Ideas for a clean environment |
Solvent recovery is a tried and tested method particularly suited for cleaning process waste air. The recovery plant is located downstream of a desorption column or a soil air exhaustion plant. Large amounts of highly polluted air are cleaned without any difficulty to the standards of the German Clean Air Regulations even if containing more than 25 g of pollutant per m³ air.
The solvents are recovered by adsorption and subsequent desorption using air activated carbon. Two air activated-carbon adsorbers are mostly used to make up a recovery plant.
While one of the adsorbers is in operation, the activity of the second is regenerated or it is hold in stand-by position.
In order to regenerate the activity of the used-up adsorber, its carbon is heated by steam so that it releases the pollutant into the gas phase. The steam is caused to condense and passed through a heavy solids remover and then a light solids remover. In the process, the solvents are separated and can be disposed of. The substances dissolved in the water are removed in a contact purification plant.
When the purification of the activated carbon is complete, the heating steam supply is turned off and the carbon is dried by hot air and subsequently cooled down by ambient air. The adsorber can be used again.
When the purification of the activated is complete, the heating steam supply is turned off and the carbon is dried by hot air and subsequently cooled down by ambient air. The adsorber can be used again.