CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2024
·
IF 3.7
Chengwei Xu,Yifu Wang,Yan Yu,Lirong Li
The wettability has an important effect on coalescence performance of filter. In this paper, we utilized a commercial glass fiber filter as the substrate to prepared the Janus filter through dip-coating and electrospraying. The Janus filter exhibited a remarkable reduction in pressure drop, with only 2.8 kPa of wet pressure drop compared to 6.1 kPa for the original filter and 5.4 kPa for the oleophilic filter. Notably, the coating depth played a critical role in enhancing the coalescence performance of the Janus filter. Furthermore, when placing the Janus filter in reverse direction, its quality factor increased by 2.87 times, highlighting that orientation is an essential factor for coalescence performance of Janus filters. The results indicate great potential in the application of Janus filters for coalescence filtration.
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
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
·
2024
·
IF 3.7
Donghai Yang,Mofan Li,Qing Yun,Huayao Sun,Qing Li,Xuedong Gao,Chaohui Chen,Limin He
Electrocoalescence technology can efficiently dehydrate waxy crude oil but the mechanisms are still unclear. Herein, the continuous microscopic behaviors of droplet falling, deformation, and coalescence were experimentally investigated to clarify the dynamic response mechanism of droplet in waxy oil under an electric field. The results showed the droplet falling under both gravity and electrostatic attraction to deform by the electric field force. Moreover, the expansion and clamping of the liquid bridge resulted from the competition between electric field force and capillary force. However, the precipitated wax crystals reduced the kinetic energy of the droplet and affected its external circulation, thus delaying the falling time. In addition, the wax crystals with interfacial activity adsorbed on the oil-water interface and cross-linked to form a spatial network structure, thereby weakening droplet deformation, hindering liquid film drainage, and inhibiting liquid bridge expansion. Importantly, the droplet adsorbed wax crystals exhibited interfacial elasticity, which makes them more inclined to partial coalescence. The low-frequency pulsed direct current (PUDC) electric field with high strength intermittent effect displayed the most obvious inhibition effect on the wax crystals. Overall, these findings look promising for future design and optimization of high-efficiency electric dehydrators and related fields.
研究领域:
石油工程
·
界面科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yantao Song,Meng Yan,Zixuan Xu,Benqiao He,Biao Wu,Jianxin Li,Zhenyu Cui
In this study, the 3-Aminopropyltriethoxysilane (APTES) was first grafted onto TiO 2 nanoparticles (APTES-TiO 2 nanoparticles), which were then introduced the membrane surface by reacting with anhydride on the membrane surface and Schiff base reaction with the PEI-TA. There are two types of hollow fiber hybrid membranes with varying nanoparticle distributions were constructed. The influence of hybrid mode on the ability of anti-oil fouling was researched. The results indicated that the PVDF@TiO 2 hybrid membrane has a flux recovery rate of 96.68 % and a total flux decline rate of 15.52 %, indicating a good anti-emulsified oil fouling performance. By characterizing the anti-oil droplets adhesion, water-binding capacity, surface charge of membrane and concentrate system coacervate size, the coalescence ability of the hybrid membrane to the oil droplets and the spreading behavior of oil droplets on the surface were uncovered. Ultimately, the anti-fouling mechanism “hydration layer &rigid layer obstruction-electrostatic coalescence” was proposed, which can reasonably explain the weakness of the interplay between the membrane surface and oil droplets, thus slowing down the attaching and spreading of emulsified oil droplets. This study laid the foundation for developing hybrid membranes with high resistance to emulsified oil fouling ability. The proposed anti-fouling mechanism can provide new ideas for the efficient purification of oily wastewater.
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
FUEL
·
2025
·
IF 7.5
Yang Liu,Peilong Li,Yan Zhang,Xiaofang Lv,Yisong Yu,Qianli Ma,Chuanshuo Wang,Xiaoyan Li,Shidong Zhou,Bingcai Sun
Addressing the blockage issues arising from hydrate formation and aggregation in complex multiphase systems has long been a significant focus in the field of flow assurance for oil and gas pipelines. There is an urgent need to develop and identify cost-effective, efficient, and environmentally friendly hydrate anti-agglomerants. A micro-mechanical force device and a rheometer were employed to investigate the anti-agglomeration effects of Span80 and amide-based surfactants (DPLA and DPCA) in gas–water and oil–water systems. The results indicated that in the gas–water system, compared to the surfactant-free system, the addition of varying concentrations of surfactants lead to a reduction in cohesive force of hydrate particles by 70.39 % to 84.10 % (1 wt% Span 80). The amide-based surfactant, DPLA, reaches a maximum reduction of 82.38 % (from 21.51 ± 0.78 mN/m to 3.79 ± 0.29 mN/m) with a concentration of 0.5 wt%. The cohesive force between hydrate particles and wall droplets was reduced by 40.35 % to 54.59 %, with the maximum reduction of 54.59 % (from 484.28 ± 26.28 mN/m to 219.88 ± 21.36 mN/m at 0.3 wt% DPCA). Compared to Span80, amide-based surfactants demonstrated similarly excellent performance in reducing cohesive forces. Considering the significant changes in the surface morphology of hydrate particles upon the addition of surfactants, this study also revealed a strong positive correlation between both liquid bridge width and circularity with cohesive force (r 1 = 0.8233, r 2 = 0.6066), while surface roughness exhibited a weak negative correlation (r 3 = − 0.3821). In the oil–water system, although the critical time for hydrate formation in DPLA or DPCA-containing emulsions was markedly shortened compared to the base emulsion, both peak viscosity and steady viscosity of hydrate slurries were significantly reduced at medium to high concentrations of DPLA or DPCA. The maximum reductions in steady viscosity and peak viscosity for the DPLA-containing system were 93.94 % (0.6 wt%) and 78.59 % (0.4 wt%), respectively, while for the DPCA system, they were 89.55 % (0.8 wt%) and 55.95 % (0.8 wt%). Although DPCA and DPLA promoted hydrate formation, they still demonstrated excellent anti-agglomeration efficacy and potential for synergistic effects. The anti-agglomeration capability of DPCA was slightly weaker than that of DPLA, with both exhibiting comparable effects at medium to high concentrations.
