Evaluation of Diluted and Undiluted Trickle-Bed Hydrotreating Reactor with Different Catalyst Volume

Abstract

In this work, a comparative study on the combined effects of hydrodynamics and kinetics on the hydrodesulfurization (HDS) of a straight-run gas oil (SRGO) using a trickle-bed reactor with and without diluent (SiC) and different catalyst volume (0.1, 0.07, and 0.050 Â 10 À3 m 3 , respectively) was carried out. The tests were conducted in a pilot plant under conditions close to those used in industrial-scale units (5492 kPa, 445.4 m 3 (STP)/m 3 H 2 /oil ratio, 623-643K, 0.9 and 2.5 h À1 LHSV values). The catalyst used was ORDER REPRINTS a commercial CoMoP/Al 2 O 3 formulation shaped as tri-lobed extrudates (1/20 in, nominal size) or as crushed particles (d p ¼ 1.2 Â 10 À3 m). Contrarily to that usually claimed, the undiluted systems showed better performance than those comprising small diluent (SiC) particles (d p $ 5 Â 10 À5 m). Calculations to evaluate hydrodynamic variables (plug-flow behavior, wall effects, wetting, and back-mixing) were carried out in order to explain the observed facts. The possible influences of the size of the diluent particles used are discussed.

Effect of 2,6-Bis-(1-hydroxy-1,1-diphenyl-methyl) Pyridine as Organic Additive in Sulfide NiMoP/γ-Al2O3 Catalyst for Hydrodesulfurization of Straight-Run Gas Oil

“…The apparent rate constant rates (k hds (Sw%) −0.5 h −1 ) were estimated at steady state conditions (after 12 h), and they were calculated according to the following equation [ 22 , 23 ]: where: k hds : Pseudo 1.5 order HDS kinetic constant (Sw% −0.5 h −1 ); S p : Sulfur in product (wt %); S f : Sulfur in feedstock (wt %); LHSV : Liquid Hourly Space Velocity (h −1 ). …”

Influence of Frame Connectivity of SBA-15 and KIT-6 Supported NiMo Catalysts for Hydrotreating of Gas Oil

“…Wetting phenomina is negligible under the studied [38,39]. Wall effects are negligible where the ratio of D b to d p is 60 [38,40]. External mass transfer effects are neglected by choosing the small catalyst particle size.…”

“…Under typical dilution of catalyst in a trickle bed reactor, the L/d p was maintained at 750, where the back mixing phenomena can be neglected [37,38]. Wetting phenomina is negligible under the studied [38,39].…”

Reaktoren für Dreiphasen-Reaktionen: Rieselbettreaktoren

“…Kleine Partikel verbessern grundsätzlich das Wärmemanagement bei exothermen Reaktionen. Isotherme Bedingungen bei Laborreaktoren können darüber hinaus durch die Verdünnung mit Inertpartikeln guter Leitfähigkeit (Gierman 1988;Ramirez et al 2004;Ancheyta et al 2002) und durch einen verbesserten Wärmetransport mit aktiver Kühlung realisiert werden. Eine Reduzierung des Reaktordurchmessers verbesserte zwar die Wärmeabfuhr, muss aber gleichzeitig unter Bewertung möglicher nachteiliger hydrodynamischer Effekte (siehe Abschn.…”