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 energyefficient technology for CO 2 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 CO 2 capture process. Each sorbents contained 20-50 wt% of Na 2 CO 3 or NaHCO 3 . 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 fluidizedbed reactor process along with good chemical reactivity. Sorb NX30 sorbent had a spherical shape, an average size of 89 µm, a size distribution of 38-250 µm, 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. CO 2 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 °C.

Characteristics of Spray-Dried K₂CO₃-MgO Solid Sorbent for CO₂ Capture from Power Plant Flue Gas

“…The lower value indicates a better attrition resistance of the bulk particles. In a circulating fluidized-bed CO 2 capture process, materials with an AI (5)<20% would be acceptable for use with flue gas under atmospheric pressure (Lee et al, 2008a). …”

“…and then are regenerated with CO 2 gas and H 2 O in the regenerator. The following reaction proceeds in each reactor (Liang et al, 2004;Lee et al, 2008aLee et al, , 2013. Regeneration:…”

“…In a circulating fluidized-bed CO 2 capture process, solid sorbents with an AI (5)<20% would be acceptable for use with flue gas under atmospheric pressure (Lee et al, 2008a). A lower value indicates a better attrition resistance of the bulk particles.…”

The Virtuous CO2 Circle or the Three Cs: Capture, Cache, and Convert

“…They chemically adsorb the CO 2 in the form of carbonates or bicarbonates; they are mostly Na-or K-based materials and they regenerate simply by heating. The adsorption capacity for the dry alkali sorbent can reach 80% efficiency [1]. The typical working conditions are temperature below 100 ∘ C in the presence of water [16], but a sorbent for higher temperature applications was also developed [17].…”

“…Direct Air Capture of CO 2 . Since the beginning of industrialization, the atmospheric concentration of CO 2 has increased by 30% to about 400 ppm today [1,2]. The Direct Air Capture (DAC) concept defined as the direct extraction of CO 2 from ambient air was introduced in 1999 [3] and a decade was spent on the viability of this technique as a potential climate change mitigation technology; in the following half decade, there was even increased interest with a large number of publications, but the current technologies do not provide energy/economical efficient separation of CO 2 since concentration in the atmosphere is too low.…”