Concept of absorption for manufacturing of CO2 by flue gas
Absorption is unit operation used to separate gas from gas mixture. An absorbent is used in which gas in absorbed. Combustion gases are mainly consists of carbon dioxide. To get pure carbon dioxide combustion gases must be cleaned and CO2 should be separated. These two important steps are carried out by absorption. Detailed process is given below. Flue gases result from burning carbonaceous material are cooled, purified and washed by passing through two water scrubbers contain Na2CO3.
(Na2CO3 + CO2 + H2O →2NaHCO3)
The reaction to left is formed by heating NaHCO3.CO2 is absorbed in absorber by counter current selective absorption. in aq. solution of ethanolamine CO2 and steam passed through reactivator and then through CO2 cooler to condensed steam which returns to the tower as reflux.CO2 passes through permagnet scrubber where traces of H2S amines are removed it is dried by passing it through dehydration drums. finely CO2 is condensed cooled in precooler and sent to liquid CO2 receiver for liquefaction.