydrophilic membranes have better wetting degrees but higher transport resistance, there should be an optimized hydrophilicity, which is found to be determined by the feed solution and the operating Δ P . The optimized hydrophilic modification is the one when the membrane can be just adequately wetted by the feed solution at the target operating pressure drops. Highest water permeability is expected to be obtained at a moderate hydrophilicity, neither at the extreme hydrophilicity nor at the extreme hydrophobicity .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qiuyue Hu,Xin Gao,Heng Zhang,Tian Si,Xiaoning Tang,Lincai Peng
Cellulose has attracted much attention in application of air filtration for the excellent ability of degradability and biocompatibility. However, limited by the strength of natural structure, air filters based on native cellulose usually have high pressure drop (ΔP) or thick volume. In this study, an efficient air filter was produced with low ΔP (6.8 Pa) using a low amount of dry material (9 ∼ 12 mg/cm 3 ) through simple preparation process with high-speed shear induced. Analysis showed the chains of regenerated cellulose (RC) were stretched and arranged orderly due to the shear induced during the entire coagulation process, letting to an increasing of crystalline of RC. Furthermore, RC filter exhibited a high PM2.5 capture efficiency (over 99.65 %) with high-quality factor (0.853 Pa −1 ) under high PM concentration conditions. This work gave a novel sight on the potential of air filtration produced by agricultural waste bioresources furthermore, offered an interesting and simple avenue for daily respiratory protective media.
研究领域:
材料科学
·
环境科学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）