Experimental and numerical investigation of a micro-structured bubble column with chemisorption

\u3cp\u3eA novel micro-structured bubble column reactor (MSBC) is studied by a combined experimental and simulation approach, for the chemisorption of CO2 into NaOH. To understand the reactor behavior different reactor configurations are tested for chemisorption by varying the internals (single wire mesh, staged wire meshes, Sulzer packing). Bubble size distribution, pH and holdup data are obtained from chemisorption experiments using an advanced digital image analysis technique. The effect of superficial gas velocities ranging from 5 to 25. mm/s and varying number of wire mesh stages (1, 6 and 10) is deduced from the experiments. The experimental results are used for the validation of the detailed VoF-DBM simulations.\u3c/p\u3

Experimental study of the bubble size distribution in a pseudo-2D bubble column

This work presents an experimental study of the bubble size distribution of a bubbly flow using digital image analysis (DIA). In order to facilitate the image measurement technique a pseudo-2D bubble column is chosen for the experiments. To obtain well-defined inlet conditions a gas sparger, consisting of 20 needles, is used. By employing DIA, the bubble size distribution (BSD) has been measured for a range of superficial gas velocities. The resulting BSD's are expressed in terms of a probability density function (PDF). For low superficial gas velocities of 5 and 10mm/s the PDF has a unimodal shape, while for higher superficial gas velocities of 15 and 20mm/s the PDF has a bimodal shape. The effects of coalescence and break-up of bubbles are visible by evaluating the changes of the resulting BSDs for increasing superficial gas velocity. A comparison of gas hold-ups is made between the calculated BSD and the liquid expansion height. This comparison shows how well the BSD obtained with DIA describes the actual gas hold-up in the column