Waste air purification are solvent recovery
The laws for pollution control often do not allow the emission of solvents or other hydrocarbons into
the atmosphere. The adsorption by means of activated carbon often is the most favourable and economical process. With the aid of correspondingly designed units and processes it is no problem to observe very low residual concentrations, as for instance requested for chlorinated hydrocarbons or benzene.
These skids are used for recovery of benzene, toluene, xylene, alcool, hydrogenated hydrocarbons, mixtures of solvents like diluting agents etc..
Recovery of vapours with membrane
In tank farms but also in other ranges there are often small hydrocarbon-enriched waste air steams.For purification of this waste air and recovery of hydrocarbons a combination process is used consisting of a membrane and an adsorption system. In a membrane separation unit the waste air
is prepurified, the final purification takes place in the following adsorption stage.
The adsorption system is executed as pressure swing adsorption unit.
By using this process we can guarantee the compliance with the regulations limit values for hydrocarbons.
Purification by adsorption
Mainly by using molecular sieves unwanted contaminations can be removed from gases successfully. Molecular sieves with homogeneous pore size are able to adsorb selectively, i.e. the sieves only adsorb molecules of a definite size and allow the other molecules to pass. Often purifying is performed together with the drying process.
Application:
Removal of CO2, H2S, NH3, hydrocarbons.
Drying of liquids
Not only gases but also liquids can be separated from water by adsorption.
This process often is superior to all other separation procedures. Not only water-insoluble solvents are treated but also watersoluble alcohols, ketones, ester etc...
Application:
Drying of propane, propylene, butane, hexane, benzine, toluene, xylene, halogenated hydrocarbons, ethanol, propanol, acetone, ethylacetate.
Air and Gas drying
For many technical processes dried air or gases are necessary.
The most effective physical method is drying by adsorption.
For drying all well-known desiccants are at our disposal and can be applied according to qualification and economical operation.
It is possible to attain residual humidities of less than 1 ppm ( approx. Dew point -80° ), in most cases, however, it is sufficient to dry down to several 100 ppm (dew points of -20°C to -50°C).
