We have all heard about Cashew nuts and how delicious and crunchy they are. But did you know that the shell of Cashew nuts contains a liquid? No? well here is what you need to know about the Cashew Nut Shell Liquid (CNSL) in a nutshell.
CNSL is a versatile byproduct of the Cashew Nut. The nutshell of Cashews contains a thick honeycomb composition containing a dark reddish coloured liquid.
CNSL is a thick and caustic substance which has a similar quality and heat content to Light Fuel Oil. It is used as a biomass fuel for clean power generation.
There is a growing demand for CNSL due to its innumerable uses (including for: paints and varnishes, laminating resins and intermediates for the chemical industry).
USES OF CASHEW NUT SHELL LIQUID (CNSL)
MEDICAL APPLICATIONS
It has been used in traditional medicine to heal wounds and treat conditions such as ulcers and tooth abscesses, also as anesthetic for conditions such as leprosy and psoriasis.
The antibacterial activity of CNSL has been attributed to it containing Anacardic acid and Cardol which were reported to have anti-tumor and anti-microbial activities.
Gram-positive bacteria which causes tooth decay, acne, tuberculosis and leprosy are killed by Anacardic chemicals. These acids have been used effectively against tooth abscesses. The use of CNSL element in bacteriostatic antibiotics is just now gaining attention.
INDUSTRIAL APPLICATIONS
The industrial applications of CNSL-based products are numerous and include fungicides, pesticides, insecticides, brake linings, paints & primers, foundry chemicals, lacquers, cements, specialty coatings and resin. CNSL/cardol-based surface coatings have superb gloss and surface finish with a high level of durability and elasticity.
CNSL AS A FUEL
CNSL is also useful in fuel blends and fuel mixtures and for producing diesel oil. Cracking on CNSL with a molecular sieve at 500 degrees Celsius for 2hours generates brown colored liquid product which is diesel fuel. A study showed that CNSL can be used as an alternative fuel for diesel engine. Although CNSL has a higher density than diesel, it can be reduced by degumming and trans-esterification.
CNSL AS A BIO ADDITIVE
CNSL in engines increases the durability of the equipment, they improve flexibility and reduce brittleness, hence the application of CNSL as a bio additive will reduce the dependency on Petroleum Products besides preserving the environment by lowering pollutant residues from fuel combustion products.
OTHER POSSIBLE USES
CNSL effect on plant growth, acid activity, wood preservatives is also currently being studied.
In Summary, the Cashew Nut Shell Liquid (CNSL) is a good and promising chemical with a wide variety of different uses. A country like Nigeria where Cashews are grown almost everywhere will stand to benefit significantly. It also has the added advantage of being Environmentally friendly.