STUDYING HYDRODYNAMICS IN A CO-CURRENT UPFLOW PACKED BED REACTOR (U-PBR) USING INVASIVE AND NON-INVASIVE MEASUREMENT TECHNIQUES

Abstract

Upflow Packed Bed Reactors (U-PBRs) are three-phase systems where the liquid and the gas phases are pumped upwards through the catalytic bed against gravity. These reactors are used in high-pressure operations such as air oxidation of phenol and hydroprocessing of crude oil (i.e., hydrotreating and hydrocracking). However, many issues related to the use of these reactors for hydroprocessing have been found, such as the maldistribution of the liquid and gas phases due to coking and catalyst agglomeration, reducing the efficiency and conversion rate of these reactors. The plenum of the reactor has been identified as the cause of the non-uniformity in the distribution of the flowing gas and liquid phases along the height and diameter of the catalyst bed in the core of the reactor. In order to maximize the efficiency of these reactors, it is essential to develop a plenum design that would allow the uniform distribution of the flowing phases through the bed. However, the studies and publications that deal with (U-PBRs) in general and specifically the effect of the design of these reactors on their complex hydrodynamics are limited. Therefore, this research project investigates the hydrodynamics of (U-PBR), with multiple plenum designs in order to develop a design that improves the efficiency of these reactors by enhancing the distribution of the gas and liquid phases. To this end, the liquid and gas holdups in the plenum were measured to assess the distribution of the flowing phases with the multiple designs of the plenum using a sophisticated invasive technique called Optical Fiber Probe (OFP) and a non-invasive technique called Gamma-ray densitometry (GRD). Subsequently, the influence of reactor design and operational conditions on the complex hydrodynamics of these reactors has been quantified.