| 摘要 |
<p>Gaseous impurities such as CO2, H2S, HCN and SO2 are recovered from gaseous mixts. contg. these impurities using an absorption stage in which the gas mixt. is contacted with an alkaline absorption agent such as an alkali metal carbonate at 40-135 degrees C, opt. activated with glycine or other amino acids, ethanolamines, As2O3, solns. of amino acids, ethanolamines, alkali metal phosphates, -sulphites, -bisulphites or -borates, followed by a regeneration stage in which the exhausted absorbing soln. is regenerated by stripping the absorbed impurities with steam, whereby two absorption columns are used in the absorption stage, namely a main column and a secondary column, such that the main column operates at a higher pressure and with externally applied heat and the secondary column operates at a lower pressure with the aid of steam resulting from the expansion of the soln. in the main column, while the pressure in the main column is adjusted such that the resulting steam can be recovered such as described in NL 7402037, whereby practically the whole of the exhausted soln. to be regenerated is fed first into one of the two regenerating columns, where the soln. is incompletely regenerated, and the regeneration is completed in the other column. Method improves the heat usage of the process described in parent specification by making use of the heat still present in the soln. to be regenerated.</p> |
