Research at IISc: Shock waves to extract sandalwood oil
Sharath Ahuja, a Technical Officer at the Department of Instrumentation and Applied Physics at the Indian Institute of Science (IISc), talks about the cutting edge research being carried out at IISc.
At the Laboratory for Hypersonic and Shock Wave Research (LHSR), Aerospace Engineering Department - Indian Institute of Science (IISc), Bangalore, a team of scientists led by Prof G. Jagadeesh, in a joint collaborative research programme with A N Arunkumar, Y B Srinivasa, G Ravikumar and K H Shankaranarayana from the Institute of Wood Science and Technology (IWST), Bangalore, are looking at a new shock wave assisted sandalwood oil extraction technique.
Jagadeesh says, "shock waves have been historically associated with supersonic flight. However, in recent times utilizing the nearly instantaneous changes in fluid velocity and pressure produced by these waves, many innovative techniques have been developed, especially for bio-technology applications”. He adds, “There have been very few scientific reports on the possible use of shock waves in the area of wood science and more specifically for Sandalwood oil extraction, hence the need to carry out research in this area”.
The scientists have used Sandalwood samples obtained from the trees growing in the campus of the Institute of Wood Science and Technology, Bangalore and have subjected them to detailed laboratory scientific investigations. All experiments were carried out at the indigenously designed and fabricated – Diaphragm less Shock Tube at the Laboratory for Shock Wave Laboratory (LHSR) at IISc. Jagadeesh adds, “Initial results have been encouraging, the experimental data obtained, indicate that both the rate of extraction as well as the quantity of oil obtained from small quantity of sandalwood samples exposed to shock waves are higher (15-40 per cent) compared to steam distillation, the most commonly employed method for extraction of sandalwood oil, where yields are about 1.5 to 4.0 per cent.
“Scientific investigations, including the use of sophisticated analytical instrument and high power electron microscopy techniques indicate that, “the squeezing of the interior oil globules in the sandalwood specimen due to shock wave loading appears to be the main reason for the enhancement in the oil extraction process." He says. It must be mentioned that - Sandalwood - Santalum allbum L, is the species of sandalwood found abundantly in the southern part of the Indian peninsula, especially in the two states of Karnataka and Tamil Nadu. To extract oil from sandalwood, the cut wood, also known as heartwood, is used.
Heartwood from sandal trees upon distillation yields the oil that is characterized by a unique long lasting aroma, and as a result it is also used in the manufacture of a variety of perfumes, cosmetics, incense sticks and is also useful in the medical industry as an antiseptic, diuretic and for treating bronchitis. Sandalwood has been a part of the religious and spiritual traditions of India since prehistory and has been effectively used in traditional medicine for thousands of years. Sandalwood oil, is perhaps the costliest oil in the world and retails at about ` 2, 40,000 per liter.
In on-going research work, the scientists are trying to understand the basic micro scale dynamics of shock wave interaction with sandalwood. They are also working on the modification of the technique for commercial scale operation, for which a prototype reactor is being designed and fabricated at IISc.
Sharath Ahuja, joined IISc in 1980 and is a Technical Officer at the Department of Instrumentation and Applied Physics at the Indian Institute of Science (IISc), Bangalore. He con-currently holds the position as Coordinator, Archives and Publications Cell at IISc. He is a freelance writer on Science and Technology related subjects and an amateur photographer.
(This is an updated write up; it first appeared in a longer version in the Deccan Herald Student Edition – Bangalore).