Sorption Equilibrium of Methanol on new composite sorbents «CaCl2/Silica Gel»

This paper presents experimental data on methanol sorption on new composite sorbents which consist of mesoporous silica gels and calcium chloride confined to their pores. Sorption isobars and XRD analysis showed the formation of a solid crystalline solvate CaCl2 center dot 2MeOH at low methanol uptake, while at higher uptake the formation of the CaCl2-methanol solution occurred. The solution confined to the silica pores showed the sorption properties similar to those of the CaCl2-methanol bulk solution. Calorimetric and isosteric analyses showed that the heat of methanol sorption depends on the methanol uptake, ranging from 38 +/- 2 kJ/mol for the solution to 81 +/- 4 kJ/mol for the solid crystalline phase CaCl2 center dot 2MeOH. The above mentioned characterizations allowed the evaluation of the methanol sorption and the energy storage capacities, clearly showing that the optimal applications of these new composite sorbents are the methanol removal from gaseous mixtures, heat storage and sorption cooling driven by low temperature heat.