Sorption of C6 alkanes in aluminophosphate molecular sieve, AlPO4-5

Sorption of C-6 alkanes viz., n-hexane, 2-methylpentane, 2,2-dimethyl butane, 2,3-dimethyl butane, cyclohexane and methyl cyclopentane in AlPO4-5 is studied and sorption capacity and thermodynamic parameters (Delta H-0, Delta H, Delta G, Delta S and S-a) at various sorption coverage for these sorbates have been estimated. The initial heat of sorption (Delta H-0) is found to increase with the degree of branching in the alkane chain. The sorbate-sorbate interactions are found to be more prominent during the sorption of doubly branched alkanes and cyclic alkanes and a higher sorption capacity has been observed for cyclic alkanes. Based on the results obtained, a packing model has been proposed for various C-6 alkanes inside the AlPO4-5 channel.