Palladium-based Selective Membranes for Hydrogen Production

Palladium-based Selective Membranes for Hydrogen Production 

Italy Faculty of Engineering, University Campus Bio-Medico of Rome, via Alvaro del Portillo 21, 00128 Rome, Italy Process Innovativi, Corso Federico II, 67100 L Aquila, Italy 

3 The original idea of coupling catalyst and membranes dates back to the 1960s. 

Criticism of membrane integration has to be carefully faced. If the selective membrane is directly integrated in the reaction environment, coupling catalyst and membrane operating conditions leads to the necessity to define a compromise 

Gas-separation Problems Combined with Membrane Reactors 

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Dense palladium-alloy membranes are generally used for the production of ultrapure hydrogen, although their high cost prevents their widespread use. However, their properties, such as infinite selectivity to hydrogen, chemical and thermal resistance, allow the use of the Pd-based membranes in MRs. Theoretical studies on the adsorption of gases on palladium-alloy surfaces... 

In recent years, new concepts to produce hydrogen by methane SR have been proposed to improve the performance in terms of capital costs reducing with respect to the conventional process. In particular, different forms of in situ hydrogen separation, coupled to reaction system, have been studied to improve reactant conversion and/or product selectivity by shifting of thermodynamic positions of reversible reactions towards a more favourable equilibrium of the overall reaction under conventional conditions, even at lower temperatures. Several membrane reactors have been investigated for methane SR in particular based on thin palladium membranes [14]. More recently, the sorption-enhanced steam methane reforming (Se-SMR) has been proposed as innovative method able to separate CO2 in situ by addition of selective sorbents and simultaneously enhance the reforming reaction [15]. 

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