Pelletizing and Coating of Synthetic Zirconia Stabilized Calcium-Based Sorbents for Application in Calcium Looping CO₂ Capture

Abstract

Calcium oxide (CaO) has been investigated as a high-temperature performance sorption material for carbon capture due to its high carbon dioxide (CO 2 ) capacity, low cost, and environmental benignity. Unfortunately, commercialized application of CaO materials has been hindered by severe capacity loss during cycling operations. In an attempt to overcome these problems, this study investigated the effects of adding zirconia-based ceramic dopants and coating sorbents with highly crystalline zirconium dioxide (ZrO 2 ) layers derived from the hydrolysis of zirconium butoxide to control the growth of ZrO 2 crystals. Uncoated natural Cadomin delivered a high CO 2 capture capacity of more than 13 mole CO 2 / kg, while the zirconia-coated sorbents showed excellent cycling stability corresponding to a maximum capacity of retention of 79% after 21 cycles at high temperatures. More importantly, the highly crystalline ZrO 2 -coated sorbents doped by zirconia-based sorbents exhibited a significantly lower decay capacity compared to the uncoated sorbents, which could be attributed to the formation of a perovskite structure that is resistant at high temperatures and a high-temperature-resistant ceramic layer through the solidstate reaction of the highly mesoporous crystalline ZrO 2 layer with CaO. These results shed light on the development of sorbents with special structures and superior chemical and mechanical properties for high-performance calcium looping or regenerative calcium cycle processes.

Scale‐up production and process optimization of Zr‐doped CaO‐based sorbent for CO2 capture

“…Besides, doping of different inert solid materials was identified as an effective way to ameliorate thermal stability of the CaO‐based adsorbents, for instance, Zr‐, Al‐, Mn‐, Mg‐, Ce‐, Li‐, Sr‐, Ti‐, C‐, Y‐, Si‐, Cu‐, La‐, Co‐, Nd‐, Pr‐, Yb‐, Zn‐, Ba‐, and Fe‐doped CaO‐based sorbents 11–21 . Thereinto, the Zr‐doped sorbent showed excellent CO 2 capture performance in which the Ca‐Zr oxide generated a “barrier” between nanoparticles in the CaO sorbents, so that it could prevent the sorbents from agglomerating and sintering due to its high Tammann temperature 22–26 . Our research group has prepared CaO sorbents using sol–gel technique in which the sorbent with a Ca/Zr ratio of 30 exhibited exceptional CO 2 capture capability (14.55 mol‐CO 2 /kg‐ads) and excellent durability (up to 18 cycles) 23 …”

Stabilized Performance of Al‐Decorated and Al/Mg Co‐Decorated Spray‐Dried CaO‐Based CO2 Sorbents

“…Until now, the researchers mainly focus on developing a number of effective inert supports to improve the CO 2 capture stability of CaO‐based sorbents, commonly including Al‐based , , Mg‐based , , Si‐based , , Ti‐based , , Zr‐based materials , etc. .…”

Cyclophosphazene-Based Hybrid Nanoporous Materials as Superior Metal-Free Adsorbents for Gas Sorption Applications

“…The massive consumption of fossil fuel to satisfy the ever-growing energy demand with the rapid population growth has contributed to the dramatic increase in the emission of CO 2 in the atmosphere that crossed 400 ppm in the recent times. − The uncontrolled CO 2 emission has led to rise in the earth’s surface temperature at an unusually rapid rate and has risen by 0.83 °C since preindustrial era. , If not taken proper care now or in the near future to control the CO 2 emission, several devastating calamities are predicted, for example, submerging of many populous cities due to the rise in the sea level owing to the melting of glaciers. − Further, the lower albedo would cause a faster melting of the glaciers . Additionally, the increased earth’s temperature will cause problems such as drought, downpour, and typhoon …”