Recovery of Anacardic Acids from Cashew Nut Shell Liquid with Ion-Exchange Resins

Anacardic acids might have the potential for industrial and pharmaceutical applications, which could represent an important diversification option for the cashew industry. However, industrial separation processes for high-purity anacardic acids are challenging because of the presence of phenolic components (cardols and cardanols) with similar chemical behavior but lower market price. In this work, the feasibility and operating conditions for a method to separate anacardic acid by resin adsorption is proposed. An anion-exchange resin is employed to purify anacardic acids from cashew nut shell liquid (CNSL) alcoholic solutions. Anacardic acid quantification was performed by spectrophotometry, and the optimum operation conditions were determined by varying pH, temperature, and CNSL/resin ratios. Using the optimal conditions, a high-purity mixture of anacardic acids (>95%) was obtained.