Enhancing CO-water mass transfer by functionalized MCM41 nanoparticles
Organic groups are grafted to ∼250-nm-diameter MCM41 nanoparticles with a spherical morphology to enhance the CO-water volumetric mass-transfer coefficient (kLa) for synthesis gas fermentation. The results indicate that (i) ∼250-nm MCM41 nanoparticles show a higher kLa value than large silica particles (1.4 and 7 μm), (ii) surface hydroxyl groups on MCM41 nanoparticles play an important role in mass-transfer enhancement, (iii) organic groups grafted to MCM41 modify the mass-transfer enhancement, and (iv) mercaptan groups grafted to MCM41 show the most mass-transfer enhancement of ∼1.9 times that of no nanoparticle addition. The CO-water mass-transfer enhancement depends on the interaction between the nanoparticles and the CO molecules, which is influenced by the hydrophobicity of the nanoparticles and the functional group on the nanoparticles.
Reprinted (adapted) with permission from Industrial and Engineering Chemistry Research 47 (2008): 7881, doi: 10.1021/ie800238w. Copyright 2008 American Chemical Society.