Details

Autor(en) / Beteiligte

• Diego, M.E.
• Abanades, J.C.

Titel

Experimental investigation of a diffusion-controlled chemical looping air reactor for energy storage applications

Ist Teil von

• Chemical engineering journal (Lausanne, Switzerland : 1996), 2022-01, Vol.428, p.132083, Article 132083

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •A new chemical looping air reactor for energy storage is investigated.•Diffusion-controlled oxidation of a packed bed of solids is experimentally tested.•The oxidation rate can be tuned by limiting O2 diffusion through a porous wall.•The O2 diffusion-based model developed fits the experimental data well. This study investigates a novel chemical looping air reactor for CO2-free energy storage applications, where a large packed bed of solids in reduced form is slowly oxidised by air at high pressure and temperature. This is achieved by arranging the bed of solids to be separated from the air, which flows within a number of empty air conduits with permeable walls that traverse the reactor. A slow diffusional flow of O2 is established from the air towards the reacting solids, leading to a release of power that heats the flowing air. This work provides a first experimental proof of the diffusion-controlled reactor principle. To achieve this, dedicated thermogravimetric experiments were carried out using a small reactor set-up representative of a control volume of the large-scale reactor. Slow and steady oxidation of solids having a very high affinity for reaction with O2 (such as graphite or activated carbon) has been demonstrated over time-scales of up to 8 h at temperatures between 600 and 1000 °C, using a range of porous diffusion walls having porosities between 0.05 and 0.40 and thicknesses of 3–19 mm. The developed O2 diffusion-based model fits the observed experimental data well, providing a basis for further reactor scale-up.