Materials, Devices and Processes for Energy and Environmental Sustainability
Current Research Group
Research in Progress
Degrees Granted

Mixed Ionic and Electronic Conducting Membranes
for Hydrogen Generation and Separation:
A New Approach
(Funded by DOE and CTP Hydrogen)

Prof. Srikanth Gopalan, Prof. Uday B. Pal, Mr. Haibing Wang

View a PDF presentation about Pure Hydrogen Generation and Separation
Employing Mixed Ionic Electronic Ceramic Membranes

Our team comprising Boston University, Air Products and Chemicals, and ChevronTexaco Technology Ventures brings together extensive processing experience, expertise in membrane materials science and solid state electrochemistry, state-of-the-art experimental facilities and unique perspectives in energy related technologies.

In this program we are developing a novel approach to separate and upgrade hydrogen from a mixture of gases containing hydrocarbons using O2- conducting MIEC membranes. The central device that makes hydrogen separation possible here is a dense membrane which has a high conductivity of O2- and electron-hole (h+) and/or electron (e-) at elevated temperature. The membrane can be self-standing, i.e. unsupported, or supported on a porous substrate. During the separation process, hydrocarbon reformate containing mixtures of carbon monoxide (CO) and hydrogen (H2) is fed to one side of this membrane (feed side-FS) and pure steam to the other (permeate side-PS) at elevated temperature (700-1000oC). This sets up a chemical potential gradient in H2, and through the H2-H2O chemical equilibrium, a chemical potential gradient in O2 across the membrane. O2- created through water-splitting transport from the PS across the membrane to the FS where they react with CO and H2 to form CO2 and H2O. The O2- flux is compensated by a flux of h+ to maintain zero net current through the membrane. Thus the calorific value of the CO and H2 on the FS is segregated as pure H2 on the PS. Since the membrane separator also combines chemical reactions, it is properly described as a membrane based chemical reactor.

This process has tremendous economic and environmental advantages compared with conventional methods of hydrogen synthesis and separation.