Fabrication of a new MgO/C sorbent for CO2 capture at elevated temperature

Abstract

A synergistic effect between a self-dispersion of MgO and biomass-derived carbon in the adsorption of CO 2 is reported for the first time. Magnesia and carbon mixed particles are formed in situ during the carbonization of magnesium acetate on activated carbon made from coconut, increasing the accessibility of basic sites for CO 2 adsorption. With these complementary effects of the hierarchical structural support, the composite containing 20% magnesia can trap 5 times more CO 2 than 20% MgO/ SiO 2 , in the harsh instantaneous adsorption of CO 2 at 100 and 150 C, offering a new candidate for the adsorption of CO 2 in flue gas vents.

Novel CO2-Capture Derived from the Basic Ionic Liquids Orientated on Mesoporous Materials

“…Immobilization of ILs on mesoporous supports such as MCM-41, MCM-48, SBA-15, and pA significantly enhances the CO 2 adsorption capability of IL at 393 K (Figure 2a), even in the harsh instantaneous adsorption test in which the contact time with CO 2 is shorter than 2 s and the CO 2 concentration in gas flow is about 5%. 6 With 50 wt % of PAP dispersed, these adsorbents exhibited a capacity of 51−64 mg g −1 at 393 K, which was even higher than that of PAP itself (49 mg g −1 ). However, zeolite NaY, graphene oxide (GO), and activated carbon (AC) failed to promote the CO 2 adsorption capability of PAP, and the capacities of PAP immobilized on these materials were no more than 30 mg g −1 (Figure 2a).…”

“…To assess the instantaneous adsorption ability of the sample under dynamic conditions, 6 30 mg of the sample was activated at a given temperature such as 393 K for 1 h, and then, 0.164 mL of CO 2 was Scheme 1. Optimized Structure of Ionic Liquids PAP (left, Mw = 341) and PI (right, Mw = 326) injected each time accompanied by carrier gas (30 mL min −1 ).…”

Hierarchical Composites to Reduce N-Nitrosamines in Cigarette Smoke

“…Zeolite NaY (Si/Al = 2.86) and HZSM-5 (Si/Al = 12.5) were commercially available powders, the activated carbon with average pore size of 3–5 nm was made from coconut shell [2,43], and all reagents used were of AR grade. The cigarette used in this investigation was a Virginia type purchased from the market.…”

Insight Into the CO2 Capturer Derived From Graphene/MgO Composite

“…There were two characteristic peaks of MgO in the XRD patterns of the three graphene/MgO composites ( Fig. 1a), with 2u values of 43.0°a nd 62.3°corresponding to the MgO with face-centred cubic structure [21,22,29], and the sharp peaks widened in the patterns of G/MgO Ã . The crystallite sizes of MgO in G/MgO Ã were estimated as 7 AE 2 nm according to the Scherrer equation, apparently smaller compared with G/MgO (32 AE 2 nm).…”

“…So, the main contribution of the pores in the warm CO 2 capturer is just to increase the BET surface area [28,29]. Increasing the efficiency of MgO-based sorbent includes but not limits to increasing the BET surface area of MgO, especially for warm CO 2 capture because adsorption of CO 2 at >423 K relies on the strong basic sites of MgO rather than the BET surface area [22,32]. These strong basic sites are well known to depend on special surface defects of MgO crystals [38] where the Mg 2þ cation is absent due to some reasons [39], hence some low-coordinated O 2À defect sites form with enriched negative charge.…”