Plants are providing us with an ever-increasing number of resources. Besides food, drugs and building materials, they are now also supplying fuel and even plastics. But are all these uses of plants quite as 'green' as they are made out to be? 'Only a few thousandths of the solar energy gets converted in biomass', says Prem Bindraban.
The desire for an energy supply that is not dependent on other countries is a powerful political motive for switching to energy generated from biomass. And yet energy should not be at the top of the wish list for a bio-economy, said the Rathenau Institute in a recent report called To the heart of the bio-economy: the sustainability potential of biomass in perspective.
Biomass has been used in paper and cardboard for a long time in the Netherlands. It is now also used as a supplementary fuel in power stations and is added to petrol and diesel for use in cars. The government strongly encourages this, for example by implementing the EU regulation obliging fuel producers to add biofuels to their mix, with the goal of reaching 10 percent by 2020. The large-scale use of crops for energy can lead to food shortages and hunger, as food supplies disappear into fuel tanks. A question mark also hangs over the sustainability of the system, as the production of crops adds to CO2 emissions too, certainly when large amounts of artificial fertilizer are involved. What is more, fuel crop cultivation can lead, indirectly, to deforestation, which means less CO2 is stored.
The social side
It is not really so clever to use biomass to generate energy, say some - now including the Rathenau Institute. Energy is an inefficient way to use biomass, so it would be smarter to use it for products with a higher added value, such as food and drugs. Then come raw materials for plastics, building materials and chemicals, and last of all comes energy. This would follow the principle known as 'optimal added value'. This should be the guiding principle in policy, according to Rinie van Est, one of the Rathenau Institute researchers. 'In 2007 the concept of optimal added value was put on the agenda of the Balkenende IV cabinet by Wageningen researchers', says Van Est. Biomass should not be swallowed up by power stations in its crude form, but should be refined, just as oil is refined. Once foodstuffs and other materials with higher added value have been extracted, the waste material can be burned to generate power.
'But that still doesn't automatically make the bio-economy sustainable', says Van Est. That depends, she explains, on how the crop is grown and how it will eventually be used. Moreover, more weight is given to social aspects such as local food security or the labour conditions of those producing the crop.
'You have to measure to know for sure', says Van Est. 'Sustainability criteria must be established which can identify whether a process is sustainable on a case-by-case basis.' Van Est sees this as an appropriate task for researchers at Wageningen UR. The Rathenau Institute's report argues against coming up with a blueprint for the bio-economy and for learning as we go along from new processes in operation.
Sustainable and profitable
The Rathenau Institute's report has had a mixed reception in Wageningen. One positive response is that of Erik van Seventer, who leads the Biobased Economy research theme for Wageningen UR. 'The recommendation to make optimal added value central is a good one. Ensure food security and use the waste products efficiently, in biobased processes, for example.'
According to Van Seventer, this is important not just to make the biobased economy more sustainable, but also to make the use of biomass more profitable. After all, agricultural resources are becoming more expensive too. Van Seventer: 'Power stations are now becoming interested in biorefinery, with which they first extract the high added value materials from the crop. Sustainability is not just better in the long term; it is also more profitable.'
But if the bio-economy is to be sustainable, agricultural production will need to become more sustainable across the globe. Lotte Asveld, another of the Rathenau Institute researchers, therefore argues for more stringent sustainability criteria for biomass. Biofuels which are mixed into petrol and diesel already need a sustainability certificate. This is comparable to the fairtrade labels familiar from the supermarket. 'But the requirements are not very strict yet', says Asveld. 'The indirect consequences for land use should be taken into consideration too, for example. So that no forest is cut down to make way for a new palm oil plantation.'
Van Seventer agrees that a sustainable bio-economy requires sustainable agriculture. 'But to expect all agricultural production to be certified is just not realistic, of course. What is more, it is strange that wheat produced for fuel should have to have a sustainability certificate, while wheat for human or livestock consumption does not have to.'
Prem Bindraban, a researcher at Plant Research International, is not happy with the analysis of the report. 'I am pleased that this report challenges the usual rosy picture of the biobased economy. But it nevertheless misses the point. Which is that we really must start using our natural resources more efficiently.'
It is far from efficient to use plants as a green factory for the production of energy, says Bindraban. Only a few thousandths of the solar power is converted into biomass. 'There are more efficient ways of generating energy. Energy use is a physical process for which we do not need to make use of biology or ecology. There are alternatives for energy, but none for food.' The criterion against which applications in the bio-economy should be measured, according to Bindraban, is the burden they place on natural resources, compared to the alternatives.
Lotte Aveld agrees with Bindraban that there are alternatives for generating energy. But she also sees the advantages of biofuels. 'Stimulating the use of biofuels has opened people's eyes to the potential of the bio-economy. That is why so many companies and researchers are working on it now.' According to Asveld, it is now time to sift the proverbial wheat from the chaff by testing each of the various applications for its sustainability. 'We must demystify the concept of sustainability by making it concrete.' This brings risks of its own, however. Because which consumer is going to remember what the difference is between sustainable and unsustainable uses of biomass? The sustainable image of the bio-economy is bound to suffer some damage along the way. It is also doubtful whether western countries really care very much whether their oil substitute proves to be less sustainable that it was thought to be. After all, not being at the mercy of unstable oil states is worth a lot to them too.
The report can be found at www.rathenau.nl