Biochar from Delonix regia pod: consideration of an updraft retort carbonisation process

Abstract

Retort carbonisation is a novel technology especially suited to the sub-Saharan Africa energy conversion challenges. This study aims to produce and characterise biochar from Delonix Regia pod (DRP) via the retort carbonisation process. The process achieved a Delonix Regia pod biochar (DRPB) yield of 29.48 wt% at a peak temperature of 375 °C and a process time of 150 min. The average pore volume, specific surface area, and average pore size of DRPB were 0.0352 cm3/g, 88.03 m2/g, and 1.6 nm, respectively. Morphological analysis revealed that DRPB had a heterogeneous surface morphology with an average roughness of 12.96 × 103 µm. Functional groups such as C-O, N-O, O-H, C = O, CO-O, and C-H are present in the biochar. DRPB compares well with other retort carbonisation biochar. Potential applications were also discussed based on the biochar properties and the product can be tested for water treatment applications and as an additive for improving the tribological and rheological properties of lubricating oils.