(38e) Design and Operation of a Pilot Plant for Studies on Scaleup, Liquid Distribution, Liquid Holdup, Hydraulics, Heat and Mass Transfer, and Carbon Dioxide Removal Using Chemical Solvents

A 14 cm diameter Perspex packed column has been designed to study liquid distribution, dry and wet pressure drop, gas phase heat and mass transfer, liquid phase mass transfer, axial mixing, and interfacial area. A 16 cm diameter Stainless Steel column packed with IMTP #15 has also been designed to study gas phase heat and mass transfer between steam-air mixture and hot water besides absorption and steam de-sorption of carbon dioxide into/from chemical solvents. A 30 cm diameter stainless steel packed column has been designed to study scaleup of liquid distribution, and gas phase heat and mass transfer.In all the columns the effect of packing type has been proposed to be studied by taking two modern packings, namely IMTP and Sulzer structured packing.The objectives of the proposed study are a) to collect experimental data on all transport phenomena and validate with the help of mathematical models. b) to obtain scaleup information, and c) study experimentally and theoretically mass transfer accompanied or preceded by reaction in the liquid phase with special reference to carbon dioxide removal systems. The effects of height of packing, gas and liquid flow rates have been proposed to be investigated on all the transport phenomena. The gas phase heat and mass transfer has been proposed to be studied between hot dry air and chilled water to realize near pure physical heat transfer conditions, and between between hot air ?steam mixture and water at near boiling conditions to realize near pure mass transfer conditions. The experimental setup designed for studying gas phase heat and mass transfer has been fitted with computer control systems for controlling pressure, levels, flows and inlet temperatures. The studies conducted so far revealed the following: a) To ensure proper liquid distribution, Rosette type of rings need to be installed at intervals of height equal to one diameter of the column. b) The gas side heat transfer coefficient was found to be strongly correlated to the gas side mass transfer coefficient c) The gas side heat transfer coefficient was found to decrease with increasing height and approached a constant value at height/diameter ratio greater than 5. d) Wet pressure drop per unit length and liquid holdup were found to decrease with increase in bed height e) Flooding velocity was found to increase with increase in height of bed f) Bodenstein number and liquid phase volumetric mass transfer coefficient were found to increase with increase in liquid rate g) Volumetric mass transfer coefficient determined under conditions of desorption of carbon dioxide into air was found to be much higher than the values determined under conditions of absorption of carbon dioxide into pure water h) Installation of Rosette type of liquid redistributor rings at intervals of column height equal to one column diameter was found to cause marginal improvement in the values of liquid phase volumetric mass transfer coefficient and negligible change in the bodenstein number i) The increase in bodenstein number due to increase in height of the column was less than proportionate indicating strong entrance effects j) Liquid phase volumetric mass transfer coefficient was not found to be affected by increase in height of the column.