Studies of physicochemical properties, kinetic behaviour, and thermal degradation profile of waste bio-crude derived from slow pyrolysis in a nitrogen atmosphere

The present study is focused on the physicochemical characterization and thermal degradation studies of waste bio-crude. The study of bio-crude kinetics was executed in a thermogravimetric analyzer (TGA), using Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Friedman (FM), Starink (ST), Cots-Redfern model (CR), and master plot method. Detailed characterization of the bio-crude was carried out by using elemental analysis, examining ash content, viscosity, cold properties, heating value, moisture content, FTIR, GC–MS, and acidity. The results of the physicochemical investigations of bio-crude revealed significant carbon content (67.70%), higher heating value (26.12 MJ kg⁻¹), lower moisture (0.09%), and ash content (1.57%). The kinetic results underscore multi-step reactions and apparent activation energy that increases with progressive conversion. FTIR study established the occurrence of water, alkenes, acids, aromatics, and oxygenated products, whereas the GC–MS study confirmed higher hydrocarbon (14.20%) and lower oxygenated product in BO-1 compared to BO-2.