MICRO –ALGAE AS A SOURCE OF BIO DIESEL: CHALLENGES AND FUTURE PROSPECTS K.Sudhakar Assistant professor, Energy Department, MANIT, Bhopal-462007, MP,India Dr. S. Suresh Assistant Professor, Department of Chemical Engg., MANIT, Bhopal-462007, MP, India Dr. (Mrs) M. Premalatha Associate Professor, CEESAT, NIT Trichi, TN, India Presented at All India Seminar On Energy Management Through Renewable Sources and Efficient technologies Institution of Engineers, Madhya Pradesh State Centre, Bhopal, 08-09th Jan, 2011 ‘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 Assessment First Report - 1990 Second Report - 1995 Third Report - 2001 Fourth Report - 2007 Average global temperature increase 1906-2005 – 0.74oC Expected Temperature rise up to the Year 2100 2.4 to 6.4 oC Expected 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. Coping with Global Warming Greenhouse Gases Earth Interactions Air interaction S P C R CAUSE EFFECT I E E D N I Global T Mitigation Strategy C Warming Climate Change Impacts -Adaptation I Renewable sources T Crop Productivity F I Energy Efficiency Frequent Disasters I V C Clean Coal Technology Water Scarcity E CCS Vector borne diseases The World’s Energy Resources Are Limited! Why Micro-algae? – 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 Algae Growing Methods : What is needed Sunlight CO2 Nutrients Storage of Energy Lipids and oils Carbohydrates Other Dependent parameters: Temperature , pH (Physical factors) Pathogen ,predation, competition (Biotic factors) Algae Species and Typical oil content Micro algae Oil content (% dry weight) Botryococcus braunii 25-75 Chlorella sp 28-32 Crpthecodinium cohnii 20 Cylindrotheca sp 16-37 Dunalielia primolecta 23 Isochryais sp 25-33 Monallanthus salina >20 Nannochloris sp 20-35 Nannochloropsis sp 31-68 Neochloris oleoabundans 35-54 Nitzschina sp 45-47 Schiochytrium sp 50-77 Tetraseknus sueica 15-23 Algae Open Pond Algae Photo bioreactor Algae cultivation Open Pond & Photo Bioreactor Parameter Open pond Closed photo bioreactor Construction Simple More complicated- varies by design Cost Cheaper to construct, More expensive operate construction, operation Water losses High Low Typical biomass Low, 0.1-0.2 g/L High: 2-8 g/L concentration Temperature control Difficult Easily controlled Species control Difficult Simple Contamination High risk Low risk Light utilization Poor Very high C02 losses to atmosphere High Almost none Typical Growth rate(g/m2- Low:10-25 Variable:1-500 day) Area requirement Large Small Depth/diameter of water 0.3m 0.1m Surface: volume ratio ~6 60-400 Overview of micro-algae technology for carbon sequestration and bio-diesel production Algal Biotechnology Converts Flue Gases & Sunlight into Biofuels “Used” Algae have through Photosynthesis Multiple Potential Uses Cleaned Gases Sunlight Co-Firing Power Plant / Green Power Energy Source Photo bioreactor Esterification Biodiesel Flue Gases Fermentation Ethanol Protein Meal NOx + CO2 from combustion flue gas Algal emissions Biotechnology Closed Cycle Biomass Carbon Management Fuel Carbon (100%) Open Cycle Carbon Clean Gases Fuel Carbon (60%) Algae Biomass as Fuel Source (40% Fuel Carbon) Closed Cycle Carbon Management 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 Laminar Flow chamber Algae Strains Algae Strains Gas chromatography 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) Algae Biodiesel Carbon Credits 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 1L of Biodiesel will save 2.09 Kg of CO2 Biodiesel reduces net emissions of CO2 by 78.45% Ref:NREL/SR-580-24089 UC Category 1503 100 Mega L of Biodiesel will save 209 Kt of CO2 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. 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