Plastic waste is a huge problem in the world. Because of its durability, plastic waste accumulated in landfills and oceans tends to be trapped for centuries, causing a global environmental crisis. Even though we produce about 300 million tons of plastic waste each year, only 9% is recycled. But why are we only recycling so little? The reason is the current inefficiency and high cost of recycling plastic waste, resulting in a lack of incentives. Recently, researchers from Washington State University discovered a more efficient method that can drastically improve the efficiency of chemically recycling plastic waste.

Currently, there are three types of plastic waste recycling: mechanical recycling, incineration, and chemical recycling. Mechanical recycling is the most widely used recycling option, and it involves mechanically grinding or compounding plastic waste for re-use in similar products. However, this process will result in poorer plastic quality, and thus these recycled products are not widely used by industries. Incineration can convert plastic waste into heat and electricity, but the process may result in the emission of toxic pollutants such as acid gases and heavy metals. Therefore, the last option, chemical recycling, where plastics are converted to fuels, is considered to be the most promising plastic waste recycling process with the least adverse effects. However, the current technology of chemical recycling requires extremely high temperatures (over 300°C), which is expensive and inefficient. 

In order to improve this, these researchers investigated the effects of using different metals as catalysts, which are materials that can speed up the conversion process, while also varying other process conditions such as temperature and pressure. They discovered that, using a combination of ruthenium metal and carbon as the catalyst, they can convert 90% of plastic waste into fuel in just one hour, at a lower temperature of 220°C. This condition is significantly more efficient and cost-effective than the current chemical recycling standard.

If we continue our current rate of only recycling 9% of plastic waste, our ocean will contain more plastic than fish by 2050. This new discovery may provide a promising and more incentivized approach for ramping up the recycling process of plastics in the near future. These researchers are now working on trying to scale up and commercialize this process, which will be very useful in the global goal of reducing plastic waste. 

The first author of the study, Chuhua Jia, is a PhD student in the Department of Chemical Engineering at Washington State University.

Managing Correspondent: Wei Li

Press Article: Plastic waste can now be turned into jet fuel in one hour, The Academic Times.

Original Article:Deconstruction of high-density polyethylene into liquid hydrocarbon fuels and lubricants by hydrogenolysis over Ru catalyst, Chem Catalysis.

Image Credit: RitaE from Pixabay

40 thoughts on “Converting Plastic Waste into Fuel

  1. It is my understanding that the heat from nucleur power stations is dissipated by a series of steam turbines stepping the temperature down. Could designers of new power stations not incorporate a closed system at the approriate temperature level where plastic could be converted to methane and extracted as a by product. I realise there would be a number of issues the obvious risk of having an explosive gas in the area of a power station, a possible issue with cleaning out any residual waste, security and the issue of getting plastic waste to the site.

  2. Bugs. We can make bacteria that will convert plastic into biodegradable gunk. If we are clever the bugs will emit a burnable gas as a byproduct.

  3. Its fascinating and wonderful to read these ideas. With over 139 million metric tons of single use plastic in 2019 and growing every year we have to utilize as many approaches as we can. It has taught me to be a wiser consumer, wonderful at repurposing, and makes me look at possible recycling strategies that make sense. The recycling into building supplies appeals to me most. Having dug up a 20 year old “dump site” on our property there were discarded clothing articles and plastic twine that showed no decomposition, makes me wonder if our housing demands could benefit from this source. For me our planned obsolescence is detrimental in the general , if we could make building supplies last as long as our trash!!! Our energy needs seem to grow exponentially so recycling for fuel seems to be a natural, if we don’t increase other pollutants seems a great alternative.

  4. From a business perspective;
    1. How clean would the plastic have to be to burn in the process?
    2. How much would a system like this cost to purchase and operate?
    3. Would it be feasable to charge companies to take there waste plastic, then sell the oil to offset the cost to run the equipment?

    1. From my understanding the plastics do not need to be cleaned however the tank would need to be cleaned out more often with dirty plastics. As well the plastic does not need to be sorted by colour or grade either. The cost to operate and or purchase would depend on the size of the operation. Charging the companies would end up costing the consumer regardless of who pays the up front costs. From my research melting plastic without flame entering the melting chamber is how it is done. There isn’t much profit and may cost more then the product gotten from the process. I do not believe in global warming agenda however plastics a tossed aside without much thought and it is taking up large spots in the oceans and filling landfills. I am going to try a small pilot project to try it out.

  5. Burning the plastic in kilns and for power is a great way to get rid of plastic. Instead of dumping it in the ocean and landfills. They need to work on better ways to clean and recover fumes and gases.

  6. The petrol being produced after plastic conversion is it usable in car engine as well?
    Has anyone studied it’s effects in engine operations and what’s the difference between the organic oil and this

  7. Has anyone studied what happens to PE or PP when put under extreme heat and pressure in a vacuum for a long period of time?

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