Removal Of Impurities From Cyclohexanone With Zeolites

It is of great significance to effectively remove hexanal and2-heptanone in refining process of cyclohexanone. The removal of hexanal and2-heptanone was investigated using ZSM-5zeolites as adsorbent, and the desorption and regeneration of zeolites were also studied in this paper.In the research of removing impurities from cyclohexanone by different types of zeolites, it was found that the adsorption level of the impurities by H-zeolites was higher than that of Na-zeolites. As for the effects of SiO2/Al2O3ratio, adsorption time, temperature, and zeolite quantity to cyclohexanone volume ratio on the removal of hexanal and2-heptanone, it was shown that80H-zeolite could remove impurities in highest level after20h saturated adsorption although other H-zeolites (SiO2/Al2O3ratio ranging from25to360) have better removal ability. For80H zeolite, the removal ratio of hexanal and2-heptanone reached as high as9.52%and100%after20h adsorption in30℃in the condition of zeolite quantity to cyclohexanone volume ratio=0.08g/ml. The adsorption isotherms of hexanal and2-heptanone accorded with Langmuir and anti-Langmuir model, respectively.The desorption-regeneration of80H,360H and50Na zeolites were investigated using water and ethanol as desorption agents and calcining method. And the desorption results were characterized through the removal ratioes of impurities by regenerated zeolites. The results indicated that the three desorption methods had certain effects on regeneration of zeolites. The method of water desorption was best for the80H-zeolite, calcining method was more favorable to the360H-zeolite, and the removal ratio could reach80.75%and80.95%.This study provides a better experimental basis for the effective removal of the impurities in the refining process of cyclohexanone.