Performance characterization and steady-state modelling of spinning basket membrane module
TL;DR: In this paper, the performance of this module has been reported in the ultra-filtration operation and it is a special type of shear-enhanced device with inbuilt cleaning facility.
Abstract: Spinning basket membrane module is a special type of shear-enhanced device with inbuilt cleaning facility. In this article, the performance of this module has been reported in the ultrafiltration o...
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18 May 2021
TL;DR: In this paper, a review of different phenomenological and non-phenomenological models for permeate flux prediction in UF, and a comparison, between selected models, of the predictive capacity.
Abstract: In any membrane filtration, the prediction of permeate flux is critical to calculate the membrane surface required, which is an essential parameter for scaling-up, equipment sizing, and cost determination. For this reason, several models based on phenomenological or theoretical derivation (such as gel-polarization, osmotic pressure, resistance-in-series, and fouling models) and non-phenomenological models have been developed and widely used to describe the limiting phenomena as well as to predict the permeate flux. In general, the development of models or their modifications is done for a particular synthetic model solution and membrane system that shows a good capacity of prediction. However, in more complex matrices, such as fruit juices, those models might not have the same performance. In this context, the present work shows a review of different phenomenological and non-phenomenological models for permeate flux prediction in UF, and a comparison, between selected models, of the permeate flux predictive capacity. Selected models were tested with data from our previous work reported for three fruit juices (bergamot, kiwi, and pomegranate) processed in a cross-flow system for 10 h. The validation of each selected model’s capacity of prediction was performed through a robust statistical examination, including a residual analysis. The results obtained, within the statistically validated models, showed that phenomenological models present a high variability of prediction (values of R-square in the range of 75.91–99.78%), Mean Absolute Percentage Error (MAPE) in the range of 3.14–51.69, and Root Mean Square Error (RMSE) in the range of 0.22–2.01 among the investigated juices. The non-phenomenological models showed a great capacity to predict permeate flux with R-squares higher than 97% and lower MAPE (0.25–2.03) and RMSE (3.74–28.91). Even though the estimated parameters have no physical meaning and do not shed light into the fundamental mechanistic principles that govern these processes, these results suggest that non-phenomenological models are a useful tool from a practical point of view to predict the permeate flux, under defined operating conditions, in membrane separation processes. However, the phenomenological models are still a proper tool for scaling-up and for an understanding the UF process.
14 citations
TL;DR: In this article, the authors presented the modeling, simulation, and characterization studies of a dynamic shear-enhanced (DSE) filtration system with an inbuilt cleaning facility.
Abstract: Membrane-based low-cost recovery of nutritional and therapeutic proteins from wastewater is regarded as a leap towards sustainability. However, membranes are heavily fouled by proteins, and thus, frequent chemical or hydrodynamic cleaning is needed even in the advanced dynamic shear-enhanced (DSE) filtration devices. This article presents the modeling, simulation, and characterization studies of a DSE system, namely the ‘Spinning Basket membrane’ (SBM) module with an inbuilt cleaning facility. The device has been established to be specifically suitable for the recovery of proteins from synthetic wastewater. It can perpetually regenerate the flux with its simple and, moreover, online cleaning facility. A two-parameter transient model, purely based on an analytical approach, has been developed to simulate the device. Moderately low deviation (±12 %) of the simulated flux from the corresponding experimental data obtained from ultrafiltration of synthetic wastewater unambiguously validates the proposed model. The present modeling strategy demonstrates how a DSE filtration system with highly complex modes of mass and momentum transfer could be easily simulated.
1 citations
References
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TL;DR: In this paper, a high-frequency, reverse-filtration strategy was proposed to maximize the flux for washed yeast suspensions through 0.2-μm cellulose acetate flat sheet membranes.
Abstract: A primary method of reducing membrane fouling during cross-flow microfiltration is periodic reverse filtration. This in situ method of cleaning the membrane forces clear fluid in the reverse direction through the membrane and readjusts the particle or solute accumulation on the retentate side of the membrane. This work focuses on the design of a high-frequency, reverse-filtration strategy to maximize the flux for washed yeast suspensions through 0.2- μm cellulose acetate flat sheet membranes. Several experiments were conducted with reverse-filtration times ranging from 0.5–4 s and forward-filtration times ranging from 1–40 s. For every back-filtration time, there exists an optimum forward-filtration time that gives the maximum global average flux. The optimum average flux increases with decreasing back filtration times and feed concentrations, but shows little dependence on cross-flow velocity and reverse filtration transmembrane pressure. The optimum flux with rapid backflushing is 20 to 30 times higher than the long-term flux in the absence of backflushing. A theory presented assumes that cake formation during forward filtration follows dead-end filtration theory and the cake is instantly removed during reverse filtration. The measured average flux per cycle follows the trends predicted by the theory, but the measured values exceed the predictions, presumably due to brief delays in cake removal and cake formation at the start of reverse and forward filtration, respectively, during each cycle.
