Sodium-based dry regenerable sorbent for carbon dioxide capture from power plant flue gas

Abstract

Dry regenerable sorbent technology is one of the emerging technologies as a cost-effective and energy-efficient technology for CO2 capture from flue gas. Six sodium-based dry regenerable sorbents were prepared by spray-drying techniques. Their physical properties and reactivities were tested to evaluate their applicability to a fluidized-bed or fast transport-bed CO2 capture process. Each sorbents contained 20-50 wt% of Na2CO3 or NaHCO3. All sorbents except for Sorb NX30 were insufficient with either attrition resistance or reactivity, or both properties. Sorb NX30 sorbent satisfied most of the physical requirements for a commercial fluidized-bed reactor process along with good chemical reactivity. Sorb NX30 sorbent had a spherical shape, an average size of 89 mu m, a size distribution of 38-250 mu m, and a bulk density of approximately 0.87 g/mL. The attrition index (AI) of Sorb NX30 reached below 5% compared to about 20% for commercial fluidized catalytic cracking (FCC) catalysts. CO2 sorption capacity of Sorb NX30 was approximately 10 wt% (>80% sorbent utilization) in the simulated flue gas condition compared with 6 of 30 wt% MEA solution (33% sorbent utilization). All sorbents showed almost-complete regeneration at temperatures less than 120 degrees C.