Green chemical production based on thermal cracking of inedible vegetable oil

This work evaluated the process for heptaldehyde, undecylenic acid, and methyl undecenoate production from castor oil, methyl ester of castor oil, and ricinoleic acid. Experiments were performed in a continuous pilot-plant scale pyrolysis reactor. Those are very important green chemical products that the thermal cracking of castor oil might produce. Transesterification of castor oil produces methyl ricinoleate, and its thermal cracking generates methyl undecenoate and heptaldehyde. The pyrolysis temperatures tested were 530 degrees C, 545 degrees C, 560 degrees C, and 575 degrees C, with residence time from 17 s to 32 s and mass flow at 400 g/h of the mixture of materials with 25% distilled water. It was observed that the temperature influenced the bio-oil yield in different degree for each material. The bio-oil was characterized by iodine index, acid number, and mass, and the contents of its compounds were obtained by GC-FID chromatography. The best result for the undecylenic acid mass yield of the desired compounds occurred at 530 degrees C, achieving 17.8% from ricinoleic acid and 16.5% from castor oil. For the heptaldehyde, the highest production was also obtained at 530 degrees C, with a value of 20.7% from methyl ester and 15.2% from ricinoleic acid.