研究领域:
石油工程
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2020
·
IF 4.302
Hongyan Sun,Ruyuan Jiao,Guangyu An,Hui Xu,Dongsheng Wang
More and more attention has been paid to the aggregation behavior of nanoparticles , but little research has been done on the effect of particle size. Therefore, this study systematically evaluated the aggregation behavior of nano-silica particles with diameter 130–480 nm at different initial particle concentration, pH, ionic strength, and ionic valence of electrolytes. The modified Smoluchowski theory failed to describe the aggregation kinetics for nano-silica particles with diameters less than 190 nm. Besides, ionic strength, cation species and pH all affected fast aggregation rate coefficients of 130 nm nanoparticles . Through incorporating structural hydration force into the modified Smoluchowski theory, it is found that the reason for all the anomalous aggregation behavior was the different structural hydration layer thickness of nanoparticles with various sizes. The thickness decreased with increasing of particle size, and remained basically unchanged for particles larger than 190 nm. Only when the distance at primary minimum was twice the thickness of structural hydration layer, the structural hydration force dominated, leading to the higher stability of nanoparticles. This study clearly clarified the unique aggregation mechanism of nanoparticles with smaller size, which provided reference for predicting transport and fate of nanoparticles and could help facilitate the evaluation of their environment risks.
研究领域:
环境科学
·
胶体化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2021
·
IF 6.609
Peng Shi,Yuxia Gou,Jiao Li,Qiulu Zheng,Xiao Zhong,Ming Duan,Wanfen Pu
Oily wastewater is a potential resource for recycled crude oil; however, the formation of oil sludge during water disposal makes the oil unrecyclable. In this study, a hydrogel coalescer was prepared by polymerization grafting of acrylamide on a metal tube filter, which separated the emulsion into layers of water and oil when the oily water permeated the 1-mm-thick wall. The oil was easily recycled without any oil sludge formation. The material had an oil removal efficiency of 98% at a high flux up to 5000 L/(m 2 ·h) up to an inlet pressure of 3 bar. The oil exhibited weak adhesion to the coalescer and could be easily flushed away. The fouling analysis showed bubbles, and the formation of the water-in-oil (W/O) emulsion led to the blocking of the pore. After the addition of a demulsifier into the hydrogel, the formation of the W/O emulsion was strongly suppressed, and the material showed an enhanced anti-blocking performance and higher flux. Hence, we developed a potential reagent-free solution for the disposal of oily wastewater and a recycling technique for obtaining crude oil from it.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2023
·
IF 4.3
Kai Guo,Yin Bai,Fei Yuan,Xiaoya Liu,Xiao Ling,Lei Wang,Ling Du
Electromagnetic synergy is a more effective physical method than a single AC electric field (ACEF) to enhance oil–water separation. However, the critical coalescence conditions and transformation mechanism of droplets adsorbing surfactant molecules in the synergistic electromagnetic field (EMSF) still lack research. Herein, a series of Triton X-100-adsorbed droplets with different surface tensions were prepared, and the critical coalescence electric intensity ( E c ) of the droplets under ACEF and EMSF were compared. Micro high-speed experiments revealed that E c of droplets under EMSF is higher than under ACEF. The electric intensity, E c , increased with the increase in interfacial tension γ under both ACEF and EMSF. This study provides valuable results for designing high-performance devices by introducing electromagnetic synergy in water-in-oil emulsion treatment. For the equipment with electromagnetic synergy to strengthen oil–water separation, the allowable optimal voltage should be higher than that of the electrostatic coalescer, and the adjustment range is 2.99%−9.57%.
