A Chemical and Thermal Characterization Analysis of Coconut Shell Powder

The chemical characterization of Coconut Shell Powder (CSP) is analyzed with thermogravimetric analysis (TGA) and Fourier Transform Infrared (FTIR). TGA was performed as part of the thermal characterization to provide an understanding of the thermal stability and thermal degradation of CSP. The TGA performed was conducted under nitrogen with a sample weight of 20 mg and the % weight loss was reported from 50 °C to 650 °C at 10 °C/min according to the ASTM E1131. The TGA revealed that CSP was thermally stable up to 150 °C with a small mass loss of about 6.097% corresponding to the initial loss of moisture and volatiles. The larger mass loss of 75.369% occurred between 156.07 °C and 655.37 °C due to the degradation of hemicellulose, cellulose, and lignin where the final residue was 18.291% indicating a high char yield and thermal stability. The FTIR analysis was performed on the CSP in the wavenumber range of 4000-500 cm⁻¹ Biomass Characterization as per ASTM E1252 standard to determine important functional groups. The CSP displayed broad absorption bands defining O-H stretching (3297.73 cm⁻¹), C-H stretching (2918.39 cm⁻¹) and C=C stretching (1622.28 cm⁻¹) demonstrating oxyhydroxyl, aliphatic, and aromatic structures, respectively. The cellulose and hemicellulose structures corresponded to peaks located at 1424.289 cm⁻¹, 1253.354 cm⁻¹, and 1100.206 cm⁻¹. The peaks that were observed below 700 cm⁻¹ correspond to functional groups which would be representative of both aromatic and inorganic compounds. In conclusion, the results of TGA and FTIR support the CSP's thermal stability and organic complexity, adding further weight to the case for the CSP as a value-added, sustainable material.