Model iSorb-HP - High Pressure Gas Adsorption
High pressure adsorption measurements are important in the fields of carbon dioxide sequestration, methane storage, hydrogen storage, and gas separation. The iSorb-HP instruments (volumetric sorption or Sieverts apparatus) generate automatic measurements of full adsorption and desorption isotherms over a wide range of pressures and temperatures. These isotherms can be displayed in the traditional surface excess vs. pressure plot or as a PCT (Pressure-Composition-Temperature) plot.
The iSorb series is a family of four such high pressure sorption instruments; one and two-sample models each available with an upper pressure limit of 100bar or 200bar, complete with built in vacuum pumps and sample degassing capability. All models feature pressure transducers both in the dosing manifold and on the sample cell for maximum sensitivity; this also provides the iSorb-HP2 model the capability to simultaneously analyze two samples.
High pressuregas sorption measurements are defined in terms of pressure or dose amount for both adsorption and desorption, equilibrium criteria, sample temperature (according to the heating /cooling device selected) and choice of equation of state (EoS)*:
- Schmidt-Wenzel type, defined in terms of Helmholtz free energy (NIST recommended)
- MBWR (Modified Benedict-Webb-Rubin type, Jacobsen 32-coefficients, NIST recommended).
- Lee-Kesler (generalized Benedict-Webb-Rubin).
- Van der Waals
- Ideal gas
Analysis temperatures are achieved either by recirculator bath (-20oC to 100oC, see below), cryocooler (77K-320K), or heating mantle (up to 400oC).