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

Abstract

Both chemical looping processes and oxygen permeable ceramic membranes require 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 10 further hydrogen separation from the synthesis gas). The two approaches are compared and contrasted.

Direct combustion of recyclable metal fuels for zero-carbon heat and power

“…Chemical looping reactors enable the separation of carbon dioxide, produced when burning hydrocarbons for power generation, and its subsequent sequestration [84][85][86]. The combustion of the reduced iron powders within the proposed metal-fuel combustors could improve the performance of the metal-oxidation step within chemical-looping power plants, compared to the relatively-slow oxidation of large iron particles within the fluidized-bed reactors currently employed.…”

“…Metal-air batteries require high-purity metals for their anodes to prevent the parasitic corrosion reactions, leading to high costs, with metal-water reactions taking advantage of these same parasitic corrosion reactions [48]. Metals are also widely used as energy carriers within chemical-looping combustion systems, suggesting that they can be economical as part of power systems [84][85][86]. As for metal-air batteries, the most abundant metals/metalloids, such as iron, aluminum and silicon, will be promising metal fuels on a cost basis.…”

“…Iron can be reduced from iron-oxide powders by reacting them with hydrogen or syngas at moderate temperatures below 1000°C [50,84,158], enabling the reduction of iron using hydrogen produced from clean sources, such as the artificial leaf [159,160].…”

Perovskite ceramics and recent experimental progress in reactor design for chemical looping combustion application

“…This perovskite structure was also examined in twostep steam-reforming of methane towards the simultaneous production of syngas and pure hydrogen and was shown to be a promising oxygen carrier (Evdou et al, 2010). Hydrogen can be produced as a by-product of chemical looping processes during the steam-reforming of carbonaceous fuels via the watersplitting reaction discussed extensively by (Thursfield et al, 2012).…”

Si–Zr–C–N-based hydrophobic plasma polymer membranes for small gas molecule separation

“…There are several sources for hydrogen production, some existing and others under development, starting from fossil fuels or water, and using nuclear or renewable energy for molecule cracking [1]. The general common point between several methods to produce, it is that the resulting gas is a mixture consisting mainly of H 2 , CO and/or CO 2 and H 2 O.…”