Algae Biodiesel: The Facts

The idea of producing algae biodiesel is not a new one. The idea is simple enough: harvest sunlight to grow algae. Then harvest the algae, extract the fatty content of the cells and convert it to diesel fuel.

Advantages Of Algae

There are many advantages to this approach over using food crops to produce fuel.

Firstly, algae must be grown in tanks. These tanks can be put anywhere where there is a lot of sunlight. Desert areas are ideal, and this does not impact on the amount of available farming land. This will become increasingly important as global food shortages worsen throughout this century.

The second major advantage is that algae reproduce far more quickly than crop plants. Consider algal blooms which usually feed off fertilizer runoff. These can appear virtually overnight.

The benefits just keep coming. Useful algae can be grown in sea water so there is no need to use precious drinking water to grow the fuel. This makes desert or near desert areas by the coast very attractive prospects for algae farming.

When the algae have been processed and the oil removed, the remaining matter can make an excellent mulch, feedstock or even fertilizer.

A Controlled Algal Bloom

Effectively, algae farming is just maintaining the correct conditions for algae to bloom as they do in nature, then harvesting the vast amounts of matter produced.

Interestingly, research has shown that desert dust can help the algae to grow because of the iron content in the dust. The higher the iron content the better. That gives even more reason to build algae farms in barren areas.

Where's The Oil?

Every living cell has a membrane surrounding it that is made of lipids. Lipid is a fancy name for oil. In the picture at the right, each little organ inside the algae cell also has its own lipid membrane in addition to the main outer membrane.

If the cell is crushed thoroughly and mixed with water, the oil will separate and float to the top. It can then be collected and processed.

Of course this is not as easy as it sounds, but the process has been shown to be economically viable.

Algae Biodiesel VS Crops

How is it that algae can produce more oil per hectare than regular biodiesel crops such as canola, soy and rapeseed?

In regular crops such as these, it is only the seed of the plant that is used for oil. All the rest of the plant is effectively waste. The time, energy and water spent growing the plant are also wasted.

This waste is vastly reduced in algae farming. The lipid layer is a large part of the cell. It is certainly a higher percentage of the mass of the algae compared to a canola plant and its seeds.

Are There Any Problems
With Algae Biodiesel?

As with all large scale production of crops, it is inevitable that difficulties will arise. Algae, like everything else, are prone to disease. Various types of viruses attack algae which will no doubt need to be considered in the long run.

But even then the news is fairly good. If a batch of algae gets an infection it can still be processed into fuel. This is different from food crops where a disease can kill the plants before they produce fruit or seeds. With algae, the plant is the crop.

Algae Biodiesel And Carbon

As algae grow they absorb Carbon Dioxide from the air. When processed, a good deal of this carbon is made available in the diesel fuel. This carbon is returned to the air once the fuel is burned.

However some of the carbon is left behind in the waste matter. If a way is found to lock this carbon into an inactive form such as charcoal, there will be an overall reduction in the amount of Carbon Dioxide in the air.

The Verdict

Algae farming looks set to become a major player in fuel production this century. Expect to see futuristic looking and foul smelling algae farms mushrooming in the desert in the near future.

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