The Effect of Flue Gas Contaminants on CO2 Capture at High Temperature by Li4SiO4-Based Sorbents

Abstract

In this study, high-temperature CO₂ capture by solid sorbent based on lithium orthosilicate (Li₄SiO₄) was investigated in the presence of gas contaminants, such as NO and SO₂. Simulated flue gas containingCO₂ (4 vol%), SO₂ (up to 2,000 ppm), and NO (up to 1,000 ppm) was used during the CO₂ capture process. The CO₂ sorption properties of the sorbent were investigated at high temperature (580 °C) by a thermal gravimetric analyzer (TGA).
The tested sorbent showed high CO₂ sorption capacity (210 mg CO₂/g sorbent) along with high absorption rates, and lower regeneration temperature than other solids such as calcium oxide. The results also showed that the solid sorbent is inert with respect to NO. Instead, the presence of SO₂ resulted in a negatively effect on the sorption capacity of the sorbent, due to an irreversible reaction with the adsorbent. Thus, industrial application would require desulfurization of flue gas prior to contacting the sorbent.