Biofuels: the historical energy sources with a burning bright future

With the threat of climate change looming, biofuels are seen as a source of energy that will help to control the carbon emissions blamed for global warming.

Mette Hedegaard Thomsen, assistant professor at the department of chemical and environmental engineering at Masdar, examines a halophyte plant. Ravindranath K / The National 
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The resource rich UAE is going beyond oil to solar and biofuels, where science says something as simple as camel dung is a blessing.

Turn the clock back 350,000 years, perhaps much longer, and our ancestors were regularly using fire, with wood their primary source of energy.

It shows there is nothing new about the use of biofuels.

But despite its importance in pre-history, the practice of releasing energy from recently produced biomass – as opposed to using oil, which can date back millions of years – is seen as an energy source of the future.

With the looming threat of climate change, biofuels are seen as a source of energy that will help to control the carbon emissions blamed for global warming.

“The idea is that it’s derived from carbon fixed the same year or recently,” says Prof Rod Scott, a plant molecular biologist who researches biofuels at the University of Bath, in the UK.

“You’re releasing carbon already fixed. You’re not adding to the overall burden. It’s in marked contrast to fossil fuels.”

Biofuels, for example, could become a mainstream source of power for transport.

Their ability to do this was demonstrated as far back as 1900, when Rudolf Diesel demonstrated a car that ran on peanut oil.

In Brazil, biofuels account for about 19 per cent of road energy, up from about 14 per cent in 2000, according to World Energy Council figures. In Sweden, the only other country into double figures, biofuels have a 12 per cent share of transport energy.

But using biofuels is not without controversy. First-generation biofuels – typically food crops used to produce oil or fermented to create bioethanol – have been criticised for cutting food supplies and pushing up global prices, while there are also concerns that their production generates large amounts of greenhouse gases, defeating the object in cutting carbon emissions.

Waste from food crops or non-food plants, known as second-generation biofuels, have fewer drawbacks, although they are typically eclipsed by third-generation biofuels, which are crops, mostly algae, developed to provide fuel.

In the UAE, biofuels represent untapped potential but recent work by researchers at the Masdar Institute of Science and Technology could encourage greater use.

The scientists, including Muhammad Tahir Ashraf, Chuanji Fang and Dr Mette Hedegaard Thomsen, an assistant professor of chemical engineering, looked at the potential of 26 types of biomass from 18 species, including various lignocellulose forms of biomass, such as date palm leaflets, date palm trunks and several seagrasses.

Also analysed in the study, published recently in the Emirates Journal of Food and Agriculture under the title Estimation of Bioenergy Potential for Local Biomass in the UAE, were halophytes – plants that grow in salty conditions– macroalgae and organic municipal waste, including camel and sheep dung.

The biomass was analysed and complex formulae used to work out its potential for directly generating bioethanol or, after fermentation by microorganisms, producing biomethane.

The potential for biomethane production, for example, depends on the “degradable carbohydrate” fraction of the material, such as cellulose, the carbohydrate that forms plant cell walls.

Lignocellulose forms of biomass were found to be especially suitable for bioethanol production, highlighting a potential use for the 2 million tonnes of date-palm waste generated each year in the UAE.

Macroalgae, the study concluded, also offer promise for bioethanol production because they are very productive for a given area and, because they grow in water, do not reduce land available for food production.

When it comes to biomethane production, the halophyte Salicornia bigelovii, or dwarf saltwort, showed great potential.

“Biomass analysed showed promising results for bioenergy production in the UAE,” the authors concluded.

Camel manure was also one of the highlighted biomass types for biomethane production, something that is especially noteworthy given that the UAE has almost 400,000 camels, which collectively generate vast quantities of waste.

The latest study follows work, described in The National last year, in which Dr Thomsen and co-researchers analysed local halophytes for the useful chemicals, known as secondary metabolites, they contain.

The research has been published as scientists at the Masdar Institute, working with the Abu Dhabi waste management centre Tadweer, announced they had completed a project to improve methods for turning waste cooking oil into biodiesel.

A pilot project to promote the recycling of cooking oil is now going out into the community.

A centre at Masdar City will test the use of fish-farm effluent for growing oil-rich plants that can be turned into aviation fuel.

But as the UAE moves to encourage the use of biofuels, what are the prospects like globally?

Interest in biofuels is being stifled by the oil price: at about $35 a barrel it “kills it completely at the moment”, Prof Scott said.

“You need it to be $130 to $140 a barrel to make it look credible.”

Despite an unfavourable economic climate, people such as Anastasios Melis, a professor of plant and microbial biology at the University of California, Berkeley, are looking to improve methods of growing biofuels and to increase yields of crops such as microalgae.

These are unicellular organisms seen as more efficient in terms of carbon emissions than some alternatives.

“We’re taking different approaches to increasing productivity by as much as 300 per cent compared to what’s out there in nature, and to redirect [production] towards products we think will be useful to society,” Prof Melis said.

Prof Melis is focusing on terpenoids – hydrocarbons that can be turned into diesel. They can be used to also create pharmaceutical products until now synthesised from petroleum.

“We’re establishing technology to permit future generations or maybe entrepreneurs to use microalgae or bacterial [photosynthetic bacteria] for fuel or chemical production,” he said.

Other researchers are looking at how, for example, fungi such as moulds can be better employed to produce fuels.

“Progress is being made. Right now our society does not need fuels but maybe down the road it will be necessary to bring them to the fore,” Prof Melis said.

Daniel Bardsley is a UK-based freelance journalist and former reporter at The National.