PURE-SCALE

Introduction

Polyurethanes (PU) are part of the six “commodity plastics”, yet over 95% of end-of-life PU in Europe is still landfilled or incinerated. Moreover, the polyol and isocyanate building blocks are 2–5 times more expensive than typical monomers of other commodity plastics, which forms a strong economic incentive to develop viable chemical recycling methods. While several innovative PU chemolysis technologies have shown promise at the lab-scale, scaling them up into (semi-)continuous processes remains challenging due to the low-density and thermoset nature of PU and PIR foams. Furthermore, while PU producers recognize a clear market demand for recycled content in PU products, which is further increased by EU regulations, they generally lack the expertise and equipment for upscaling low-TRL PU recycling processes.

Goal

The project focuses on the development of a versatile 5 L pilot setup to evaluate novel PU chemolysis technologies at a relevant scale and process conditions to bring them closer to industrial implementation in Flanders. Using the pilot setup, we will (i) transform the optimal batch methods into (semi-)continuous processes, (ii) obtain kg-scale quantities of recycled building blocks, enabling industrial quality validation of the recycled products by using them to make new PU products, (iii) accurately compare our novel PU recycling technologies with the state-of-the-art processes, and (iv) guide the techno-economic assessments and evaluate the business cases.

Approach

This project aims to realize an ambitious PU recycling strategy by following four well-synchronized steps. First, a pilot-scale semi-continuous recycling setup will be designed and commissioned, capable of processing up to 1 kg/h of low-density PU using a twin-screw feeder and pressurized 5 L CSTR reactor. Second, innovative PU recycling routes will be upscaled to continuous operation to convert rigid PU/PIR and other PU wastes into high-purity polyols and isocyanate derivatives with high yields and space-time yields. Third, kilogram-scale batches of near-virgin recycled building blocks will be produced and validated by industrial partners in new PU formulations with up to >75 wt% recycled content. Finally, techno-economic and sustainability benchmarking against state-of-the-art processes will be performed to build a business case and to pave the way toward full-scale industrial implementation in Flanders.

Expected impact and valorization

PURE SCALE will go beyond current PU recycling strategies by recovering both polyols and isocyanates with a quality close to virgin materials. This will results in new PU products that contains at least 50 wt% recycled content, which is much higher than what is possible with today’s glycolysis processes (<10 wt%). The project relies on a set of patented technologies, which makes it possible to separate pure building blocks in high yields without using toxic phosgene. Strategically, the project is highly relevant for Flanders, which is home to a large part of Europe’s PU producers (25%) and has a pioneering role in PU waste collection (e.g. mattresses, refrigerators and construction waste). By demonstrating that high quality recycled PU building blocks can be produced in a scalable and cost-effective way, PURE SCALE will strengthen circularity and open the path toward full industrial implementation in collaboration with a spin-off or via direct sublicensing of the IP.