A hybrid solar-redox scheme for liquid fuel and hydrogen coproduction

Abstract

A ferrite based oxygen carrier promoted with a mixed ionic–electronic conductor support is used in a hybrid solar-redox scheme. Based on both experiments and simulations, this scheme has the potential to co-produce liquid fuel and hydrogen from methane and solar energy at high efficiency with near zero life cycle CO2 emission.

Perovskite nanocomposites as effective CO 2 -splitting agents in a cyclic redox scheme

“…As can be seen, equilibrium P O2 of Fe/FeO redox pair, which is a commonly used redox material, is away from the ideal (high performance) region for the hybrid solar-redox scheme. This is confirmed by a number of studies that reported low syngas selectivity and limited CO 2 conversions ( 16 , 34 – 38 ). Thermodynamic analysis suggests that no first-row transition metal oxide has redox properties located in this region ( 39 ).…”

“…To address this challenge, we proposed a hybrid solar-redox scheme for water splitting, wherein concentrated solar energy is used to drive the reduction reaction in the presence of methane (CH 4 ) that undergoes partial oxidation (POx) to produce Fischer-Tropsch (F-T) ready syngas. Using perovskite-supported Fe 3 O 4 as the redox material, up to 77% steam-to-hydrogen conversion was achieved ( 16 , 36 ). Although such a methane-assisted solar-thermal water-splitting scheme is applicable for CO 2 splitting, further increases in water/CO 2 -splitting conversion is desirable from process efficiency and product separation standpoints.…”

Isothermal reverse water gas shift chemical looping on La0.75Sr0.25Co(1−)Fe O3 perovskite-type oxides

“…Typically, chemical looping studies use O 2 from air as an oxidant to recuperate the oxygen mobile material [26,27], and recent studies have also used steam [28]. Because of the poorer oxidative nature of CO 2 when compared to these two oxidants, maintaining the phase stability of the oxygen carrier is desired because less energy is required to re-oxidize an oxygen vacant material as opposed to recovering its crystalline phase.…”

Ca1−A MnO3 (A = Sr and Ba) perovskite based oxygen carriers for chemical looping with oxygen uncoupling (CLOU)

“…As a support, mixed ionic and electronic conductive (MIEC) perovskites such as La 1Àx Sr x FeO 3 (LSF) have shown to enhance the redox activity of iron oxides by nearly two orders of magnitude [51][52][53][54]. Perovskite and perovskite supported iron oxide have also been explored as redox catalysts for syngas generation and water-splitting [42,56]. In terms of CLOU applications, La containing perovskite supports are reported to be effective to enhance the oxygen donation properties of mixed Mn-Fe and Co-Fe oxides [23].…”