Obtaining 2-octanol, 2-octanone, and sebacic acid from castor oil by microwave-induced alkali fusion

Abstract

In this study, the effect of microwave irradiation on alkali fusion of castor oil was investigated using different NaOH/oil ratios (8:15, 12:15, and 14:15), reaction temperatures (473, 493, 503, 513, and 523 K), and reaction times (15, 20, 25, and 30 min) in order to obtain oleochemicals (2-octanol, 2-octanone, and sebacic acid) in the presence of 1% catalyst (Pb3O4) by weight (w/w). The yields of 2-octanol (4.4-62.6%), 2-octanone (1.6-37.4%), and sebacic acid (9.1-76.2%) were obtained according to reaction conditions. Maximum yields of oleochemicals were obtained using methylated then presaponified castor oil (sodium ricinoleate), 14/15 NaOH/oil ratio at temperature 513 K and 20 min reaction time. 2-Octanol, 2-octanone, and sebacic acid were determined by GC and GC/MS analysis, and purity of sebacic acid (98.7%) was further assessed by its acid value (444) and melting point (406.5 K). Reaction time compared to conventional heating was dramatically decreased by microwave heating system from 5 h reaction time to 20 min.