APPLICATION OF A DROPLET COLUMN TYPE 2-PHASE REACTOR FOR THE EPOXIDATION OF CYCLOOCTENE IN WATER AS AN ALTERNATIVE SOLVENT

Droplet columns are used for their ability to greatly enhance liquid-l iquid interfacial areas. The use of a droplet column for the two-phase epoxidation of cyclooctene by oxone in aqueous solution was studied a s an application of pollution prevention, i.e., the replacement of haz ardous solvents with water. The dispersion of alkene droplets in aqueo us oxone solution was generated by pumping the organic phase through a sparger at the bottom of the column. Then, organic droplets rise to t he top of the aqueous phase. As the alkene droplets rise, they are oxi dized by the oxone solution to form epoxide. The study of aqueous epox idation in a droplet column shows that the epoxidation of alkenes can be represented as a first-order reaction in alkene and a first-order r eaction in oxone under mass transfer limiting conditions. By recycling the cyclooctene, over 60% yield of cyclooctene epoxide can be achieve d in 3 h. However, due to epoxide crystals formation, a second reactor is needed to remove the solid and to bring the yield up to 80%. we fo und that a stirred tank reactor, which avoids the need to put the crys tallized mixture through the small holes of a sparger, performed well in this application as a second reactor.