研究领域:
化学工程
·
环境科学
·
物理学
✓ 已验证
DOI
高影响因子
LAB ON A CHIP
·
2015
·Vol. 15
·期 9
·2018-2024
·
IF 6.115
Zhou Liu,San To Chan,Hammad Ali Faizi,Robert C. Roberts,Ho Cheung Shum
In this work, we investigate the coalescence of emulsion droplets in a controlled electric field. Two contacting droplets stabilized by surfactants can be forced to coalesce into a combined one when the applied voltage is above a critical value. The critical voltages change with the types, concentrations of surfactants and temperature. By exploring the drainage of a thin oil film trapped between emulsions, we interpret that the coalescence occurs as the electric compression overcomes the disjoining pressure barrier and squeezes the film to a critical thickness. Based on this, we have devised an approach to probe the threshold disjoining pressure which can help predict the emulsion stability and surfactant efficacy quantitatively. We have confirmed the validity of our approach for measuring the threshold disjoining pressure by comparing the result with other proven tests that involve centrifugation and thermal heating. Our approach is simple, reliable and robust in predicting emulsion stability and will facilitate the design of emulsion-based formulations by accelerating the testing of emulsion stability.
研究领域:
生物医学工程
·
胶体科学
·
界面物理
·
药物递送系统
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Di Wang,Zhiqiang Zhou,Tianle You,Bing Liu,Qingqing Xie,Lingyun Wang,Guilong Xu,Yun Liang,Min Tang
Air pollution has necessitated the large-scale utilization of air filters in aerospace, healthcare, personal protection, and manufacturing sectors. However, high-efficiency filters often exhibit high airflow resistance, increasing energy costs, especially when filtering liquid airborne pollutants like oil aerosols. These pollutants tend to coalesce into liquid films on the filters. Although regulating the wettability of a filter can reduce airflow resistance, the dynamic coalescence behavior and its effects on airflow transport remain unclear. Herein, we present a dual-scale Janus filter for oil aerosol capture. This filter, produced using an industrial papermaking process, features a pore-size gradient and asymmetric wettability. The dynamic coalescence behavior between oil aerosols and filter surfaces at the micro/nanoscale indicates that the superoleophilic layer serves as an oil-guiding layer, destroying the integrity of the oil film deposited on the superoleophobic filter layer and thereby facilitating airflow transport across the Janus filter. The Janus filter exhibits a 30 % lower steady-state pressure drop, higher filtration efficiency (99.4 %), higher dust-holding capacity (286 g m −2 ), and >8 times longer lifetime than those of commercial filters. As a proof-of-concept, the performance of an air purifier comprising Janus filters is demonstrated. These findings promote the development of efficient, energy-saving coalescence filters.
研究领域:
材料科学
·
环境科学
·
过滤技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
Xiaoming Luo,Haoran Yin,Haipeng Yan,Xin Huang,Donghai Yang,Limin He
The electrocoalescence behavior of surfactant-laden droplet pairs in oil under a DC electric field was investigated in this paper. The characteristic parameters such as coalescence time, liquid bridge diameter and contact angle were analyzed for varying surfactant concentrations and electric capillary numbers. The results show that the horizontal electrocoalescence of two identical droplets with the same physical properties is symmetrical. Moreover, the surfactant has a significant influence on the pressure difference at the liquid bridge, which results in a variation of the liquid bridge growth and coalescence time. The pressure difference between the droplet and the liquid bridge is significantly dependent on the initial contact angle, which is determined by the electric capillary number Ca and surfactant concentration. The theoretical analysis and experimental results show that the large initial contact angle restrains the growth of the liquid bridge in the initial coalescence stage. Considering the effect of the initial contact angle, a characteristic time is proposed to describe the evolution of the liquid bridge.
研究领域:
物理学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Yang Zhao,Yuna Gu,Guandao Gao
Recovering oil from oily wastewater is not only for economic gains but also for mitigating environmental pollution. However, demulsification of oil droplets stabilized with surfactants is challenging because of their low surface energy. Although the widely used oil/water separation membrane technologies based on size screening have attracted considerable attention in the past few decades, they are incapable of demulsification of stabilized oil emulsions and the membrane concentrates often require post-processing. Herein, the piezoelectric ceramic membrane (PCM), which can respond to the inherent transmembrane pressure in the pressure-driven membrane processes, was employed to transform hydraulic pressure pulses into electroactive responses to in situ demulsification. The pulsed transmembrane pressure on the PCM results in the generation of considerable rapid voltage oscillations over 3.2 V and a locally high electric field intensity of 7.2 × 10 7 V/m, which is capable of electrocoalescence with no additional stimuli or high voltage devices. Negative dielectrophoresis (DEP) force occurred in this membrane process and repelled the large size of oil after demulsification away from the PCM surface, ensuring continuous membrane demulsification and oil/water separation. Overall, PCM provides a further opportunity to develop an environmentally friendly and energy-saving electroresponsive membrane technology for practical applications in wastewater treatment.
研究领域:
环境科学
·
材料科学
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）