Heptaldehyde and Undecylenic Acid from Ricinus Communis: Kinetics and Process Design

Ricinus communis is a non-food plant, one of the main products of the plant are the seeds from which castor oil is extracted. Castor oil pyrolysis produces heptaldehyde and undecylenic acid. A kinetic model of this reaction is not reported in the literature. The simulation and economic evaluation of this process are not possible without an appropriate kinetic and thermodynamic model. A pseudo-first-order kinetic model for the pyrolysis reaction was obtained in a semicontinuous reactor. Kinetic parameters were obtained at 2.67 kPa, the frequency factor of 19.2 s, and the activation energy of 54013.3 kJ/kmol. A conceptual design for the process was proposed. The process was simulated in Microsoft Excel® using add-ins developed for the authors. The main equipment was sized. Capital costs, operating costs and financial profitability were estimated. In accordance with an internal rate of return of 44%, the project proved attractive for the investors. Finally, the results indicated that the castor oil pyrolysis is feasible, thus the Ricinus communis crop could be valorized into high value-added products.