High‐Temperature Capture of CO₂ on Lithium‐Based Sorbents Prepared by a Water‐Based Sol‐Gel Technique

Abstract

A convenient water-based sol-gel technique was used to prepare a highly efficient lithium orthosilicate-based sorbent (Li 4 SiO 4 -G) for CO 2 capture at high temperature. The Li 4 SiO 4 -G sorbent was systematically studied and compared with the Li 4 SiO 4 -S sorbent prepared by solid-state reaction. Both sorbents were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and thermogravimetry. The CO 2 sorption stability was investigated in a dual fixed-bed reactor. Li 4 SiO 4 -G exhibited a special Li 4 SiO 4 structure with smaller crystalline nanoparticles, larger surface area, and higher CO 2 adsorption properties as compared with Li 4 SiO 4 -S. The Li 4 SiO 4 -G sorbent also maintained higher capacities during multiple cycles.

MgO-based adsorbents for CO2 adsorption: Influence of structural and textural properties on the CO2 adsorption performance

“…CO 2 desorption was carried out by using TGA from 0 to 850°C, with a heating ramp of 20°C/min. According to Wang et al (2014), this study is necessary because long-time stability of an adsorbent is a critical parameter for the commercialization of a CO 2 scavenger. It is well-known that the characteristic of an adsorbent in a practical application point of view is its useful life-time, because longer period of time brings to a meaningful decrease in cost of the synthesis.…”

CO2 Capture on Metallic Oxide Powders Prepared Through Chemical Combustion and Calcination Methods

“…In this context, recent investigations have highlighted that one of the most pressing environmental concerns is CO 2 capture from postcombustion flue gases using solid adsorbents, CO 2 retention in coal-fired power plants, and many other industrial sources; adsorption is currently a promising, low-cost, and efficient technology (Cai et al 2014). Therefore, numerous studies have focused on preparing porous and high surface area adsorbents for gas adsorption, developing a wide variety of natural or synthetic solid materials that have been screened and tested for selectivity during CO 2 capture or separation: metalorganic frameworks (Anbia et al 2012), zeolites (Chen et al 2014), molecular sieve carbons (Carruthers et al 2012), silicoaluminophosphates (Cheung et al 2012), lithium aluminate materials (Wang et al 2013), organoamines-grafted on nano-sized silica (Czaun et al 2013), porous polymers (Lu et al 2012), activated carbons (Zhu et al 2012), amine modified commercial activated carbon (Chidi and Salome 2013), carbon materials , cellulose matrices (Kang 2013), lithium sorbents (Wang et al 2014a), and limestone (Wang et al 2014b) among others. These adsorbents are relevant for CO 2 capture and separation processes, and many microporous solids have demonstrate considerable potential as CO 2 adsorbents, particularly those with small pores.…”

Understanding the flue gas components on the mechanism governing CO2 adsorption on the Li4SiO4 surface

“…Kato and Nakagawa first synthesized Li 4 SiO 4 from Li 2 CO 3 and SiO 2 precursors via a solid‐state reaction route. In later studies, identifying potential silicon sources and Li precursors , emerging synthesis routes (impregnated suspension , precipitation , carbon templating , and sol‐gel methods ), and the incorporation of hetero elements into the Li 4 SiO 4 crystal structure have been substantially used to prepare effective Li 4 SiO 4 sorbents. Despite these improvements in capture capacity, most sorbents still suffer from slow kinetics at low CO 2 partial pressures .…”