Desorption of high-molecular n-paraffins from CaA zeolite beds

Summary

• 1. The desorption of n-dodecane and n-pentadecane in the liquid phase from CaA beds was studied with n-paraffin eluants of various molecular weights (n-hexane, n-octane, n-decane). A high zeolite operating capacity for n-paraffin (8–9 wt.%) is achieved with any of the eluants studied. The molecular weight of the n-paraffin eluant has a marked influence on its consumption in the desorption process. Identical eluant effect is obtained in the desorption when 2.5 times more hexane than n-decane is used.

• 2. It was found that the eluant quality has a marked effect on the desorption characteristics of high-molecular n-paraffins. The presence of polar oxygen-containing impurities in the eluant decreases the zeolite operating capacity for n-dodecane (by 30%) with a simultaneous increase in eluant consumption (of 10–20%).

• 3. It was found that the optimum size of the CaA zeolite particles is 0.2–0.4 mm for liquid phase separation of high-molecular n-paraffins. An increase in the zeolite particle size to 0.4–1.0 mm leads to a marked decrease in its operating capacity for n-pentadecane (to 30%) even when the amount of eluant for the desorption is increased.