KINETIC MODELING OF PHENOL ACYLATION WITH ACETIC-ACID ON HZSM5

We have developed a kinetic model that quantitatively describes the fo rmation of the main products of phenol acylation with acetic acid (AA) on HZSM5 at 280 degrees C, namely, phenylacetate (PA), o- and p-hydro xyacetophenones (o-HAP and p-HAP, respectively), p-acetoxyacetophenone (p-AXAP), and water. Analyses of the experimental data and kinetic mo deling results lead to the following conclusions. Formation of PA occu rs rapidly via O-acylation of phenol with acetic acid. o-HAP is produc ed via C-acylation of phenol with AA and PA. The latter reaction is re sponsible for the formation of about 90% of o-HAP. A part of p-HAP is produced via acylation of phenol with PA, the other one through hydrol ysis of p-AXAP resulting from the autoacylation of PA. Kinetic modelin g of phenol acylation with acetic acid shows that the maximum possible selectivity and yield of the desired product (o-HAP) can be obtained with P + AA mixtures with a low P/AA ratio.