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Presented at All India Seminar On Energy Management Through Renewable Sources and Efficient technologies
Institution of Engineers, Madhya Pradesh State Centre, Bhopal, 08-09 th Jan, 2011
MICRO –ALGAE AS A SOURCE OF BIO DIESEL: CHALLENGES AND FUTURE PROSPECTS
K.SudhakarAssistant professor, Energy Department,
MANIT, Bhopal-462007, MP,India
Dr. S. SureshAssistant Professor, Department of Chemical Engg.,
MANIT, Bhopal-462007, MP, India
Dr. (Mrs) M. Premalatha Associate Professor, CEESAT, NIT Trichi, TN, India
‘Climate change poses a great challenge to our development prospects…....we need global response, a national response and a local response’
-------Hon. Dr. Manmohan Singh
Concerns for Global warming- Current Assessment
IPCC AssessmentFirst Report - 1990Second Report - 1995Third Report - 2001Fourth Report - 2007Average global temperature increase 1906-2005 – 0.74oCExpected Temperature rise up to the Year 2100 2.4 to 6.4 oCExpected Sea Level rise 18 to 59 cm
Major and Minor Greenhouse Gases and Global Warming Potential
Major greenhouse gas concentrations of CO2, NOx, CFCs, Methane have increased 20-30% since pre-industrial era
o The Energy generating plants contributes mostly to increasing atmospheric CO2 concentrations.
o CO2 concentration increased from 280 ppm to 390 ppm in the present
o Average global temperature increase by 1.5-5 degree.
SCIENTIFIC
PREDICTIVE
Coping with Global Warming
Air interactionGreenhouse Gases Earth Interactions
Global Warming Climate Change Impacts -AdaptationMitigation Strategy
Crop Productivity
Frequent Disasters
Water Scarcity
Vector borne diseases
Renewable sources
Energy Efficiency
Clean Coal Technology
CCS
EFFECTCAUSE
The World’s Energy Resources Are Limited!
– High Growth rate– Minimal resource
requirement– High Photosynthetic
efficiency– Up to 70% of algae
biomass is usable oils– does not compete for land
and space with other agricultural crops
– can survive in water of high salt content
Why Micro-algae?
Algae Growing Methods :
What is neededSunlightCO2
Nutrients
Storage of EnergyLipids and oilsCarbohydrates
Other Dependent parameters: Temperature , pH (Physical factors) Pathogen ,predation, competition (Biotic factors)
Micro algae Oil content (% dry weight)
Botryococcus braunii 25-75Chlorella sp 28-32Crpthecodinium cohnii 20Cylindrotheca sp 16-37Dunalielia primolecta 23Isochryais sp 25-33Monallanthus salina >20Nannochloris sp 20-35Nannochloropsis sp 31-68Neochloris oleoabundans 35-54
Nitzschina sp 45-47Schiochytrium sp 50-77Tetraseknus sueica 15-23
Algae Species and Typical oil content
Algae Open Pond
Algae Photo bioreactor
Algae cultivation
Parameter Open pond Closed photo bioreactor
Construction Simple More complicated-varies by design
Cost Cheaper to construct, operate
More expensive construction, operation
Water losses High LowTypical biomass concentration
Low, 0.1-0.2 g/L High: 2-8 g/L
Temperature control Difficult Easily controlled Species control Difficult SimpleContamination High risk Low riskLight utilization Poor Very highC02 losses to atmosphere High Almost noneTypical Growth rate(g/m2-day)
Low:10-25 Variable:1-500
Area requirement Large SmallDepth/diameter of water 0.3m 0.1mSurface: volume ratio ~6 60-400
Open Pond & Photo Bioreactor
Power Plant / Energy Source
Flue Gases
NOx + CO2 from combustion flue gas
emissions Algal
Biotechnology
Cleaned
Gases
Photo bioreactor
Algal Biotechnology Converts Flue Gases & Sunlight into Biofuels through Photosynthesis
