The reactivity of calcium oxide towards carbon dioxide and its use for energy storage

✍ Scribed by Barker, Ronald

• Publisher: Wiley (John Wiley & Sons)
• Year: 2007
• Tongue: English
• Weight: 303 KB
• Volume: 24
• Category: Article
• ISSN: 0375-9210
• DOI: 10.1002/jctb.2720240405

✦ Synopsis

Abstract

By using calcium carbonate powder of particle size ∼ 10 nm (and therefore of high surface area) it has been shown that the reaction CaCO~3~ ⇄ CaO + CO~2~ can be made almost wholly reversible. A reactivity of 93% was achieved, (i.e. 93% of the calcium oxide reacted with carbon dioxide) and this was maintained for 30 24‐h decomposition‐back reaction cycles at 629 °C with no detectable decrease. This material has an energy storage capacity of 200 Wh/lb, but only about 1 kWh/ft.^3^ When this calcium carbonate was pressed, however, to increase its bulk density (from 0.1 to ∼ 1 g/ml) there was a large decrease in its surface area and a smaller decrease in its reactivity on undergoing a few decomposition and back reaction cycles. Scaling up of the sample size from 20 mg to 10 g only had a small (× 3) effect on the rates of decomposition and back reaction.