Use of sunflower oil as a renewable-energy source researched

20th September 2013 By: Zandile Mavuso - Creamer Media Senior Deputy Editor: Features

Astudy on biofuels being undertaken by the Agricultural Research Council (ARC) aims to develop sunflower oil as an alternative fuel source in South Africa.

The study, which started in April this year and is scheduled to end in March 2016, aims to develop high oil-yielding sunflower cultivars with better processing characteristics, together with better harvesting and processing practices, to improve the value chain and enable the use of this crop in renewable-energy technologies.

The ARC says the study is currently in Phase 1 and is led by Dr Dirk Swanevelder, a molecular biotechnologist, with a research team comprising various sunflower breeding experts and agri- cultural engineers from the ARC.

In the Department of Minerals and Energy’s White Paper on Renewable Energy 2003, government states that renewable energy will contribute to the diversification of energy resources through the implementation of a properly managed programme of action that will provide sufficient incentive for the sustainable development of renewable-energy-based industries.

Government states that, although renewable- energy technologies often have higher investment costs, their operation and maintenance costs are generally lower than those of conven- tional fossil fuel-based energy technologies. The result is that many renewable-energy technologies, compared with fossil fuel-based energy technologies the country relies on, are not cost-competitive.

This costing difference is a worldwide phenomenon; however, tax breaks, mandatory legis- lated mixing of energy fuel types, rising fossil fuel prices and the development of new production technologies, are all driving the widespread conversion to biofuels. In recent years, there have also been some significant cost reductions, with some renewable-energy technologies competing with fossil fuel-based energy.

“Increased energy prices, the concern of depleting fossil fuels, the negative environmental impacts of fossil fuels and government’s renewable-energy drive have spurred the research for an alternative to mineral diesel fuel,” says ARC renewable-energy programme director Petrus Britz.

He notes that the wars in the Middle East in the 1970s resulted in a drastic increase in oil prices, which awakened fears of the unavailability of diesel fuel. This, in turn, resulted in the Department of Agriculture researching the use of alternative fuels and, after extensive laboratory tests, conducted from 1981 to 1983, it was found that indirect-injection diesel engines could run on pure sunflower oil.

“Further tests at that time indicated that direct-injection diesel engines could run on an ester manufactured from sunflower oil. The only precautions necessary were the use of sunflower- resistant rubber hoses and special additives for engine oil to prevent it from turning into a rubbery sludge,” Britz points out.

He mentions that, despite the technical feasibility of sunflower oil ester as a replacement for diesel fuel, it was about 200% more expensive than fossil fuel using the older conversion technologies of the time. It was also estimated, previously, that a farmer would have to sacrifice 10% of his sunflower harvest to produce biodiesel for the tractor used to till, plant and harvest the sunflower seeds from which income is generated.

For South Africa to benefit economically from renewable energy, Britz says that more funding for research must be made available, as the research results could be a potential driver of the country’s economy.

He explains that more research may lead to more alternative uses of renewable energy being discovered. This not only broadens the scope of use for renewable energy but also makes it more sustainable. The new ARC research programme aims to do just that: reduce biodiesel production costs by looking at the whole value chain, from crop development to oil pressing, all done by working within the guidelines set out in government’s November 2003 White Paper on renewable energy.

“The results of the study we are conducting will point out the key areas of research that need to be addressed to make the legislated feedstocks, and the production thereof, more feasible for bio- fuel production, as well as the key production steps in the conversion technologies that need to be made more efficient, even if it is not at present economically competitive,” he concludes.