Hydrogen purification from plastic waste valorization streams using vacuum pressure swing adsorption

This work investigates the recovery of H 2 from gas streams generated during plastic waste pyrolytic valorization using a dual-layer vacuum pressure swing adsorption (VPSA) process packed with activated carbon and zeolite 5A. The influence of adsorption pressure, time and regeneration strategy (purge or vacuum) on H 2 separation performance was systematically evaluated through a design of experiments (DoE) combined with response surface methodology (RSM). The results demonstrate the characteristic purity-recovery trade-off of PSA processes, while the developed RSM models accurately represented the experimental results (R 2 > 0.99) and were subsequently used to optimize the process for H 2 purity targets of 98.000 and 99.999 vol%. Furthermore, the optimized conditions were applied to gas streams derived from pyrolysis & steam reforming of polypropylene (PP), high-density polyethylene (HDPE) and polyethylene terephthalate (PET), achieved H 2 recoveries up to 96.9 and 75.9% while producing H 2 suitable for industrial and ultra-high-purity applications respectively, highlighting the potential of VPSA technology for H 2 recovery from plastic waste valorization gases.