Cashew nutshell liquid (CNSL) is extracted from cashew nutshells using a cold maceration method. The cashew nuts were rinsed with water to remove any sand or debris, and then left to air-dry. The nuts were peeled, chopped lengthwise, and macerated. The specific procedure is as follows: 350 g of ground or macerated cashew nutshells were steeped in 2 litres of hexane at room temperature. The mixture was left to stand for 72 hours, with occasional stirring to enhance solvent penetration. After maceration, the extract was filtered, and a rotary evaporator was used to vacuum-separate the solvent from the extracted natural cashew nutshell liquid (nCNSL)[2].
Cashew nut shell liquid (CNSL) is a dark brown viscous liquid found within the soft honeycomb structure of the cashew nut shell and is a very important agricultural by-product of cashew production by the cashew tree (Anacardium occidentale). CNSL is the pericarp liquid of the cashew nut. Natural CNSL is a mixture of phenolic compounds with aliphatic side chains, consisting of 70% stearic acid, 5% stearyl alcohol and 18% stearyl phenol.
Cashew nut shell liquid (CNSL) can be used as a biodiesel fuel. Studies have shown that thermally cracked cashew nut shell liquid (TC-CNSL) exhibits a longer ignition delay due to a reduction in physical delay and a lower cetane number, thereby resulting in a longer combustion duration. In addition, it serves as a sustainable raw material for the development of durable polymer materials and environmentally friendly surface coatings[2].
Extractives and their physically modified derivatives. Anacardium occidentale, Anacardiaceae.
Cashew nut shell liquid is obtained from the nut shell of Anacardium occidentale species and it belongs to the family Anacardiaceae. This species native to Brazil and the major producers are Vietnam, Nigeria and India. This liquid is the by-product of the cashew industry which is yellowish in colour. The chemical composi tion of Cashew nut shell liquid (CNSL) is mostly composed by anacardic acids, cardanoland cardol[1].
[1] P. Tamilselvan , S. R., N. Nallusamy. (2017). A comprehensive review on performance, combustion and emission characteristics of biodiesel fuelled diesel engines. Renewable and Sustainable Energy Reviews, 79, Pages 1134-1159. https://doi.org/
10.1016/j.rser.2017.05.176[2] Sampson Kofi Kyei. (2026). Cashew nutshell liquid derivatives as a sustainable route to alkyd-free surface coatings. Scientific Reports, 16 1, 6463. https://doi.org/
10.1038/s41598-026-35993-6
