PLINKE offers its proprietary NOx Absorption technology for maximum yields and lowest environmental emissions. Nitrous gases from vent streams are recovered as Nitric Acid in a highly efficient cooled tray absorption tower without consumption of chemicals. This technology normally uses only water and atmospheric air. After treatment, effluent gases comply with all environmental standards for NOx worldwide.
|High Pressure NOx Absorption |
A mixture of NOx-containing gas and air is compressed to 6 barg using proven liquid ring compressors and fed into the absorption tower which is equipped with special internals for high efficiency cooling and mass transfer. PLINKE's proprietary tray design minimizes tower volume, resulting in smaller plot plan and lower capital investment. NOx is recovered as Nitric Acid at about 50–60 wt% concentration. This technology can be applied on vent gases with high NOx content and strong environmental standards for the effluent gas. PLINKE has built such systems worldwide both as stand-alone units and paired with PLINKE plants.
|Medium Pressure NOx Absorption |
Similarly to the High Pressure system, NOx-containing gas and air are compressed using liquid ring compressors, but pressure is kept around 3-5 barg. The absorption tower can be a tray tower, similar to the one used in the high pressure system or a packed column. Because of the medium pressure, the absorption tower is larger, when compared to the one used in the high pressure absorption process. This technology can be applied on vent gases with high NOx-content and moderate environmental standards or additional oxidizers may be used to achieve strong environmental standards.
|Low Pressure NOx Absorption |
A mixture of NOx-containing gas and air is compressed to only 2 barg by standard blowers and fed into a packed column. Because of the low operating pressure, the absorption tower is larger, when compared to the previous two technologies. Usually oxidizers are used in order to achieve sufficient NOx removal. Preferred application is on vent gas with low NOx content and moderate environmental standards.
|Caustic Washer |
For gas streams with very low NOx content, the technologies above may not be economically viable. Caustic washing removes NOx as nitrates, which are subsequently treated in the waste water treatment facility.