<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Process optimization of sandalwood (<i style="mso-bidi-font-style:normal">Santalum album</i>) oil extraction by subcritical carbon dioxide and conventional techniques</span>

Abstract

Sandalwood oil has been extracted using subcritical state carbon dioxide (SC-CO₂) at 200 bars and 28^oC using the two experimental conditions, and the fractionation of the extract is analyzed intermittently. Comparative studies with regards to extraction using steam distillation, hydro distillation, soxhlet extraction and pre-treatment studies have also been carried out. All these studies reveal that the subcritical carbon dioxide extraction is much more efficient in terms of physical properties of the oil as compared to commercial sandalwood oil. Acid value of the liquid CO₂ extracted oil is found to be the best next to the value of ethyl alcohol extracted oil. SC-CO₂ yields 4.11% of oil in the first hour, 1.21% in second hour, 0.89% in third hour and 0.30% finally in the fourth hour. The first hour gives α-santalene (0.55%), β-santalene (1.30%), α-santalol (51.30%), β-santalene (27.94%); second hour gives 0.48, 1.08, 54.50, 28.16% third and fourth hour give 1.00, 1.92, 50.27, 26.18% and 1.14, 2.17, 51.99, 26.76% respectively. Benzene extraction yields 3.01% of an absolute out of 6.30 g of concrete, diethyl ether yields 2.58% of an absolute out of 5.25 g of concrete, EtOH yields 3.70% of an absolute out of 10.90 g of concrete (under the 5 hour of process time). Hydro distillation (alkaline treated) yields 2.68% of sandalwood oil in 48 h, steam distillation gives 1.60% of sandalwood oil in 10 h of process time. Yield of 4.11% is obtained by SC-CO₂ only.