High Yield Synthesis of Green Pyrolytic Oil via Thermal Cracking of Ricinoleic Acid Methyl Ester

Castor oil has the potential to be a renewable resource for the synthesis of high‐value‐added chemicals. This work focuses on the thermal cracking of ricinoleic acid methyl esters (RAME), the major component of castor oil in a micro fixed bed reactor that was used to produce methyl undecenoate (MU) and heptaldehyde (HEP). MU and HEP have wide applications in polymers, cosmetics, and drug industries. The effect of flow rate, sweeping gas flow rate, preheating and reaction temperatures were examined briefly. Thermal cracking of RAME at a preheating temperature of 350 °C and reaction temperatures of 550 °C, produced high yields of MU and HEP at 46.7 and 27.3 wt.% respectively. The increase in sweep flow rate from 15 ml min⁻¹ to 25 ml min⁻¹ enhanced the production of pyrolytic oil yield to 92.6 wt.%. Density functional theory (DFT) was performed to examine the experimental results and distribution of the products involved in the dissociation of RAME. Assuming C−C bond scission followed by the cleavage of the OH bond, the reaction energy of MU and HEP thermal cracking is computed using DFT. This research may provide an alternative pathway to produce important chemicals from castor oil for upscaling and process development for the industry.