Amine modified and pelletized mesoporous materials: Synthesis, textural–mechanical characterization and application in adsorptive separation of carbondioxide

Abstract

Adsorption-mediated CO2 separation can reduce the cost of carbon capture and storage. Amine modified sorbents are promising candidates for carbon capture. To investigate the details of CO2 adsorption, three types of mesoporous materials, MCM-41, MCM-48 and SBA-15 were synthesized, pelletized and further pellets were impregnated with 50wt.% of polyethyleneimine (PEI) in methanol to evaluate the performances of the materials in terms of CO2 adsorption. The powdered mesoporous materials were also impregnated with 50wt.% of PEI. The materials were characterized by XRD, TGA, FT-IR, SEM, TEM, N2-physisorption and BET techniques. The mechanical strength of pellets was examined by vertical crushing method. The surface area, pore volume and pore diameter of pellets were lower than powdered materials. This decrease may be due to partial blocking of pore entry and surface coverage of additives during shaping of pellets. A detailed TGA study is carried out of pellets by varying the composition to optimized the wt.% composition of the different ingredients to attain the maximum mechanical strength and high adsorption of CO2. All the PEI-loaded pelletized materials exhibited substantially higher reversible CO2 adsorption–desorption behaviors with >99% recovery. The results indicate pellets containing methyl cellulose and activated carbon show better mechanical strength and CO2 adsorption. The above study also proved that MCM-48 is a better material as compared to MCM-41 and SBA-15 for pelletization and loading of PEI. The material with 50wt.% loading of PEI on MCM-48, showed maximum adsorption of 1.094W/W0 at 80°C with an impressive mechanical strength of 6.1MPa.