Abstract
Crude sulphate turpentine (CST), containing α-pinene, 3-carene, other terpene isomers, and organic sulphur compounds, was used as feedstock in the production of cymenes with commercial zeolite catalysts. The catalysts used were not sensitive to sulphur, and the desulphurisation step was not needed prior to cymene synthesis. The experiments were performed in a continuous fixed bed reactor. Promising results were obtained after initial optimization at temperatures close to 300 °C with faujasite Y zeolite under 5 bar N2 pressure. Cymenes were produced with 54% yields from model compound α-pinene and with 28% yields from CST. The mechanistic route of the reaction can be divided into three steps: (1) ring opening, (2) rearrangement, and (3) dehydrogenation. The final step in the formation of p-cymene can occur via dehydrogenation or disproportion; here the effect of reaction conditions and catalyst plays a crucial role.
Original language | English |
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Pages (from-to) | 1468-1475 |
Journal | Organic Process Research and Development |
Volume | 18 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2014 |
MoE publication type | A1 Journal article-refereed |
Keywords
- turpentine
- catalysts
- chemical reactors
- dehydrogenation
- isomers
- monoterpenes
- sulfur
- chemical synthesis
- commercial zeolite
- faujasites
- fixed bed reactor
- initial optimization
- model compound
- reaction conditions
- ring opening
- Y zeolites