Abstract: An extrusion die useful for forming helical extrudate particles of inorganic oxide materials, is made by molding the die around pins having helical outer surface to form extrusion holes in the die. Helical walls of the extrusion holes are formed by the helical shape of the pins. When the molded die is formed, the helical pins are unscrewed out of the helical holes in the die to avoid damage to the die.

Abstract: Improvement of pressure drop in fixed bed reactors is obtained using catalysts or catalyst support particles which are helical lobed, polylobal extrudates having the shape of three or four strands wound helically about the axis of extrusion along the length of the particles. Catalysts are described for use in hydrotreating of petroleum distillation fractions and residues.

Abstract: Spherical particles of alumina are prepared by agitating a slurry of solids comprising rehydratable alumina solids in water with a hot immiscible liquid to disperse droplets of the slurry in a continuous phase of the immiscible liquid. The droplets are shaped by interfacial surface tension and are hardened by heat while in the immiscible liquid, then are separated and calcined to produce finished spherical alumina beads. The preferred beads are of size less than one millimeter. These are used as supports for catalysts that are used in several oil refining processes such as hydrotreating for removal of sulfur or for reforming or cracking.

Abstract: Disclosed is a process for preparing shaped alumina particles for catalysts or catalyst supports by passing droplets of an aqueous slurry of a rehydratable alumina composition through a shaping medium, such as a column of water-immiscible liquid. The alumina composition undergoes rehydration while being shaped as it passes through the shaping medium, and accordingly, firm, discrete alumina bodies are produced.