Stability of electroless pore-plated Pd-membranes in acetic acid steam membrane-reformers for ultra-pure hydrogen production

• Published in: Fuel processing technology Vol. 212; p. 106619
• Main Authors: Adduci, G., Martinez-Diaz, D., Sanz-Villanueva, D., Caravella, A., Calles, J.A., Sanz, R., Alique, D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2021; Elsevier Science Ltd
• Subjects: Acetic acid; Catalysts; Cerium oxides; Electroless plating; Hydrogen production; Membrane; Membrane reactors; Membranes; Palladium; Reactors; Reforming; Selectivity; Steam reforming; Membrane; Steam reforming; Palladium; Acetic acid; Electroless plating; Hydrogen production
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2020.106619

Electroless Pore-Plated (ELP-PP) membranes were successfully incorporated for the first time into a membrane reactor to produce hydrogen by acetic acid steam reforming (AASR), exhibiting adequate resistance against harsh operating conditions. Membranes were prepared onto tubular PSS supports modified with Pd/CeO2 particles and scaled-up around four times in length with high reproducibility respect previous studies. H2 permeances from 4.49 to 5.67·10−4 mol m−2 s−1 Pa-0.5 were found for pure H2 at 350–450 °C, decreasing for mixtures due to concentration-polarization at higher pressures but also certain inhibition caused by CO2 at pressures below 50 Pa0.5. The combination of membranes with Ni/SBA-15 catalysts in packed-bed membrane reactors (PBMR) evidenced the simultaneous improvement of acetic acid conversion and hydrogen yield respect to analogous experiments in traditional packed-bed reactors (PBR). A very similar product distribution was obtained for both configurations, PBR and PBMR, when using fresh catalysts, although marked deviations were found in case of regenerating the catalysts. Then, higher selectivity towards coke reached for PBMR, which lead to around 30% for the most elevated pressure under investigation. However, even at these harsh conditions, the mechanical integrity of ELP-PP membranes was maintained. Thus, the benefits of combining catalysts and ELP-PP membranes in a PBMR for AASR were demonstrated. •Successful scale-up of an ELP-PP membrane with Pd/CeO2 barrier to 110 mm in length.•Pd thickness around 15 μm with no marked differences along the axial direction.•H2 permeances from 4.49 to 5.67·10−4 mol·m−2·s−1·Pa-0.5 for pure H2 at 350–450 °C.•Noticeably inhibition caused by CO2 was found in permeation tests with mixtures.•Mechanical integrity of ELP-PP membrane in PBMR and improvement of H2 production.