Effect of nanoscale curvature sign and bundle structure on supercritical H2 and CH4 adsorptivity of single wall carbon nanotube

The adsorptivities of supercritical CH(4) and H(2) of the external and internal tube walls of single wall carbon nanotube (SWCNT) were determined. The internal tube wall of the negative curvature showed the higher adsorptivities for supercritical CH(4) and H(2) than the external tube wall of the positive curvature due to their interaction potential difference. Fine SWCNT bundles were prepared by the capillary force-aided drying treatment using toluene or methanol in order to produce the interstitial pore spaces having the strongest interaction potential for CH(4) or H(2); the bundled SWCNT showed the highest adsorptivity for supercritical CH(4) and H(2). It was clearly shown that these nanostructures of SWCNTs are crucial for supercritical gas adsorptivity.ArticleADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY. 17(3):643-651 (2011)journal articl

Holdup correlations in slurry-solid fluidized beds

The use of slurry-solids fluid beds plays an important role in the development of synthetic fuels and the hydrogen processing of petroleum resids. In the H-Coal process in particular, coal oil slurries are processed over extrudates of hydrodesulfurization catalyst. The objective of this note is to present a model which describes the volume fraction occupied by the slurry phase. The accurate prediction of the liquid holdup is important not only for the calculation of the bed height in liquid solid fluidized beds, but also is required for the development of a model predicting the holdup in three-phase fluidized beds. In the present publication, the application of two different correlations is considered: (1) the Richardson and Zaki; and (2) Ramamurthy and Sabbaraju