| This paper brings forward a systemic methodology which is at view of thermochemistry to evaluate the adsorption pairs. This methodology combines indexes including the adsorption amount, the desorption ratio, the heat of adsorption and the heat of desorption together, linked with thermal kinetics properties of adsorption pairs, to evaluate them.At temperatures of 30, 60, 90 and 120, this paper adopted static adsorption-metage method to measure the saturated adsoiption amount(SAA) of water on 3A, 4A, 5A and 13X zeolites. Based on the research, this paper considered that SAA has a maximum. In common, this maximum exits from 40 to 80, exactly near 60. This paper proved this opinion by Langmiur theory, and gave an adsorption equilibrium model for 13X zeolite.In the temperature ranged from 300 to 320, by means of vacuum-heat, this paper determined the desorption ratio of these zeolites. The results showed the desorption ratio was just related to the chemical properties and physical structures of the zeolites theirselves.By means of micro-calorimetry, the paper determined the heat of zeolite/water adsorption at 30, in the same way, the paper measured the heats of desorption at 30 60, 75 and 90. The results showed 4A, 5A and 13X zeolites' heat of adsorption and desorption changed in the same way, but 3 A is special, the heat of adsorption is highest while the heat of desorption is lowest.Based on the amount equilibrium properties and thermal equilibrium properties, the paper evaluated the four typer zeolites with a new index, i.e.the integrated property parameter, the results showed type 3A is the best.Thermal kinetics is used to analyze zeolite/water adsorption. A thermal kinetics model, Brounshtein-Ginsttling formula, which describes tri-dimension diffuseness, is selected from six models to calculate the thermal kinetics constant and the desorption activation energy.
|
PDF Full Text Request