“Used” Algae have Multiple Potential Uses
Sunlight Co-Firing
Fermentation
Esterification
Drying
Green Power
Biodiesel
Ethanol
Protein Meal
Overview of micro-algae technology for carbon sequestration and bio-diesel production
Fuel Carbon(60%) Day Time Carbon
Emissions(50%)
Flue Carb
on
(100 %)
Fuel Carbon(100%) Open Cycle Carbon
Closed Cycle Carbon Management
Closed Cycle Biomass Carbon Management
CleanGases
Algae Biomass as Fuel Source (40% Fuel Carbon)
Night Tim
e Carbon
Emissions
(50%)
Algae growth and harvesting process
INITIAL PLAN OF WORK
• Laboratory Phase: Techniques presently in use will be tested & optimized in laboratory, and most feasible techniques will be identified for the available conditions
• Testing Phase: Techniques identified in the lab will be scaled up to the semi-pilot scales, exposed to environmental conditions present and Improvements will be made as required
• Utilisation Phase: The process identified will be used to produce Bio-Diesel
Open pond for algae cultivation Spectrophotometer
Magnetic Stirrer pH Measurement device
Gas chromatographyAlgae Strains
Algae StrainsLaminar Flow chamber
Limits to productivity of Microalgae
• Physical factors such as light (quality and quantity), temperature, nutrient, pH, O2 and CO2
• Biotic factors including pathogens, predation and competition by other algae, and
• Operational factors such as: shear produced by mixing, dilution rate, depth and harvest frequency
Physical factors• Climate
– Cold weather reduces algae oil production– Optimum temperature: 25-29 0C
• Nutrients– Nitrogen & phosphorus: 0.8% and 0.6% of
volume of pond
• Light– High pressure sodium & Metal halide lamp
• CO2
– Optimum supply of CO2 during day time
Algae harvesting
• Microfiltration
• Centrifugation
• Flocculation
• Sonochemical
• Solvent Extraction and others.
Table. Theoretical estimation of biodiesel from algae
Yield/day (g dry weight/day) 60
40% oil content (g/day) 24
Oil content can go up if growth conditions
optimize
Volume of Oil (ml/day)
26.6
Density = 0.9g/mL
Volume of Biodiesel (ml/day)
26.6
Assumed 1:1 ratio between oil content and
diesel
Volume of Biodiesel (gal/day)
0.0075
Small scale production of biodiesel
• Combine 4 g NaOH (Lye) with 250 ml CH3OH (Methanol) to form CH3O- (Methoxide).
• Mix until NaOH is completely dissolved in CH3OH (approx.1 min).
• Combine CH3O- with warm (60˚C) oil.
• Thoroughly agitate (roughly 5-10 min)• Allow resulting mixture to settle into layers (roughly
8 hours until fully settled)
1L of diesel = 2.67 Kg of CO2 Ref: http://www.epa.gov/otaq/climate/420f05001.htm
Biodiesel reduces net emissions of CO2 by 78.45%Ref:NREL/SR-580-24089 UC Category 1503
1L of Biodiesel will save 2.09 Kg of CO2
100 Mega L of Biodiesel will save 209 Kt of CO2
1L of diesel = 2.67 Kg of CO2 Ref: http://www.epa.gov/otaq/climate/420f05001.htm
1L of Biodiesel = 0.58 Kg of CO2 Ref: http://www.epa.gov/otaq/climate/420f05001.htm
Algae Biodiesel Carbon Credits
Summary• Micro-algae biodiesel is a newly-emerging field • Algae is a very efficient means of producing biodiesel
and oil production from algae farms is feasible and scalable
• By coupling algae production with a CO2 pollution control process, the economic viability of micro algal based biodiesel is significantly improved
• Genetic Engineering and advancement in the design of bioreactor can improve the productivity of micro-algae
• Further research necessary for economic production of biodiesel from algae.
A N Y
Q U E S T I O N S ?