High pressure adsorption
Technological solutions for gas storage and gas separation devices of different kinds are becoming crucial for finding methods to solve future environmental problems. This includes gas storage devices for new propulsion methods (H2-storage) as well as possibilities for underground CO2-sequesterisation and machines for separating different gas and vapor mixtures. This processes are usually conducted at conditions highly different from those suitable for standard texture analysis by means of N2-physisorption at 77K. In order to determine adsorption capacities at real conditions, high pressure adsorption generates important results by itself or can be used to put adsorption analysis at lower temperatures and pressures into the correct physical and experimental context.
The adsorption of pure gases by high pressure up to 200bar (20MPa) and a wide temperature range is useful to get technical relevant sorption equilibrium data. The following figure shows so-called excess isotherms of methane on activated carbons at different temperatures and at pressures up to 200 bar.
Excess isotherms of Methane on an active carbon for different temperatures
2. Dynamic adsorption (flow method up to 10 bar)
In order to model technical adsorption processes as well as gas mixture adsorption as best as possible, a representative aliquot of the sample and an authentic simulation of the field of flow are required within the reactor column (see figure).
With the mixSorb L a robust stainless steel construction is available to carry out investigations at temperatures up to 450°C and pressures up to 10bar. Up to four integrated mass flow controllers allow for virtually any gas flow and gas composition, including the addition of vapors. The detection of the gas composition is achieved by means of an integrated thermal conductivity detector or an additional mass spectrometer. Reversion of the flow allows substantial investigations with regards to desorption on technical adsorbents, also allowing for the analysis of regenerability and cyclic durability as well as the experimental reconstruction and simulations of complex pressure swing adsorption processes.
mixSorb S series:
Measurement of breakthrough curves; vapor option; designed for very small sample amounts
mixSorb L series:
Measurement of breakthrough curves; vapor option; safe and easy-to-use bench-top instrument