TAILIEUCHUNG - Study the hydro-isomerization of light paraffin over bifunctional catalysts at elevated pressures
Noble metal based catalysts being wt.%Pd and wt.%Pt supported on HZSM-5 zeolite were subjected to the investigation. Physico-chemical characteristics of catalysts were determined by the methods of nitrogen physi-sorption, SEM, XRD, TEM, NH3-TPD, TPR, and Hydrogen Pulse Chemi-sorption (HPC). Activity of catalysts in the isomerization of n-C6 and n-C5 + n-C6 mixture was studied in a micro-flow reactor in the temperature range of 225 − 325 oC at pressure of MPa and MPa; the molar ratio H2/ hydrocarbon: , concentration of n-C5 or n-C6: mol.%, GHSV 2698 h-1 . | SCIENCE & TECHNOLOGY DEVELOPMENT, , - 2016 Study the hydro-isomerization of light paraffin over bifunctional catalysts at elevated pressures Dao Thi Kim Thoa Luu Cam Loc Ho Chi Minh City University of Technology,VNU-HCM (Manuscript Received on October 13th, 2015, Manuscript Revised January 15th, 2016) ABSTRACT Noble metal based catalysts being wt.%Pd and wt.%Pt supported on HZSM-5 zeolite were subjected to the investigation. Physico-chemical characteristics of catalysts were determined by the methods of nitrogen physi-sorption, SEM, XRD, TEM, NH3-TPD, TPR, and Hydrogen Pulse Chemi-sorption (HPC). Activity of catalysts in the isomerization of n-C6 and n-C5 + n-C6 mixture was studied in a micro-flow reactor in the temperature range of 225 − 325 oC at pressure of MPa and MPa; the molar ratio H2/ hydrocarbon: , concentration of n-C5 or n-C6: mol.%, GHSV 2698 h-1. The stability of catalysts was also determined. The obtained catalysts expressed high acid density, good reducing property, and high metal dispersion with the cluster size in the range of nanometer. They were an excellent contact for isomerization of n-hexane or n-C5 + n-C6 mixture with high conversion, selectivity, and yield. At optimal temperature, n-paraffin conversions were as high as 57 – 63 % and selectivity was 90 %. Pressure had the positive effect to the catalyst conversion, selectivity, and stability. At MPa, both catalysts produced 6669 RON liquid product containing friendly environmental iso-paraffins which is superior blending stock for green gasoline. Key words: isomerization, light paraffin, Pd/HZSM-5, Pt/HZSM-5, pressure. 1. INTRODUCTION The production of gasoline for automobiles has been becoming challenged in the aspect of environmental concerns. Being toxic tetraethyl lead, MTBE, benzene, and its derivatives are banded or gradually eliminated from the gasoline pool. In order to meet the strict gasoline specifications refineries have been .
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