A group of researchers at Washington State University has found a technique for converting the plastic waste products which are generated every day to jet fuel. Hanwu Lei of WSU and his colleagues have been successful in melting plastic waste at a very high temperature with the help of activated carbon, which is a processed carbon with a greater surface area to form jet fuel. The study has been published in the journal Applied Energy.
Lei, an associate professor at Department of Biological System Engineering in WSU commented that waste plastic is a major problem worldwide. But they have been able to recycle the plastic in a very simple way.
For the experiment, several low-density polythenes and a variety of waste plastic products such as water bottles, plastic bags were tested by the research group and they were ground to a very small size, around the range of three millimetres which is equal to the size of a rice grain. The granules of plastic were then kept above activated carbon, placed in a tube reactor at very high temperature, in the range of 430 to 571 degrees Celsius, which translates to 806 to 1060 Fahrenheit. The activated carbon plays the role of a catalyst which is a substance for increasing the rate of a chemical reaction without itself being consumed in it.
Lei remarked that since plastic is very difficult to be decomposed to smaller particles, the help of a catalyst has to be taken in order to break the chemical bonds. Plastics contain a very high amount of hydrogen, which is an important component in fuels.
Once the carbon catalyst has been used for one set of conversion, it can be again separated and reused for the next batch of conversion of plastics. If the catalyst loses its activity, it can be also be regenerated. Researchers tested several combinations of plastics and the best result obtained was a mixture of 85 per cent jet fuel and 15 per cent diesel fuel.
According to the estimates of Environmental Protection Agency, landfills located in the United States received close to 26 million tonnes of plastic in the year 2015. This is the most recent statistics which are available currently. Scientists estimate that at least 4.8 million tonnes of plastic enter the oceans in the world.
This new technique would help in making the best use of plastic and hence minimize its wastage. Lei said that almost 100 percent of the energy can be recovered from the plastic which is tested. The fuel which is obtained is of decent quality and the byproduct gases are of good quality as well. This process is even highly scalable.