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Transcript of Lab-scale technologies for the Cultivation and biorefinery ...e4water.eu/_media/1625_DTU E4Water...
LAB-SCALE TECHNOLOGIES FOR THE CULTIVATION AND BIOREFINERY OF MICROALGAE
SPEAKER: DAVIDE DE FRANCISCI TECHNICAL UNIVERSITY OF DENMARK
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 280756.
E4Water Final Conference, Brussels, April 19-20, 2016 2
MICROALGAE CHARACTERISTICS STRENGHTS AND BENEFITS
Diameter: 0,5 µm – 2 mm
Salt, brakish and fresh water Amount to 0.2 % of the total global standing biomass Produce app. 55 % of the total global annual biomass
1 ton of algae can fixate 1.8 tons CO2
High lipid content (up to 77% of DW)* *Chistie, 2007
E4Water Final Conference, Brussels, April 19-20, 2016 3
ADDED VALUE FROM MICROALGAE
E4Water Final Conference, Brussels, April 19-20, 2016 4
Algal biomass = high added value products and bioenergy
(Bruton et al, 2009)
ADDED VALUE FROM MICROALGAE
E4Water Final Conference, Brussels, April 19-20, 2016 5
Trend alert: Biofuel companies have shifted focus to high-value products: Algenol Sapphire Synthetic Genomics Aurora Cellana Solix
ADDED VALUE FROM MICROALGAE
E4Water Final Conference, Brussels, April 19-20, 2016 6
Production is costly (cultivation , harvesting) - Open pond - Photobioreactor
> Economically unfeasible
CHALLENGE
E4Water Final Conference, Brussels, April 19-20, 2016 7
Algal biomass
Harvesting
Bioprocessing Biofuels
• Bioethanol • BioH2 • BioCH4 • Biodiesel
Extraction processing
• Food (dietary) • Biochemicals (vitamins,
minerals, pigments, enzymes, etc.)
Biofertilizer
Rice, wheat, cultivation
• Feed (fish, poultry)
N, P, K nutrients recycling Recycle exhaust gas for a carbon source
Algal biomass = high added value products and bioenergy
BIOREFINERY
E4Water Final Conference, Brussels, April 19-20, 2016 8
POSSIBLE SOLUTION
Integration of algae production and wastewater treatment
16.04.2016
Remove pollutants Obtain bio-products
Utilities - CO2 - Power
E4Water Final Conference, Brussels, April 19-20, 2016 9
STRATEGY
Pond-like Lab scale
Photobioreactor
Flat panel Lab scale
Photobioreactor
Comparison of potential yield
vs. cost
Cultivation system choice
Raceway pond
Photobioreactor
Biomass separation
Biomass characterization
High added value products
Biogas potential
Productivity comparison
Best algal species for
each wastewater
1. Different species are screened for their potential to grow in different wastewaters
2. Upscaling strategy
Candidates
E4Water Final Conference, Brussels, April 19-20, 2016 10
• Variety of microalgal species can be screened for their potential to grow in waste-waters
Best algal species for
each wastewater
Microplate Reader
MICROPLATE SCREENING
E4Water Final Conference, Brussels, April 19-20, 2016 11
SYMBIOSIS
11
E4Water Final Conference, Brussels, April 19-20, 2016 12
Fluorescence measurements have a lower limit of quantification and can therefore extend the observable period of exponential growth
Fluorescence has less variation among triplicates and a signal more quickly separated from the blank. Chlorella vulgaris growth curve.
FLOURESCENCE TO DETERMINE EXPONENTIAL GROWTH RATE
E4Water Final Conference, Brussels, April 19-20, 2016 13
VALIDATION OF THE SCREENING METHOD
Microplate-based measurements enable predictions comparable to reactor-based ones
E4Water Final Conference, Brussels, April 19-20, 2016 14
Microplate screening is a fast and cost effective
method to test hundreds of different waste-waters/strains combinations
The microplate screening method fits perfectly into the Symbiosis scenario
SCREENING – STRENGTHS AND BENEFITS
E4Water Final Conference, Brussels, April 19-20, 2016 15
APPLICATION
Effluent TN: 180 mg L-1
TP: 10 mg L-1
VFA: ~300 mg L-1
Novozymes Kalundborg WWTP
E4Water Final Conference, Brussels, April 19-20, 2016 16
FRESHWATER
Bothryococcus braunii
Chlorella sp
Euglena gracilis
Galdieria sulphuraria
Haematococcus pluvialis
Nitzschia palea
Scenedesmus acutus
MARINE
Brachiomona submarina
Dunaliella tertiolecta
Isochrysis sp.
Nannochloropsis oculata
Phaeodactylum tricornutum
Porphyridium cruentum
Rhodomonas salina
MICROALGAE SPECIES CANDIDATES
E4Water Final Conference, Brussels, April 19-20, 2016 17
NOVOZYMES WASTEWATER
C. protothecoides
S. acutus
H. pluvialis
C. vulgaris
Unidentified diatom
The best candidate resulted to be Chlorella spp. S. obliquus and H. pluvialis also shows good growth on 100% WW.
