Biodiesel From Microalgae Lecture 1

Outline Biodiesel from algae Feasibility of algae Oil collection and refining

Algae Overview

Algae and Biodiesel Algae Biodiesel is a good replacement for standard crop Biodiesels like soy and canola Up to 70% of algae biomass is usable oils Algae does not compete for land and space with other agricultural crops Algae can survive in water of high salt content and use water that was previously deemed unusable

Storing the Sun’s Energy (Photosynthesis) What is needed Sunlight CO2 Nutrients Storage of Energy Lipids and oils Carbohydrates http://www.veggievan.org/downloads/articles/Biodiesel%20from%20Algae.pdf

What affects oil production? Climate Cold weather reduces algae oil production Overcast days reduce sunlight and lower oil production Nutrients Depletion of Nitrogen and Silicate

Controlling Nutrients Nitrogen Aids in cell division Silicate Aids in cell wall production Depleting Nutrients Starving the algae of these two nutrients reduce the rate of cell division Oil production remains constant Results in an increase in the oil to mass ratio

CO2 The Glenturret Distillery in Perthshire, UK – home to The Famous Grouse Whisky – percolate CO2 made during the whisky distillation through a microalgae bioreactor. Each tonne of microalgae absorbs two tonnes of CO2. Scottish Bioenergy, who run the project, sell the microalgae as high value, protein-rich food for fisheries. In the future, they will use the algae residues to produce renewable energy through anaerobic digestion

The Algae Pond http://www.veggievan.org/downloads/articles/Biodiesel%20from%20Algae.pdf

Mass Production of Algae http://www.veggievan.org/downloads/articles/Biodiesel%20from%20Algae.pdf

Choosing an Algae Important characteristics of Algae High % of total biomass is oil Maintains a high % of oil even under stress Compatible with the area climate

What Type of Algae Botryococcus braunii Converts 61% of its biomass into oil 86% of it is long chain hydrocarbons Drops to only 31% oil under stress Grows best between 22-25oC (71-77oF)

Where To Grow It Extensions onto our water treatment plants Clean up our waste and generate fuel Agriculture runoff Exploit the county’s many farms and vineyards Soda Lake Salt lake east of Santa Margarita Vast open space of Carrizo Plain Only has water in winter/spring months National Monument status may prevent development

Pressing oil from the algae Dry the algae and press the oil from it. Can retrieve up to 70% of the oil. While drying must prevent the algae from becoming contaminated. Cheapest and simplest method

Chemical Oil Extraction Use hexane solvents to remove the oil. Hexane is a neurotoxin. Must be careful when using. Removes oil out of almost all things. http://forums.biodieselnow.com/topic.asp?TOPIC_ID=3414

Super Critical Oil Extraction Most efficient method. Uses carbon dioxide at critical pressure and temperature (CO2 is almost a liquid). Carbon dioxide. Rapid diffusion of the oil. Very expensive process. http://www.organix.net/organix/supercritical.htm

TAG (triacylglycerol) Three chains of fatty acids attached to a glycerol Natural oil from the algae http://www.nrel.gov/docs/legosti/fy98/24190.pdf

Transesterification Start with triacylglycerol (TAG) End up with alkyl ester alcohol (biodiesel) http://www.nrel.gov/docs/legosti/fy98/24190.pdf

Three ways to produce biodiesel Base catalyzed transesterification with alcohol. Acid catalyzed esterification with methanol. Convert the oil to fatty acids. Then acid catalyze to alkyl esters. http://biodiesel.org/pdf_files/fuelfactsheets/Production.PDF

Base Catalyzed with Alcohol Most common process Most economical Low pressure (20psi) Low temperature (150oF) No intermediate steps High conversion rate (98%) http://biodiesel.org/pdf_files/fuelfactsheets/Production.PDF

General Process http://biodiesel.org/pdf_files/fuelfactsheets/Production.PDF

Diesel Hybrid GM Hybrid Bus

Hybrid Bus Statistics GM Hybrid Bus EP system Clean Hybrid technology Hydrocarbon and carbon monoxide reduction of about 90% Nitrous oxide reduction of about 50% Already in service in many cities Up to 60% improved fuel economy http:www.gm.com/company/adv_tech/300_hybrids/index_bus.html

Conclusion Algae is a very efficient means of producing biodiesel The oil production from algae farms is feasible and scalable Further research necessary to unlock full potential of algae