Chemical recycling vs. enzymatic recycling: which will emerge as the winner?

-Chemical recycling of rPET enables true closed-loop recycling (bottle-to-bottle, textile-to-textile).

-BHET route gains dominance due to lower cost and simpler process compared to DMT route.

-Enzymatic technology, though still in pilot stage, is a highly promising direction for PET recycling.

Chemical recycling of recycled PET is advancing from laboratory research to large-scale industrial application driven by the global dual-carbon goals and brand owners' policies for recycled product traceability. Unlike mechanical recycling, which only changes physical forms, chemical recycling adopts the process of depolymerization, purification and repolymerization. It can remove impurities and restore virgin-grade performance, enabling true closed-loop recycling such as "textile-to-textile" and "bottle-to-bottle". Globally, chemical recycling of rPET has entered a critical phase featuring large-scale commercialization, dominance by leading enterprises and diversified technical routes. Among various chemical depolymerization technologies, the DMT (dimethyl terephthalate) route and BHET (bis-hydroxyethyl terephthalate) route are the two mainstream solutions. They differ in process design, product forms, economic efficiency and application adaptability, jointly shaping the technical landscape of the recycled polyester sector.

Compared with the DMT route, the BHET route eliminates one transesterification step, featuring a shorter production flow, lower costs and energy consumption, as well as lower entry barriers. Therefore, the BHET route is expected to be adopted more widely in new chemical recycling projects in the future.

Currently, some recycled polyester fiber producers procure chemically recycled PET chips priced between 11,000 and 15,600yuan/mt to produce differentiated functional fibers. Some buyers report unsatisfactory application results. Products priced at 15,000-15,600yuan/mt deliver relatively better performance with whiter color, while lower-priced products show mediocre quality and poor color tone. Meanwhile, the CCFGroup 3A-grade white PET flakes is at 6,650yuan/mt, recycled chips at 7,800yuan/mt, and semi-dull virgin PET chips at 7,200yuan/mt. By comparison, chemically recycled chips show poor cost performance. Market purchasing interest remains weak without the T2T (Textile-to-Textile) concept. That said, costs of chemical recycling are gradually declining alongside technological upgrades.

The enzymatic recycling technology uses degrading enzymes as catalysts to depolymerize PET into PTA and MEG monomers under mild conditions (ambient temperature & pressure or moderate temperature). It is now in the pilot test stage and stands out as a highly promising development direction for the recycling industry.

In the next few years, BHET route may become the mainstream for new chemical recycling capacity expansion thanks to its low cost and integrated process advantages. DMT route will maintain its differentiated market edge with strong adaptability to mixed waste materials and export premium. The two chemical routes will dominate domestic chemical recycling capacity. Restrained by high costs of enzyme preparations, enzymatic technology stays at the pilot stage yet gains rapid traction in the waste textile recycling segment. In the long run, continuous technological breakthroughs will cut costs for both chemical and enzymatic recycling. This will reshape the cost structure of PET recycling and drive the industry to shift increasingly from mechanical recycling to full closed-loop chemical recycling.