Use of silica nanopowder to accelerate CO2 sorption by Ca(OH)2--颗粒学报PARTICUOLOGY

Quintanilla, M. A. S., & Valverde, J. M. (2013). Use of silica nanopowder to accelerate CO2 sorption by Ca(OH)2. Particuology, 11(4), 448–453. https://doi.org/10.1016/j.partic.2012.06.015

Use of silica nanopowder to accelerate CO₂ sorption by Ca(OH)₂

M.A.S. Quintanilla, J.M. Valverde^*

Faculty of Physics, University of Seville, Avenida Reina Mercedes s/n, 41012 Sevilla, Spain

10.1016/j.partic.2012.06.015

Volume 11, Issue 4, August 2013, Pages 448-453

Received 9 January 2012, Revised 18 June 2012, Accepted 20 June 2012, Available online 21 January 2013.

E-mail: jmillan@us.es

Highlights

► Synthetic CO₂ adsorbent is made by dry mixing of Ca(OH)₂ and nanosilica powders.

► Acting as dispersant for Ca(OH)₂, nanosilica enhances contact efficiency between CO₂ and Ca(OH)₂.

► Addition of nanosilica helps increase CO₂ adsorption rate during fast carbonation stage.

Abstract

Promising technologies have recently emerged to capture CO₂ from postcombustion flue gas and to enhance the production of hydrogen from natural gas by steam-methane reforming, on the basis of sorption of CO₂ by Ca-based powders. The rate of CO₂ sorption on Ca-based powders is limited by both carbonation kinetics and transport of CO₂ to unreacted sorption sites. Ca-based powders may exhibit cohesive aggregation, thus hindering gas–solids contact efficiency. In our work, we tested the sorption rate of powder samples prepared by dry mixing of a cohesive Ca(OH)₂ powder with a silica nanopowder used as additive. The silica nanopowder serves to improve the dispersibility of Ca(OH)₂. Consequently, when a CO₂ enriched gas and the modified sorbent are brought into contact, the rate of CO₂ sorption is enhanced in the initial fast phase of interest for practical applications.

Graphical abstract

Keywords

Fluidization; Fine powders; CO₂ sorption; Nanoparticles

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