Scaling Up the Performance of a Reactor Model for Hydrotreating Vegetable Oil from Bench-Scale to Pilot-Scale Reactors

Abstract

Scaling up and validation of a trickle-bed reactor model were performed with the experimental information obtained during the hydrotreatment of vegetable oil in a pilot-scale reactor. The scale-up is carried out with a previously developed bench-scale reactor model that demonstrated good agreement with the experimental data. The differences in the characteristics of both reactor scales affected catalyst wetting efficiency, diffusion limitations inside the catalytic particle, and wall effects. These alterations were attributed mainly to the use of larger catalytic particles and higher surface velocities of the feedstock used in the pilot-scale reactor compared with the bench-scale reactor. In addition, the catalyst used in the pilot-scale reactor showed more effectiveness than that in the bench-scale reactor, thus presenting more triglyceride conversion. Simulations with the rector model also indicated that the higher feed flow rate and the large amount of catalyst used in the pilot-scale reactor generate a greater release of heat that makes it difficult to stabilize the reactor to reach steady state.

Prediction of Temperature Profiles for Catalytic Hydrotreating of Vegetable Oil with a Robust Dynamic Reactor Model

“…Different simulations were carried out to analyze the effect of the feedstock inlet temperature on the reactor performance at WHSV of 3 h –1 , 8 MPa of total pressure, and 1500 Nl/l of hydrogen/oil ratio. The liquid temperature profiles obtained show lower values than those reported when simulating a pilot-scale reactor . It should be commented that the commercial reactor model includes an equation for the variation of superficial gas velocity that may affect the temperature profiles.…”

“…The liquid temperature profiles obtained show lower values than those reported when simulating a pilotscale reactor. 14 It should be commented that the commercial reactor model includes an equation for the variation of superficial gas velocity that may affect the temperature profiles.…”

“…Then, the scaling-up of the reactor model was successfully carried out by predicting the experimental yields reported under certain operating conditions and analysis of different hydrodynamic phenomena characteristic of pilot-scale reactors. 14 Table 1 summarizes the main characteristics of the model that have been previously developed, the experimental data used for validation, and the main findings. Among the main results obtained, it has been observed from the temperature profiles of the three phases that the extent of the reaction involves a high release of heat, which needs to be properly examined by modeling and simulation of a large-scale reactor.…”

“…In addition, the model was conditioned to predict the temperature profiles of the three phases (gas, liquid, and solid) through a system of energy balance equations. Then, the scaling-up of the reactor model was successfully carried out by predicting the experimental yields reported under certain operating conditions and analysis of different hydrodynamic phenomena characteristic of pilot-scale reactors Table summarizes the main characteristics of the model that have been previously developed, the experimental data used for validation, and the main findings.…”

Analysis of Heat and Mass Transfer and Parametric Sensitivity in an Experimental Fixed-Bed Reactor for the Catalytic Cracking of Heavy Hydrocarbons Based on Modeling and Experiments

“…2 One-dimensional axial dispersion was considered for gas flow in the reactor due to the low ratio of L B /d p = 35 (axial dispersion can be ignored for L B /d p > 100). 51 3 The temperature profile is constant within the catalytic pellet (homogeneous catalytic particle). 4 The feedstock completely vaporized before entering the catalyst bed.…”