Researchers have developed an innovative way to convert plastics to ingredients for jet fuel and other valuable products, making it easier and more cost effective to reuse plastics. The researchers converted 90% of plastic to jet fuel and other valuable hydrocarbon products within an hour at moderate temperatures and easily fine-tuned the process to create the products that they want.
Plastics recycling has been problematic. The most common mechanical recycling methods melt the plastic and remold it but that lowers its economic value and quality for use in other products. Chemical recycling can produce higher-quality products but it has required high reaction temperatures and a long processing time, making it too expensive and cumbersome for industries to adopt. Because of its limitations, only about 9% of plastic in the U.S. is recycled every year.
The researchers developed a catalytic process to efficiently convert polyethylene to jet fuel and high-value lubricants. Polyethylene, also known as #1 plastic, is commonly used in a huge variety of products from plastics bags, plastic milk jugs, and shampoo bottles to corrosion-resistant piping, wood-plastic composite lumber, and plastic furniture.
For the process, the team used a ruthenium on carbon catalyst and a commonly used solvent. They were able to convert about 90% of the plastic to jet fuel components or other hydrocarbon products within an hour at a temperature of 220 °C (428 °F), which is more efficient and lower than temperatures that typically would be used. Adjusting processing conditions — such as the temperature, time, or amount of catalyst used — provided the critically important step of being able to fine-tune the process to create desirable products.
The process could work effectively with other types of plastics.