Process for regenerating a carbonaceous adsorbent loaden with sulfuric acid and water

摘要

1. A process of regenerating in a columnlike regenerator an adsorbent which is laden with sulphuric acid and water and comes from a desulphurization of flue gas and travels as a pile of bulk material through the regenerator from top to bottom, wherein the sulphuric acid is reacted with sulphur-containing reducing gas (H2 S and/or CS2 and/or CCS) at temperatures of 150 to 300 degrees C in a reducing zone to form elementary sulphur, part of the elementary sulphur is reacted in a desorbing zone at temperatures of 300 to 600 degrees C with hydrogen to form hydrogen sulphide and the remainder is removed with reducing gas from the adsorbent, reducing gas which contains elementary sulphur is withdrawn from the region between the top end of the desorbing zone and the bottom end of the reducing zone and is cooled and elementary sulphur is condensed out and drained and the adsorbent which has substantially been free of its loading is conducted before its reuse through a cooling zone, characterized in that the laden adsorbent first travels through a drying zone which has a height amounting to 5 to 30% of the height of the pile of bulk material in the regenerator, the cooled reducing gas from which the condensed-out elementary sulphur has been removed is heated, a partial stream of the heated reducing gas is fed to the region between the drying and reducing zones at entrance temperatures of about 250 to 400 degrees C and the remainder of the heated reducing gas is fed to the desorbing zone at entrance temperatures of 400 to 650 degrees C, the adsorbent is heated in the drying zone by rising reducing gas to temperatures of 80 to 150 degrees C and is partly or completely dried and the adsorbent is subsequently fed to the reducing zone, part of the reducing gas, which is at temperatures of 90 to 160 degrees C and virtually free of elementary sulphur, is removed from the top end of the drying zone and is cooled in a condenser, water vapour is condensed out and removed and cooled reducing gas coming from the condenser is fed to the cooling zone.