Going green

Green solutions that will change our world

Last November we saw Britain’s first ‘Bio-Bus’, powered entirely by biomethane gas (produced from human and food waste), take to the streets between Bath and Bristol, trialling an innovative scheme to provide a sustainable fuel source for public transport. This recent innovation is just one example of how biofuels and biowaste are providing sustainable and low-cost solutions to our energy says Samarthia Thankappan from the Environment Department at York.

“The transport sector is a significant contributor for greenhouse gas emissions.” Samarthia, whose research focuses on sustainability in the automotive sector, explains: “Although cars now have reduced pollution levels, the fossil fuels they burn emit as much carbon dioxide as they did 100 years ago. With the world’s population projected to reach 8.6 billion in the next two decades, global energy consumption is also projected to grow significantly.

“Many existing biofuels are produced from crops which can be used for food, and therefore this does have a negative impact on global food security but using a trash-based biofuels like the bus does, eliminates the need to cut down trees and can free up the use of land that could be used for growing food crops. Further, the environmental benefits of making it from trash means that it reduces the demand for landfills and cuts greenhouse gas emissions.”

Biofuels can be created from materials such as waste plant and animal matter but they can also be created from a range of crops such as sugar cane, sugar beet and rapeseed oil which require vast tracts of land, causing food prices to soar and creating food shortages globally.

Researchers have highlighted that biofuels developed from trash could bring down global emissions by about 80 per cent.

With so much at stake, research into identifying the best way to address these issues is crucial and in order to meet the demand for a sustainable energy source, a mix is required indicating that the use of both biowaste and biofuels is clearly the way forward.

As Samarthia in the Environment Department explores the impact of biowaste or ‘trashanol’ as the industry calls it, researchers from the University’s Centre of Novel Agricultural Products (CNAP) and the Departments of Biology and Chemistry are looking at ways to optimise the strength and resistance of the biofuel crops. They are finding ways to extract and break down the simple sugars needed to produce ethanol in plants. This means biofuel is an added bonus and not the core reason for growth and production.

York researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC) have recently discovered a variant of straw whose cell walls can be more easily broken down to make biofuels, but isn’t significantly smaller or weaker than regular plants.

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The discovery could help ease pressure on global food security as biofuels from non-food crops become easier and cheaper to make. York Professor Simon McQueen-Mason explains: “This work sets the stage for identifying similar high-digestibility lines in commercial crop species that will pave the way to more cost-effective and sustainable biofuels.

“Using plant by-products such as straw provides a double benefit as we can harvest the food from the plant, then use the straw to produce a carbon neutral fuel.”

Simon is also working with researchers in Europe and Brazil to find ways to convert woody plant material, including residues from sugar cane, into environmentally friendly biofuels.

“As one of the world’s largest sugar producers, Brazil produces around 600 million tons of sugar cane each year. Only 10 to 15 per cent of this crop consists of easily-extractable sugar with the remaining lignocellulosic biomass, known as bagasse, offering a plentiful supply of raw material for sustainable, second generation biofuel.”

“The research identified the genes that affect the composition of the cell walls in the target plants, so that in the future, breeders might be able to tailor-make plants with more digestible biomass.”


Maximising land production

Maximising the biofuels production process and optimising the use of land used to grow biofuels crops is something biology alumnus Dr Wei He (Biology, Wentworth, 2012), from the Northwest University in Xian, China is also focusing on. He is working to identify biofuel plants that can be easily propagated in north China.

Dr Wei He explains: “Many biofuel plants grow well under optimal conditions, such as sufficient water and fertilisation, but in order to achieve these conditions, a lot of money and energy is needed which therefore reduces the output and thus net value of biodiesel.”

Wei aims to address the fact that in north China (and elsewhere around the world), traditional biofuel plants are difficult to grow. He has now discovered one called Amygdalus pedunculata pall. which can grow in sandy areas.

He says: “It doesn’t need extra water and fertiliser, however, like many biofuels plants, the yield needs to be boosted to make the plants truly ‘valuable’ for commercial use.”

Wei and his team are currently collecting samples of A. pedunculata from a wide range of geographical locations in northern China, as they aim to establish the germplasm bank for its future breeding effort.