ASSESSMENT OF NEW MEMBRANE CONFIGURATIONS FOR AN ULTRA-LOW-PRESSURE MEMBRANE BASED MICROALGAE FILTRATION

• Main Author: WAN OSMAN, WAN NUR AISYAH
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/22795/1/Wan%20Nur%20Aisyah%20Wan%20Osman_19001650.pdf; http://utpedia.utp.edu.my/22795/

The demands for microalgae as a source of biofuels have escalated recently. However, the process of processing microalgae into biofuels is still costly, including harvesting biomass from cultivation medium. This study assesses the performance of an ultra-low pressure membrane (ULPM) filtration system for Chlorella vulgaris broth filtration. Two membrane types, namely flat (FM) and corrugated (CM) membranes were evaluated in terms of their properties and filtration performance. Both membranes were characterized in terms of surface morphology, cross-section, thickness, average pore size and contact angle. Besides, other parameters to evaluate the membrane filtration performance, which includes the type of system (single phase and air lift), transmembrane pressure, TMP (2.5 – 19 kPa) and membrane panel orientation (tilting angle were varied from 0⁰ to 90⁰), were also conducted. Results revealed that the FM has a smoother surface than CM due to the presence of surface corrugation on top of the CM. Furthermore, the CM was thicker (269 μm), had a larger average pore size (0.78 μm) and higher contact angle (105.525⁰) than the FM. In addition, a noticeable impact of membrane compaction was revealed due to the applied TMP to drive the filtration. Hence, lower TMP was suggested able to reduce the compaction phenomenon. In addition, the membrane fouling formation rate for CM at the lowest TMP (2.5 kPa) was the highest (47.05%) due to the increased likelihood of foulant deposit on the valley sites as there was an insufficient force to remove the foulant. However, the installation of aeration was able to overcome this limitation of standalone CM as fouling control. The percentage increment due to the effect of aeration for CM (45%) was found out to be higher than FM (33%), especially at the lowest TMP (2.5 kPa). Moreover, it was found that the best combination of vertical CM coupled with aeration operated under the lowest TMP was able to achieve higher permeability (2393 ± 0 L/(m2hrbar)) with a higher percentage of permeability increment due to the effect of surface patterning (22%).