E4Water Final Conference, Brussels, April 19-20, 2016 18
REACTOR CONFIGURATION
High light Low light
E4Water Final Conference, Brussels, April 19-20, 2016 19
Flat-panel photobioreactors (0.4 L) 200 and 2100 µmol m-2s-1 PAR Optimal temp and pH maintained by build in feedback systems C. sorokiniana 100 % waste-water Optical density, dry weight and nutrients
REACTOR CONFIGURATION
E4Water Final Conference, Brussels, April 19-20, 2016 20
Photosynthetic yield (n, g mol-1 ), and percentage of light (PAR) absorbed (p, % ).
REACTOR CONFIGURATION
High light Low light
E4Water Final Conference, Brussels, April 19-20, 2016 21
NUTRIENT REMOVAL
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Legend. Pigment content in Chlorella sorokiniana biomass. Dilution rate in decreasing order.
BIOREFINERY
E4Water Final Conference, Brussels, April 19-20, 2016 23
Dilution rate is in decreasing order Linoleic acid (18:2) is an omega-6 fatty acid α-linolenic acid (18:3) (ALA) is an omega 3 fatty acid
BIOREFINERY
Fatty acids
E4Water Final Conference, Brussels, April 19-20, 2016 24
UTILIZATION OF ORGANIC CARBON
waste streams offer a low cost, sustainable source of N, P and other minerals
they may also contain organic carbon, which can me metabolized by microalgae
acetate is characteristic of AD effluents
Aim: develop a strategy for adding AD effluent to bioreactor in order to maximize productivity
E4Water Final Conference, Brussels, April 19-20, 2016 25
UTILIZATION OF ORGANIC CARBON
• Strategy 1. Autotrophic: M8a Dilution during light cycle 2. Mixotrophic: + 1 g/L Acetate during light cycle 3. Cyclic Autotrophic/heterotrophic Constant rate: +2 g/L during dark cycle, + acetate free medium during the light. 4. Cyclic Autotrophic/heterotrophic only diluting at night: +2 g/L during dark cycle, no dilution during the day. “enhanced heterotrophy”
Conditions: Mimic Kalundborg, Ecoduna + Anaerobic Digestor effluent 16:8 light:dark cycle, 190-200 μmol m-2 sec-1
E4Water Final Consortium Meeting, Antwerp, April 18, 2016 26
UTILIZATION OF ORGANIC CARBON
Day
0 2 4 6 8 10 0
1
2
3
4
5
6
2 mixotrophic reactor 3 cylcic reacfor
tota
l har
vest
(g)
Acetate addition increased productivity Highest substrate efficiency came when adding acetate
at night
E4Water Final Consortium Meeting, Antwerp, April 18, 2016 27
CONCLUSIONS
identified a waste-water stream that can replace culture medium
identified the preferred vertical orientation demonstrated a new method to characterize
growth, composition and nutrient removal in microalgae cultivation in waste-waters
identified a possible route to optimize biomass productivity mixotrophically
validated a microplane-based screening method
E4Water Final Conference, Brussels, April 19-20, 2016 28
• Due to high protein and lipid content (over 70% in total), microalgae can be dedicated for biofuels production, such as biogas (methane).
• Biogas derived from the digestibility of microalgae has a high methane content, i.e. over 60%
• Methane content is 7–13% higher compared to biogas from energy crops, like maize silage.
• Biogas derived from the digestibility of microalgae does normally not contain sulphur.
• Co-digestion of manure with several organic wastes is a common practice applied in the Danish centralised biogas plants.
• Biogas plants currently utilise around 8 % of available manure and a large part of the organic wastes from the Danish industries.
BIOENERGY
E4Water Final Conference, Brussels, April 19-20, 2016 29
SUBSTRATE CHARACTERISATION
Parameters Unit Microalgae Swine manure
TS g/L 24.60 33.50 VS g/L 22.69 23.00 pH - 5.87 8.50 TKN g/L 1.78 4.31 Ammonium nitrogen g/L 0.18 3.09 Organic N g/L 1.60 1.22 Proteins g/L 10.00 7.63 Lipids g/L 2.63 1.30 Carbohydrates g/L 8.19 6.53 Total VFA g/L 0.27 6.33 Acetate g/L 0.13 4.91 Propionate g/L 0 1.07
Iso-butyrate g/L 0 0 Butyrate g/L 0 0 Iso-valerate g/L 0 0.35 Valerate g/L 0 0 n-hexanoate g/L 0.14 0
E4Water Final Conference, Brussels, April 19-20, 2016 30
BATCH ASSAY
0
175
350
525
700
0 5 11 16 21
Met
hane
yie
ld
mLC
H4/
gVS
Days
Experimental BMP of swine manureExperimental BMP of microalgae
Theoretical BMP of swine manureTheoretical BMP of microalgae
0
175
350
525
700
0 5 11 16 21
Met
hane
yie
ld
mLC
H4/
gVS
Days
80/20 60/40
40/60
Manure /algae ratio
E4Water Final Conference, Brussels, April 19-20, 2016 31
Batch experiments
• The addition of 40% wastewater microalgae in swine manure exhibited the highest methane yield (38% higher compared to swine manure). Further addition affected negatively the biomethanation process.
• Possible synergistic effect (further investigation needed)
Continuous experiments
• Co-digestion of SM/M at a ratio of 60/40 presented 21.6% higher methane yield compared with the corresponding one from the degradation of SM as mono-substrate.
E4Water Final Conference, Brussels, April 19-20, 2016 32
Thank you for your attention
This project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 280756.