2. Characteristic values

The characteristic quantities of commercially available gas permeability membranes have been grouped into five groups. These are :

• of supply, which specifies the manufacturer's name, brand and membrane code;

• structural properties, which indicate the type of membrane, the nature of the active layer material, its surface affinity and the nature of the support;

• transfer properties, in the form of examples for certain gas or vapor molecules, which include the nature of the organic compound, the gas content of the feedstock, the operating temperature, the density of the permeate stream and the organic compound content of the permeate;

• the type of module produced and its model if possible;

• the type of operation...