Humble algae could be our saviour

We are approaching a time of limited supplies of oil and gas in Australia. It is time we started to think of alternative sources of fuel for our cars. We should look into the diesel engine technology coupled with a novel source of fuel that doesn’t compete with the production of food.

The Association for the Study of Peak Oil and Gas Australia was officially launched in Perth on November 21. At the press conference, Swedish Professor Kjell Aleklett had the following dire predictions for global oil supply:

“We face a permanent shortfall in global oil supply (peak oil) which is inevitable and imminent,” he said. “Long-term oil shortages are likely, followed by very steep price rises, petrol rationing and economic downturns,” he concluded.

The message from Professor Aleklett was that we need to prepare now for a future where we lessen the dependence on oil.

The issue is not one of "running out" of oil so much as it is one of not having enough oil to keep our economy, our trucks, cars and buses running.

Already we are seeing sales of “Toorak tractors” with gas guzzling six or eight cylinder petrol engines under the pump. New motor vehicle sales fell 6.7 per cent in October compared to last year. Sales of four-wheel drives dropped even more, down by 11.9 per cent as higher petrol prices turned buyers away.

However there is a solution for Australia’s oil dependence and it is relying on technology that has been with us for more than 100 years, combined with new sources of fuel to feed it.

The inventor of the diesel engine, Rudolf Diesel, originally conceived the diesel engine to enable independent craftsmen and artisans to compete with large industry. In order to do so, he created an efficient engine that would be fuelled by locally-sourced vegetable oil. The first diesel engine - fuelled by peanut oil - ran on August 10, 1893 in Augsburg, Germany.

Vegetable oil, or bio-diesel as it is now known, can go into the same fuel distribution infrastructure, replacing petroleum diesel wholly or partly.

The manufacture of bio-diesel involves a chemical process called "transesterification" where triacyl glycerol and methanol is mixed and heated. This releases glycerol and the esters of the fatty acids. This reaction is catalysed by a base or acid. Recent development of a carbon powder catalyst makes this process more environmentally friendly and more efficient and provides the means for large-scale production of bio-diesel (Toda et al. "Biodiesel made with sugar catalyst" Nature 438:178).

There is one major drawback with bio-diesel though. It places a non-food use for vegetable oil in direct competition with the use of the oilseed crop as food: and we have only got a limited amount of land on which to grow crops.

The European Union wants 6 per cent of the oil used to fuel their cars to be bio-diesel by 2010 and 20 per cent by 2020. (The European Union, May 8, 2003. Directive 2003/30/EC).

It has been pointed out that in order to meet the EU target from locally farmed canola oil, the land set aside in the UK for growing an oilseed crop for the exclusive use for fuel would be 5.2 million hectares of the total of 5.7 million available. Evidently there isn’t enough land in the UK to grow oilseed for bio-fuel even to meet the EU 2020 target and to grow crops to feed people.

Already this has opened up a market for Canadian genetically modified canola. The strong oil demand from the EU bio-diesel industry already led to a sharp increase in Canadian canola crushings in October. The EU could import around 200,000 tonnes of rape oil in 2005-06, with most supplies coming from Canada. However all the GM canola grown on the Canadian prairies is not going to be sufficient to meet the future EU bio-diesel targets.

Bio-diesel is a form of solar energy. We are harvesting what the plant produced using photosynthesis to convert solar energy into chemical energy stored in the form of oils, carbohydrates and protein. The most efficient plants in converting solar energy into chemical energy are various types of algae.

Some species of algae are ideally suited to bio-diesel production due to their high oil content (some well over 50 per cent oil), with extremely fast growth rates. Algae farms would let us supply enough bio-diesel to completely replace petroleum as a transportation fuel.

The National Renewable Energy Laboratory in the US has performed research on harvesting bio-diesel from algae farms. They were using saltwater ponds in deserts to grow algae for biodiesel. NREL's research (pdf file 3.58MB) showed that 28.3 million tonnes of bio-diesel could be produced from 200,000 hectares of desert land which would almost cover the requirements of UK in 2020. In fact algae technology offers the opportunity to utilise land and water resources that are, today, unsuited for any other use. Land use needs for microalgae complements, rather than competes, with farming of crops for food.

In Western Australia and South Australia there already exists a nucleus of an industry that has been built up around growing algae in ponds with salt water and the extraction of high value added products such as beta carotene out of them.

Australia would be ideally placed to develop an alternative bio-diesel industry based on algae that could be grown in brackish bodies of water using an abundance of sunlight. In a recent project funded by RIRDC researchers at Flinders University has investigated the use of a green alga as a supplier of biological hydrocarbon. It is an avenue that is worth exploring before our oil-based economy runs into trouble.