EFFECT OF SORBENT PORE VOLUME ON THE CARBONATION REACTION OF LIME WITH CO2

S M M Nouri,H Ale Ebrahim

doi:10.1590/0104-6632.20160332s20140245

Abstract

The reaction of calcium oxide with carbon dioxide is one of the most important methods for the capture and concentration of greenhouse gas from the flue gases of industrial plants. In this work, the carbonation reaction of CaO obtained from various sources with CO2 was investigated by a thermogravimetric method. These sources include commercial lime or CaO, CaCO3, Ca(OH)2, CaC2O4.H2O, a synthesized nanoporous sorbent, limestone and acetic acid washed limestone. The effect of structural parameters of the sorbents on the reactivity and CO2 capture capacity were studied using pore size distribution data. Also, the changes in the solid texture during the carbonation reaction were investigated. It was found that there is a direct relation between the pore volume of the sorbents and their reactivity. It was found that sintering is one of the main reasons for decreased activity in the carbonation/calcination cycles.

Highlights

Global accumulation of CO2 greenhouse gas in the atmosphere has increased from 280 ppm in around 1860 to approximately 316 ppm in 1957 and rapidly to 390 ppm in 2010 (Kenarsari et al, 2013)
This study suggested that a mesoporous structure with a pore size range between 5-20 nm would be less susceptible to pore blockage and, provide higher CO2 capture capacity and better stability
There is a direct relation between the parameter β and the reactivity of the sorbent, especially in the fast stage of reaction

Summary

Introduction

Global accumulation of CO2 greenhouse gas in the atmosphere has increased from 280 ppm in around 1860 to approximately 316 ppm in 1957 and rapidly to 390 ppm in 2010 (Kenarsari et al, 2013). Fossil fuels are the dominant form of energy utilized in the world (86%), and are responsible for more than 75% of the current CO2 emission (Houghton et al, 2001). The need to reduce CO2 emissions is globally accepted and represents the driving force to reconsider the environmental aspects of current technologies used for power generation plants (Herzog, 2001). The use of CaO as a regenerable CO2 sorbent has been reported from several works. A process using twin circulating fluidized bed reactors for the large scale carbon dioxide capture from flue.

Methods

Results

Conclusion