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April 29, 2010

Algal Oil

Way back last June, I discovered an article suggesting that certain types of algae might be useful as an alternate source of oil. I wrote it up, here, and mentioned I hoped to see how it panned out. Most of these "breakthroughs" fade away after an initial media burst, however, so I rather expected this story to die out as well.

A species of microalgae:
Haematococcus pluvialis
Instead, however, a research team at the University of Michigan is further investigating the idea, and has exciting preliminary results. They've discovered that pressure-cooking the algae could be a way to make crude oil in minutes, rather than millenia. According to Philip Savage, the principle investigator on the project, the process isn't terribly complicated. "We make an algae soup. We heat it to about 300 degrees and keep the water at high enough pressure to keep it liquid as opposed to steam. We cook it for 30 minutes to an hour and we get a crude bio-oil." With the type of primitive algae the team is using, this is enough to break down the plants and release natural oil, carbohydrates, and proteins.

Now, the method is far from perfect. The oil produced can't just be pumped into an automobile; it has to be refined and processed significantly first. It looks more like tar than gasoline when it comes out of the pressure-cooker. And it is still gasoline; there are lots of pollutants released by burning any oil, whether it came out of the ground or is recently squished algae. But there are a lot of advantages to the system.
An Algae Farm
First off, using biofuels is much more sustainable than using fossil fuels. We can always grow more algae; we can't magically continue to drill 70 million barrels of crude oil out of the ground every day. Second, it is somewhat better for the environment. Using algal biofuels is carbon-neutral. During their lives, the algae consume some amount of CO2, which is released again when the oil is burned. Technically, this is true for fossil fuels as well, but the CO2 they release has been in storage for millions of years, so the amount in the atmosphere increases. Biofuels are also much easier to clean up; chemical and biological processes can be used to take sulphur and nitrogen out.
This particular method is also a breakthrough among its competitors. It is a much more efficient method. Conventionally, to create an algal biofuel, one has to take a very oily algae, dry it out, and then extract the oil. It's a time-consuming, low-yield process, which makes it expensive and not likely to compete with drilling. The pressure-cooker method, however, is faster, has a higher yield, and produces much less waste. In fact, the researchers hope that, eventually, this technique can be used in waste-free refineries. It's a promising step. While there are many advantages to heading away from oil altogether, the technology just isn't in place yet. So, waste-free biofuel refineries would be a great intermediate step until hydrogen or electric technology is ready to take the place of oil.

Source: Science Daily- Pressure-cooking algae into a better biofuel
Crude oil data from the EIA.