Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO_(2)capture in fluidized beds,suffering from insufficient contact with CO_(2)for the high-level CO_(2)capture capacity.This s...Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO_(2)capture in fluidized beds,suffering from insufficient contact with CO_(2)for the high-level CO_(2)capture capacity.This study focuses on promoting the fluidizability of hard-to-fluidize pure and synthesized silica-coated amine-functionalized carbon nanotubes.The novel synthesized sorbent presents a superior sorption capacity of about 25 times higher than pure carbon nanotubes during 5 consecutive adsorption/regeneration cycles.The low-cost fluidizable-SiO_(2)nanoparticles are used as assistant material to improve the fluidity of carbon nanotubes-based sorbents.Results reveal that a minimum amount of 7.5 and 5 wt%SiO_(2)nanoparticles are required to achieve an agglomerate particulate fluidization behavior for pure and synthesized carbon nanotubes,respectively.Pure carbon nanotubes+7.5 wt%SiO_(2)and synthesized carbon nanotubes+5 wt%SiO_(2)indicates an agglomerate particulate fluidization characteristic,including the high-level bed expansion ratio,low minimum fluidization velocity(1.5 and 1.6 cm·s^(–1)),high Richardson−Zaki n index(5.2 and 5.3>5),and lowΠvalue(83.2 and 84.8<100,respectively).Chemical modification of carbon nanotubes causes not only enhanced CO_(2)uptake capacity but also decreases the required amount of silica additive to reach a homogeneous fluidization behavior for synthesized carbon nanotubes sorbent.展开更多
文摘Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO_(2)capture in fluidized beds,suffering from insufficient contact with CO_(2)for the high-level CO_(2)capture capacity.This study focuses on promoting the fluidizability of hard-to-fluidize pure and synthesized silica-coated amine-functionalized carbon nanotubes.The novel synthesized sorbent presents a superior sorption capacity of about 25 times higher than pure carbon nanotubes during 5 consecutive adsorption/regeneration cycles.The low-cost fluidizable-SiO_(2)nanoparticles are used as assistant material to improve the fluidity of carbon nanotubes-based sorbents.Results reveal that a minimum amount of 7.5 and 5 wt%SiO_(2)nanoparticles are required to achieve an agglomerate particulate fluidization behavior for pure and synthesized carbon nanotubes,respectively.Pure carbon nanotubes+7.5 wt%SiO_(2)and synthesized carbon nanotubes+5 wt%SiO_(2)indicates an agglomerate particulate fluidization characteristic,including the high-level bed expansion ratio,low minimum fluidization velocity(1.5 and 1.6 cm·s^(–1)),high Richardson−Zaki n index(5.2 and 5.3>5),and lowΠvalue(83.2 and 84.8<100,respectively).Chemical modification of carbon nanotubes causes not only enhanced CO_(2)uptake capacity but also decreases the required amount of silica additive to reach a homogeneous fluidization behavior for synthesized carbon nanotubes sorbent.
