Enhancement of CO₂Sorption Uptake on Hydrotalcite by Impregnation with K₂CO₃

Abstract

The awareness of symptoms of global warming and its seriousness urges the development of technologies to reduce greenhouse gas emissions. Carbon dioxide (CO(2)) is a representative greenhouse gas, and numerous methods to capture and storage CO(2) have been considered. Recently, the technology to remove high-temperature CO(2) by sorption has received lots of attention. In this study, hydrotalcite, which has been known to have CO(2) sorption capability at high temperature, was impregnated with K(2)CO(3) to enhance CO(2) sorption uptake, and the mechanism of CO(2) sorption enhancement on K(2)CO(3)-promoted hydrotalcite was investigated. Thermogravimetric analysis was used to measure equilibrium CO(2) sorption uptake and to estimate CO(2) sorption kinetics. The analyses based on N(2) gas physisorption, X-ray diffractometry, Fourier transform infrared spectrometry, Raman spectrometry, transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were carried out to elucidate the characteristics of sorbents and the mechanism of enhanced CO(2) sorption. The equilibrium CO(2) sorption uptake on hydrotalcite could be increased up to 10 times by impregnation with K(2)CO(3), and there was an optimal amount of K(2)CO(3) for a maximum equilibrium CO(2) sorption uptake. In the K(2)CO(3)-promoted hydrotalcite, K(2)CO(3) was incorporated without changing the structure of hydrotalcite and it was thermally stabilized, resulting in the enhanced equilibrium CO(2) sorption uptake and fast CO(2) sorption kinetics.

Hydrothermal Fabrication of High Specific Surface Area Mesoporous MgO with Excellent CO2 Adsorption Potential at Intermediate Temperatures

“…Among these, solid adsorbents have been commonly fit for the integrated gasification combined cycles (IGCC) related pre-combustion CO 2 capture processes [4,5], e.g., sorption enhanced water gas shift (SEWGS) and sorption enhanced biomass reforming (SEBR) reactions [12][13][14][15]. Among the abundant solid adsorbents which tend to capture CO 2 at moderate temperatures [5,[14][15][16], layered double hydroxides (LDHs) derived metal oxides [17][18][19][20][21] and magnesium oxide (MgO) based compounds [22][23][24][25][26] are promising for the SEWGS and SEBR technologies in the temperature range of 200-400 • C [10,[27][28][29][30]. LDHs have the reputation of outstanding thermal stability and relatively fast CO 2 adsorption kinetics.…”

Characteristics of Na–Mg double salt for high-temperature CO2 sorption

“…However, the CO 2 sorption capacity of hydrotalcite is relatively low for use in large-scale industrial applications. In order to improve the CO 2 sorption capacity of hydrotalcite, impregnation of hydrotalcite with alkali metals such as K 2 CO 3 has been studied [25,[29][30][31][32]. Other high-temperature CO 2 sorbents, NaO-promoted alumina and calcium oxide, have also been examined [33][34][35][36][37].…”

Surface modification of Ni/Al2O3 with Pt: Highly efficient catalysts for H2 generation via selective decomposition of hydrous hydrazine

“…The much lower energy needed for product desorption may effectively enhanced the reactivity of hydrous hydrazine decomposition. To further examine the influence of metal-H bond strength on activity, we introduced small amounts of alkali (such as potassium) to Ni/Al 2 O 3 to strengthen the Ni-H bond [34][35][36]. The results show that the heat of H 2 adsorption on Ni/Al 2 O 3 was raised by doping with trace potassium (Supporting information, Fig.…”