Claude Dodet

Study of the texture of monodisperse silica sphere samples in the nanometer size range

Abstract The texture of monodisperse silica spheres in the diameter range 8–200 nm, and in the form of powders and slabs is examined. The analysis of nitrogen adsorption—desorption isotherms shows the respective contributions of the voids between particles and the internal microporosity, as well as the influence of pelletization on texture. The importance of the adsorbent—adsorbate interactions on the selection of the standard isotherms to obtain a self-consistent picture of the solid texture is also emphasized.

Texture of manganese nodules used as a catalyst for demetallizing and desulphurizing petroleum residua

Abstract The porous texture of oceanic polymetallic nodules used as catalysts for demetallation and desulphurization of petroleum residua in a trickle bed reactor was studied after reaction. Four techniques were considered: analysis of nitrogen physical adsorption—desorption isotherms, X-ray diffractometry, mercury penetration and electronic microscopy. The nodules present a remarkable specific surface area and porosity, which are partially conserved at high temperatures even under the drastic conditions of hydrotreatment.

Hydrodemetallation of petroleum atmospheric residua using oceanic manganese nodules in a trickle bed reactor

Abstract Oceanic polymetallic nodules could be used as a catalyst and adsorbent for hydrodemetallation and hydrodesulfurization of petroleum residua in a trickle bed reactor because of their particular composition and porous texture. A kinetic study of these reactions has been undertaken in a micro-pilot unit using operating conditions similar to those encountered in industrial reactors. The effect of the main operating parameters (pressure, temperature, mass flow rates) was investigated. Moreover, the evolution of the porous texture during reaction was examined and the performance of an industrial reactor estimated.