Multi‐fuel scaled‐down autothermal pure H₂ generator: Design and proof of concept

Abstract

This article presents experimental results of an autothermal scaled‐down system for H2 production. Pure atmospheric pressure H2, separated in situ by Pd–Ag membranes, is produced by steam reforming (SR) of methane, ethanol, or glycerol. Oxidizing the SR effluents in a separate compartment supplies the heat. The oxidation feed is axially distributed to avoid hotspots. The 1.3 L system, comprises 100 cm2 of membrane area, and generates H2 flow rate equivalent to 0.15 kW at an efficiency of ∼25%. This process leads to comparable performance when different fuels are used. A mathematical model, validated by the measurements, predicts that increasing the membrane area relative to the outer surface area will substantially increase the efficiency and power output. This design serves as proof of concept for on‐board pure H2 generators, with flexible fuel sources, and holds a great promise to reduce the need for special H2 transport and storage technologies for portable or stationary applications. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2112–2125, 2016

Modeling Fixed Bed Membrane Reactors for Hydrogen Production through Steam Reforming Reactions: A Critical Analysis

“…In any case, it has been shown that the apparent permeance can be considerably smaller than the one measured in pure hydrogen, even after accounting for dilution, concentration gradients, and inhibition. The occurrence of hydrogen-consuming reactions on the surface of the membrane has also been proposed as a possible reason for the drop in the observed hydrogen flux [ 5 , 32 , 112 ] and may strongly affect the reactor performance.…”

“…Membrane reactors (MRs) have received significant attention for their potential use in decentralized hydrogen production systems, allowed by the integrated production and separation of hydrogen [ 1 , 2 , 3 ]. The reactions most commonly carried out are those of steam reforming of different carbon-based feeds such as methane [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], methanol [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ], ethanol [ 22 , 23 , 24 , 25 , 26 , 27 ], biogas [ 28 , 29 ], and glycerol [ 30 , 31 , 32 ]; water-gas shift [ 33 , 34 , 35 , 36 , 37 , 38 ]; ammonia decomposition [ 39 , 40 ]; and the dehydrogenation of alkanes [ 41 , 42 , 43 , 44 ]. In all cases the equilibrium of the reaction is shifted by removing hydrogen through a membrane.…”