Sub-Product

Sulfides, nitrogenous materials, and minerals contained in the crude Cashew Nuts Shell Liquid (CNSL) directly affects the quality of the oil. Hence CNSL is often subjected to chemical treatment with materials such as hydrocarbon sulfates and sulfuric acid before industrial use. Several acid treatment processes have been found to reduce the poisoning or vesicant action. Aqueous solutions of acids such as hydrochloric acid, sulfuric acid, acetic acid, chloroacetic acid or phosphoric acid, or acid sulfates such as sodium hydrogen sulfate are employed for this purpose. This performs two important functions: mineral salts of ammonium, calcium, and potassium are precipitated and here is a reduction in the content of skin vesicant present in CNSL. The chemical treatment is accompanied by the evolution of hydrogen sulfide. The reduction in sulfur content has been found to correspond roughly to the removal of the agent responsible for the skin irritation. Treatment with amines or with hydroxides of the metals of