Magnesium Oxide-Based Absorbents for CO2 Capture at Medium Temperature

Silica Supported MgO as An Adsorbent for Precombustion CO2 Capture

“…21−23 Of various CO 2 capture materials such as zeolites, 24−26 metal−organic frameworks, 27−29 mixed metal oxides, 30,31 layered double hydroxides, functionalized boron nitride nanosheets, 32 functionalized silica nanosheets, 33 etc., magnesium oxides have been reported as promising adsorbents, particularly in the elevated temperature range of 150−400 °C, due to their low cost, safe handling, and high theoretical CO 2 capacity (25 mmol/g). 34,35 However, for the pristine MgO, the capacity is only 0.4 mmol/g, which is far lower than the theoretical value due to the limited porosity of highly crystalline MgO samples and limited reactive adsorption caused by the formation of impervious carbonate layer on the MgO surface. 35,36 The capacity of MgO has been reported to improve remarkably in the nanocrystalline or mesoporous forms which provide a more exposed surface for interaction with CO 2 .…”

“…34,35 However, for the pristine MgO, the capacity is only 0.4 mmol/g, which is far lower than the theoretical value due to the limited porosity of highly crystalline MgO samples and limited reactive adsorption caused by the formation of impervious carbonate layer on the MgO surface. 35,36 The capacity of MgO has been reported to improve remarkably in the nanocrystalline or mesoporous forms which provide a more exposed surface for interaction with CO 2 . 9,37−41 Our earlier work using nanocrystalline mesoporous MgO adsorbents showed considerable enhance-ment in the CO 2 capacity as compared with microcrystalline MgO; however, the capacity drops by more than 38% over multiple cycles of regeneration carried out at 400 °C due to sintering.…”

“…At the heart of the adsorption-based capture is the adsorbent design which dictates the efficiency of the overall capture process. − Of various CO 2 capture materials such as zeolites, − metal–organic frameworks, − mixed metal oxides, , layered double hydroxides, functionalized boron nitride nanosheets, functionalized silica nanosheets, etc., magnesium oxides have been reported as promising adsorbents, particularly in the elevated temperature range of 150–400 °C, due to their low cost, safe handling, and high theoretical CO 2 capacity (25 mmol/g). , However, for the pristine MgO, the capacity is only 0.4 mmol/g, which is far lower than the theoretical value due to the limited porosity of highly crystalline MgO samples and limited reactive adsorption caused by the formation of impervious carbonate layer on the MgO surface. , The capacity of MgO has been reported to improve remarkably in the nanocrystalline or mesoporous forms which provide a more exposed surface for interaction with CO 2 . ,− Our earlier work using nanocrystalline mesoporous MgO adsorbents showed considerable enhancement in the CO 2 capacity as compared with microcrystalline MgO; however, the capacity drops by more than 38% over multiple cycles of regeneration carried out at 400 °C due to sintering . Another modification of MgO which leads giant enhancement of CO 2 capacity (up to 16 mmol/g) is modification of MgO with alkali nitrate salts .…”

NaNO3‐Promoted Mesoporous MgO for High‐Capacity CO2 Capture from Simulated Flue Gas with Isothermal Regeneration

“…Its potential as a promising candidate for CO 2 sorption grew even further following a report that porous MgO promoted by molten alkali metals enabled higher CO 2 sorption capacity and faster uptake kinetics in an intermediate temperature range (250–400 °C) than a bare MgO sorbent . As a result, there has been a growing interest in using such molten‐alkali‐metal‐promoted MgO for CO 2 capture in an intermediate temperature range . Zhang et al.…”

Synthesis and Structural Analysis of Magnesium Oxide Nanomaterial Using Ethanol as Polymerization Solvent

“…One of these nanomaterials is MgO. MgO nanomaterial is a material that has quite a lot of applications, including as additional material for the manufacture of ceramics [1], paint additives [2], superconductors [3], catalysts [4] and catalyst carriers [5], absorbing toxic waste materials in waters [6], and gas adsorbents [7]. Other applications as layers to grow thin film materials,there are the widely used other advantages of MgO nanomaterials which have large bandgap and hightemperature stability [8].…”