The economic feasibility of growing Nannochloropsis sp. at the commercial scale was evaluated for the production of biodiesel and co-products. A local isolate of Nannochoropsis was grown in (6) 200-L raceway ponds at Alexandria University wherein cultures reached maximum cell concentrations ~ 4–6 × 10⁷ cells/mL (0.63–0.88 g/L dry weight) and a peak biomass productivity of 0.09 g/L/day during mid- to late-log growth. Areal productivity was estimated at 17.65 g/m²/day when ponds were operated on a semi-batch schedule, harvesting 50% every 2 days and recycling 60% of the media. Areal productivity was estimated around 10.3 g/m²/day for batch schedules. Late-log cultures harvested from all ponds yielded 10 kg of wet algal paste, which was reduced to 1.05 kg of dried algal powder. The biomass was composed of valuable co-products approx. 14.0% carbohydrate, 37.3% protein, 0.01% chlorophyll-a, and 0.02% carotenoids (w/w). Total lipid made up 38% of the biomass (w/w); 34% of the biomass was determined to be neutral lipid which are transesterified to biodiesel and 4% are polar lipid. Fatty acids from glycerolipids were quantified by gas chromatography-flame-ionization detector (GC-FID) as fatty acid methyl esters (FAMEs) revealing carbon-chain lengths from C6 to C22. A preliminary economic evaluation was conducted to determine the feasibility of constructing commercial-scale algae biodiesel production facilities in Egypt. The return on investment (ROI) of the current economic feasibility study for biofuel production alone was 22% after considering the market prices of the biodiesel, cake, and glycerol by-products. Based on this assessment, additional high-value products are needed to improve the ROI. Noting that the valuable co-products are considered as added cost in the biomass left after biodiesel production.

生长Nannochloropsis sp。的经济可行性。以商业规模评估了生物柴油和副产品的生产。亚历山德里亚大学的（6）个200升水道池塘中生长了一种拟南芥的局部分离株，其中培养物达到最大细胞浓度 〜4–6 ×10 ⁷细胞/ mL（干重0.63-0.88 g / L），并达到了峰值生物量生产力在对数增长的中后期达到0.09 g / L /天。按半分批时间表操作池塘时，估计每天的地域生产力为17.65 g / m ² /天，每2天收获50％，回收60％的培养基。估计地域生产力约10.3 g / m ²/天的批处理时间表。从所有池塘收获的对数log-log养殖物产生10千克湿藻糊，然后减少为1.05千克干藻粉。生物质由有价值的副产物组成。14.0％的碳水化合物，37.3％的蛋白质，0.01％的叶绿素-a和0.02％的类胡萝卜素（w / w）。总脂质占生物质的38％（w / w）；确定了34％的生物质为中性脂质，它们被酯交换为生物柴油，而4％为极性脂质。通过气相色谱-火焰电离检测器（GC-FID）将甘油脂中的脂肪酸定量为脂肪酸甲酯（FAME），显示出从C6到C22的碳链长度。进行了初步的经济评估，以确定在埃及建设商业规模藻类生物柴油生产设施的可行性。考虑到生物柴油，饼和甘油副产品的市场价格，仅就生物燃料生产而言，当前经济可行性研究的投资回报率（ROI）为22％。基于此评估，需要其他高价值产品来提高ROI。注意，有价值的副产品被认为是生物柴油生产后剩余的生物质中的增加成本。