120 citations
"Performance characterization and st..." refers background in this paper
...Fouling can be minimized by a number of standard techniques, such as pretreatment of the feed solution,([9]) physicochemical modification of the membrane,([10]) back-pulsing, back-washing or back-flushing,([11,12]) chemical cleaning,([13]) using external force fields (electric, sonic and centrifugal fields) and many others....
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TL;DR: In this paper, axial vibration of submerged hollow fiber membranes is found to be an effective means of preventing membrane fouling with critical fluxes of 60 − 80 − 1 ǫm − 2 at vibrational frequencies as low as 10 Hz.
111 citations
"Performance characterization and st..." refers background in this paper
...Accordingly, it has been suggested that either a rotating accessory, for example stirrer,([1,2]) rotating membrane([3,4]) or a vibrating surface([5,6]) must be an integral part of these devices....
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TL;DR: In this article, a vibrating hollow fiber membrane module is used to increase the shear rate at the membrane surface, which makes it possible to filtrate at low feed cross-flow velocity and thus at a low transmembrane pressure.
92 citations
TL;DR: Experimental results have shown that the flux increases with disk rotating speed, increases with transmembrane pressure at higher cell concentrations, and can be sustained at high levels under constant flux mode, and an order of magnitude improvement over the crossflow microfiltration control was projected for large scale production.
Abstract: To develop a highly efficient cell harvest step under time constraint, a novel rotating disk dynamic filtration system was studied on the laboratory scale (0.147-ft. 2 nylon membrane) for concentrating recombinant yeast cells containing an intracellular product. The existing crossflow microfiltration method yielded pseudo-steady state flux values below 25 LMH (L/m 2 .h) even at low membrane loadings (<10 L/ft. 2 ). By creating high shear rates (up to 120,000 s -1 ) on the membrane surface using a rotating solid disk, this dynamic filter has demonstrated dramatically improved performance, presumably due to minimal cake buildup and reduced membrane fouling. Among the many factors investigated, disk rotating speed, which determines shear rates and flow patterns, was found to be the most important adjustable parameter. Our experimental results have shown that the flux increases with disk rotating speed, increases with transmembrane pressure at higher cell concentrations, and can be sustained at high levels under constant flux mode. At a certain membrane loading level, there was a critical speed below which it behaved similarly to a flat sheet system with equivalent shear. Average flux greater than 200 LMH has been demonstrated at 37-L/ft. 2 loading at maximum speed to complete sixfold concentration and 1.5-volume diafiltration for less than 100 min. An order of magnitude improvement over the crossflow microfiltration control was projected for large scale production. This superior performance, however, would be achieved at the expense of additional power input and heat dissipation, especially when cell concentration reaches above 80 g dry cell weight (DCW)/L. Although a positive linear relationship between power input and dynamic flux at a certain concentration factor has been established, high cell density associated with high viscosity impacted adversely on effective average shear rates and, eventually, severe membrane fouling, rather than cake formation, would limit the performance of this novel system.
91 citations
"Performance characterization and st..." refers background in this paper
...Accordingly, it has been suggested that either a rotating accessory, for example stirrer,([1,2]) rotating membrane([3,4]) or a vibrating surface([5,6]) must be an integral part of these devices....
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TL;DR: Protein, produced by a bacterial culture of recombinant Vibrio cholerae, was separated from cells in a fermentation broth by cross‐flow microfiltration by a new, mechanically agitated shear filter from Pall.
Abstract: Protein, produced by a bacterial culture of recombinant Vibrio cholerae, was separated from cells in a fermentation broth by cross-flow microfiltration. A new, mechanically agitated (rotational) shear filter, the DMF(TM) filter from Pall, was used to perform the separation. Higher protein recovery and permeate flux than commonly obtained during cell harvesting were demonstrated using sixfold concentration followed by twofold diafiltration. The transmembrane pressure only increased by 10 kPa when the flux was kept constant at 150 L/m(2) h during both concentration and diafiltration. The protein transmission was about 100% initially, and over 90% at the end of the concentration process. The protein transmission during the diafiltration was over 80%. The total recovery of protein was 97%. When using an enzymatic cleaning agent, no significant pure water flux decrease was detected during the course of the experiments. (c) 1996 John Wiley & Sons, Inc.
65 citations
"Performance characterization and st..." refers background in this paper
...Accordingly, it has been suggested that either a rotating accessory, for example stirrer,([1,2]) rotating membrane([3,4]) or a vibrating surface([5,6]) must be an integral part of these devices....
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