Enhancing bio-oil extraction using instant controlled pressure drop texturing.

Abstract

Abstract Instant controlled pressure drop technology (in French: Detente Instantanee Controlee or DIC) was used as a texturing or pretreatment process to intensify bio-oil extraction from oil containing seeds. Safflower and castor seeds were selected and the impact of the most important factors including steam pressure (1–3.5\xa0bar), heating time (20–120\xa0s), number of cycles (1–5) and mean particle diameter (1.0–4.0\xa0mm) was evaluated by applying response surface methodology (RSM). Optimum operating conditions were obtained as 2.4\xa0bar, 20\xa0s, 5 cycles and 1\xa0mm for safflower seeds; and 3.5\xa0bar, 20\xa0s and 1 cycle for castor seeds. Under optimized conditions, solvent extraction of DIC-treated samples showed improved mass transfer and the oil extraction yield were increased 70.43% and 14.15%; that is, from 17.52 and 43.24\xa0wt% to 29.86 and 49.36\xa0wt% for the untreated safflower and castor seeds, respectively. In both cases, the fatty acid profiles were not considerably affected by the texturing process. The morphological structures of the seeds were observed and compared by scanning electron microscopy (SEM). The SEM images revealed more porous structures which improved mass transfer within the plant matrix.