(521eg) Studying Local Hydrodynamics of Co-Current Upflow Packed Bed Reactor (U-PBR) Using Advanced Measurement Techniques

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 hydroprocessing of crude oil (i.e., hydrotreating and hydrocracking). However, many issues related to the use of these reactors for crude oil hydroprocessing have been found, such as the maldistribution of the liquid and gas phases due to coke formation and catalyst agglomeration. The lower plenum of the reactor has been identified as the cause of the non-uniformity in the distribution of the flowing gas and liquid phases in the reactor. Due to the design of the lower plenum, with one deflector in the center, maldistribution of the flowing liquid and gas phases at this lower plenum, is the main reason behind the non-uniformity of the distribution of the phases in the reactor’s core. In order to maximize the efficiency of these reactors, it is essential to develop a plenum design that would allow the uniform mixing and distribution of the flowing phases through the bed. However, the studies and publications that deal with the effect of the design of these reactors on their complex hydrodynamics are limited. Therefore, this research project investigates the hydrodynamics of a (U-PBR), with modified plenum designs in order to develop a design that improves the efficiency of these reactors by enhancing the mixing and distribution of the gas and liquid phases. To this end, the liquid and gas holdups in the plenum were measured to assess the distribution and mixing of the flowing phases with the original design and the modified designs using a sophisticated non-invasive technique called Gamma-Ray Densitometry (GRD). Subsequently, the distribution, mixing, and flow regimes in the catalysts bed with the new plenum design were studied using GRD.