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 presento 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

NutrientsStorage of Energy

Lipids 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 Carbon

(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 Time 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 ?