A New Commercial Instrument for Gas Sorption Measurements Under Extreme Conditions

A new commercial microbalance has been developed in order to characterize the gas sorption properties of adsorbents under a range of challenging conditions. The instrument, called the XEMIS, features a new type of microbalance in which the sensitive detection and control components are located outside the main chamber of a symmetrical beam balance. The design allows the gravimetric measurement of the adsorption and desorption of a range of gas species, including corrosives, at pressures of up to 200 bar and temperatures of 500°C. To demonstrate its operation, we have performed measurements on a series of samples under different conditions of temperature and pressure. We have selected a Metal-Organic Framework (MOF), a shale and a zeolite. We present hydrogen adsorption and desorption isotherms on a 50 mg sample of Na-X zeolite up to 150 bar at 77 K, high resolution SO₂ adsorption and desorption isotherms on a novel MOF (NOTT-300) at sub-ambient pressure and a range of near-ambient temperatures, and CH₄ adsorption isotherms up to 100 bar on a shale. These data demonstrate the operation of the XEMIS for the characterization of different types of adsorbent for a range of practical gas adsorption applications.