ABSORPTION – DESORPTION

OPERATION OF THE PLANT / TECHNICAL FEATURES

The main element of the trainer is a column of 1400 mm. height and 80 mm in diameter made in glass. The column is supplied filled with glass Rasching rings 9×9 mm, and also supplied with polypropylene Pall rings, for the replacement of the glass Rasching rings in order to be able to study the effect of the filler on the efficiency of the absorption and desorption process.   In both cases, the column filling maximizes the gas ‐ liquid contact surface, so that it produces the maximum possible absorption or desorption. The plant has pressure taps at the bottom and at the top of the column and two intermediate taps, through quick couplings connected to a water column differential manometer that allows determining the pressure drop within the column and the effects of the speeds of the liquid and of the gas on the pressure drop within the column. The plant also has three intermediate samplers for sampling both the liquid phase and the gas phase and 4 temperature probes with digital display. The liquid phase is stored in a tank of about 30 liters of capacity made of polyethylene. Water or absorption liquid is led into the reaction column through a metering pump, which allows setting the incoming water flow to the column. In a flow meter positioned on the liquid inlet line can be displayed the liquid inflow. This flow meter is made of borosilicate glass and stainless steel AISI‐316, with stainless steel float. The liquid is introduced through the top of the column through liquid diffuser, which permits the dispersion of the liquid and thus a better distribution of the fluid within the column.

For the plant operation, network air is used. The flow of air into the installation can be regulated and visualized with a rotameter 0‐5 m3 /h of methacrylate provided with regulating valve. The plant is designed for the performance of practices of dissolved CO2 absorption in air on a liquid stream. To do this, in a T it occurs the mixing of air and CO2 whose inlet can be visualized and regulated in a rotameter 0‐2 m3 /h. Subsequent to the mixing point between CO2 and air, we have the inlet of the gas stream at the bottom of the absorption column. The contact between the liquid and the gas inside the column above the surface of the filling rings favors the transfer of material. To study the desorption processes, the circulating water will be contaminated by means of a volatile component, for example ammonia in concentrations of 100‐5000 mg/l.   By circulating air in countercurrent, this produces the desorption of the contaminant dissolved in the liquid phase, and it is possible to determine the effectiveness of the process by analyzing the concentrations of ammonia at the inlet and outlet. The output fluid is stored in a glass container, when operating in continuous mode, or can be returned to the feed tank when operating in batch regime. To determine the effectiveness of the operation the plant has a gauge of CO2 concentration in air, with infrared CO2 meter; it includes a water filter before the meter. This meter may be used for determining the concentration of this compound both at the inlet and at the outlet of the column. Likewise, at the bottom of the column there is a water seal to prevent loss of gas through the bottom of the column. The gas is collected in a container made of glass