Intermediate layer free PVDF evolved CMS on ceramic hollow fiber membrane for CO2 capture

The use of carbonized polymers has ushered in a new class of materials with profound implications for the gas separation industry. This study explored the transformation of polyvinylidene fluoride (PVDF) into microporous carbon structures coated onto ceramic substrates, enabling in situ growth of carbon molecular sieve (CMS) materials over hollow fibers. This material featured more robust CMS membranes than alumina and demonstrated exceptional capability in vital gas separations, particularly for CO2/CH4. This novel approach increased the selectivity for gases and exhibited remarkable aging resilience, so the material is a compelling candidate for high-performance gas separations. Furthermore, after 31 days, the weathered carbon dioxide membrane exhibited a slight permeability drift from 234.88 barrers to 195.35 barrers, while the CO2/CH4 ratio increased from 24.21 to 57.14, surpassing the Robeson 2008 upper bound. The PVDF-derived supported hollow fiber carbon membranes provide a blueprint for designing membranes for carbon capture. With the high packing density of the hollow fiber membrane and improved mechanical strength of the supported carbon membrane, this approach overcame the high fabrication costs and brittleness of other carbon membranes. In addition, the entire process for preparation of the PVDF carbon films is easily scaled up and has great potential for future practical application

Online monitoring of particle fouling in a submerged membrane filtration system using a photointerrupt sensor array

[[abstract]]Online monitoring techniques can play a major role in understanding and controlling the mechanisms involved in the fouling of membrane filtration systems. The present study describes the application of an in situ optical method to monitor the growth of a fouling layer using a photointerrupt sensor array. To verify the validity of this method, the effects of the voltage applied, slurry concentration and membrane materials on the signal from the sensor array were examined. In addition, the application of this method in monitoring the growth of the fouling-layer thickness during the filtration of a high-turbidity influent stream under constant flux was studied. The results from three-dimensional (3D) fouling contour studies showed that the average fouling-layer thickness increased proportionally with time during the initial period in response to the rapid deposition of particles on the membrane surface, after which the growth rate of the fouling layer decreased. The 3D fouling contour analyses suggest that this online monitoring technique provides an effective in situ measurement of fouling-layer thickness and distribution. The photo-sensor array proved to be a promising online monitoring technique for scanning membrane surfaces on demand and can be applied to a pilot-scale water treatment unit for use in the real-time profiling of changes in fouling-layer thickness.[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[booktype]]電子版[[countrycodes]]NL

Analysis and Prediction of Fouling Layer Structure in Microfiltration

[[abstract]]A dynamic analysis procedure has been adopted based on mass and force balances for particle deposition on the membrane surface to analysis and predict the particle fouling layer structure in microfiltration. The local properties in a fouling layer, say porosity distribution, resistance to fluid flow and hydraulic pressure distribution can be estimated by the proposed dynamic analysis with a preliminary request of a set of filtration data and the surface porosity of fouling layer only. A prototype software for the analysis of the fouling layer properties in microfiltration has been devised and can be used both for design of a membrane filtration system and later to predict or monitor its performance during plant operation.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]E

Effect of calendering of filter cloth on transient characteristics of cake filtration

In this article, the effects of a filter fabric calendering treatment and the permeability of filaments with regards to the particle deposition phenomena onto or into filter fabrics at the initial stage of filtration are conducted quantitatively using a microscopical forces analysis. The flow pattern and the resistance to fluid flow in the calendered interstice were obtained numerically by using the fluid-flow software FLUENTTM. Based upon the numerical data of continuous phase, a program is devised to simulate the transient behaviours of pore clogging and cake formation by ways of the Lagrangian approach and this estimates the change of filtrate clarity at the initial stage of filtration for various calendered fabrics porosities and various filament permeabilities. Results show that in the case of tightly woven filter cloths, the flow is predominantly through the yarns of the cloth; while flow will generally be directed around the yarns of a loosely woven cloth, especially if the yarn is twisted tightly. Therefore, filtrations with tightly woven but loosely twisted yarn can increase the unfavourable but inevitable clogging problem. The simulated results further show that although the filtration resistance of woven filter fabric increases after calendering, the permeability is rectified and the clogging of the filter pores is also improved. After the calendering finishing of the filter fabric has taken place, only the cake formation mode in accordance with the law of blocking for all types of pore is evident shown. The critical concentration proposed by previous investigators is not observed for the calendered filter fabrics

Design of disk structure for improving filtration performances of rotating-disk dynamic microfiltration.

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Editorial of SI: Filtering a better future

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