Oh plastic dear plastic, the thing that’s more troublesome than helping right now (in most cases). Turning it into something beneficial is rare, but it’s apparently achievable to turn plastic into fuel.
A mechanical engineer from Hyderabad called Professor Satish Kumar has successfully made petrol out of used plastic. He made petrol with the help of a three step process known as plastic pyrolysis and he’s selling it at aroundRs 40 (USD 0.58) per litre.
“The process helps recycle plastic into diesel, aviation fuel and petrol. About 500-kg of non-recyclable plastic can produce 400 litres of fuel. It is a simple process which requires no water and doesn’t release wastewater. Neither does it pollute the air as the process happens in a vacuum,” said Kumar.
For now, this fuel only works for industry machines but it hasn’t been tested on vehicles. All kinds of plastics, except for Polyvinyl Chloride (PVC) and Polyethylene Terephthalate (PET), can transform into fuel and no segregation.
Now, plastic pyrolysis sounds pretty promising, and Kumar claims that this process does not pollute the atmosphere nor require any water. Some experts disagree, though. Non-profit the Low-Impact Living Initiative spoke with energy engineer Dr. Andrew Rollinson, and he argued that recycling plastic into fuel is actually not as sustainable as it sounds.
Even if plastic pyrolysis becomes more common and eventually improves the (extremely flawed) plastic recycling process, that will only make people feel like it’s OK to use more plastic. When in reality, humans need to use less plastic and not rely on recycling entirely.
Moreover, experts who disagree believe that pyrolysis requires more energy to be put in than what actually comes out, suggesting that it isn’t a sustainable form of recycling. This calls for more research to determine if this process could actually help reduce the number of virgin plastic used on Earth and mitigate climate crisis.
On the other side of Hyderabad
Apparently, Professor Kumar isn’t the only one who had the idea to turn plastics into fuel. A team of chemists at Purdue University has discovered a way to convert polypropylene (PP) into gasoline and diesel-like fuel. The researchers said that this fuel is pure enough to be used as blendstock, a main component of fuel used in motorized vehicles.
In order to turn this type of plastic into fuel, the team used supercritical water. It’s a phase of water that demonstrates characteristics of both a liquid and a gas depending on the pressure and temperature conditions. The chemists then heated water to between 716 and 932 degrees Fahrenheit at pressures approximately 2300 times greater than the atmospheric pressure at sea level.
Once purified polypropylene waste was added to the supercritical water, it was converted into oil in a few hours, depending on the temperature. At about 450 degrees celsius, conversion time reduces to under an hour.
According to Purdue researchers, the byproducts of this process include gasoline and diesel-like oils. They stated that this process could convert about 90% of the world’s polypropylene waste each year into fuel.
“Plastic waste disposal, whether recycled or thrown away, does not mean the end of the stor. Plastics degrade slowly and release toxic microplastics and chemicals into the land and the water. This is a catastrophe because once these pollutants are in the oceans, they are impossible to retrieve completely,” said Linda Wang, a Purdue chemist.
Wang stated that this discovery/process/innovation might encourage recycling industry to adopt it due to its profitability and ultimately reduce plastic waste.
It’s still unclear of how difficult it will be to implement this new plastic conversion process at scale, but at least for once it looks like there might be hope to reduce plastic waste.
Turning plastic waste into hydrogen
Before, in 2018,. scientists at Swansea University developed a way of turning plastic waste into hydrogen and hope it could one day fuel cars. The process involves adding a light-absorbing material to plastic, placing it in a solution and exposing it to sunlight.
Dr. Moritz Kuehnel from Swansea University’s chemistry department said it that this process could be be cheaper than recycling plastic as any plastic can be used and it does not need cleaning.
“There’s a lot of plastic used every year – billions of tonnes – and only a fraction of it is being recycled.The beauty of this process is that it’s not very picky. It can degrade all sorts of waste,”
“Even if there is food or a bit of grease from a margarine tub, it doesn’t stop the reaction, it makes it better. The process produces hydrogen gas. You can see bubbles coming off the surface. You can use it, for example, to fuel a hydrogen car,” said Dr. Kuehnel.
Dr. Kuehnel said the remains of the plastic could be recycled to make new plastic. He said, “For PET, it consists of terephthalic acid and ethylene glycol – two components that make a chain that makes a polymer,”
“In the process we degrade one bit, ethylene glycol. This is what produces hydrogen and CO2, and the other bit stays intact and remains in the solution. We get the hydrogen fuel and we get a chemical we can use to make new plastic. We don’t make a full new plastic, we use just half of the material to make new plastic and the rest can be recycled – a clean, clear water bottle out of plastic.”
As you can see, we’ve got ourselves three kinds of process or innovation to turn something problematic into something else. But what do you think of this? In the end, fuel leaves carbon footprint and it isn’t good for the environment as well. Tell us your take on this potential fuel of the future in the comments below.