(89e) Study about Formation Al2o3-Tio2 Nanofibers as Supports for Hydroprocessing Catalysts

Introduction: Refineries have undergone restructuring and revamping units due to changes of petroleum feeds properties and the demand of more environment friendly products. The increasing demand of lighter products and middle distillates will be continuing in near future and the demand of heavy crudes, at the same time, will be decreased. To meet this demand, a substantial quantify of heavy crudes has to be upgraded and hydroprocessing is one of the mostly used processes in this regard [1]. The need for better hydroprocessing catalysts capable of complying with the present and the future environmental regulations has promote research on the use of new supports and active phases. Among the new supports, alumina-titania, have shown interesting properties [2]. In this regard, different studies concerning various aspects of hydrotreating catalysts on Al2O3-TiO2 have been undertaken by several groups [3]. They have reported that modification of alumina by TiO2 improves not only the hydrodesulfurization but also the hydrogenation reaction [4]. In this work, the textural and structural property variations in alumina with varying of incorporation titania method and titania source were studied and discussed. Experimental: Aluminas were prepared by a pH-swing method, which is based on the exponential U-shaped solubility curve of hydroxylated aluminas, and described elsewhere [5]. The effect of TiO2 incorporation (15 % wt) into the Al2O3 using three different methods such as precipitation, co-precipitation and multi-deposition of titania, and the effect of titania source (K2[TiO(C2O4)2]2H2O and TiOSO4xH2SO4xH2O) are reported. All supports were characterized by nitrogen physisorption, XRD, TEM, UV-vis and Raman spectroscopies. Results and conclusions: Nano-fibrillar morphology Mixed oxides Al-Ti were prepared and BET surface area of the Al2O3-TiO2 was in the range 306-343 m2/g and after calcination at 500 °C in the range 311-342 m2/g (due to fibrillar morphology, this materials exhibits strong resistance to sintering), average pore size of 13-15 nm and total pore volume in the range of 1.0-1.15 cm3/g. The results from XRD, texture, TEM and Raman indicate that better titania dispersions are obtained by deposition method and the titania source have great impact in the titania dispersion in this fibrillar aluminas. References: 1. Ramirez J., Macías G., Cedeño L., Gutierrez-Alejandre A., Cuevas R., Castillo P., ?The Role of Titania in Supported Mo, CoMo, NiMo, and NiW Hydrodesulfurisation Catalysts: Analysis of Past and New Evidences?, Catalysis Today, 98, 19-30, 2004. 2. Rana M. S., Ancheyta J., Rayo P., Maity S. K., ?Effect of Alumina Preparation on Hydrodemetallisation and Hydrodesulfuration of Maya Crude?, Catalysis Today, 98, 151-160, 2004. 3. Maity S. K., Ancheyta J., Alonso F., Rana M. S., ?Preparation, Characterization and Evaluation of Maya Crude Hydroprocessing catalysts?, Catalysis Today, 98, 193-199, 2004. 4. Santes V., Herbert J., Cortez M. T., Zarate R., Díaz L., ? Catalitic Hydrotreating of Heavy Gasoil FCC Feed on Alumina-titania supported NiMo Catalysts?, Appl. Cat. A, 281, 121-128, 2005. 5. Ono T., Ohguchi Y., Togari O., Preparation of Catalysts III, edited by Poncelet G., Grange P., and Jacobs P., Elsevier Science, Amsterdam-Netherlands ,631-641, 1983.