A comprehensive investigation of thermal coke formation during rapid non-catalytic pyrolysis of rubber seed oil

Abstract

Due to coking deposits, catalyst deactivation severely affects the upgrading of triglyceride biomass. Understanding the chemical nature and development of coke species is essential for mitigating the degree of coking and for the regeneration process of the catalysts. In this study, SEM, XRD, FT-IR, Raman and XPS are employed to gain insights into the coking behavior of RSO during the rapid pyrolysis process. The results show that pyrolysis of RSO produces high quality syngas with 98.72 % H2 and CO. The unstable O-containing functional groups in the cokes continue to be lost, which indirectly promotes the condensation reaction of aromatic hydrocarbons. The hydroxyl group is the main functional group that affects the reactivity of cokes, and it is one of its more active groups. Although the crystal size of the cokes is growing, its degree of graphitization is decreasing with the temperature increases. The size of the aromatic ring system in the cokes gradually increases with increasing temperature. The cross-linking structure in the coke is constantly being destroyed. Resulting in some O-containing functional groups entering the cokes. Based on this work, the coke evolutionary route of rapid pyrolysis of RSO is proposed.