Microalgae-based biofuel technology

Transcription

1 Microalgae-based biofuel technology Peer Schenk School of Biological Sciences Faculty of Science The University of Queensland Australia 6 October Microalgae Technology Conference Taiwan

2 IMPORTANCEOF CO 2 SEQUESTRATION

3 RENEWABLE ENERGY SOURCES SOLAR: 126,000 TW Plants GEOTHERMAL: 92,000 TW-YR GEOTHERMAL: 92,000 TW Renewable, CO 2 -free energy sources TIDAL POWER: 0.1 TW-YR WAVE: 2 TW-YR WIND: 5 TW-YR OCEAN THERMAL: 10 TW-YR BIOMASS: 172 TW-YR vs. current energy demand WORLD ENERGY DEMAND: 13 TW

4 Search for renewable fuels increased attention on climate change decline in fossil fuel reserves fuels account for ⅔of global energy demand increasing cost environmental damage need for sustainable biofuel production without competing for arable land

5 BIO-FUEL PRODUCTION: PHOTOSYNTHESIS IS CENTRAL 1. DRIVES FIRST STEP IN THE CONVERSION OF LIGHT TO CHEMICAL ENERGY 2. PRODUCES FEEDSTOCKS FOR FUEL SYNTHESIS 3. BUT CONVENTIONAL CROPS HAVE ~1-3% PHOTOSYNTHETIC EFFICIENCY 4. INCREASING PHOTOSYNTHETIC EFFICIENCY INCREASES ECONOMIC VIABILITY

6 Why Algae biofuels? Increasing demand for Biofuels Fossil fuel depletion / Effect on Climate change Transport fuels: 66 % of total energy use biodiesel: high energy content and easy to process. Problems with Terrestial Biofuels: Large land requirements (low energy conversion efficiency) Only possible on scarce arable land Competition with food production Deforestation High water consumption (runoff, evaporation) Inefficient nutrient consumption (runoff N 2 O emissions)

7 Advantages of Algae Fuel No Arable land required High yields due to: High biomass density no roots, leaves, stems High growth rates (DT as fast as ~3.5 h) High tryacylglyceride(tag) content (~20-70 %) Low water consumption: Seawater/ agricultural runoff water / waste water. No loss due to runoff No evaporation in closed bioreactor Efficient use of nutrients CO 2 capture possible Residue methane/ethanol, cattle feed,

8 The ultimate energy cycle CO 2 & NO X Hydrogen Production Waste from Sewage plant Biodiesel & Bioethanol Production Waste to Power plant

9 Algae Biotechnology Biohydrogen Agrichar (carbon sequestration)

10 The University of Queensland Algae Biodiesel Project Collection & culture of microalgae freshwater, brackish, marine environments (SE Queensland) Pure culture Identification (microscopy/ribosomal DNA sequencing) Selection criteria Growth rate Biomass Lipids Flocculation/oil extraction Algae breeding Midscale outdoor cultivation

11 Microalgae collection -BR

12 Pure culture

13 identified microalgae Culture ID Given Name Accession Number BR2 Scenedesmus sp. isolate BR2 EU BR8a Scenedesmus sp. isolate BR8a EU BR8b Desmodesmus sp. isolate BR8b EU AR1, BR17, PAG Chlorella ducis EU BR19 Desmodesmus tenuis EU BR25 Desmodesmus irritus EU BR30 Chlorella caelum EU SD3 Chlorella optimates EU ESK TOWER Chlorella sp. Esk Tower EU P1 Desmodesmus viridis EU Timmins, et al., 2008 Eukaryotic Cell

14 Nile red staining Nile red stained culture x400 uv fluorescence

15 Lipid analysis (TLC and GC-MS) Fatty Acid BR2 BR8 BR20 BR21 BR30 ORI1 ORI4 ESK TOWER C10: C12: C14: C14: C16: C16: C16:1 iso 5.51 C16: C16: C18: C18: C18:1 iso C18: C18: C18: C18: C20: C20:4 1 Quality of fuel Low PUFA (polyunsaturated fatty acids) Less oxidation Long term storage High PUFA Good cold flow properties Overcomes cold filter plugging point (CFPP) An Ideal mix (Schenk, et al., 2008 Bioenergy Research) 16:1, 18:1 and 14:0 in the ratio 5:4:1 TOTAL

16 Search for inexpensive nutrient sources Soil extract medium Wastewater UQ Tennis courts AWMC

17 Algae testing and media optimisation Raceway pond (low nutrient) 10-Litre Bioreactor

18 Split system design for synchronised TAG induction and avoidance of contamination Bioreactor (high nutrient) sun Clean water Batch transfer Raceway pond (low nutrient) Wastewater CO 2

19 Split system design for synchronised TAG induction and avoidance of contamination Laboratory inoculum (exponential growth) Bioreactor (continuous exponential growth) Raceway pond (low nutrient) Nutrients, Wastewater, Seawater, CO 2 Open raceway ponds

20 TAG Induction, Extraction and Biodiesel Synthesis Open raceway ponds (low nutrient water) Oil extraction (foam fractionation) Harvest after 3 days and replace with culture Biodiesel synthesis (transesterification)

21 ALGAE BREEDING Adaptive evolution of microalgae to select for high TAG cells yellow red

22 BR2 evolved for high TAG production (synchronised induction) Raceway pond (low nutrient) Nutrients, Wastewater, Seawater, CO 2

23 Bioreactor team Raceway pond (low nutrient)

24 UQ Algae biodiesel team Coordination Peer Schenk Algae collection Skye Thomas-Hall Eugene Zhang Stephanie Ewert Bart Nijland Priyanka Nayak PUFA analysis Matthew Timmins Philipp Keymer Media Fauzi Haroon Alex Metcalf Algae Breeding/Adaptive Evolution Adam Posthuma Yamini Kashimshetty Midscale Outdoor Cultivation Miklos Deme Kalpesh Sharma Sourabh Garg Oil Extraction/Biodiesel Synthesis Liguang Wang Steve Welsh Christopher Beavon Grant applications Stephen Su North Queensland & Pacific Pty Ltd

25 Photo-Biological Hydrogen Production in the Green Alga Chlamydomonas reinhardtii MOLECULAR BIOLOGY GENETIC SCREENING

26 Focus: Developing economic solar-powered H 2 production from H 2 O using engineered green algal cells. Solar Solar Energy Energy Algae Algae 22 H 2 O 2 22 H 2 O PHOTOSYNTHESIS NATURAL SURVIVAL MECHANISM BIOCHEMISTRY MOLECULAR BIOLOGY GENETIC SCREENING

27 Photosynthetic H 2 production in green algae Small scale Experimental set-up: Measurement of gas purity via GC Gas-volume determination Monitoring Dissolved Oxygen and ph Sampling and injecting possible H 2 produced can power a fuel cell car

28 Photosynthetic H 2 production in green algae MOLECULAR BIOLOGY GENETIC SCREENING

29 Mutant with high efficiency H2 production Stm6 Stm6 Starch StarchStore Store WT WT 1. H20 > H+ + e- > H2 2. STARCH > H+ + e- > H2

30 BIOCHEMISTRY: SOLAR POWERED H 2 PRODUCTION FROM H 2 O -S

31 Hydrogen production during anaerobiosis

32 Microarray Analysis 4650 genes differentially expressed 644 genes significantly induced or repressed.

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35 Rearrangement of photosynthetic antenna

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37 Skye Thomas-Hall, Anh Vu Nguyen, Alizée Malnoë, Matthew Timmins, Evan Stephens, Jan H. Mussgnug