“…The flow regime in the reactor changes with different operating conditions such as superficial gas velocity, column dimensions, sparger arrangement and specifications, gas and liquid properties and reactor operating pressure and temperature (Buwa & Ranade, 2003;Deen, Solberg, & Hjertager, 2000;M. T. Dhotre, Niceno, Smith, & Simiano, 2009;Díaz et al, 2008;Masood & Delgado, 2014;Pourtousi, Ganesan, Kazemzadeh, Sandaran, & Sahu, 2015;Pourtousi, Ganesan, Sandaran, & Sahu, 2016). There are two main flow regimes such as homogeneous (low rate of break-up and coalescence) and heterogeneous regime (high rate of break-up and coalescence) (Masood, Khalid, & Delgado, 2015;Silva, d'Ávila, & Mori, 2012;Sobrino, Acosta-Iborra, Izquierdo-Barrientos, & De Vega, 2015).…”