BiofuelsImagine your next flight fuelled by leftover hot chip fat instead of jet fuel.
Flight VS100 made history in November 2023 by becoming the first commercial passenger aircraft to fly across the Atlantic Ocean fuelled mostly by waste chip fat and fruit sugar.
In the effort to transition away from fossil fuels, create cleaner and cheaper energy and reduce waste, scientists needed to think creatively. Developing and using biofuels is just one solution already playing a key role in the transition.
What are biofuels?
Biofuels are a type of fuel made from processing biomass- organic matter like plants, algae or animal waste. This can include by-products from forestry, crop and animal waste from farms, sewerage and even some waste from landfill. They are renewable because the living matter used to make them can be grown again whereas fossil fuels cannot.
Biomass can be processed and refined to create biofuels in all three states of matter:
1. Solid biofuels
If you’ve ever lit a campfire then you’ve used a biofuel: burning wood is one of the oldest biofuels that humans have used. Wood can also be compressed into smaller wood pellets which can be used to heat homes or generate electricity.
Image: Harvesting crops. Crops like sugarcane can be processed and refined to produce biofuel.
2. Liquid biofuels
These include biodiesel made from plant oils and bioethanol which is made from fermenting sugar and wheat. Corn or sugarcane can also be processed and added to existing fuels, like gasoline, and then used in transport.
Image: Anaerobic digester. These digesters use microorganisms like bacteria to break down the organic material rather than oxygen.
3. Gaseous biofuels
These include Biogas and Syngas:
- Biogas consists mainly of methane and carbon dioxide. It is naturally produced as organic matter is broken down by microorganisms in a process called anaerobic digestion.
- Syngas, as its name suggests, is a synthetic, human-made gas produced by chemically processing biomass waste products. Gaseous biofuels are most often used in heating and generating power in gas turbines.
How do biofuels help?
Biofuels will play a vital role in the energy transition towards Net Zero by 2050 because of the accessibility, renewability and sustainability of fuel sources.
We know that fossil fuels are a finite resource, taking millions of years to form. Biofuels can capitalise on pre-existing industries like farming and forestry and convert their problematic waste into useful fuels. As these industries are integral for growing food and building houses, there will always be an ongoing, renewable and importantly, accessible supply.
Fossil fuels like oil and gas can only be found in very specific, often inaccessible locations like reservoirs deep underground, whereas biofuel production can be established anywhere farming or forestry takes place. This means a wider group of communities and industries can produce their own fuel without relying on a “geographic lucky dip”. As a result, this reduces the import and export of fuel, helping to build more resilient economies and countries during energy disruption.
Currently, the aviation industry contributes around 2.5% of global carbon dioxide emissions, with the wider transport sector contributing a quarter of our greenhouse gas emissions in the UK alone. As we move towards net zero, how we fuel our transport sector will need to change and part of this will include using biofuels; whether it’s bioethanol in cars or a Sustainable Aviation Fuel alternative using cooking oil, vegetable fats and animal waste.
What are the limitations of biofuels?
Whilst incredible innovation and creativity have gone into developing biofuels, they are not without their challenges or a perfect solution to clean, sustainable energy.
Biofuel uses the same part of the crop that we eat as food, as the fuel source. For example. Corn kernels. With the world’s growing food demands, choosing to use food crops like corn and wheat for fuel instead of food has become a controversial issue. Land is also a limited resource and using it to grow fuel instead of food could affect the availability or prices of these foods.
Scientists describe biofuels as carbon neutral: the carbon that is released during their production balances out because growing these crops again in the future will, ideally, recapture this carbon. At the moment, the farming and production processes which grow, harvest and refine these crops into biofuel are intensive in their energy and water use and still release some carbon emissions into the atmosphere. Biofuels have the capability of being a clean source of energy, but it depends entirely on how they are produced and if future technologies can reduce the amount of water and energy input into their production.
Biofuels are an important part of the energy transition, but there is still more investment and innovation required before it’s an ideal system of energy production.
How dependent should we be on this method?
What changes to the biofuel industry would you make to increase its sustainability and improve its potential?
