Design aspects of the cyclic hybrid adsorbent-membrane reactor (HAMR) system for hydrogen production

As a result of stricter environmental regulations worldwide, hydrogen is becoming an important clean energy source. For it to replace fossil fuels in mobile applications, however, it will require the creation of a production and delivery infrastructure equivalent to the one that currently exists for fossil fuels, which is an immense task. As an alternative and interim step towards the new hydrogen economy, various groups are currently studying steam reforming of methane (SRM) for the on-board generation of hydrogen, or for on site production, in order to alleviate the need for compressed or liquid hydrogen storage. One such technology is the hybrid adsorbent-membrane reactor (HAMR) system, which couples reaction and membrane separation steps with adsorption on the reactor and/or membrane permeate side. Our early studies involved the development of a mathematical model for the HAMR system applied to hydrogen production through SRM. Recently, experimental investigations with the water-gas shift reaction, using microporous membranes and hydrotalcite-type CO₂ adsorbents, were carried out in order to validate the HAMR design model. In this paper, we focus on the practical process design aspects of the HAMR hydrogen production process. A continuous, four-bed HAMR process scheme is proposed and investigated both experimentally and through modeling studies.