Computational fluid dynamics of gas-liquid bubble column with hydrocracking reactions

Abstract A gas-liquid Eulerian computational fluid dynamics (CFD) model coupled with a population balance equation (PBE) was presented to investigate hydrodynamics of a bubble column with hydrocracking reactions in H 2 -vacuum residue oil system (H 2 -VR) in terms of pressure drop, gas holdup, mean bubble size, and bubble surface area. The column had a height 1.9 m and 0.05 m in inner diameter. The column was initially filled with a vacuum residue (VR) and vacuum gas oil (VGO) mixture of a height of 1.9 m. The VR/VGO mixture with 80% VR and 20% VGO by weight, was injected at a velocity of 0.271 mm/s. The H 2 was injected through the gas distributor at a superficial gas velocity of 6.4 mm/s. The bubble column was operated at 160 bar, 430°C. For the H 2 -VR system at the high pressure and temperature, the pressure drop, the total gas holdup, the mean bubble size and the specific bubble surface area were estimated to be 5,984 Pa/m, 8%, 3.2 mm and 150 m 2 /m 3 , respectively, using the CFD-PBE model. The compositions of the components were also calculated. This CFD study provides a potential to design the bubble column and to optimize the operating conditions.