Northwestern University Touts Nickel-Based Plastic Recycling Tech

Chemists at Northwestern University have introduced a new plastic upcycling process that could significantly reduce or even eliminate the need for pre-sorting mixed plastic waste. The process uses a new, inexpensive nickel-based catalyst to selectively break down polyolefin plastics, which include polyethylene and polypropylene.

The research addresses the primary challenge in recycling polyolefins, which dominate nearly two-thirds of global plastic consumption but have very low recycling rates. Their sturdy carbon-carbon bonds make them difficult to break down, and current recycling methods are either energy-intensive or require meticulous sorting. “One of the biggest hurdles in plastic recycling has always been the necessity of meticulously sorting plastic waste by type. Our new catalyst could bypass this costly and labor-intensive step for common polyolefin plastics, making recycling more efficient, practical, and economically viable than current strategies,” said Tobin Marks, the study’s senior author.

When the catalyst is applied, it breaks down the solid polyolefin plastics into liquid oils and waxes, which can then be upcycled into higher-value products such as lubricants and fuels. The new single-site catalyst operates at lower temperatures and pressures than existing methods and is made from an abundant, inexpensive nickel compound. This single-site design allows it to act with high precision, operating at a temperature 100° lower and at half the hydrogen gas pressure than other nickel-based catalysts. According to the researchers, their process uses 10 times less catalyst loading but achieves 10 times greater activity.

A key finding from the study was the catalyst's interaction with polyvinyl chloride (PVC), a common contaminant that typically renders plastic waste unrecyclable. The researchers found that not only did their catalyst withstand PVC contamination, but the presence of PVC actually accelerated its activity, improving its performance even when the waste mixture was made up of 25% PVC.

Nickel Supply Challenges 

The development of this new recycling process highlights the growing importance of nickel, a key metal for the energy transition and green technologies. Nickel is a critical component in the manufacturing of stainless steel and is essential for the cathodes in most lithium-ion batteries used in electric vehicles (EVs). According to market analysts and the International Energy Agency (IEA), demand for high-purity nickel is projected to increase significantly through 2030, driven primarily by the EV battery sector.

The global nickel supply chain is highly concentrated in China and Indonesia. In 2024, these two countries controlled 75% of the world's refined nickel, with Indonesia accounting for over 50% of the market and China for 25%.

This dominance is projected to continue through the end of the decade. According to the International Energy Agency (IEA), by 2030, Indonesia is expected to account for over 67% of global nickel mining, followed by the Philippines with over 6% and Russia with 5%. In refining, IEA projects that Indonesia will hold a 45% share of global capacity by 2030, followed by China with 33% and Russia with 3%.

This high concentration of supply has created significant market volatility and vulnerabilities. The dominance of a few producers has already forced the closure of higher-cost nickel operations in jurisdictions like Australia and Canada, as noted by Adrián Juárez, CEO, Consultoría y Tecnología Ambiental (CTA). This situation creates a particular challenge for the United States, which has minimal domestic reserves and is therefore more vulnerable to these global supply chain disruptions, a risk further exacerbated by ongoing environmental and safety concerns at some production sites in Indonesia, and trade tensions with China.