Defence Tim G. W. Engels: "Catalytic pyrolysis of rigid polyurethane foams for aniline recovery"
Promotors: first promotor: Prof Peter Deuss second promotor: Prof Erik Heeres
Abstract: The research described in this dissertation provides insights into the catalytic pyrolysis of MDA-based rigid polyurethane foams for the production of aniline and toluidine. At the molecular level, catalyst screening has shown that alumina and amorphous silica-alumina based catalysts are promising candidates for further scale-up. In addition, a mechanistic study on the catalytic pyrolysis process contributed to future developments in tailor-made catalyst formulations. Furthermore, catalyst stability experiments yielded identification on relevant deactivation mechanisms. These insights will contribute to the development of efficient strategies for catalyst reuse and recycling, thereby lowering the costs associated with catalyst use. At the process level, the concept of catalytic pyrolysis was scaled up to pilot scale (5 kg feedstock h⁻¹), achieving a combined aniline yield of 25% on a nitrogen basis. The results of this research will support the further scale-up of the process and, more broadly, contribute to the development of efficient recycling strategies for plastic waste.