Could Algae change the world?

Dr Greg Martin from the Department of Chemical & Biomolecular Engineering is leading a team of researchers investigating efficient methods for producing liquid fuels from various biomass feedstocks, including algae. The potential of these so-called biofuels is considerable given they are renewable, can be produced in large volumes, can be close to CO2-neutral, and can be used directly in today’s vehicles.

 However, despite these environmental advantages, Dr Martin says interest in this alternative fuel source has been somewhat cyclical and is usually tied to petrol prices.

“On occasions when the oil price peaks, as happened in the 70s, there is a real push for biofuel research, but when the price of oil goes down and the availability of petrol seems limitless again, governments tend to lose interest because biofuels no longer seem economically viable,” Dr Martin says.

Another major obstacle to biofuels has been the well documented ‘food versus fuel’ debate. In a United Nations report on biofuels, then UN Special Rapporteur on food Jean Ziegler concluded that while biofuels’ energy efficiency was commendable, the effect of implementing the large-scale production of biofuels that require arable land for fuel sources would be “catastrophic” for the world’s hungry.

However, Dr Martin says research into biofuels has moved away from forms of biomass which compete with food sources.

“While some may still think of the food versus fuel debate when the term biofuel is mentioned, the majority of research has now moved onto second generation biofuels,’ he says.

“This means either using inedible waste crop material, or biomass such as algae that can be grown on land not suitable for conventional agriculture.

“While second generation biofuels avert the ethical problems of the food versus fuel debate, the processes used to convert these materials to liquid fuels are technologically more difficult and expensive.”

In the case of waste crop material, it is usually what is known as lignocellulosic biomass. This material is much more resistant to chemical and biological conversion to fuel than first generation feedstocks which are comprised of simple table sugar or starch.

“The first challenge is that these materials consist largely of cellulose fibres, which are difficult to pull apart and break down into simple sugars that can be fermented to ethanol,” Dr Martin says.

“The next difficulty is that another large component of the biomass, while relatively easy to break down, is comprised of sugars that are not easily fermented by native yeasts.”

One of the main focuses of Dr Martin and his colleagues’ research is to contribute to the development of chemical and biotechnological solutions to these problems. This includes investigating the use of genetically modified yeast and bacteria that are able to utilise all of the sugars present in the feedstock. Dr Martin says these improvements will increase the efficiency of the process and make the technology a more viable option for mass scale implementation.

 “There is real promise in this technology, and compared with other renewable fuel options, it’s ready to go. We know the technology works; it’s just a matter of making it more and more efficient. Whether or not implementation will have to wait until these fuels can be produced more cheaply than petroleum depends on government policy.”

His research team is also looking into the possibility of producing biofuels from microalgae – microscopic plant-like organisms that directly convert carbon dioxide and sunlight into biochemical energy. Although Dr Martin is somewhat cautious about much of the recent hype surrounding algae, he still believes in their potential.

“There have been some highly ambitious figures thrown around regarding the potential of algae as an energy source, but at the very least, algae could provide five to ten times the amount of biofuel per unit of land compared with conventional crops currently being used,” he says.

“It also has the advantages of being able to grow in places not suitable for crops, and potentially use saline water instead of fresh water.”

In a project recently funded by the Department of Resources, Energy and Tourism, Dr Martin and his colleagues have teamed up with Victorian based company, Bio Fuels Pty Ltd, a division of the Victor Smorgon Group. Bio Fuels have been operating a pilot-scale photobioreactor at International Power, Hazelwood, that feeds carbon dioxide from the coal-fired power plant to the algae.

In addition they are currently setting up on the rooftop of the University of Melbourne’s School of Chemistry building outdoor algae growth facilities that will provide access to algae biomass material on campus. While there are still many challenges involved in growing algae at large scale, Dr Martin and his team are primarily interested in discovering how to best process the algae once it has been grown.

“Certain species of algae accumulate large quantities of “oils” that can be converted directly to biodiesel. We are currently investigating ways to efficiently extract these oils as well as options for effectively utilising the remaining biomass,” he says.

Despite his enthusiasm for second generation biofuel technologies, Dr Martin plays down suggestions that they are the complete answer to our energy crisis.

“Although it is difficult to predict, I believe biofuels will play their most effective role in complementing other sustainable energy sources such as photovoltaic, wind and geothermal. One of its key benefits, particularly in the medium term, is its capacity to provide immediately useable transportation fuel, and in turn, counter our reliance on petroleum.”

Dr Martin acknowledges that that large-scale implementation of biofuel production should be properly managed, but believes the time is now for the world to really start taking second generation biofuels seriously.

“Whether we run out of petrol in ten or a hundred years, the reality is that we are going to run out. The recent oil spill in the Gulf of Mexico is an example of the urgency that’s needed for replacing our energy resources. As the more easily accessed sources of oil dry up, there is an increased risk of things going wrong when extracting oil from more challenging locations,” he says.

“I believe biofuels will play an important role in our shift from unsustainable to sustainable energy. Whether this role will simply be in the short to medium term, or part of a long-term solution however, is yet to be discovered.”