The search for a viable alternative to fossil fuels has been ongoing for many years. Our oil reserves are not unlimited, and the question of "what to do when the oil runs out" has been hanging in the air like exhaust fumes from a diesel engine.
Consequently, the search for new and innovative ways to create biofuels is an area of research that is receiving global attention and plenty of funding, and scientists believe that they have found a viable answer to the world's long-term fuel requirements.In a ground-breaking study, researchers at the U.S. Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington have managed to condense a fossilisation process that normally takes millions of years into just one hour.
The team, led by Professor Paul Falkowski, created a slurry made of algae and water and pumped it into a chemical reactor. In just under sixty minutes, the process inside the reactor turns the slurry into a useful crude oil that can be made into combustible gases like jet fuel, gasoline or diesel using conventional refining methods. The algae mixture is an unlikely savior for the world's fuel crisis: it is a muddy green paste with the consistency of pea soup, but this pond-weed-like mush has a wealth of potential. Even the by-products from the process are useful, as it yields water and a chemical substances containing phosphorus and other minerals that can be recycled to produce more algae, and can also be utilised to create electricity, natural gas and fertilizer.
Falkowski explained the driving force behind the project: ""When we take petroleum out of the ground, we are buying a resource that was created millions of years ago and we don't pay for it. We're using nature's inventory of carbon."
Though biofuels have been made from other sources, such as vegetable oil, algae are a very viable source as they are abundant and proliferate very quickly. At this point in time, scientists are still searching for a type of algae that would be suitable for large scale production, and are considering genetically engineering a variety specifically for the purpose.
The use of algae to create biofuel is not a new concept, but cost has previously been an issue. The new technology is more efficient and has incorporated new methods to make the process cost-effective.
"Cost is the big roadblock for algae-based fuel," said Douglas Elliott, the laboratory fellow who led the PNNL team's research. "We believe that the process we've created will help make algae biofuels much more economical."
The researchers found ways to improve production by condensing the number of procedures required into one continuous process, and by finding a method that worked using wet algae. Previously, it had been necessary to dry the algae before processing, making this a costly factor due to the time and energy required, as it was only possible to process wet algae one batch at a time. The new system is able to run continuously, as it would do if it was being produced on a large scale.
"Not having to dry the algae is a big win in this process; that cuts the cost a great deal," said Elliott. "Then there are bonuses, like being able to extract usable gas from the water and then recycle the remaining water and nutrients to help grow more algae, which further reduces costs."
Another significant factor that has made the process even more slick is that it is no longer necessary for complicated measures to be taken in order to extract the energy-producing oils from the algae; the new method uses the whole of the organism, subjecting it to intense heat and water pressure which reduces it to liquid and releases the vital substances.
"It's a bit like using a pressure cooker, only the pressures and temperatures we use are much higher," said Elliott. "In a sense, we are duplicating the process in the Earth that converted algae into oil over the course of millions of years. We're just doing it much, much faster."
Consequently, the research attracted the attention of big fuel corporations, and the Utah-based start-up Genifuel Corporation has worked closely with Elliott's team since 2008, licensing the technology and working initially with PNNL through DOE's Technology Assistance Program to assess the technology. Genifuel plan to develop the technology further and eventually produce it commercially, potentially undercutting the cost of conventional oil as it is predicted that the new biofuel could be sold for as little as $2 per gallon.
"This has really been a fruitful collaboration for both Genifuel and PNNL," said James Oyler, president of Genifuel. "The hydrothermal liquefaction process that PNNL developed for biomass makes the conversion of algae to biofuel much more economical. Genifuel has been a partner to improve the technology and make it feasible for use in a commercial system. "It's a formidable challenge, to make a biofuel that is cost-competitive with established petroleum-based fuels," Oyler added. "This is a huge step in the right direction."