Characterization of Cashew Nutshell Residue for Energy Application

Cashew nutshell residue constitute about 35-50 % of the total weight of the cashew fruit depending on the species. The nutshell is typically discarded through burning or left to decompose, leading to environmental pollution and wasted potential resources. This research aims to contribute to sustainable waste management practices, reduce environmental pollution from agricultural residues and explore new avenues for renewable energy sources and applications.

The CNS was collected from Global Confluence Nigeria Limited Odo-Omu, Area, Iseyin, Oyo State, Nigeria. The collected samples were manually decorticated, cleaned and sorted to separate immature shells, stalks, leaves and other impurities from the shells. Thereafter, the cleaned CNS was sun dried for 10 days to reduce the moisture content of the residues to safe storage level of about 10 – 12 % dry basis. The cleaned and sun dried CNS was also milled and sieved into 2 mm sample sizes for further studies. The ground sample was collected for characterization of their proximate compositions analysis of moisture content, volatile matter, ash content and fixed carbon content, ultimate compositions analysis of H, C, O, N and heating values and structural compositions of cellulose, hemi-cellulose and lignin contents following the American Standard for Testing and Material, ASTM E872-82 and ASTM D1102-84.34 standards.

The study revealed proximate, ultimate, energy and structural compositions of CNS. The moisture, ash, volatile matter, fixed carbon and dry matter contents for cashew nutshell were 11.12, 2.5, 65.23, 28.14 and 89.88 % while C, O, H, N, S and energy content were 45.13, 45.79, 5.12, 1.25, 0.20 % and 14.29 MJ/kg while structural composition was 14.78, 25.19 and 29.65 % for hemicellulose, lignin and cellulose, respectively. This study emphasizes the promise of CNS as a better feedstock for bioenergy production with environmental and economic benefits in terms of promoting sustainable waste management practices and explore new avenues for renewable energy applications.

Keywords: Cashew nutshell, proximate, ultimate, energy, structural compositions, ASTM standards.