What Is Citronella Oil?

Citronella oil is also known as vanilla oil or osmanthus oil. From the whole grass of lemongrass by steam distillation. Light yellow liquid. Has a strong aroma of pepper. The main ingredients are citronellal, geraniol and citronellol. Used to extract citronellal for synthesis of hydroxycitronellal, geraniol and menthol. It can also be used as insecticide, mosquito repellent and soap perfume.

Chinese name: Citronella oil
Foreign name: citronellol

Chinese alias: Vanilla oil; citronellol
Molecular formula: C10H20O

Lemongrass Rape Product Features

Citronella Basic Information

Chinese name lemongrass oil

CAS NO. 106-22-9

Chinese alias vanilla oil; citronellol

English name citronellol

English alias dl-citronellol; 3,7-Dimethyl-6-octen-1-ol; 2,3-Dihydrogeraniol

EINECS 203-375-0

Molecular formula C10H20O

Molecular weight: 156.27

Citronella Safety Terms

S24 / 25Avoid contact with skin and eyes.

Avoid contact with skin and eyes.

Citronella risk terminology

R36 / 37 / 38Irritating to eyes, respiratory system and skin.

Irritation of eyes, respiratory system and skin.

Citronella oil properties

Citronella oil is a pale yellow to pale brown yellow clear liquid. The relative density of Java citronella oil is 0.880 ~ 0.895 and the refractive index is 1.466 ~ 1.473; the relative density of Sri Lanka citronella oil is 0.894 ~ 0.910 and the refractive index is 1.479 ~ 1.487. The main ingredients are citronellal, geraniol, citronellol, citral, and citronellene. Has a strong grassy aroma.

Citronella oil production method

It is obtained by steam distillation of the semi-dry whole grass of lemongrass, and the oil yield is 1.2 ~ 1.4% ^[1] .

Citronella oil application and recommended dosage

Mainly used for daily chemicals, such as soap, dishwashing liquid, mosquito repellent, according to the needs of different additions, the general amount is 0.5 to 4%.

It is mainly used to separate citronellal and geraniol to further synthesize citronellol, hydroxycitronellol, roseol, menthol and other important spices; it can also be used in a small amount to prepare edible essence ^[1] .

Citronella oil practice

Citronella vapor pressure

Citronella products (17 photos)

Temperature is an important factor governing the penetration rate of citronella oil. Increasing the steam pressure and the steam temperature correspondingly can accelerate the distillation speed and shorten the distillation time. According to tests, a small steam distillation plant with a boiler volume of about 2.5 cubic meters and a steam pressure of up to about 3.5 to 4 kg / cm2, when the top pressure of the steamed mash is 1 kg / cm2, its oil yield is 1.3 kg / With a height of 0.06% per square centimeter and 0.05% higher aldehyde content, there is not much difference in distillation time. Therefore, it is necessary to proceed from the safety of production, and it is advisable to use a top pressure of 1 kg / cm2. Regardless of water distillation or steam distillation, the air pressure must be kept stable. The high or low air pressure will reduce the oil yield. Therefore, the distillate firepower on water must be kept fierce, but it must not be too small. For steam distillation, the inlet steam must be from small to large to make the steam pressure rise smoothly.

Citronella oil steam volume

During the distillation process of citronella, the citronella oil exposed on the leaf surface is taken away by water vapor. Therefore, during the distillation process, a certain amount of steam is required. Reasonable units of steam production can be determined by themselves. It is necessary to shorten the distillation time and increase the oil output rate, and also to use steam economically in order to improve the equipment utilization capacity and reduce fuel consumption.

Citronella oil condensation

That is, the high-temperature oil-water mixed steam becomes a low-temperature oil-water mixture through the cooling effect of the condenser tube. The condensed oil-water mixture should be at 30-35 ° C. If it is above 60 ° C, the oil content will partially evaporate, especially vanillin. The condensate pipe should be placed straight in the center of the ditch. The flow direction of the mixed liquid is opposite to the flow direction of the cooling water. At the same time, the condensate tube cannot be buried in the mud of the ditch. . The condensate from the condenser tube must enter the oil-water separator to separate citronella oil from water.

Citronella oil benefits

Save fuel

Production units that use water distillation throughout China have accumulated rich experience in saving fuel. In the lemongrass processing plants in Zhanjiang and Hainan, Guangdong, most of them use citronella slag as a processing fuel. The quality of the citronella slag has a great impact on shortening the distillation time and improving oil yield. The citronella residue dried on the same day can shorten the distillation time by 20 to 30 minutes and increase the oil yield by 0.02 to 0.28%.

Citronella oil varieties

There are two main types of citronella oil used for spices: Javanese and Sri Lanka. The main components of both are citronellal, citronellol and geraniol, and the acetates of these two alcohols. Javanese species have relatively high aldehyde content and total alcohol content, so the planting volume is also large. China is currently a big country for the cultivation, export and consumption of Javan citronella oil. Indonesia and Vietnam also have large production, but not much consumption.

Citronella oil nutritional value

Citronella oil can directly extract citronellal, citronellol and geraniol. It is also the main natural source of these three spices. Generally Javan citronella oil contains citronellal 35-40%, citronellol 20-25%, geraniol 15-20%, citronella acetate and geranyl acetate about 5%. Because the boiling points of citronellol and geraniol are close, and they are both rose aromas, natural citronellol always contains a lot of geraniol, and natural geraniol always carries more Citronellol. Some people directly use rectification to extract the remaining part of citronellal and sell it as "crude rose alcohol", which can be used to formulate some low-end daily flavors, especially incense flavors.

Citronellol can be obtained by reducing citronellal. Many perfume plants use citronella oil as a raw material to reduce citronellal in the "high-pressure hydrogenation method". Due to the "high-pressure hydrogenation method", a small amount of tetrahydro fragrance is inevitable Folyl alcohol makes the product aroma poor. Researchers at Xiamen Mudan Xianghua Industrial Co., Ltd. have found a new reducing agent a few years ago. This reducing agent can specifically reduce the "aldehyde group" of citronellal, like a missile, without interacting with other double bonds. The product obtained from the reduction of citronella oil in this way (also known as "rose alcohol") does not contain tetrahydrogeraniol, has a sweet aroma and is full of natural rose fragrance. It can be directly used to prepare various daily fragrances ( Instead of expensive rose oil), it can also be used to extract citronellol and geraniol of excellent quality.