Abstract
The sorption isotherms of xylenes in CoAlPO
4-5 were measured by the gravimetric technique at 342
K. The isotherms of
para- and
meta-xylenes followed typical type-I and could be well fitted by the Langmuir model; while the isotherm of
ortho-xylene did not show a distinct saturation with the increase of pressure and could be then described by the Freundlich equation. In opposition to the adsorption in AlPO
4-5, the isotherms of
para- and
meta-xylene in CoAlPO
4-5 lay above that of
ortho-xylene. The free energy change (Δ
G) of adsorption increased with the loadings, while the diffusivities of xylenes decreased with the loadings. Moreover, the diffusivities of
ortho-xylene were slower than those of other two isomers.