1 research outputs found
Synthesis, Pelleting, and Performance Evaluation of a Novel K‑Promoted γ‑Alumina/MgAl-Layered Double Oxide Composite Adsorbent for Warm Gas H<sub>2</sub>/CO<sub>2</sub> Separation
Development
of stable solid adsorbent in pellet form is of importance for CO<sub>2</sub>/H<sub>2</sub> separation at elevated temperature (250–450
°C). This study provides a novel synthesis method by adding K<sub>2</sub>CO<sub>3</sub> solution into alumina sol soaked MgAl-layered
double hydroxide paste. The delay time of K<sub>2</sub>CO<sub>3</sub> addition is studied to demonstrate that the formation of K-promoted
γ-alumina is facilitated by an immediate addition. Extruded
adsorbent of higher CO<sub>2</sub> capacity (0.65 mmol/g) and radial
crushing strength (75.6 N per pellet) is obtained. The existing crystalline
phase of obtained adsorbent is screened by X-ray diffraction. The
adsorption capacity and adsorption kinetics of the developed adsorbent
is characterized by a thermogravimetric analyzer in terms of calcination
temperature of both dominant constituent materials, MG63 hydrotacite,
and K-promoted pseudo boehmite. Crystal transit temperatures of the
constituents are considered in selecting the optimal calcinations
temperature. The adsorbent pellets, pretreated with the optimal parameters
studied, are packed in a fixed-bed to test breakthrough curves of
CO<sub>2</sub>, consistent dynamic capacity compared to that of thermogravimetric
testing data were obtained. Results of multicycle CO<sub>2</sub> adsorption
and desorption, steam sweeping, pressure change, and wear tests prove
the stability of the adsorbent both in CO<sub>2</sub> capacity and
mechanical strength