Analysis of the Thermophysical Properties of Nigerian Agricultural Biomass for Thermochemical Conversion

Thermochemical conversion of agricultural biomass through combustion, pyrolysis, and gasification offers a pathway for clean energy generation and biochar production from Nigeria's substantial agricultural waste streams. Accurate thermophysical property data are essential for thermochemical reactor design and process modelling. This study measures and analyses the thermophysical properties of five agricultural biomass feedstocks abundantly available in Nigeria: rice husk (Ebonyi State), sugarcane bagasse (Adamawa State), groundnut shells (Kano State), cassava peel (Oyo State), and palm kernel shells (Edo State). Proximate and ultimate analyses, higher heating value by bomb calorimetry, specific heat capacity by DSC, thermal conductivity by hot wire method, and thermogravimetric decomposition kinetics under nitrogen and air atmospheres are determined. Results indicate higher heating values ranging from 14.2 MJ per kilogram for rice husk to 19.1 MJ per kilogram for palm kernel shells. Thermogravimetric kinetic analysis using the Kissinger method yields activation energies of 98 to 178 kJ per mole for the devolatilisation stage. Rice husk exhibits anomalously high ash content of 17.8 percent due to silica, requiring ash management in gasification applications. The comprehensive thermophysical dataset enables reactor design for Nigeria's emerging biomass energy sector. Keywords: biomass, thermophysical properties, thermogravimetry, pyrolysis, agricultural waste