As advanced biofuels get more attention from the media, governments and the public it is important to remember that not all biofuels are alike. The technologies to make them are varied, the locations they can be made are diverse, and the inputs needed to make them can range from crops, to wood, to streams of industrial waste gases. And of course, there are algae!
Algae-derived fuels come with some unique advantages:
Algae reduce greenhouse gas emissions
Producing fuels and other products from algae has been shown to dramatically reduce greenhouse gas emissions. Recent research has demonstrated that Sapphire Energy’s algae-based fuel results in a 68% reduction in greenhouse gas emissions compared with fossil fuels. Algenol’s process can utilize one tonne of CO2 to produce more than 140 gallons of algae-derived ethanol. BioProcess Algae is operating a production facility that grows algae with CO2 generated as a byproduct of ethanol production. Accelergy Corporation has developed carbon capture and recycling technology that utilizes CO2 emitted during coal-to-liquid fuel production to grow concentrated algae.
Some estimates have shown that annual production of 2.4 million barrels of gasoline with algal oil would consume 1.5 billion tons of CO2, or more than 40% of total U.S. annual emissions from stationary sources.
Algae don’t need freshwater
Algae grow in saltwater, allowing us to grow fuel, feed and other products without diverting a lot of the freshwater we need for other uses.
In 2012, Dr. Stephen Mayfield, a professor of biology at UC San Diego demonstrated the commercial feasibility of growing productive algae species in saltwater environments. Unlike fresh water, saltwater is not a limited resource. Algae can be produced in ocean or brackish water, or on agricultural land where crops can no longer grow because of high salt content.
Many algae companies are taking advantage of algae’s ability to multiply in sources other than freshwater. Algenol combines seawater and CO2 to produce 8,000 gallons of ethanol and other liquid fuels per acre annually. Sapphire Energy grows their algae in ponds filled with brackish water that is not suitable for human consumption or farming. Sapphire’s model is zero-waste, allowing for 100% of the water to be recycled throughout the process. BioProcess Algae acquires its wastewater for algae production from the neighboring Green Plains’ ethanol plant to satisfy demand for cost-effective fuel, food and animal feed.
Algae don’t need land that can be used to grow food
Algae have much larger yields than any other crop and can grow on land that isn’t used for agriculture or other purposes. Deserts and marginal lands, even the open seas, can all be used to grow a new generation of sustainable products in a way that enhances, not diminishes, our ability to grow food. Algae can yield more than 5,000 gallons of oil per acre per year – tenfold more than other crops.
Algae could be used with existing available resources to produce a large portion of our fuel needs. In 2011, a study by a team of scientists at the Pacific Northwest National Laboratory concluded that with current technology, algae could provide a volume of oil equivalent to 48% of current U.S. petroleum imports for transportation.
All of these issues will play a big role As advanced biofuels become commercially available. Fortunately, the scientists and entrepreneurs in the algae industry have each of them covered!