The oncoming energy vector: Hydrogen produced in Pd-composite membrane reactor via bioethanol reforming over Ni/CeO2 catalyst

• A Pd/Al2O3 membrane reactor produces concentrated H2 via bioethanol reforming.
• The H2/N2 ideal perm-selectivity of the Pd/Al2O3 membrane is higher than 4000.
• Ethanol conversion was higher than 98% during bioethanol reforming.

A model bioethanol steam reforming reaction is performed in a thin composite Pd membrane reactor by using Ni/CeO2 catalyst. A 7.5 wt.% Ni/CeO2 catalyst was prepared by Solution Combustion Synthesis using urea as fuel. The obtained powder was characterized by X-ray diffraction (XRD), N2-physisorption, CO-chemisorption and temperature programmed reduction (TPR). A 8 μm thin Pd-layer deposited onto a porous Al2O3 support constitutes the membrane allocated in the membrane reactor module, where the catalyst is packed in the annulus. The H2 perm-selectivity of the composite membrane (expressed as H2/N2 ideal selectivity) is around 4700 at 400 °C, Δp = 0.5 bar and in fresh membrane conditions.The bioethanol reforming is carried out at 400 °C and the reaction pressure ranges from 2.0 to 3.0 bar as well as GHSV from 5000 to 15,000 h−1. The best performance of the membrane reactor is achieved at 400 °C, 3.0 bar and GHSV = 5000 h−1 where the ethanol conversion is around 98%, with more than 65% of hydrogen recovered in the permeate side. Furthermore, the influence of the byproducts present as impurities in the model bioethanol mixture on the membrane reactor performance is also evaluated.

Ethanol conversion and hydrogen recovery vs. GHSV at T = 400 °C, reaction pressure = 3.0 bar during ESR in a Pd/Al2O3 MR by feeding a model bioethanol mixture.Figure optionsDownload high-quality image (86 K)Download as PowerPoint slide