Some algae species are 50% or more lipid oil by weight. This oil can be pressed from the algae and refined into diesel. The process for extracting algal oil, at its most basic level, is similar to pressing an olive. Up to 75% of the oil can be squeezed from algae with a simple mechanical press. Hexane can be used as a solvent to increase extraction up to 95%. Once extracted, the oil is refined through transesterification. A catalyst such as sodium hydroxide is mixed with alcohol to produce biodiesel and glycerol. Does the resulting biodiesel burn cleaner than fossil-based diesel? A study by Consumer Reports, using a 2002 Volkswagen Jetta TDI modified to run on multiple fuels, found that pure biodiesel had similar emissions to petroleum diesel. The biodiesel produced slightly higher hydrocarbons and mono-nitrogen oxides (NOx) while creating less particulate matter. Carbon dioxide levels were the same. However, a major factor with fuels sourced from plants is that the process consumes as much CO2 as it produces. The California biotech firm Solazyme fueled a Mercedes Benz C320 with algae-sourced biodiesel.
They drove the car around the 2008 Sundance Film Festival in Park City Utah to promote Josh Tickell's film 鈥淔ields of Fuel鈥? which features Solazyme. Algal oil can also be used to make cleaner forms of jet fuel, methane, ethanol, butanol and gasoline. In order for algae-sourced fuel to compete economically with petroleum diesel, manufacturers must make the most of every part of the process. The glycerol that is created in biodiesel production must be harnessed and not wasted. Glycerol is a colorless, odorless simple sugar alcohol. It connects three fatty acids to form a triglyceride. One use for the glycerol by-product is as a feedstock for algae. Researchers have found that algae grown with glycerol have greater mass and higher lipid content. Therefore, they are even better for the purpose of biodiesel. The food industry uses glycerol as a sweetener, preservative, thickener and moistener. Glycerol is used in lotions, lubricants and other skin care products.
The Formula E electric car racing series has found perhaps the most revolutionary purpose for glycerol. All of their cars are charged with it. The vehicles are moved around the globe from race to race. Charging them from potentially dirty power grids would contradict the message about sustainability Formula E is sending. So the league brings its own chargers powered by algae glycerol. Aquafel Research built a pair of glycerol-fueled generators which travel in a shipping container with the teams. Not only is the fuel nearly emissions-free, but it runs cleaner in the machines as well. The generators are modified Cummins KTA50 models which typically run on diesel. Running on glycerol, there is no soot, no clogging and increased lubricity. The machines are more efficient and require less maintenance. The algae glycerol is such a clean fuel that Sir Richard Branson, sponsor of the Virgin Formula E team, drank a shot of it at a press conference.
Do that with your racing fuel. Polyurethane foam is central to surfboard construction. It is also used in hard plastics, flexible plastics, upholstery foam, shoe insoles and more. Petroleum is central to polyurethane production. UC San Diego is fighting the irony that the sport of surfing is reliant on clean, healthy oceans and petroleum-based materials at the same time. Researchers worked with Solazyme to create a better algae-based oil for making polyurethane. Then they joined Arctic Foam, the largest manufacturer of surfboard bodies in the US, to build an algae-foam base coated with renewable resin and fiber glass. The result is a board that if mass-produced would be competitive in price with petroleum-based board. Arctic Foam is distributing the boards to professional surfers for testing and promotion. Fish are an important source of Omega-3 fats, which are important for heart, brain and joint health. But where do the fish get them? By eating smaller fish which, at the bottom of the food chain, get the fats from algae.
