Hydrogen Capacity and High Pressure Isotherms
Micromeritics Analytical Services now offers engineers, assistance by measuring a adsorption isotherms from 0.01 atm up to 10 atm. The typical report is a gas composition isotherm. The benefit of a high pressure adsorption isotherm is that it allows the researcher to quickly and inexpensively see how a material behaves when exposed to conditions close to reactor conditions. Typical Applications
The performance of the metal hydride is characterized by its hydrogen storage capacity (adsorption) and subsequent release (desorption) of hydrogen. The adsorption capacity of alkaline-exchanged zeolites is a key parameter for the design and optimization of pressure swing adsorption processes.
High Pressure Reactions
HPTPR – High pressure TPR to emulate a commercial activation of a supported metal catalyst Fuel cell applications that require reforming hydrocarbon feeds to hydrogen Hydrogen storage applications using mixed metal hydrides that change hydrogen capacity as temperature changes - the user can vary hydrogen pressure to determine storage capacity as a function of pressure. Simple chemical reactions where the product mix changes as a function of pressure - the AutoChem 2950 HP functions as a microreactor at typical process temperatures and pressures, allowing the user to collect reaction data at commercial conditions.
DVS - Dynamic Vapor Sorption
DVS is a gravimetric moisture sorption measurement technique to measure an adsorption isotherm of liquid vapors. The isotherms can be measured at temperatures from 5 to 60 ºC
Common Applications for DVS
• Studying hygroscopicity of powders, fibers, and solids
• Kinetics of water sorption and desorption
• Water and solvent-induced morphology changes
• Surface energies of powders
• Determination of amorphous content
• Studying hydrate/solvate formation
• Heats of sorption
• Diffusion coefficients and activation energies
IGC – Surface Energy
As the name suggests, IGC is the inverse of a conventional gas chromatograph. A cylindrical column is uniformly packed with the solid material of interest, typically a powder, fiber, or film. A pulse or constant concentration of gas is then injected down the column at a fixed carrier gas flow rate, and the time taken for the pulse of gas to elute is measured by a detector. A series of IGC measurements with different gas phase probe molecules then allows access to a wide range of physico-chemical properties of the solid sample. This technique is commonly used to calculate the surface energy of materials.
DSC - Differential Scanning Calorimetry
DSC measures temperatures and heat flows associated with thermal transitions in a material. Common usage includes investigation, selection, comparison and end-use performance evaluation of materials in research, quality control and production applications. Properties measured by TA Instruments’ DSC Differential Scanning Calorimeters techniques include glass transitions, "cold" crystallization, phase changes, melting, crystallization, product stability, cure / cure kinetics, and oxidative stability.
TGA - ThermoGravimetric Analysis
TGA measures weight changes in a material as a function of temperature (or time) under a controlled atmosphere. Its principal uses include measurement of a material's thermal stability and composition. Thermogravimetric Analysis instruments are routinely used in all phases of research, quality control and production operations.