p-Cym.ene production from orange peel oil using some metal catalyst in supercritical alcohols

Abstract

In this study, orange peel oil which had been produced by cold press technique was processed. The catalytic reaction of limonene composed of 90-95% of the orange peel oil carried out in different supercritical alcohols, and it was obtained the compound p-cymene mainly. The experiments processed in a packed bed reactor using Pt/Al2O3, Ni/AAl(2)O(3)and Pd/AAl(2)O(3) catalysts in over supercritical conditions of ethanol and 2-propanol. Experiments of reaction time, temperature and pressure scanning were carried out in the ranges of 10-50 s, 245-340 `'C and 6.5-12.5 MPa, respectively. It was observed that Ni/AAl(2)O(3) was ineffective to the conversion of limonene. However, when Pd/AAl(2)O(3) and Pt/AAl(2)O(3) catalysts were used, p-cymene was produced mainly. Especially, when Pd/AAl(2)O(3) catalyst was used, it was detected that limonene converted completely and obtained p-cymene in yield of 80%. Furthermore, p-cymene selectivity of Pd/AAl(2)O(3) was much better compared with Pt/ AAl(2)O(3).