Utilizing CO2 and rejected H2 from FP-PEMFC system: A combined experimental and modelling study on CO2 methanation with low H2/CO2 over Ni–La/Al2O3


ÖZTEPE C., Mutlu E. C., SELEN ÇAĞLAYAN B., AKSOYLU A. E.

International Journal of Hydrogen Energy, cilt.88, ss.815-829, 2024 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 88
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.ijhydene.2024.09.168
  • Dergi Adı: International Journal of Hydrogen Energy
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.815-829
  • Anahtar Kelimeler: Ni-La bimetallic catalyst, Box-behnken (BB) design, Statistical analysis, Response surface methodology (RSM), Response surface methodology (RSM), CO(2)methanation, Low H-2/CO(2)methanation feed
  • Boğaziçi Üniversitesi Adresli: Evet

Özet

In an FP-PEMFC system vent, recycling a fraction of CO2 provides clear benefits for CO2 utilization and rejected H2 conversion to methane. However, the low H2/CO2 ratio, deviating from the ideal stoichiometric value, presents challenges. This study examines the effects of temperature, H2/CO2 ratio, residence time (F/Wcat ratio), and La promoter loading on CO2 and H2 conversions and CH4 selectivity over Ni–La/γ-Al2O3 catalyst using a Box-Behnken design. Experimentally, higher CO2 conversion is observed with increased temperature, H2/CO2, La loading, and reduced F/W. CH4 selectivity, however, decreases with higher temperature and F/W but improves with higher H2/CO2 and La loading. Modeling highlighted significant interactions, revealing two optimal conditions: for low La loading, high temperature, H2/CO2, and F/W are favorable; for high La loading, lower temperature and F/W, coupled with a high H2/CO2, are optimal. These findings necessitate precise control over input factors, especially H2/CO2, in optimizing methanation under low H2/CO2 conditions.