With climate change gathering pace and the world’s easily accessible oil deposits running low, we have to find environmentally-friendly versions of petrol and diesel if we want to continue using our cars and their technology in the future.
Based on current levels of output, scientists have estimated that the world has around 55 years of oil use left before reserves run out. So that means that we should really be looking for, and developing alternative fuels that could be a viable, if not better substitute than oil-based fuels for powering engine technology.
What are alternative fuels?
There are number of alternative fuels that already exist or that are currently being developed. Viable alternative fuels for powering cars need to be able to do two things:
- Provide efficient, cheap, readily available fuel
- Give off no carbon-neutral emissions
Hydrogen is a gas that makes up around three quarters of the universe. It can be used to power batteries in cars and there are a number of cars on the market that already actually use hydrogen in their cars.
You can extract hydrogen from the environment by reacting steam with coal or gas or by passing an electric current through water.
The only thing that's given off when you burn hydrogen is water and heat, making it a completely emission free fuel, if you use hydrogen fuel cells as the sole form of power. Hybrid hydrogen power has been shown to provide cleaner emissions too – combined hydrogen fuel cells and conventional internal combustion engines, for instance, have been shown to reduce emissions by around 30%.
Obviously hydrogen isn’t a renewable resource so it will run out one day. This means it’s not exactly perfect when it comes to finding a sustainable fuel. It also produces quite a lot of emissions and isn’t particularly environmentally friendly. If you could use renewable energy to extract hydrogen, the process could be made slightly better for the environment.
Biodiesel is a promising fuel that could help reduce emissions of cars whilst still providing similar levels of performance to other types of oil-based fuels. Biodiesel is made from plants and trees so it’s essentially renewable. As long as you’ve got the seeds and the soil to grow it in, you’ll have the ability to create fuel.
In terms of emissions, pure biodiesel, in theory, is carbon neutral. Plants absorb carbon dioxide (one of the main causes of global warming) from the atmosphere when they’re growing, and they give out oxygen. The excess carbon that is unleashed when the fuel is burnt is cancelled out by the amount that is absorbed when the plants are growing.
There are a few problems with biodiesel and other biofuels at the moment. Oxygen compounds can form over time in the fuel, if it’s not created in the right way or if it’s stored in correct.
Ethanol is another biofuel that can be used to power cars. It’s actually the substance that we know (and love) as alcohol. It’s extracted from the glucose that’s present in plants like sugarcane and corn and burned as fuel.
In terms of performance, ethanol has a higher octane rating than petrol and diesel giving it better performance. It does have less energy per gallon though.