Plastic Pyrolysis: An Advanced Recycling Technology

The EPA has classified pyrolysis as an advanced recycling technology and excluded it from the regulatory framework governing incinerators under the federal Clean Air Act. This move has complex implications for the plastic pyrolysis industry, primarily affecting regulatory status, project permitting, and capital investment. However, it does not equate to a complete exemption from environmental emission regulations.

The EPA currently defines Advanced Recycling uses chemical and thermal treatment processes to break down the polymeric structures of plastics into feedstocks that can be recycled into new products. Pyrolysis involves high temperature (typically 400-800°C) treatment in the absence of oxygen, producing pyrolysis oil, hydrocarbon gases, and char.

Pyrolysis oil is the primary product of the plastic pyrolysis process. Once refined via distillation plant, it can be converted into diesel fuel. Alternatively, after further purification, plastic pyrolysis oil can serve as a naphtha substitute and be fed into ethylene crackers to be repolymerized into virgin plastic.

Impact of Advanced Recycling on the Platic Pyrolysis Industry

For a long time, the U.S. regulatory system classified pyrolysis units as solid waste incinerators, subjecting them to stringent air emission standards for waste incineration. Consequently, plastic pyrolysis projects faced lengthy approval processes and high costs for environmental compliance infrastructure, which significantly hindered commercial implementation.

In a recent proposal, the EPA recommended removing the phrase Pyrolysis Units from the legal definition of Municipal Waste Combustion Units. Once this change is adopted, pyrolysis plant will no longer be classified as incinerators under federal law. EPA Administrator Zeldin has also publicly characterized pyrolysis technology as Reverse Manufacturing rather than incineration, advocating for its scaled-up development through regulatory relief.

Recycled plastics destined for use as feedstock in pyrolysis processes—a form of advanced recycling—are no longer automatically classified as solid waste. Pyrolysis itself is being redefined as a manufacturing process rather than a waste volume reduction or disposal activity.

Once the policy is implemented, plastic pyrolysis plant would no longer be automatically subject to the stringent emission standards applied to waste incinerators. Instead, they would be regulated as standard chemical manufacturing facilities, significantly simplifying the permitting process and reducing environmental compliance and operational costs.