Now, MacroCycle, a startup spun out of MIT, claims to have found a way to close the loop—cleanly and affordably.
Rather than breaking plastics down to their molecular base and rebuilding from scratch, MacroCycle’s process forms circular polymer structures—“macrocycles”—that can be easily purified and reassembled into high-quality polyester.
The result is a chemical shortcut that uses 80% less energy than virgin polyester production and performs more efficiently than conventional chemical recycling methods, which typically save only 20–30%.
By eliminating the need for manual sorting and handling of mixed or contaminated inputs, the process reduces both the cost and complexity of recycling hard-to-use plastics and textiles.
After earning support from the Breakthrough Energy Fellows program, MacroCycle has quickly moved from pilot scale to production. The company is building a reactor 2,000 times larger than its initial lab prototype and now produces 100-kilogram batches for partner testing.
These partners include major fashion brands seeking sustainable materials without financial trade-offs. MacroCycle’s goal: deliver recycled polyester at price parity with fossil-based plastic.
CEO Peña Feliz says the incentive is clear. “Change won’t come from within oil companies,” she said. “We have to make it costly for them not to change.”
If the company’s technology scales successfully, its implications reach far beyond textiles:
MacroCycle’s method turns the long-standing recycling challenge into a market opportunity—where sustainability isn’t a luxury but a logical step forward in efficiency and resource management.
