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The XEMIS is a high accuracy gravimetric sorption analyzer operating to 200 bar. Changes in sample mass are measured as a function of applied temperature and pressure to determine isotherms, isobars and sorption kinetics. Designed for operation with a full range of gas and vapor species including corrosives and flammables, the XEMIS features active pressure regulation from 10-2 mbar: a controllable pressure range covering 7 orders of magnitude.
The XEMIS offers reproducible, high resolution, high accuracy measurements even with small sample sizes or small uptakes, and performance unrivalled in a high pressure sorption analyzer.
- Isotherm, isobar and high pressure TGA measurements in a single automated analyzer
- Compatible with flammable, corrosive and toxic gases and vapors
- Symmetric geometry, with ultra-low total system buoyancy for high accuracy measurements
- Measurements at temperatures from 77 K to 500 °C
- Fast and accurate analysis of equilibria and kinetics using the IGA method
- Full automation and advanced programmability
XEMIS analyzers are used for isotherm, isobar, kinetic and thermal desorption measurements across a range of application areas. Typical applications include:
- Gas storage capacity evaluation for porous and non-porous materials
- Full isotherm determination including high resolution sorption-desorption measurements
- Sorption and reaction kinetics
- Diffusion and permeation studies
- Gas solubility in low vapor pressure liquids (ionic liquids)
- TGA measurements including operation to 200 bar with integrated TG-MS analysis
- Operation with flammable and corrosive species
Figure 2 shows SO2 adsorption-desorption isotherms on a novel MOF, NOTT-300 , at five temperatures, each 12.5 K apart in the range 298 – 348 K. Note the pressure resolution on the x-axis, with pressure setpoints controlled from 3 mbar upwards.
Figure 3 shows CH4 adsorption isotherms on alum shale, at five temperatures, each 15 K apart in the range 298 – 358 K. Pressures up to 100 bar are studied and it can be seen that the data are of high quality, given the μmol g-1 scale on the y-axis.
Figure 4 shows H2 adsorption-desorption isotherms at 77 K measured on a 50 mg sample of Na-X zeolite, at pressures up to 150 bar.