Effects of reduction conditions on the cycling performance of hydrogen storage by iron oxides: Storage stage

A study of surface and structural changes of magnetite cycling material during chemical looping for hydrogen production from bio-ethanol

“…This should consequently lead to the formation of graphite on the cementite surface. If this formation increases, the carbon activity increases at the graphite/cementite interface, which becomes unstable and starts decomposing according to eqn (2). The formed metallic particles, which should not be present in large amounts, may be carburized but, most importantly, act again as catalysts for further carbon deposition.…”

“…These cycles have been the focus of constant attention over the past twenty years and various reducers have been studied. [1][2][3][4][5][6] Numerous papers have been published on the gasified coal conversion with this process because it allows a control of the CO 2 formed and it makes possible successive capture. [7][8][9] However, methane has also been extensively studied as a reducer.…”

In Situ DRIFTS-MS Study of the Anaerobic Oxidation of Ethanol over Spinel Mixed Oxides

“…5 In cycle reforming (sometimes also called chemical looping) there is a first step of reduction of the solid, which acts as an electron and O 2− carrier, with a suitable stream instead of performing the thermal reduction (see Scheme 1); then the reoxidation with water is carried out in a second step. Among the options available to use as reduction stream, the most common are hydrogen (chemical storage), 6 methane (an alternative to the classical steam reforming but with the drawback that it is still hydrocarbon-based), 7 pyrolysis oil, 8 biomass gas (must be purified in a tar extractor before using it in cycle reforming), 9 and bioalcohols, which is the one explored in this research. The use of bioethanol and biomethanol to produce hydrogen by methods other than autothermal and steam reforming is currently an active research field 10,11 because the technology to produce these bioalcohols, especially ethanol, from biomass is already accessible.…”

Effect of Hydrogen Addition on Reduction Kinetics of Iron Oxides in Gas-injection BF

“…The effect of external diffusion can be negligible as the gas flow rate is above 5 cm/s. Therefore, it is presumed that the reaction rate might be controlled by three mechanisms: 34) 1) the intrinsic interfacial chemical reaction (Eq. (8)), 2) the diffusion including internal diffusion of reactant and product gas species through solid product layer (Eq.…”