Over the last few weeks there has been a lot of discussion in the mainstream media about the volume of waste humans produce. Part of the discussion centres around the fact that both India and China are now stopping imports of other countries waste products. To make it worse, humans are still consuming lots of products wrapped in plastic and have no desire to slow down that behaviour.
Despite many retail outlets trying to reduce plastic usage and companies like BMW using recycled plastics in their cars, the volume of this material heading to landfill is going to substantially increase as countries figure out what to do with all the waste. So the interesting thing about plastic is that it starts its life underground as crude oil and during the refining process, ethylene is extracted which is then used as a foundation for the material.
Today, most non-recyclable waste is either dumped in landfill to slowly degrade or is burnt to create electrical energy – a byproduct of that last process is poor air quality and pollution whilst the first process can cause leaching of chemicals into ground water. Now, if it was possible to convert plastic waste into a form of fuel to power machines like cars, then we can go full circle.
Well that last idea is actually possible. Using a process called Cold Plasma Pyrolysis it is apparently possible to split waste plastics into several components including hydrogen, methane and ethylene. The downside is that basic pyrolysis needs to have very high temperatures to work – which uses lots of energy, so using true pyrolysis would use all the energy it created! Adding in the cold plasma as the pyrolysis process means that the temperatures are reduced and therefore reduces the amount of energy required to run it.
Cold plasma is created using two electrodes with enough power to help split the plastic into several components. The process is already in use to help sterilise medical equipment and has been repurposed in this instance to help the environment.
Once the pyrolysis process has been completed, the “oil” that comes out of that process has to be distilled to refine the energy content. That is the key: the energy content provided by the constituent components has to have a fairly high rating to justify the process and provide a fuel source capable of moving a vehicle.
If the boffins can make this work with minimal energy consumption, then all the waste can be converted into different products that can be reused in many different machines – not necessarily cars. Some of the energy created could be directed back to continue the process which means that it could become self-sufficient. In theory, a cold plasma pyrolysis unit could be added to all landfill sites to use all the waste and get it out of the ground and recycled cleanly.
That would be the biggest ecological step forward the world has seen in decades if not centuries. We will hear more about this idea over the next few years as the technology improves and hopefully we see more waste being recycled and perhaps some blended diesel fuels coming on the market.
It would be interesting to see more bio-diesel and recycled waste powered car coming on the market – it would help clean the environment not pollute it!