Algae Biodiesel InDepth Reference - More Points & Links on Biodiesel from Algae

Some algae can grow in saline water. It is worth exploring the possible economic production of biodiesel from algae using saline ground water in the growing ponds, which are covered by greenhouses as used by the horticultural and floral industries. Once the water becomes too salty for the algae to grow, it could be drained to evaporation ponds to recover the salts for use by the chemical industry.
Micro-algae are the fastest growing photosynthesizing organisms. They can complete an entire growing cycle every few days.
At an assumed recovery rate of 30% of the weight of algea, 45.6 tonnes of oil/hectare/year can be produced from Diatom algae.
Algae production can be increased by increasing the carbon dioxide concentration in the water.
For best conditions, algae ponds would need to be covered by greenhouses, which would require additional capital expediture to set up.
Different algae species produce different amounts of oil. Some algae ( diatoms for instance) produce up to 50% oil by weight.
Cyanobacteria, also known as blue-green algae, use solar energy to split water into oxygen and hydrogen, but they do it under limited conditions and for very brief periods of time. One of the goals is to extend the time and conditions under which these bacteria produce hydrogen. The major challenge that must be overcome is that cyanobacteria only produce hydrogen in the absence of oxygen. Success is dependent upon finding oxygen-tolerant strains of cyanobacteria.
Under optimum growing conditions micro-algae will produce up to 4 lbs./sq. ft./year or 15,000 gallons of oil/acre/year.
One of the problems with growing algae in any kind of pond is that only in the top 1/4" or so of the water does the algae receive enough solar radiation. So the ability of a pond to grow algae is limited by its surface area, not by its volume.

More reference articles on algal oil: Visitors may kindly have a look at the Oilgae Blog Directory for relevant blog articles.

See also:
A Look-back at the US Dept of Energy’s Aquatic Species Program (PDF)
Future of Algal Culture & Algal Biodiesel
Algae for Bio-diesel – Slide Presentation from Veggie Van
Biodiesel from Algae in Sewage
Bio-engineered Algae Bringing Hydrogen Fuel-cells Closer?
Algae-based Fuel – from Green Fuel Online (PDF)
Commodities of the Future – How about Algae & Manure?
More Good News about Biodiesel – Dymaxion World
Pond Scum to the Rescue – Salon Magazine
Oil Substitutes from Biomass - FAO
Culturing Algae for Carbon-di-oxide Bioremediation (PDF) – see page 13 of this report
Biohydrocarbons from Algae – Impact of Sunlight, Temperature & Salinity on Algae Growth
Concentration of Chlorophyll, Proteins, Carbohydrates & Lipids in 16 Species of Micro-algae
Role of Lipids & Fatty Acids in Stress Tolerance in Cyanobacteria (PDF) (Cyanobacteria are also known as blue-green algae)
Tests of Biogas Productivity from Algae Using Flue Gas CO2 (PDF)
Roadmap for Biofixation of CO2 & Greenhouse Gas Abatement with Microalgae (PDF) ( see also Proposal to Establish International Network for Biofixation & Greenhouse Gas Reduction with Microalgae - PDF)
Approach for Screening Marine Micro-algae for Maximum Gas CO2 Biofixation Potential (PDF)
Photo Bioreactors – Production Systems for Phototropic Microorganisms (PDF)
Solar Lighting for Growth of Algae in a Photobioreactor
CellPharm Tubular Reactors
Greefield Bioreactor Photo – News.com
Valuable Products from Microalgae (Microsoft Word File)
Algal Production – from FAO
Quick Tour of Ecogenics Research Center, Tennessee
Algal Cultivation Products – from CellPharm Aquaculture
Chlorella vulgaris Made in Germany
The Culture Collection of Algae at University of Texas @ Austin
Oil from Algae Yahoogroup
Algae Culture Source – Biodiesel Now Forums
Micro-algal Mass Cultures for Co-production of Fine Chemicals & Biofuels (PDF)
Biodiesel from Algae is Here – from Sydney Biodiesel Users Group
CEE Algae Blog
Sunlight + Algae = Hydrogen Fuel - Slashdot
Use of Botryococcous Braunii for Hydrocarbon Production & CO2 Mitigation (PDF)
Culivating Algae for Liquid Fuel Production – Thomas Riesing
Using Microalgae for CO2 Utilization & Agricultural Fertiliser Recycling (PDF)
Biotechnology of Algae – A Bibliography
Hydrogen from Algae – ZDNet Article (Original Paper – Molecular Dynamics & Experimental Investigation of H2 and O2 Diffusion in [Fe]-Hydrogenase PDF)
Algae as a Biomass Source – Energy Bulletin
Energy Resources Group
Biodiesel from Algae Compared with Ethanol from Crops
R & D Project on Microalgae Bio-fixation of CO2 (PDF)
An Algae-based Fuel – Green Fuel Online (PDF)
Yahoo Group Messages – This, this


