| 摘要 |
<PICT:0740252/III/1> In an apparatus for the absorption of hydrogen chloride from gases in a packed tower 1 which is supplied at 3 with water or aqueous absorption liquid, e.g. additional dilute hydrochloric acid which may be impure, and through which the gases containing hydrogen chloride flow upwardly from 2, a heat-exchanger 6 for the effluent hydrochloric acid is arranged below tower 1 and a cooler 10 for a desired condensation of steam and other condensable components is arranged above tower 1, the tower, the heat-exchanger, and the cooler forming a unit connected by cup seals 7, 9 which, respectively, prevent gas containing hydrogen chloride passing into the heat-exchanger 6 with effluent hydrochloric acid, and prevent condensate formed in cooler 10 from passinto tower 1 while allowing free passage to gases. The heat-exchanger 6 may be operated as a water cooler when cooled acid is withdrawn at 8, or at a heater when concentrated hydrogen chloride is generated from the acid and withdrawn at 16, while the resultant dilute hydrochloric acid withdrawn at 8 may be returned to the tower at 3 for concentration. In this apparatus HCl may be recovered from gases containing contaminants from chlorination reactions, e.g. benzene, toluene, xylene, cresols, phenol, naphthalene, or their chlorination products, which are condensed in cooler 10 and can be separately recovered at 11. If cooler 10 is put out of operation the gases or vapours pass out at 12 or may be precipitated by water spray 13 and removed at 11. If the steam developed during absorption is insufficient to attain 100 DEG C additional steam may be added at 4 or concentrated hydrogen chloride, if available, may be added to the gases treated. An additional cooler 15 may be provided in the absorption part of the tower. The tower may be built up with a plurality of rings provided with grooves and projections made of a mixture of graphite and resin. |
