Physicochemical Properties and Chemical Compositions of Cashew Nut Shell Liquid extracted with Carbon Dioxide–Expanded Hexane

Authors

• Neema Msuya, Department of Chemical and Process Engineering, University of Dar es Salaam, Dar es Salaam, TanzaniaFollow
• Joseph YN Philip, Department of Chemistry, University of Dar es Salaam, Dar es Salaam, TanzaniaFollow
• Frank Jacob, Department of Chemistry, University of Dar es Salaam, Dar es Salaam, TanzaniaFollow
• Kando K. Janga, Department of Chemical and Process Engineering, University of Dar es Salaam, Dar es Salaam, TanzaniaFollow

ORCID

0009-0004-3215-5127

Abstract

Cashew nut shell liquid (CNSL) is a mixture of phenolic compounds that can effectively replace commercially available phenols in various applications. This study investigated the physicochemical properties and chemical composition of CNSL extracted using CO₂–expanded hexane (CXH) and compared to the traditional Soxhlet extraction method. Steamed cashew nut shells (sCNS) were used in both cases.  The CXH was carried under varying CO₂-mole fractions (0.468-0.892) and temperatures (20-36 °C) whereas Soxhlet extraction was performed at atmospheric pressure and hexane boiling point. Response Surface Methodology (RSM) with Central Composite Face-Centred Design (CCFD) was employed to evaluate the effect of operating variables on the physicochemical properties of the extracted CNSL, namely gum content, wax content, Free Faty Acids (FFA), density and viscosity. The chemical compositions of the extracted CNSL were analysed using FTIR and GC–MS. Results showed that both physicochemical properties and chemical composition of the CNSL extracted by CXH were significantly affected by the operating conditions, except for FFAs, which remained unaffected by temperature.  The CNSL extracted with CXH exhibited superior properties compared to those extracted by Soxhlet. FTIR analysis confirmed the presence of phenolic compounds in the CNSL, while GC–MS analysis identified the chemical composition, which included 69.56% cardanol, 20.75% cardol, and 5.52% polymeric materials. These findings suggest that CXH yields CNSL with enhanced properties.

Recommended Citation

Msuya, N., Philip, J. Y., Jacob, F., & Janga, K. K. (2026). Physicochemical Properties and Chemical Compositions of Cashew Nut Shell Liquid extracted with Carbon Dioxide–Expanded Hexane. Tanzania Journal of Engineering and Technology (TJET), 45(1), 128-140. https://doi.org/https://doi.org/10.65085/2619-8789.1282

Publisher Name

University of Dar es Salaam