Making Lubricants From Plastic Waste

Single-use plastics have a bad reputation for contributing to the earth’s environmental and pollution issues. With the world’s ever-vigilant focus on protecting the environment, society is determined to halt the use of single-use plastics, such as those plastic bags used at grocery stores.

However, there is good news on the research front regarding these single-use plastics, as discovered by a team of researchers from multiple institutions. Led by Kenneth R. Poeppelmeier from Northwestern University, Massimiliano Delferro from Argonne National Laboratory and Aaron D. Sadow from Ames Laboratory the researchers developed an alternative method to upcycle (or creatively reuse) single-use plastics into liquid products of higher quality, including lubricants, motor oils, cosmetics and detergents. Additionally, researchers determined improved methods for recycling single-use plastics than those methods currently employed.

Kenneth R. Poeppelmeier, from Northwestern University, states that the new technology will help combat the growing problem of accumulating plastic waste. Poeppelmeier feels that the research findings provide hope of a future that benefits from the use of plastics in an environmentally friendly manner.

The research focused on converting polyethylene molecules into high-value commercial products with the use of a catalyst. The catalyst consisted of platinum nanoparticles, which were deposited onto perovskite nanocubes using atomic layer deposition. Atomic layer deposition is a controlled process, depositing thin atomic layers of film one layer at a time. Perovskite is a calcium titanium oxide mineral that is easily synthesized. It displays properties such as magnetoresistance and superconductivity.

The catalyst splits the strong carbon-carbon bonds found in plastic to create higher quality liquid hydrocarbons. Possible uses of the resulting liquid include lubricants, motor oil, or even cosmetics and detergents.

This new technology provides a method to help support a circular economy. A circular economy is based on the principles of designing out pollution and waste, keeping materials and products in use, and regenerating natural systems.

Plastic waste is an ever-growing environmental concern. Some estimate that by the year 2050, there will more plastic in the ocean than fish. The fish ingest the plastic, and other animals, including humans, eat the fish, thereby ingesting the plastic themselves. Needless to say, plastic consumption is harmful to the health of fish, animals, and humans alike.

Unfortunately, plastics remain useful in many circumstances and are often difficult to replace. One of the main concerns is that most of these plastics are thrown out after only a single use. Current plastic recycling processes melt and reprocess the material. However, the resulting material is of a lower quality than the original material.

Due to the strong carbon-carbon bonds found in plastics, the material does not degrade after being thrown into the garbage or in landfills. Instead, the plastics break down into smaller pieces, called microplastics. It is these microplastics that end up in the fish and other animals.

However, the researchers viewed the strong bonds as a benefit rather than a detriment. They capitalized on the strong carbon-carbon bonds, which are held together by high energy, in the process of converting the polyethylene molecules into useful products. A further benefit of the new technology is decreased waste production compared to current methods, which create toxic by-products and greenhouse gases.

Perhaps the idea of a circular economy is not as far-fetched as it once seemed. Turning single-use plastics into useful products that are used on a daily basis can only help provide for a better and cleaner future.

Further information regarding the research results can be found in the article “Upcycling Single-Use Polyethylene into High-Quality Liquid Products” https://pubs.acs.org/doi/abs/10.1021/acscentsci.9b00722.