Energy and Water Resource Efficient Production of Microalgae Lipids Kelsey Price, Chemical Engineering Dept., University of New Hampshire, Durham, NH 03824 Background • Algae require nutrients, light, CO2 & a water medium to grow in a photobioreactor (PBR) and produce lipids • Lipids are hexane solvent-extracted from algae • Lipids (algae oil) are feedstock to renewable biodiesel Process Results Monitor algae growth with spectrophotometer turbidity readings and microscope cell counts Algae Growth Stages: Measured Turbidity: Turbidity 1.6 1.4 RO water,8000 LUX 1.2 Waste water, 8000 LUX 1 40 Scale Scale up: 80 up: L 80 PBR L PBR using using Fluorescent Fluorescent Light Light (8000 (8000 LUX) LUX) Scale Up: of Water Source Chlorella C2mass Productivity and Effect Effect of Effect Medium of Medium Source Source on Chlorrella onon Chlorrella C2 C2 mass Production, Production, 80LLipid PBR, 8000 LUX Fluorescent Light andinand Lipid Content. Content. 40 Lipid/oil Concentration 35 35 Productivity, Productivity, mg/L-day mg/L-day 30 30 Lipids, Lipids, g/100 g/100 g of galgae of algae 25 25 20 20 15 15 10 10 RO water,2000LUX 0.8 26.5 26.5 Waste water, 2000 LUX 0.6 0.4 4.93 4.93 0.2 0 3 4 5 6 7 8 11 12 Days 5 5 0 0 FreshFresh water water Advantages Disadvantages No food vs. fuel concerns Fresh water consumption Reduce land requirements Energy Intensive Consume CO2 while growing Unfavorable economics Goal/Objectives Goal: Determine energy and fresh water efficient conditions to grow algae rich in lipids/oil Objectives: To study: • Replacement of Fluorescent light with LEDs • Oil production in waste water vs. fresh water • Light intensity effect on lipid/oil production (Chlorella C2 Algae Lipid Production, mg lipids/L Solution-day) 6.296.29 • LEDs produce more lipids than fluorescent lighting, while saving energy • A greater light intensity increases lipid production • Waste water is a viable option for growing algae and conserving fresh water 6.706.70 6.006.00 5.005.00 3.983.98 3.523.52 4.004.00 3.003.00 2.002.00 1.001.00 0.380.38 0.290.29 0.000.00 Fresh water, Waste water, Fresh water, Waste water, Fresh water, Waste water, Fresh water, Waste water, Fresh water, Waste water, Fresh water, Waste water, LEDs RedRed Red-Blue Red-Blue FluorescentFluorescent Fluorescent RedRed LEDs LEDsLEDsRed-Blue LEDsLEDs Red-Blue LEDsLEDs Fluorescent LEDs influence the production of more lipids, and waste water lipid results are comparable if not better Methodology/Techniques Effect of light intensity on lipid production (Chlorella C2 Algae Lipid Production, mg lipids/L Solution-day) • In-situ production of Biodiesel (integrated lipid extraction and transesterification) • Reduced and effective nutrient solution specific to algae growth in waste water • Replace hazardous hexane lipid extraction solvent - Less hazardous alternative - Inexpensive alternative Acknowledgments PBR 5500 LUX 8000 LUX 2000 LUX m • Grow algae in PBR using Fluorescent light and Red and Red-Blue LEDs (48% less energy) • Measure light intensity in LUX • Monitor algae growth • Harvest/dry algae, get algae production rate • Extract oil and determine algae oil content Future Investigations Red LEDs Fluorescent PBR Waste Waste water water Conclusions Effect of light and water source on lipid production 8.008.00 7.007.00 3.88 3.88 Waste water produces more algae, and comparable lipids Results Algae Pros & Cons 34.5 34.5 2000 LUX A higher light intensity influences a greater lipid production. • • • • • • • • Hamel Center for Undergraduate Research Dr. Ihab Farag (Mentor) Marian Elmoraghy Dr. Nancy Whitehouse Daniel Eltringham Kristen Blackwell John Newell Dover Wastewater Treatment Facility