Science - October 9, 2008

Quest for the utterly sustainable

The European parliament will formulate criteria for biofuels this fall. What exactly they will be is still unclear in view of Brussels’ unfathomable ways, but expectations are that they will be strict. After all, they must prevent that food disappears into fuel tanks, and that growing the required biomass gobbles up energy. Three scientists are willing to take a little gamble.

After the grains have been removed corn cobs are still rich in energy. But nowadays they end up in low-grade applications such as compost or cattle feed.
Professor Johan Sanders is ticked off. ‘Was about to get gas yesterday and they’d run out!’ says the professor in Valorisation of Plant Production Chains. The gas station ran out of gas? It sounds strange. But ‘Professor Biobased’ does not drive an ordinary car. His new Saab runs on E85, a type of gasoline that contains 85 percent bio-ethanol, or in plain English, alcohol that was made by fermentation of cane sugar. ‘The national network for this alternative fuel does anything but cover the nation’, grumbles Sanders who was thus forced to put Euro unleaded into his car. He spent his vacation in France this summer. ‘You can get E85 anywhere there, and even at half of what I pay for it in The Netherlands.’
That definitely makes The Netherlands a straggler within Europe. The European Commission wants 5.75 percent of the transport fuels gasoline and diesel to consist of renewable, vegetable ingredients in 2010. That percentage must be ten by 2020. At the moment, approximately three percent is admixed.
The developments were not accelerated by the criticisms of the past 18 months. ‘The SUVs in the States run on grain that belongs in the bellies of hungry children in Africa’, say the environmental and development organizations. Moreover, the energy crops require so much fertilizer and tractor movements that the sustainability of biofuels isn't exactly a given.

Good vision
To address the criticisms, the EU will set requirements for biofuels. The result is anything but unambiguous so far, but it looks like the EU is about to set course for stringent criteria for the energy contents. Biofuels have to emit at least 35 percent less CO2 than their fossil counterparts. In 2015 or 2017, this requirement may be tightened to fifty or even sixty percent, reported EU diplomats recently. In addition, the EU wants to formulate guidelines for land use, biodiversity and social, economical aspects such as involvement of the local population.
Sanders thinks that the criteria reflect ‘a good vision at the EU’. ‘The more CO2 we save, the better. It is wise to accept a somewhat lower score per liter – though also start working with lots of liters and get into the learning curve – instead of setting very high sustainability requirements but hardly accomplishing any liters in view of the costs being too high.’
Moreover, he says, we also need to be frugal with regard to biomass, even though it is a renewable resource. ‘To that end, we have to make the production processes more energy-efficient. We also must utilize yet unused residues from agriculture as biofuels with the aid of clever conversions.’
And that is what the research world is working on by all means at hand and more particularly, with heaps of money: innovations that bring the so-called second generation of biofuels within reach. These fuels will not be recovered from one-year food crops, but from longer-lasting vegetation such as trees and grass. They would not compete with food.
At Utrecht University, dr. André Faaij is working on making energy provision more sustainable. ‘In fact, we will soon already be talking about ‘one-and-a-half generation’ biofuels’, he states. He is referring to corn cobs after the corn grains have been removed, remnants of bagasse from cane sugar production and husks of corn grains. Each is rich in energy and ends up in low-grade applications such as compost or at most cattle feed. ‘In addition to the application of bagasse remnants, for example the ethanol production in Brazil can be tripled by improving harvesting techniques and increasing the efficiency of ethanol production from cane sugar. Then, there would be no competition at all with food production or agricultural land.’

New paths
Cramer criteria
Diplomats in Brussels have reason to believe that the European criteria for sustainable biofuels will lean heavily on the Cramer criteria. They are named after the current minister of Housing, Spatial Planning and the Environment and were formulated in 2006, when prof. Jacqueline Cramer was chairperson of the project group ‘Sustainable production of biomass’.
  1. Greenhouse gas: net emission reduction relative to fossil reference, including application, will be at least thirty percent
  2. Competition: production of biofuels may not be to the detriment of food, local energy supply, medications and construction materials
  3. Biodiversity: no damage to protected areas or valuable ecosystems
  4. Prosperity: production of biomass will contribute to local prosperity
  5. Wellbeing: biomass will contribute to the well-being of employees and local population
  6. Environment: quality of soil, air, groundwater and surface water will be maintained
Professor Jack Pronk of Delft University of Technology reports a super-fast development of the conversion of such rest streams. He specializes in a scientifically interesting bottleneck. ‘Grasses do not only produce easily fermentable glucose sugars but also C5 sugars which are much more difficult to ferment. Xylose and arabinose are the well-known examples.’
A few years ago, scientists from Nijmegen isolated a gene from a fungus from the intestine of the Indian elephant, which has to digest huge amounts of grass. That gene was successfully put into a genetically modified yeast by Pronk and colleagues in Delft and now converts xylose into alcohol pretty well. In the meantime, Pronk and his colleagues have modified Baker's yeast even further and it can also now convert arabinose into alcohol.
But there are several more interesting paths. Sanders talks about innovation that uses corn cobs for the production of high-quality ethanol. ‘The cobs are currently still converted into biogas, with which electricity is generated. The released residual heat can now successfully be applied to the destillation of the alcohol. The invention is a brainchild of Wageningen UR and though it concerns smaller-scale plants, the investments per liter of produced alcohol are smaller than for large-scale plants in the United States.’
Nevertheless, the required ‘aggressive innovations’ are accomplished in the States, feel Sanders and Pronk as well as Faaij, credit crisis or no credit crisis. ‘There, the corporate world and the government are pumping 400 million dollars into research at five companies competing with each other through pilot plants’, says Sanders. ‘That points to much more drive than I see in the Netherlands where the government only practices innovation at a modest scale, stimulates only one company and concludes after five years that it was not successful.’

Export product
And that while the entire hellish dilemma of food crops versus biofuels will be solved within five years, believe the three scientists. ‘And if we get really annoyed, we can do it in three years’, adds Faaij. Besides powerful and wealthy oil and chemical industries which stimulate a great deal of research, Faaij points out developments with biofuels in Africa. ‘Currently, more is happening in Tanzania, Kenya and Zambia than in European countries like Greece and Portugal.’
He is referring to energy crops like jatropha, which grow on marginal soils, are reasonably salt-tolerant and particularly resistant to droughts. ‘But there are also plenty of projects with palm oil, sugar cane and wood’, mentions Faaij. ‘And the good part is that these countries incorporate the process of certification, inspection and monitoring as required by the West at the same time.’
Because it is certain that these former development countries cannot only create their own energy supply through these biofuels and diminish the dependence on the import of extraordinarily expensive oil. Faaij: ‘They realize that properly certified biofuels may become powerful export products in the foreseeable future, with which they can attract investment capital to the country. Whereas additional development aid fails to improve agriculture and combat poverty, energy and biofuels may be able to break the deadlock. Biomass is the holy grail of sustainable development.’