Behavior of CaTiO₃/Nano-CaO as a CO₂ Reactive Adsorbent

Abstract

This study focuses on the preparation of a CaTiO3-coated nano-CaO-based CO2 adsorbent (CaTiO3/nano-CaO) for the improvement of sorption properties. The CaTiO3-coated nano-CaO adsorbent was prepared by forming Ti(OH)4 from the hydrolysis of titanium alkoxide in a nano-CaCO3 suspended solution. The resulting Ti(OH)4-coated nano-CaCO3 was then heated and calcined. Test results from transmission electron microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy show that an obvious film of TiO2 was formed on the surface of nano-CaCO3 after heating. X-ray diffraction analysis also showed that the nano-CaTiO3 layer was formed at 750 °C, a calcination temperature that causes the reaction of TiO2 with nano-CaO. The cyclic tests of reactive sorption capacity were conducted in a thermogravimetric analyzer under the following conditions: 0.02 MPa CO2 partial pressure, carbonation temperature of 600 °C, and calcination temperature of 750 °C. Test results showed that CaTiO3 coated onto the nano-CaO caused a significant improvement in the durability of the capacity for reactive sorption. Nano-CaO that had an optimum content of 10 wt % TiO2 showed significantly stable CO2 reactive sorption capacity (5.3 mol/kg) after 40 cyclic carbonation−calcination runs compared to the reactive sorption capacity of CaO without TiO2 coating (3.7 mol/kg).

A highly efficient CaO-based CO2 sorbent prepared by a citrate-assisted sol–gel technique

“…Researchers focused mainly on improving the structure and thermal resistance of CaO either by introducing a metal oxide stabilizer phase or exploring different Ca-precursors leading to improved properties. An extensive range of metal oxide stabilizers was used to enhance the stability of CaO, including Zr, Al, Ti and Si oxides [8][9][10][11][12][13][14][15][16]. A key point toward large-scale application of any CO 2 sorbent is its production cost.…”

Carbon dioxide removal using calcium aluminate carbonates on titanic oxide under warm-gas conditions

“…The CaO boundary should be isolated by bonding with a suitable inorganic binder as a supported material. Titanium oxide is a commercially available material that has been applied as a binder during the fabrication of absorbents for TG analysis; these include TiO 2 /nano-CaO [19], CaTi-x/limestone [20], and TiO 2 /CaLDHs [21].…”

SE-SR with sorbents based on calcium aluminates: Process optimization

“…Al 2 O 3 [13][14][15], MgO [16], KMnO 4 [17], CaTiO 3 [18], Ca 12 Al 14 O 33 [19][20][21], Ca 9 Al 6 O 18 [22,23]. Despite good performance in CO 2 sorption, these sorbents are not always applicable to SE-SR due to the presence of steam which would accelerate their deactivation [24].…”