Microwave-Assisted PUF Aminolysis: Experimental Validation, Scaling Process Assessment and LCA Evaluation

Abstract

The growing production of polyurethane foam (PUF) and increasing global PUF waste generation urges the development of a circular economy strategy to promote the recovery of its raw materials, namely polyether polyols, in a sustainable and economically feasible way. This work assesses the promising microwave-assisted PUF aminolysis technology from three different perspectives: (a) evaluating the experimental feasibility and characteristics of the recycled products; (b) modeling an industrially relevant holistic process based on experimental findings to assess energy requirements and c) comparing the environmental impacts ascribed to the production of virgin vs. recycled polyols. The most relevant findings are as follows: (1) the recycled polyols out of MW-aminolysis are indistinguishable from virgin polyols; (2) the potential energy consumption of the overall process (including post-processing steps) for a continuous PUF depolymerization process with a 14.8 kg/h RP production capacity is as low as 1.9 kWh/kg RP and (3) recycled polyols have a substantially lower environmental footprint than virgin polyols in all selected impact categories, ranging from a reduction in CO2 emissions (38% decrease) to water consumption (74% decrease). These results and analyses pave the way for enhancing material circularity in the PU sector.