Separation of m- and p-cresols in compressed propane using modified HZSM-5pellets

The separation of an equal amount of m- and p-cresol isomers on HZSM-5 pell ets using compressed propane as the carrier and as the desorbent was studie d. The pore-opening size of HZSM-5 pellets was modified by the chemical liq uid deposition technique. The water content in the original pellets and the concentration of the deposition agent, SiCl4, in cyclohexane were observed to have effects-on the adsorption capacity and p-cresol selectivity. For t he column separation using the modified HZSM-5 pellets, the effects of temp erature, pressure, and flow rate on separation effectiveness were examined. For an injection of 0.2 mi of cresol isomers and 20 g of the modified pell ets packed in a column, the most appropriate conditions were at a temperatu re of 373 K, a pressure of 3.45 MPa, and a flow rate of 2.0 mL/min. To shor ten the separation time, propane with a pressure higher than 3.45 MPa was s uggested to flow into. the column after m-cresol was completely removed fro m the column.