Turpentine valorization by its oxyfunctionalization to nopol through heterogeneous catalysis

Turpentine is a mixture of monoterpene hydrocarbons obtained as a by-product in the paper industry. In this contribution we present its transformation process towards an alcohol named nopol, that is an important household product and fragrance raw material. Reaction conditions were established for the oxyfuntionalization of crude turpentine oil over Sn-MCM-41 catalyst for the selective conversion of β-pinene to nopol. Synthesized materials were characterized by XRD, N(2) adsorption, FT-IR, TEM and chemical absorption. The reaction was tested in 2 mL glass reactor with a sample of commercial turpentine with α-pinene (55.5% w/w) and β-pinene (39.5% w/w) as main components and scaled up into a 100 mL Parr reactor, getting 92% conversion of β-pinene and a nopol selectivity of 93%. The reusability tests showed that the catalyst can be reused 4 times without loss of activity. The results showed that 86% less solvent and 37.5% less paraformaldehyde can be used with turpentine, compared to the conditions used with β-pinene for getting similar catalysts activity.