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Catalytic Reforming Catalysts
Published in Soni O. Oyekan, Catalytic Naphtha Reforming Process, 2018
The next stage in catalyst production is the alumina formation or agglomeration. Alumina is formed to specific sizes, shapes, types, and crush strengths to meet the required physical and chemical properties for the catalyst support material. Three alumina-forming procedures are utilized: disc pelletizing, extrusion, and oil-forming technologies. Extrusion and oil-drop technologies are used mainly in the forming of alumina support for catalysts that are used extensively in oil refining hydroprocessing units. A paste of the alumina is made by mixing pseudoboehmite or boehmite, essentially alumina, with water and a peptizing agent such as acetic acid. The paste is extruded to form cylindrical, trilobe, quadrilobe extrudates that could be 3/16 of an inch in length and 1/16 inch in radius. In the oil-forming or oil-drop alumina-forming technology, a sprayer is used to create droplets of the aqueous alumina paste. The droplets move vertically downward at moderate rates through a long column of oil in appropriate oil conditions conducive to forming spherical pellets. Superficial tension exerted on the droplets leads to spherical pellets or beads after moving through the high column of oil. Calcination of the alumina extrudates or pellets is conducted to harden them before use in the next platinum, promoter metal, and chloride impregnation of the shaped alumina.
Thermal stability and SO2 resistance of Pd/Rh-perovskite based three-way catalyst wash-coated on cordierite monoliths
Published in Chemical Engineering Communications, 2023
Bilal Bayram, Işık Önal, Görkem Külah
Pseudoboehmite was used as a binder material in the wash coating slurry. In the work of Nguefack et al. (2003), the sol-gel method was used to synthesize pseudoboehmite. Aluminum-tri-sec-butoxide (ATSB) (Al(OC4H9)3, Sigma-Aldrich, 97%) was first hydrolyzed and then condensed with the addition of hydrochloric acid (HCl, Sigma-Aldrich, 37%). The obtained gel was dried at 150 °C for 12 h and then calcined at 300 °C for 5 h, under dry airflow.