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.
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Hamel Center for Undergraduate Research
Dr. Ihab Farag (Mentor)
Marian Elmoraghy
Dr. Nancy Whitehouse
Daniel Eltringham
Kristen Blackwell
John Newell
Dover Wastewater Treatment Facility