Gas Hold-up in Three Phase Co-current Bubble Columns

Two-Phase Bubble Columns: A Comprehensive Review

“…Baawain et al [121], showed that the counter-current or co-current operating mode influenced ε G for about 5% of its weight, and less than 1% of its bubble size, showing that the effect observed is mainly caused by the bubble rise velocity and not only caused by the bubble size. In agreement with this explanation concerning the influence of U L on bubble motion, different studies have reported ε G decreasing in co-current operations [49,90,[122][123][124][125][126][127][128] and increasing in counter-current operations [48,49,128]. Biń et al [128] compared the three-operation mode showing that ε G increases with U L in counter-current mode and decreases or remains constant in co-current mode.…”

Bubble column reactors for high pressures and high temperatures operation

“…A higher influence of the superficial liquid velocity is observed: by changing superficial liquid velocity from 4 to 8 cm.s -1 at u G = 12 cm.s -1 , gas holdup is decreased by 28.6%. Pjontek et al (2014), Simonnet et al (2007) and Kumar et al (2012aKumar et al ( , 2012b) report a decrease of the gas holdup while increasing superficial liquid velocity in the same range than Chaumat et al A c c e p t e d M a n u s c r i p t 13 (2005). The effect is attributed to an increase of the bubble rise velocity while increasing superficial liquid velocity.…”

Comprehensive experimental investigation of counter-current bubble column hydrodynamics: Holdup, flow regime transition, bubble size distributions and local flow properties

“…For example, Akita and Yoshida (1973) (d c ¼0.152 m, H c ¼2.5 m) observed a negligible effect of U L (up to 0.04 m/s) in both co-current and countercurrent operations. At higher liquid velocities, the column operation influences the holdup: the co-current mode reduces the holdup (Biń et al, 2001;Chaumat et al, 2005b;Jin et al, 2007;Kumar et al, 2012;Otake et al, 1981;Pjontek et al, 2014;Shah et al, 2012;Simonnet et al, 2007), and the counter-current mode increases the holdup (Besagni and Inzoli, 2016a;Besagni et al, 2014Biń et al, 2001;Jin et al, 2010;Otake et al, 1981) as bubbles are either accelerated or decelerated by liquid motion (Leonard et al, 2015;Rollbusch et al, 2015a). Baawain et al (2007) showed that the counter-current or cocurrent operation modes influenced the holdup by approximately 5% in weight, and less than 1% in bubble size, showing that the effect observed is mainly caused by the bubble rise velocity and not only the bubble size.…”