Evaluating Hydrogen Production in Biogas Reforming in a Membrane Reactor

Abstract

-Syngas and hydrogen production by methane reforming of a biogas (CH 4 /CO 2 = 2.85) using carbon dioxide was evaluated in a fixed bed reactor with a Pd-Ag membrane in the presence of a nickel catalyst (Ni 3.31% weight)/γ-Al 2 O 3 ) at 773 K, 823 K, and 873 K and 1.01×105 Pa. Operation with hydrogen permeation at 873 K increased the methane conversion to approximately 83% and doubled the hydrogen yield relative to operation without hydrogen permeation. A mathematical model was formulated to predict the evolution of the effluent concentrations. Predictions based on the model showed similar evolutions for yields of hydrogen and carbon monoxide at temperatures below 823 K for operations with and without the hydrogen permeation. The hydrogen yield reached approximately 21% at 823 K and 47% at 873 K under hydrogen permeation conditions.

Latest Developments in Membrane (Bio)Reactors

“…Silva et al [22] demonstrated that methane steam reforming can be performed in a packed bed membrane reactor with an up to 47% hydrogen recovery at a 35% methane conversion (at 600 °C). In this case, the membrane reactor technology allows us to achieve the same conversions of a conventional system while working at much lower operating temperatures (550 • C for an MR compared to 850-900 • C for a conventional system).…”

“…Silva et al [22] demonstrated that methane steam reforming can be performed in a packed bed membrane reactor with an up to 47% hydrogen recovery at a 35% methane conversion (at 600 • C). Additionally, Gil et al [23] used a catalytic hollow-fiber membrane reactor where the Ni-based catalyst was supported on the hollow fiber's walls, while the selective Pd-based layer was coated on the other side of the hollow-fiber wall.…”

Recent Advances in Pd-Based Membranes for Membrane Reactors

“…Methane reforming in a packed bed membrane reactor was also performed by Silva et al [ 56 ] using a 76.2 μm thick Pd-Ag membrane and a CH 4 /CO 2 ratio of 2.85 at 600 °C resulting in 35% methane conversion, while 47% of the produced hydrogen was recovered. Larger methane conversions were obtained by Gil et al [ 53 ] using a catalytic hollow fibre membrane reactor were Ni (25 wt.…”

Sustainable H2 generation via steam reforming of biogas in membrane reactors: H2S effects on membrane performance and catalytic activity

“…On the other hand, only a few studies deal with the utilization of Pd-based MRs to carry out the steam reforming of a real or synthetic biogas stream. In these studies, both fluidized bed [31,37] and packed bed [32][33][34][35][36]38,39] MR modalities were analyzed with the purpose of producing high grade hydrogen using synthetic H2S free biogas mixtures [31][32][33][34], or considering a pre-treatment step useful to remove H2S prior to the reforming stage [40][41][42]. In particular, Ru/Al2O3 catalyst and a thick self-supported Pd-Ag membrane (200 m) were used by Itoh's group [32,33], while Ni-based catalysts were packed in self-supported Pd-Ag [38,39] and supported Pd (7 m layer)/Al2O3…”