Cardanol Processing


cardanol distillation

Cardnol is distilled from Cashew Nut Shell Liquid. A batch of Decarboxylated CNSL is heated to 280degree celcius under Vaccum in a reactor. After few minutes of heating the vapours of Cardanol come into the condenser where it is cooled using suitable coolant to convert the vapour into liquid.

The liquid is collected into a reciever. The process runs for a fixed time after which the receivers and reactors are emptied and fresh batch is started. The Cardanol is filled in tanks or barrels and Residol in barrels after few minutes of cooling.

Samples are drawn for preliminary testing of Colour, Viscosity and pH.

Cashew nut shell liquid from different sources is purchased and stored separately for distillation.

Cashew nut shell liquid is measured using a batch tank and taken into reactor where it is distilled under vacuum at 280 degree celcius.

After the stipulated batch time , Cardanol (Grade 2) is drained from the receiver and stored in vacuum tanks or packed in drums as required . Residol is drained from the reactor into a cooling tank and stored in MS drums .

Some customers prefer double distilled cardanol also known as Grade 1 Cardanol. This is manufatured by re distilling the Cardanol at low temperature under vacuum. The distillate is almost colourless liquid and has application is many products like PU resins etc.

Residol is a thick viscous liquid formed due to polymerisation on non Cardanol components in Cashew Nut Shell Liquid . Residol in cold conditions is highly viscous and often during winters requires external heating of drums to discharge the residol. To avoid this few manufacturers prefer residol to be diluted with cashew nut shell liquid . Depending upon the viscosity requirement of customers , appropriate amount of CNSL is added.