On Biofuels from Algae : On Biofuels from Algae by
Fall 2010 Algae : Algae Large and diverse group of simple, autotrophic organisms
Eukaryotes that constitute a paraphyletic and polyphyletic group
Many are photoautotrophic Algae’s Potential as Biofuel : Algae’s Potential as Biofuel Microalgae have the potential to produce 5000 to 15,000 gallons of biodiesel per year per acre Algae’s Advantage as Biofuel : Algae’s Advantage as Biofuel Growing algae consumes carbon dioxide, reducing it’s carbon footprint.
Renewable energy source.
Makes crops such as corn, soybeans, etc., more available as feedstock instead of being used for biofuel production, keeping prices for such resources low. Growing Algae Biofuel : Growing Algae Biofuel Commonly grown in ponds.
unstable growth of cultures, due to variations in the
light exposure Growing Algae Biofuel : Growing Algae Biofuel Use photobioreactors
maximizes algae biomass production
optimal colony growth
optimal light exposure
optimal carbon dioxide input Mulumba & FaragUniversity of New Hampshire : Mulumba & FaragUniversity of New Hampshire Designed photobioreactor for high yield algal biomass production
Established a technique for optimum harvesting and processing of algae Mulumba & FaragUniversity of New Hampshire : Mulumba & FaragUniversity of New Hampshire Material and Methods
Selected seven algal strains for fast growth and high oil content.
Each strain was grown in a 2L clear glass flask and was exposed to light from fluorescent lamps.
Air was provided to each flask to homogenize the growth medium and supply carbon dioxide. Mulumba & FaragUniversity of New Hampshire : Mulumba & FaragUniversity of New Hampshire Materials & Methods : Materials & Methods Photobioreactor consisted of clear PVC tubing mounted in two spirals
a main tank containing algal solution
carbon dioxide source and air sources
a pump to keep the algal solution in motion to prevent biomass from sticking to tubing. Results : Results Yield of 1g of dry algae biomass per liter of broth with a culture in less than two weeks.
The algae biomass yield contained 12.8% algal crude (0.128g of crude oil per 1g dry algal biomass).
50% improvement in yield using their described photobioreactor over a cylindrical photobioreactor with the same strain A. Results : Results Discussion & Conclusion : Discussion & Conclusion Photobioreactor demonstrated the “possibility of producing significant amount of [algae] biomass at high scale.”
Experiment lasted 2 weeks
predicted production levels are extrapolated
data Discussion & Conclusion : Discussion & Conclusion Photobioreactors are expensive to build and maintain.
Cost of manufacturing photobioreactors should be taken into account when determining the cost effectiveness of this technique. Discussion & Conclusion : Discussion & Conclusion photobioreactors cost to operate is greater than $100/m2
open ponds are less than $10/m2
John R. Brenemann, Ph.D.
International Network on Biofixation of Carbon Dioxide and Greenhouse Gas Abatement with Microalgae Discussion & Conclusion : Discussion & Conclusion Biodiesel from algae is likely still a viable additional energy source.
High yields are theoretically possible; yet to be proved
Cost to manufacture biodiesel from algae needs to come down in order to compete successfully with petroleum-based diesel.