Lu, Ningning (PhD)

Preparation and application of perovskite membrane modules in fluidized bed reactors

Room: STW 0.34, E-mail: N.N.Lu@tue.nl

Introduction

Mixed ionic-electronic conducting (MIEC) membranes are attracting increasing attention, which can carry out the separation of oxygen from air at elevated temperatures, typically 800 to 1000 °C. Perovskite membranes are one kind of the most widely researched oxygen permeable membranes, mostly based on alkaline-earth compounds. Figure 1 shows the ideal perovskite structure; in which B atoms are at the corners of the cube and the A atoms are located at the centre. The oxygen atoms are positioned in the centres of the cube edges. A1+B5+O3, A2+B3+O3 and A3+B3+O3 are the most common combinations of perovskite structure. Intense research efforts have been directed to the development and improvement of perovskite membranes, while sealing problem and long term stability problem still exist when utilized in membrane reactors.

The process of Oxygen permeation

The process of oxygen permeation through MIEC membranes can be divided into 8 steps, as shown in Figure 2:

  • Gas phase diffusion
  • Physical adsorption
  • Chemical adsorption (with dissociation)
  • Surface reaction
  • Bulk diffusion
  • Surface reaction
  • Desorption
  • Gas phase diffusion

Objective

This project will focus on a better sealing method for perovskite membranes and different types of support modules. Considering the application of perovskite membrane in a fluidized bed reactor with a typical reaction (oxidative coupling of methane, partial oxidation of methane), and studying membrane performances, reactor performances under different operation conditions, and the influence of membrane separation on the bed hydrodynamics. Mathematic models will be built to simulate the membrane permeation and also reactor performance with perovskite membrane to get a more accurate calculation equation for oxygen flux and reaction kinetics, aiming at improving the yield of desirable product.