Hydrodynamics of gas—liquid—solid fluidization under high gas hold-up conditions

Abstract

Experiments were performed to study the hydrodynamic characteristics of an annular gas—liquid—solid fluidized bed under high gas hold-up and small bubble conditions. These conditions were achieved at ambient conditions through the use of surfactants in air—water systems. The high gas hold-up conditions simulate the conditions in petroleum resid hydrotreating or coal liquefaction operations. The results indicate that gas hold-up increases with increasing gas velocity, decreasing liquid velocity, or decreasing particle size. Alcohol solutions varied over a narrow concentration range yielded nearly identical has hold-up. In systems of aqueous t-pentanol solutions with 1-mm glass beads, the gas hold-up behavior resembled that found by Tarmy et al. (1984) in a study of hydrodynamics of coal liquefaction reactors using similar-size particles.