Thermal decomposition of dolomite in the presence of CO2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an intermediate...

The effect of cyclic carbonation–decarbonation operating parameters on Zr-doped CaO sorbent CO2 uptake capacity evolution is examined. It revealed that the steady state value increases with decrease in carbonation temperature, concentration gas flow upon and increase heating rate from to decarbonation stages. rise temperature leads a dramatic performance. found if occurs at 630 °C containing 15...

25 Limestone in volcanic basements has been identified as a hazard in terms of edifice stability 26 due to the propensity of calcite to decompose into lime and CO2 at high temperatures (>600 27 ̊C), causing a decrease in mechanical strength. To date, such hypotheses have been tested by 28 experiments performed at ambient pressure. The present work determines the mechanical 29 strength of limesto...

The conversion of thermally pretreated CaO along successive carbonation/calcination cycles has been investigated, as a ected by looping-calcination conditions, by means of Thermogravimetric Analysis (TGA). Sorbent samples have been subjected in-situ to a thermal preheating program based on Constant Rate Thermal Analysis (CRTA) by virtue of which decarbonation is carried out at a low controlled ...

Received on May 16, 2007; accepted on August 23, 2007. Correspondence concerning this article should be addressed to M. Aihara (E-mail address: [email protected]). Presented at International Symposium on Innovative Materials for Processes in Energy Systems, IMPRES, Kyoto, October, 2007. Carbonation/Decarbonation of Ca-Solid Reactant Derived from Natural Limestone for Thermal-Energy Storage and...

7 Even though an increasing number of pilot-scale plants are demonstrating the potential ef8 ficiency of the Ca-looping technology to capture CO2 at a commercial level, a still standing 9 matter of concern is the loss of carbonation reactivity of the regenerated CaO by calcination, 10 which is expected to be particularly marked at realistic conditions necessarily implying a high 11 CO2 partial ...

8 We analyze the role of limestone crystallinity on its CO2 capture performance when subjected 9 to carbonation/calcination cycles at conditions mimicking the Ca-looping (CaL) technology 10 for post-combustion CO2 capture. The behavior of raw and pretreated limestones (milled and 11 thermally annealed) is investigated by means of thermogravimetric analysis (TGA) tests under 12 realistic sorbent...

Subducted oceanic metabasalts are believed to be a primary source of volatiles for arc magmatism and fluid-induced seismicity. From phase equilibria computed for an average oceanic metabasalt we present a model for subduction zone devolatilization for pressures up to 6 GPa (V180 km). Along high temperature geotherms complete dehydration occurs under forearcs, whereas dehydration does not occur ...