Effect of membrane properties on tilted panel performance of microalgae biomass filtration for biofuel feedstock

Abstract

Efficient membrane-based technology for microalgae harvesting can be achieved via application effective membrane fouling control coupled with appropriate membrane materials. This study explores the combined impact of membrane properties and the tilted panel system on filterability of Euglena sp broth, a potential source of biofuel feedstock. Four membranes from polyvinylidene difluoride (PVDF) and polysulfone (PSF) of PVDF-1, PVDF-3, PSF-1 and PSF-3 were evaluated. Generally, increasing aeration rate, tilting angle and lowering switching period enhance the system performance for all the tested membranes to give the highest permeances of 660, 724, 743 L/m2 h bar, respectively. Those values are among the highest reported in literature. The magnitude of the effect is affected by the membrane properties, mainly by pore size. Tilting without switching configuration is desirable for the membrane with a large pore size (PVDF-1, 0.42 μm) which produced the highest panel permeability of 724.3 (L/m2 h bar), which is >23% higher than the tilted with switching. For this membrane, intermittent aeration applied under switching mode worsened the pore blocking. Membranes with low pore sizes (0.11, 0.04 and 0.03 μm for PVDF-3, PSF-1 and PSF-3, respectively) excelled under switching mode since they are less prone to pore blocking due to smaller pore apertures. Overall results suggest that to gain the full benefit of the tilted panel, operational system of either one-sided without switching or two-sided involving switching must be tailored in conjunction with the desirable properties of the membranes. This finding can help to lower the energy input for microalgae-based biofuel production.