Phase distribution in an upflow monolith reactor using computed tomography



Computed tomography (CT) is known to be a viable technique for determining flow maldistribution in two-phase flow through packed beds. In this study, gamma ray computed tomography has been used to quantify the flow distribution in a monolith catalytic bed, with water as the liquid phase and air as the gas phase, flowing co-currently upward. The flow conditions were selected to bracket some commercially viable operating conditions for such reactors. In the monolith core region, fairly uniform flow distribution has been obtained for all the flow conditions used. This distribution is quantified using the standard deviation of the holdup distribution. However, maldistribution of air and water in the monolith bed wall region due to wall effects at the monolith entrance has been observed and quantified by CT. The obtained results confirm that the entrance and exit regions of the monolith bed need to be carefully designed and to be free of obstacles and vortex creating devices. © 2005 American Institute of Chemical Engineers AIChE J, 2006