Effect of Asymmetric Membrane Structure on Hydrogen Transport Resistance and Performance of a Catalytic Membrane Reactor for Ethanol Steam Reforming.

Ludmilla Bobrova,Nadezhda Vernikovskaya,Nikita Eremeev,Vladislav Sadykov,Oleg Smorygo

doi:10.3390/membranes11050332

Abstract

The performance of catalytic membrane reactors (CMRs) depends on the specific details of interactions at different levels between catalytic and separation parts. A clear understanding of decisive factors affecting their operational parameters can be provided via mathematical simulations. In the present paper, main results of numerical studies of ethanol steam reforming, followed by downstream hydrogen permeation through an asymmetric supported membrane, are reported. The membrane module consists of a thin selective layer supported on a substrate with graded porous structure. One-dimensional isothermal reaction–transport model for the CMR has been developed, and its validation has been carried out by using performance data from a lab-scale reactor with a disk-shaped membrane. Simulations demonstrate the model’s capabilities to analyze local concentrations gradients, as required to provide accurate estimates of the relationship between structure–property–performance. It was shown that transport properties of multilayer asymmetric membranes are highly related to the structural properties of each single layer.

Highlights

The scope of this paper is to describe the catalytic reaction of ethanol steam reforming and hydrogen permeation through the asymmetric supported membrane in a catalytic membrane reactor by considering reaction rates and transport through the catalyst–membrane assembly, as well as boundary layer effects
The assembly of a catalyst—an asymmetric membrane based on Ni + Cu/Nd5.5 WO11.25−δ mixed proton–electron conducting nanocomposites [30] was placed between the feed and sweep-side compartments
The analysis carried out above allows us to understand the influence of such factors as structural parameters of the constituent layers of the membrane module on the separation option of the reactor and provides the general trends of improving performance of the asymmetric membrane module with the variation of the morphology of the support layers

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. With the growing concerns about environmental issues, catalytic reforming of fuels to hydrogen-rich gas synergistically coupled with membrane technology has become a huge focus of attention, being used increasingly in a broad range of applications. Integrated chemical reaction and separation options facilitate process miniaturization, continuous operation and energy saving. This intensification technique is expected to be a promising route in creating the sustainable green chemistry-driven energy technologies for small-scale applications. Catalytic membrane reactors are able to provide higher fuel conversion with the advantage of producing a very pure hydrogen stream supply [1,2,3,4,5]

Methods

Results

Conclusion