Page 171 - Gas Adsorption Equilibria

3. Gravimetry 157

4. GRAVIMETRIC MEASUREMENT OF
MULTICOMPONENT GAS ADSORPTION
EQUILIBRIA (N>1)

4.1 Experimental

Coadsorption equilibria of gas mixtures of known initial concentrations on
porous sorbent materials can be measured fairly easily using a microbalance
combined with a gas chromatograph or mass spectrometer to analyze the
sorptive’s gas concentration at adsorption equilibrium. A schematic of such an
instrument is given in Figure 3.25. It basically consists of a microbalance, gas
supply system, a sample loop including a gas circulator to maintain equal and
constant sorptive gas concentrations within

Figure 3.25. Schematic of a gravimetric instrument to measure multicomponent gas
adsorption equilibria. Concentrations of the sorptive gas mixture supplied
are assumed to be known. After equilibration, concentrations of the sorptive
gas components are determined in a gas chromatograph or mass
spectrometer [3.16, 3.20, 3.41].