Adsorption of Carbon Dioxide from Gas Streams via Mesoporous Spherical-Silica Particles

Abstract

A relatively new mesoporous silica sorbent for environmental protection applications (i.e., mesoporous spherical-silica particles [MSPs]), was modified by N- [3-(trimethoxysilyl)propyl]ethylenediamine (EDA) solution and was tested for its potential in the separation of carbon dioxide (CO 2 ) from flue gas. The CO 2 adsorption capacity of MSP and MSP(EDA) increased with temperature from 20 to 60°C but decreased with temperature from 60 to 100°C. The mechanism of CO 2 adsorption on both samples is mainly attributed to physical interaction regardless of temperature change. The MSP(EDA) have good adsorption performance as compared with EDA-modified zeolite or granular activated carbon conducted in this study and many types of silica sorbents reported in the literature. The cyclic CO 2 adsorption showed that spent MSP(EDA) could be effectively regenerated at 120°C for 25 min and CO 2 adsorption capacity of MSP(EDA) was preserved during 16 cycles of adsorption and thermal regeneration. These results suggests that MSP(EDA) are efficient CO 2 sorbents and can be stably used in the prolonged cyclic operation. INTRODUCTIONThe carbon dioxide (CO 2 ) capture and storage (CCS) technologies from flue gas are considered to be completely feasible means to lessen the global warming issue. 1 Various CO 2 capture technologies, including absorption, adsorption, cryogenics, membranes, and so forth, have been investigated. 2 Among them, the absorption-regeneration technology has been recognized as the most matured process so far, with the amine-based or ammonia-based absorption processes receiving the greatest interest. [3][4][5][6][7] However, because the energy penalty to regenerate liquid amine or ammonia in the absorption process is high due to the high heat capacity of liquid amine/ammonia and large amount of water, 2 other technologies are being investigated throughout the world. The Intergovernmental Panel on Climate Change (IPCC) special report concluded that the design of a full-scale adsorption process might be feasible. 8 Possible CO 2 sorbents investigated in the literature include activated carbon, 9 -11 X-type zeolites, 12,13 carbon nanotubes (CNTs), 11,14,15 SBA-15 mesoporous silica sorbents, 16 -19 and mesoporous molecular sieve MCM-41. 20 -23 Mesoporous spherical-silica particles (MSPs), which were modified from the MCM-41 materials, 24 are a relatively new sorbent for environmental protection applications. 25 The MSPs possess advantages of much faster preparation time, higher packing density, and lower pressure drop than MCM-41 because of their well -defined spherical shape. 26 These advantages make MSPs more practical

Continuous generation of mesoporous silica particles via the use of sodium metasilicate precursor and their potential for CO2 capture

“…The moisture in the CO 2 gas cylinder was measured to be 5% relative humidity, which corresponds to an absolute moisture content of 0.16% (v/v) and is much lower compared to the CO 2 concentration. The effect of moisture content on the MSP can be referred to our prior study [13]. It indicated that at moisture content of less than 4% (v/v), the moisture content has no effect on the CO 2 adsorption capacity for the MSP adsorbent.…”

Adsorption of CO2 from Flue Gas Streams by a Highly Efficient and Stable Aminosilica Adsorbent

“…Hicks et al 38 fabricated a covalently tethered hyperbranched aminosilica adsorbent, which is capable of adsorbing CO 2 reversibly with a high capacity of 3.1 mmol g Ϫ1 at 298 K and multicycle stability. Recently, Lu et al 39 synthesized amine-modified mesoporous spherical silica particles, which are efficient for CO 2 capture, and their adsorption performance can be maintained during 16 cycles of adsorption and thermal regeneration.…”

Carbon Dioxide Separation from Flue Gases: A Technological Review Emphasizing Reduction in Greenhouse Gas Emissions

“…Lu et al [148] showed that mesoporous silica spherical particles (MSPs) can be synthesized using low-cost Na 2 SiO 3 thus they can be cost-effective adsorbents for CO 2 separation from flue gas [149, 150]. …”