How to Make Biodiesel From Algae

By Pamella Neely

While awareness of biodiesel and running diesel engines on vegetable oil is growing, you still have to get the oil from somewhere. The conventional choice is to buy vegetable oil, or take used vegetable oil from a restaurant. However, there is another possibility: Produce your own oil, with algae.

Algae

Algae are a form of "simple," photosynthetic, and aquatic organisms. The most complex forms of algae are commonly called "seaweed," though algae range in size and complexity from unicellular forms to this more advanced form. They are called "simple" because they lack many complex features found in land plants. The most useful feature of algae for our purposes is that algae produce significant quantities of natural oils. In fact, there are estimates that the yield from algae can be 200 times greater than that from a comparable area of other sources of conventional vegetable oils.

Algal Oils

Oil from algae is quite similar to oils produced by conventional oil crops and oilseeds. Chemists generally do not speak of oil, which is a common word for a vaguely defined group of chemicals. Biological "oils," or lipids, are chemicals called triglycerides, composed of a central glycerol unit with three fatty acids attached. Chemically, biological lipids are similar to petroleum to the extent that both groups of chemicals are based on carbon and hydrogen.

The main problem with using biological lipids as fuels is the fact that lipids are much more viscous (or resistant to "flowing," in layman's terms) than the refined petrochemicals which make up gasoline, diesel fuel, kerosene, and other petroleum-based fuels. As a result, unrefined lipids will not be completely burned off in an engine, and leftover product which did not burn can accumulate in the engine.

Biodiesel from Algae Oil

The process of making biodiesel from oil is all about lowering the viscosity of oil by removing the glycerol; the process of converting algal oils is the same as that with any conventional vegetable oils. Chemists refer to this process as "transesterification," which in the case of biodiesel means splitting the triglycerides, separating the glycerol, which will settle, and converting the fatty acids into a solution of methyl esters, called biodiesel. This is done by mixing the biological oil with sodium methoxide.

Cultivating Algae

Algae can be cultivated at home using a device known as a "photobioreactor," or a bioreactor which includes a source of light. A basic reactor can be made from clear plastic tubes or plastic bottles or a plastic container of some sort. Algae need water, carbon dioxide, and light to grow; the reactor will contain water into which has been placed a culture of algae. Depending on the type of reactor chosen, algae can be cultivated continuously or in batches. The light source can be an LED, a phosphorescent bulb, or natural sunlight.

Getting Oil from the Algae

The making of biodiesel involves a number of separation processes, even more so in the case of biodiesel from algae: separating the algae from the solution, separating the oil from the algae, and separating the glycerol from the biodiesel after the reaction is complete. All of these separation processes can be done simply with a centrifuge.

Conclusions

While even biodiesel isn't quite a free lunch, getting biodiesel from algae can bring you one step closer. The product you get from algae-produced biodiesel is equivalent to that you get from other oils and the conversion of algal oil is the same as the conversion of any other oil; the algae are simply a renewable source of oil. Algae are quite safe, being commonly used in commercial products including food.

Biodiesel Algae Could Be the Next Big Fuel Source

By Liz Micik
Biodiesel is made from a number of different source oils. Animal fats and waste vegetable oils from restaurants may be the most common image that comes to mind. There is no doubt that this portion of the overall biodiesel production market is growing rapidly. A lot of biodiesel is coming out of homemade biodiesel kits refined by home brewers, but the very individual nature of the production makes it impossible to count.

But it is safe to say that whatever that amount is, it is still dwarfed by production from plant sources destined for processing in commercial plants that provide the fuel primarily for large fleet and government users. Brazil leads the world in biodiesel production from sugar cane, while in the US most biodiesel production is from soybeans and corn.

Today's first generation biodiesel fuels are not projected to replace more than 10-30% of the world's oil supply. Yet they are hotly debated with many anticipating and fearing the disruption in food production and prices that may be seen if they reach those levels.

Proponents argue that these crops will provide both food and fuel, and that more land for fuel crops can be found. One suggestion showed a projected yield equivalent to today's total production just by utilizing the median strips of US highways for fuel crops.

Opponents cite current rising food prices that can be tied back to rising fuel prices and claim the connection is already too strong. To take crops out of food production and shift them to fuel production would only fuel a faster and higher spiraling of prices for both food and fuel.

So new fuel sources are desperately being sought. This second generation of biofuel candidates includes algae. Algae is the world's fastest growing organism and fat is half its composition, making it an ideal candidate.

However, there are numerous stumbling blocks to be overcome in the actual production end. One company, Sapphire Energy, recently announced that they have secured financing of more than $100 million dollars to figure out how and where to grow the mass quantities needed for production and how to distribute it.

Algae is one of the most efficient organisms on earth in terms of using the sun, far outstripping sugar cane or corn. That's led some to suggest the southwestern US desert as an ideal place to raise biodiesel algae because the abundant sunshine and lack of any other commercial uses for the area. However, distribution and transportation from desert algae farms to dense eastern cities could keep the price of production too high to ever make it a profitable venture.

That's just one of the hurdles to be overcome before biodiesel algae is listed as an official fuel. Just what algae strains grow best, and yield the most under commercial conditions is unknown. What's the best way to recover and refine the lipids (fats) also remains to be tested.

It's far more likely that in the near term at least, the most successful growers and refiners of biodiesel algae will be the small group or individual growers. Students at a school in Chicago IL have grown and powered their own vehicle in a 20 mile road test using algae, while large companies like Sapphire are still defining their research and production testing goals in the area.

A home brewer isn't faced with the same challenges as a large commercial brewer. Efficiencies of scale are not his problem. Mastering and refining step-by-step production activities until they become cost effective is his only concern. And costs on the home brewer scale are also extremely reasonable as they are with all home biodiesel production once you get past the initial equipment outlays.

In this case, the home brewer may turn out to hold the key to understanding and growing this crucial second generation...and profiting from it the most.


Liz Micik is a 28 year marketing veteran and freelance writer. At MakeBiodieselKits.com she shares stories and videos of real people and small companies around the globe who have built their own biodiesel kits and refining practices as well as covering the major news of this emerging industry. She invites you to share your story, or use the stories of others and the resources the site provides to build your own alternative fuel success story.