Environmental Benign Synthesis of Lithium Silicates and Mg-Al Layered Double Hydroxide from Vermiculite Mineral for CO2 Capture

Abstract

This research introduces a completely new environmental benign synthesis route for obtaining two kinds of inter-mediate and high temperature CO 2 sorbents, Mg-Al layered double hydroxide (LDH) and Li 4 SiO 4 , from vermiculite. The mineral vermiculite was leached with acid, from which the obtained SiO 2 was used for the synthesis of Li 4 SiO 4 and the leaching waste water was used for the synthesis of Mg-Al LDH. Therefore, no waste was produced during the whole process. Both Li 4 SiO 4 and Mg-Al LDH sorbents were carefully characterized using XRD, SEM, and BET analyses. The CO 2 capturing performance of these two sorbents was comprehensively evaluated. The influence of the Li/Si ratio, calcination temperature, calcination time, and sorption temperature on the CO 2 sorption capacity of Li 4 SiO 4 , and the sorption temperature on the CO 2 sorption capacity of LDH, were investigated. The optimal leaching acid concentration for vermiculite and the CO 2 sorption/desorption cycling performance of both the Li 4 SiO 4 and Mg-Al LDH sorbents were determined. In sum, this demonstrated a unique and environment-friendly scheme for obtaining two CO 2 sorbents from cheap raw materials, and this idea is applicable to the efficient utilization of other minerals.

Solid‐Waste‐Derived Carbon Dioxide‐Capturing Materials

“…[175][176][177][178] Among them, Li 4 SiO 4 has received furthera ttention due to its high sorptionp erformance, fast sorptiona nd desorptionk inetics, as well as good mechanical properties. [49] For the preparation of alkali silicate based CO 2 sorbents, generally three types of solid waste have been reported: FA,R HA, and diatomite.…”

“…[25][26][27] Amongt hem, CO 2 removal from flue gas by adsorption and stripping with solids orbents has been establishedf or several decades. [29] Many solid sorbents, such as zeolites, [30] activated carbons, [31,32] silicas, [33,34] metal-organic frameworks (MOFs), [35,36] layered double hydroxides, [32,[37][38][39][40] metal oxides, [41][42][43] CaO, [44][45][46][47] and Li 4 SiO 4 , [48,49] have already been utilized for CO 2 capture. [29] Many solid sorbents, such as zeolites, [30] activated carbons, [31,32] silicas, [33,34] metal-organic frameworks (MOFs), [35,36] layered double hydroxides, [32,[37][38][39][40] metal oxides, [41][42][43] CaO, [44][45][46][47] and Li 4 S...…”

“…[12,28] Solid adsorbentsh ave many advantages in CO 2 capture processes, such as ah igher capture capability,a bsence of solventh eating and vaporization during the regenerationp rocess, lower material heat capacities, and lower heats of adsorption. [29] Many solid sorbents, such as zeolites, [30] activated carbons, [31,32] silicas, [33,34] metal-organic frameworks (MOFs), [35,36] layered double hydroxides, [32,[37][38][39][40] metal oxides, [41][42][43] CaO, [44][45][46][47] and Li 4 SiO 4 , [48,49] have already been utilized for CO 2 capture. In recent years, solid-wastederived materials have been considered as promising CO 2 sorbents.…”

Development of an Efficient Methanol Production Process for Direct CO2 Hydrogenation over a Cu/ZnO/Al2O3 Catalyst

“…Methanol production rate in CO 2 hydrogenation process is higher than the conventional route from syngas. This can be attributed to two reasons: first, in methanol production by CO 2 hydrogenation, the feedstock considered in this study only contains CO 2 and H 2 , without any inert gas, while, in the conventional process from synthesis gas, approximately 20% of the feedstock consists of CH 4 and N 2 as the inert gases. The presence of the inert gases in the feed stream reduces the partial pressure of the reactants and consequently the reaction rates are decreased, resulting in a lower production rate.…”

“…The large contribution in total CO 2 emission originates from coal or natural gas power plants [1][2][3][4][5][6]. To reducing CO 2 concentrations, two proposed methods have been developed and implemented: carbon capture and storage (CCS) and carbon capture and utilization (CCU) [7][8][9][10].…”