Appendix A - Biodiesel from Algae Fed on Coal-fired Power Station Exhausts

The idea is that carbon dioxide from coal fired power station is used to produce algae, which is used to make biodiesel and natural gas.
If the carbon dioxide from a coal fired power station is pumped directly through a pipeline to a near by algae ‘farm’, then the amount of carbon dioxide absorbed into the algae is around 30%. The reason the value is so low is that the algae does not grow at night hence all carbon dioxide pumped then, goes straight into the atmosphere. In addition, the algae grow faster in summer than in winter. The other method is to concentrate the carbon dioxide and pressurize it and truck it to the algae farm, and then release the carbon dioxide into the ponds as and when it is needed. It is hoped that >95% of the carbon dioxide can be consumed by this method. A paddle wheel would move the water at a steady flow. The ponds would be unlined, that is made of compact clay, with gravel in the bottom to ensure no soil becomes agitated into the water.

Some estimates of biodiesel production from algae using CO2 from coal-fired power stations

Algae yield 100 tonnes/ha.
2.2 tonnes carbon dioxide needed / 1 tonnes algae
Water needed 4m3/m2. Most of the water is lost due to evaporation, some is consumed by the algae, and some is lost in the harvesting of the algae.
A 500 MW coal fired power station produces 3.67x106 tonnes of carbon dioxide
3.5 barrels of biodiesel per tonne algae produced
6 MJ methane per tonne algae generated
Energy density of LNG is 15.2 kWh/kg and density is 448 kg/m3


Appendix B – Diatoms

One of the more well-researched species of algae are the diatoms. In the context of oil yield for biodiesel, previous research has also indicated that diatoms are one of the more promising species of algae. We hence provide you more inputs on diatoms in this Appendix.

Biotechnological applications of diatoms are still in development. Because of the photoautotrophic status of the majority of diatoms, microalgal cultures suffer from the limitation of light diffusion, which requires the development of suitable photobioreactors. Thus, genetically engineered microalgae that may be cultivated in heterotrophic conditions present a new opportunity. Most of the time, metabolic stress conditions lead to an overproduction of the products of interest, with a decrease in biomass production as a consequence. Outdoor cultures in open ponds are usually devoted to aquaculture for the feeding of shrimps and bivalve molluscs (commercial production), while closed axenic indoor/outdoor photobioreactors are used for biotechnological compounds of homogeneous composition (still at the laboratory scale). In addition to the optimum culture conditions that have to be taken into account for photobioreactor design, the localisation of produced metabolites (intra- or extracellular) may also be taken into account when choosing the design. Microalgal cell immobilisation may be a suitable technique for application to benthic diatoms, which are usually sensitive to bioturbation and/or metabolites which may be overexpressed.

Currently diatoms (an algae) are being investigated for biodiesel and other things, including medicine. It appears more basic research about them is needed to be able to manage large scale diatom farms economically. Diatom study includes species that like to attach themselves to coral, sea weed, or strip of plastic. Thus harvesting diatoms is more complicated than pumping them from the sea, or a pond.