Chemical looping and oxygen permeable ceramic membranes for hydrogen production – a review

Both chemical looping processes and oxygen permeable ceramic membranes require a gas–solid surface reaction to occur in order to function; the two approaches have much in common at a fundamental level. Both approaches, through either dynamic operation in the case of looping or membrane operation, allow a degree of process intensification through simultaneous reaction and separation. Here the use of chemical looping and oxygen permeable ceramic membranes for hydrogen production is reviewed. Hydrogen production from water with various reducing gases is covered, as is synthesis gas production from hydrocarbons with various oxidants (this requiring further hydrogen separation from the synthesis gas). The two approaches are compared and contrasted.