Cashew Nut Shell Oil — A Renewable and Reliable Petrochemical Feedstock

Abstract

This study evaluates the occurrence of cashew plant, extraction processes and composition of cashew nut shell liquid (CNSL), modification and conversion processes, as well as environmental impact and controls of the liquid as petrochemical feedstock. The goal of this study is to bring the alternative usage of CNSL to the limelight and to mitigate the serious problems posed by the depleting petroleum reserves. Cashew nut shell (CNS) was obtained fresh from the wild, pulverized and then extracted by pyrolysis and solvent extraction methods using n-hexane. The liquid obtained was characterized. Experimental results corroborated the fact that CNSL contains mainly phenolic compounds such as cardanol, cardol, anacardic acid and 6methyl cardol. CNSL obtained by pyrolysis has a higher density with less moisture content, while solvent-extracted CNSL had higher contents of cardol and anacardic acid. CNSL offers innumerable applications due to the phenolic nature of its constituents, with enshrined features for transformation into high-value specialty chemicals. Varied CNSL composition with varying extraction processes are a vantage opportu‐ nity with multiple application potentials as a valuable petrochemical feedstock.