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

Abstract

A model bioethanol steam reforming reaction is performed in a thin composite Pd membrane reactor by using Ni/CeO2 catalyst. A 7.5wt.% 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 8μm 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=0.5bar and in fresh membrane conditions.The bioethanol reforming is carried out at 400°C and the reaction pressure ranges from 2.0 to 3.0bar as well as GHSV from 5000 to 15,000h−1. The best performance of the membrane reactor is achieved at 400°C, 3.0bar and GHSV=5000h−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.