A Feasibility Study Using Electrolysis Treatment (ET) As the Pre-treatment Method to Extract Lipid from Chlorella sp. for Biodiesel Production

The feasibility study on Chlorella sp. lipid extraction using an electrolysis treatment (ET) as pre-treatment was investigated. Stainless steel was used as the anode and cathode material. The ET method was conducted in a batch or continuous system with or without air aeration and recycling flow. The total lipid in Chlorella sp. AWET and AWET were not analysed due to small sample volume. Approximately same amount of lipids were attained from Chlorella sp. BWOET (7.97 ± 0.43% glipid/gdry wt) and BWET (7.95 ± 0.37% glipid/gdry wt) if treated at 5 V/cm and aerated at 16.7 µm3 /s for 1800s. Whereas, if Chlorella sp. was treated at 13 V/cm and aerated at 16.7 µm3 /s for 1800 s, the total lipid obtained in Chlorella sp. CWOET (8.18 ± 0.49% glipid/gdry wt) was 1.13-fold higher than CWET (7.22 ± 0.47% glipid/gdry wt). Meanwhile under semi-continuous system, similar pattern of result was achieved in Chlorella sp. DWOET (8.58 ± 0.49% glipid/gdry wt) with 1.11-fold higher than DWET (7.72 ± 0.54% glipid/gdry wt), if treated at 14 V/cm and recycled at 2.3 µm3 /s for 3000s. This corresponded to lipid oxidation that might have occurred during the ET method. The fatty acid methyl ester (FAME) composition of Chlorella sp. DWOET and DWET contained predominantly methyl linolenate (C18:3) and methyl palmitate (C16:0). The concentrations of methyl palmitate attained in Chlorella sp. DWOET and DWET were 0.049 ± 0.005 g/m3 and 0.045 ± 0.005 g/m3 , respectively.