A review. Pd-based membranes have gained great attention since they can be effectively used for gas sepn. or in (catalytic) membrane reactors (MRs). A Pd-based membrane reactor is a device able to combine catalytic reactions with sepn. properties of Pd-membranes which can give big improvements in terms of conversion and/or selectivity for a variety of reactions with respect to a traditional system. A defect free Pd-based membrane allowing only hydrogen to permeate can shift the equil. reaction towards the products and, at the same time, can lead to a prodn. of pure (CO-free) hydrogen useful for fuel cell applications. A Pd-based membrane can also be applied for distributive feeding of hydrogen during methanol prodn. giving an increase of conversion per pass. In this chapter the synthesis of different kinds of Pd-based membranes (self supported, composite dense, composite porous, with high/low Pd content) is introduced and discussed. In the second part of the chapter the use of Pd-based membrane reactors for the efficient pure hydrogen prodn. via different reactions (dry reforming, steam reforming, and partial oxidn. of methane/ethanol) as well as their use in methanol prodn. is considered from both a theor. and an exptl. point of view. The results show that with Pd-based membrane reactors it is possible to obtain both higher conversion and higher selectivity with respect to a traditional reactor operating at the same conditions. Some examples of catalytic membranes (Pd or other noble metals) are also presented.
|Title of host publication||Handbook of Membrane Research : properties, performance and applications|
|Place of Publication||Hauppauge, N. Y|
|Publication status||Published - 2010|
|Name||Chemical engineering methods and technology series|