Micro-Structured Adsorption Bed for Rapid CO2 Capture & Regeneration

Monday, November 8, 2010: 1:30 PM
151 F Room (Salt Palace Convention Center)
Wei Liu1, Haiying Wan2, Shari Li1 and Nathaan Canfield3, (1)Energy and Environmental Directorate, Pacific Northwest National Lab, Richland, WA, (2)Pacific Northwest National Lab, Richalnd, WA, (3)Pacific Northwest National Lab, Richland, WA

Structured beds comprising a number of parallel flow channels at sizes of micrometer or sub micrometer level will be presented for capturing CO2 from a large volume of gas stream at short residence time and low energy cost. Such micro-structured beds are fabricated by confining fine adsorbent materials with thin, macro-porous barrier sheets (<200µm). The structure looks like the monolith catalytic converter but provides adsorbent loadings (>60 wt.%) much higher than the conventional washcoating (10 to 20 wt%). The overall mass and heat transfer resistance during adsorption and regeneration process can be minimized by independent designs of channel geometries and adsorbent layer structures (thickness, pore size, porosity). As a result, the adsorption and regeneration can be performed at a much faster cycle speed than the conventional pellet-loaded adsorbent bed. Key design principles will be delineated by experimental results with 13X and silicalite zeolite adsorbent materials. The structured bed preserves adsorption kinetics of the powder material and at the same time, reduces the pressure drop by 10 times compared to the 13X bead bed. Scope engineering design and analysis shows possibility to reduce power consumption by >70% and the adsorbent bed size by >5 times for capturing CO2 from flue gas streams by use of a structured adsorption bed, compared to the conventional bead bed structure. The structured bed decouples optimization of adsorbent material properties from the adsorption bed fabrication, and enables quick scale-up of the high-performance adsorbent material from powder form to the engineered adsorption bed without going through the pelletization process.

Extended Abstract: File Not Uploaded