Regeneration Strategies for PEI
Preliminary work by the University of Nottinhgam has established that pyrolyzing silica-PEI generates silica that can retain over 80% of its initial pore volume. Virtually all of the PEI from fresh silica-PEI can be removed in nitrogen, but 5-10% PEI for a highly oxidised sample remains. However, the introduction of steam for highly oxidized Silica-PEI will remove almost 100% of the PEI. We will investigate variables such as pressure, heating rate and duration of pyrolysis to improve regeneration of silica porosity to ultimately recover >95% total pore volume of the silica from silica-PEIs of varying degrees of oxidation.
We will also focus on understanding the mechanisms of PEI degradation and investigate the recovery of potentially valuable amines. Heterogeneous catalysts will also be employed in pyrolysis to maximise the recovery of valuable amines and aromatic chemicals. Finally, a scale-up of the developed pyrolysis recycling method in pilot-scale, continuous reactors will be carried out