Cashew is a great source of fiber and rich- fats. It is widely consumed in every household for good health, but do you know that it also consists of one such ingredient that is in high demand in industries? We are talking about Cardanol oil. It is a valuable bio-based compound that is extracted from the cashew nut shell liquid (CNSL) during the processing of the dry fruit. This oil is highly used as raw- material for the production of adhesives, coating, and plastics and is also a great substitute for petrochemical-based products. Now that you know its usage, let’s discuss the step-by-step guide to its extraction process.
What is Cashew Nut Shell Liquid? (CNSL)
It is a dark-colored, viscous liquid obtained from the outer shell of cashew nut. It consists of several compounds like anacardic acid, cardanol, and cardol. All these elements have distinctive chemical properties, cardanol in particular is highly heat resistant and it can withstand harsh environmental conditions. It makes cardanol oil one of the most demanded components in industries. It is an extensively used material for manufacturing a diverse range of products like paint, rubber, plastic, inks, and even cosmetics as there are several cardanol oil benefits for the skin.
How is Cardanol Oil Extracted?
Here is the step-by-step guide of how cardanol oil is extracted from cashew nut shell liquid (CNSL).
Obtaining CNSL:
The very first step towards extracting cardanol oil is obtaining CNSL. It begins with the harvesting of the cashew nuts. Once the nuts are processed and removed from their shell, the shell is cracked open, and the liquid typically consists of a mixture of various compounds including cardanol oil. Having said that, one should be very careful while handling CNSL because it is a very toxic component and can cause skin irritation.
Decarboxylation:
One of the major steps in separating cardanol oil from cashew nut shell liquid (CNSL) is the decarboxylation of anacardic acid. It is a major unstable compound and plays a key role in the creation of cardanol oil. In the decarboxylation process, the CNSL is heated at a high- temperature (around 200-300°C) in the presence of a catalyst, which removes the cardanol group from the anacardic acid, and the reaction leads to the creation of cardanol oil. However, this process can take up to hours and also the temperature and pressure should be carefully controlled to produce the highest yielding of cardanol oil.
Extraction:
The cardanol oil created during the process consists of several other compounds like cardol and unreacted anacardic acid. So, to achieve cardanol in its pure form, it is essential to remove it from other unwanted compounds. This process is called liquid-liquid extraction. During the process, a crude product is mixed with a solvent such as chloroform or hexane. This mixture is then placed in a separating funnel. When the solvents evaporate, cardanol oil is obtained.
Purification:
In the extraction process, cardanol is obtained with a lot of impurities like unreacted anacardic acid and even traces of cardol. So, to remove all the impurities and get the pure form of cardanol, the process of distillation and recrystallization is followed. In distillation, the oil is heated at various heating points based on the compounds in it. By carefully controlling the boiling point, pure cardanol can be achieved.
On the other hand, in recrystallization cardanol dissolvent a suitable solvent with the crude product so that the pure form of cardanol crystallizes out of the solution. These crystals can be then dried and filtered to obtain a high-quality & pure cardanol oil.
Final Words
The extraction of cardanol oil from cashew nut shell liquid (CNSL) is a multi-step process and requires hours of work. Having said that, it is a valuable product for various industries because of its properties and is used for creating quality materials. It plays a great role in sustainable manufacturing as it is created from the leftover shells of cashews. If you too want sustainable, eco-friendly, yet affordable manufacturing solutions then you should invest in ‘R K Agro Processing’ cardanol oil which is an ideal component for various industrial and commercial applications, be it cosmetics or automotives.
R.K. Agro Processing
R.K. Agro Processing uses a production and packing system that meets the required standards to ensure the freshness and deliciousness of the cashews. Our company makes sure to comply with the regulations to guarantee the quality of the cashews.
