Impact of Membrane Pore Size on the Clarification Performance of Grape Marc Extract by Microfiltration

Abstract

The influence of membrane pore size on the permeate flux, fouling mechanism, and rejection of soluble and suspended solids, as well as of phenolics and anthocyanins, in the clarification of grape marc extract by microfiltration (MF) was studied. MF was operated by using three monotubular ceramic membranes with a pore size of 0.14, 0.2, and 0.8 µm, respectively, according to a batch concentration configuration in selected operating conditions (2.25 bar as operating pressure, 4.93 L/min as feed flow rate, and 25 °C as operating temperature). No significant differences in the permeate flux values were appreciated despite the difference in pore size. The mathematical analyses of the flux behavior revealed that intermediate pore blocking is the predominant mechanism for 0.14 and 0.2 µm membranes, whereas complete pore blocking prevails for the 0.8 µm membrane. Differences in the fouling mechanism were associated with differences in the total phenols rejection: the highest rejection was observed for the 0.8 µm membrane followed by 0.2 and 0.14 µm membranes. All selected membranes showed low rejection of sugars, with values lower than 10%, and no retention towards anthocyanins. All the clarified extracts showed a turbidity lower than 4.87 NTU. Based on the experimental results, the 0.14 µm membrane appeared as the best option for the clarification of grape marc extract.

Comparison of Polypropylene and Ceramic Microfiltration Membranes Applied for Separation of 1,3-PD Fermentation Broths and Saccharomyces cerevisiae Yeast Suspensions

“…These results offer vital evidence that the permeate quality is directly correlated to the membrane pore size. The similar relation between diameters of the MF membranes pore size and filtrate quality has been found in previous studies [ 79 , 85 ]. For instance, Mora et al [ 85 ] investigated the MF process of a grape marc extract characterized by the turbidity equal to 640.44 ± 380.32 NTU.…”

“…The similar relation between diameters of the MF membranes pore size and filtrate quality has been found in previous studies [ 79 , 85 ]. For instance, Mora et al [ 85 ] investigated the MF process of a grape marc extract characterized by the turbidity equal to 640.44 ± 380.32 NTU. The authors have shown that the use of ceramic membranes with the pore sizes of 0.14 and 0.80 µm provided the permeate with 3.8 NTU and 4.8 NTU, respectively.…”

Prediction of Permeate Flux in Ultrafiltration Processes: A Review of Modeling Approaches

“…On the contrary, the model developed by Yee et al [ 191 ] showed a good capacity for prediction (R 2 99.2%). It is particularly interesting that the ARIMA model and the one reported by Yee et al [ 191 ] have been validated for more than 10 h of operation with a great capacity of forecast [ 171 , 191 , 209 , 210 ]. Thus, both models appear to be adequate for the long-term prediction of permeate flux.…”

Performance Evaluation of Tight Ultrafiltration Membrane Systems at Pilot Scale for Agave Fructans Fractionation and Purification

“…The information given by the suppliers is limited to the MWCO, which is defined as the molecular weight (MW) at which 90% of the solute is rejected by the membrane; however, there is no standardized procedure for this test, so there could be variability under different conditions [ 23 ]. Furthermore, rejection is affected by the molecular shape of the solute, the membrane–solute interaction, the configuration of the membrane, and the interaction between the solutes and the concentration polarization phenomenon, which can reduce the size of the pores and affect the separation [ 24 , 25 ].…”