Hydrodynamic Properties Investigation of Ebullated Bed Reactor Using Non-Newtonian Liquid

Abstract

The importance of using EBR has been renewed recently due to the sharp increasein heavy feedstocks sent to refineries and the hydrocracking process. Most of thesefeedstocks have a non-Newtonian behavior. The performance of this type ofreactor using non-Newtonian liquid is complicated and has not been covered wellyet. Hence, the present work is devoted to elucidating the effect of the non-Newtonian behavior of fluid on the hydrodynamic properties of a three-phase (gasliquid-solid) reactor under operating conditions of different values of gas velocity(2, 4, 6) cm/sec, liquid velocity (0.9, 1.39, 1.8, 2.3) cm/sec, and recycle ratio (1.5,2, 2.5). The study observed the effect of non-Newtonian behavior usingpolymethyl Cellulose (PMC) at different concentrations (0.1, 0.2, 0.3, and 0.4)wt%. The pressure gradient method was used to elucidate the minimum liquidfluidization velocity and to estimate hold up, while the imaging method was usedto measure the bubble's size. The results showed that the higher the gas velocity,the lower the minimum liquid fluidization velocity. As the intensity of the non-Newtonian behavior increased, gas velocity showed the opposite effect. Theresults also showed that increasing the velocity of liquid and gas and the intensityof the non-Newtonian increase the gas hold-up. The bubbles characteristics,represented by bubble size results, show that small bubbles appear at low gasvelocities, and these bubbles collapse as gas and liquid velocities increase as wellas liquid viscosity.