The fuels we use are critical to our fight against global warming, especially as global energy consumption grows along with our ever-increasing population. This is where biofuels can help. Samarthia Thankappan from the Environment Department talks us through how ‘trashanol’ – household waste converted into fuel – can help us to prevent pollution, reduce demand for landfills and even avoid global food shortages.
Fuel is a critical element in the fight against global warming. The transport sector is a significant contributor for greenhouse gas emissions. Although cars have reduced pollution levels over the decades, the fossil fuel they burn emits as much carbon dioxide as it 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. To meet the growing energy demand a varied energy mix is required. This is where ‘biofuels’ can help. Biofuels are fuels which can be created from materials such as waste plant and animal matter. Biofuels can also be created from a range of crops such as sugar cane, sugar beet and rapeseed oil. However vast tracts of land used for food production will be taken up growing these crops to fuel our cars, causing food prices to soar and creating food shortages globally. Using household waste therefore gets around this problem.
We in Europe generate about 900 million tonnes of paper, food, wood and other plant material waste each year. About a quarter of which can be converted into fuel. Instead of dumping the waste in landfill sites, waste-bin collections could be taken to special processing plants where organic waste can be extracted and processed using special micro-organisms that can turn it into fuel that can be used to power our transport systems.
Significant advantages of the trash-based biofuel is that it will eliminate the need to cut down trees and can free up the use of land that could be used for growing food crops. Further, compared to making ethanol from crops, the environmental benefits of making it from trash is that it reduces the demand for landfills and cuts greenhouse gas emissions. Researchers have highlighted that biofuels developed from trash could bring down global emissions by about 80%.
In terms of the process involved, there are 4 major steps: First, trash is sorted, 40% of which can be used for biofuel production. Second step involves drying and shredding of the trash. Third, the waste is placed in a gasifier which breaks it down further. The carbon present in the waste becomes a gas. In the final stage this gas is turned into ethanol and methanol ready for use. Generally a ton of trash would yield 70 gallons of bio-fuel.
Biofuels extracted from trash are commonly referred to ‘trashanol’. It is widely believed that the process of converting trash to fuel will contribute towards energy independence. Scientists believe that ‘trashanol’ is greener than ethanol derived from corn and a major benefit of ‘trashanol’ is that it can help reduce the number of landfills and the earth-warming methane gas they produce. Though there is a lot of optimism in the scientific arena about trashanol’s environmental benefits and with businesses working towards making this economically feasible, there are several challenges still ahead.