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Wäßrige Stoffsysteme zur Absorption von SO 2
Author(s) -
Meckl Stefan,
Wunder Rainer
Publication year - 1991
Publication title -
chemie ingenieur technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.365
H-Index - 36
eISSN - 1522-2640
pISSN - 0009-286X
DOI - 10.1002/cite.330630103
Subject(s) - chemistry , aqueous solution , sodium sulfite , inorganic chemistry , absorption (acoustics) , flue gas , sulfuric acid , sulfite , sodium sulfate , flue gas desulfurization , salt (chemistry) , sodium , solubility , organic chemistry , materials science , composite material
Aqueous absorbents for absorption of SO 2 . The removal of SO 2 from flue gases is dominated by processes of absorption with aqueous absorbents. Aqueous systems are favourable in contrast to organic absorbents because the water vapour contained in the flue gas does not interfere with the separation. The transport of gaseous SO 2 into the liquid phase and the subsequent transformation into sulfite/bisulfite or sulfate after oxidation is typical for the aqueous processes of absorption. Starting from water as absorbent the addition of various basic agents makes an increase in the absorption capacity of the washing solution possible by several orders. Different solubilities of the agents or the resulting compounds, the dependence of the vapour pressure on the concentration and desired and undesired reactions determine the thermodynamics of the processes. The regenerative sodium salt processes as the Wellman‐Lord (sodium sulfite) process, the Flakt‐Boliden (sodium citrate) process and the sodium phosphate process, the regenerative ammonium sulfite process, the processes producing gypsum and the absorption with oxidation to sulfuric acid are noted. The advantages and limitations of the particular processes are pointed out by means of the vapour liquid equilibria, the solubilities of the salts and the oxidation reactions.