By Joanna Wolstenholme
You have heard of the need to find new sources of energy that do not involve fossil fuels. And you have also probably heard of bioethanol from maize and sugar cane, and the scepticism surrounding their green credentials. This scepticism comes with good reason – these sources of biofuels often divert valuable food from the food chain into fuel production, raising the cost of living. This was vividly illustrated by the food crisis in 2007/8, partly caused by America and the EU incentivising the production of bioethanol. So should we write off biofuels altogether?
Simply put – no – not all biofuels. Second generation biofuels are what you should really be talking about. Write off those inefficient first generation biofuels with their ‘food vs fuel’ baggage, but don’t write off biofuels altogether. Lignocellulosic biofuels are the next big thing – the same green pros, but less of the cons. These biofuels can be made from waste products like straw, maize cobs and bagasse (sugar cane straw), and, excitingly, these technologies are just starting to become commercially viable.
Lignocellulose is found in the plant cell wall, and is the main component in plant biomass. Unlike sugars (which whilst easily accessible for use in first generation biofuels, are only a small portion of the overall biomass), cellulose is generally an unwanted by-product that goes to waste, thanks to how hard it is to break down. However, researchers are finding new enzymes and treatment methods that are able to attack the cellulose in ever more efficient ways. The first commercial plants have already been built in Brazil and Italy, using biofuel crops like Miscanthus that can be grown on marginal or contaminated land (rather than prime agricultural land), or waste products like straw. These take advantage of government subsidies on renewable electricity to help cover the cost of generating the biofuels whilst scientists work to bring these costs down.
In the 1970s Brazil got worried about its oil supply, so started to move the country to bioethanol. The system was heavily subsidised- but now is self-sufficient, and yields have doubled. Lignocellulosic biofuels could easily go the same way, if only governments are forward-thinking enough to see the potential and invest.