Volume 12, Issue 14 p. 3343-3354
Full Paper

A Multiphase Protocol for Selective Hydrogenation and Reductive Amination of Levulinic Acid with Integrated Catalyst Recovery

Alessandro Bellè

Alessandro Bellè

Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino, 155, 30172 Venezia-Mestre, Italy

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Dr. Tommaso Tabanelli

Dr. Tommaso Tabanelli

Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale del Risorgimento, 4, 40136 Bologna, Italy

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Dr. Giulia Fiorani

Dr. Giulia Fiorani

Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino, 155, 30172 Venezia-Mestre, Italy

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Prof. Alvise Perosa

Prof. Alvise Perosa

Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino, 155, 30172 Venezia-Mestre, Italy

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Prof. Fabrizio Cavani

Prof. Fabrizio Cavani

Department of Industrial Chemistry “Toso Montanari”, University of Bologna, Viale del Risorgimento, 4, 40136 Bologna, Italy

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Prof. Maurizio Selva

Corresponding Author

Prof. Maurizio Selva

Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino, 155, 30172 Venezia-Mestre, Italy

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First published: 16 April 2019
Citations: 41

Graphical Abstract

It's a phase: Two reactions of levulinic acid (LA), hydrogenation and reductive amination with cyclohexylamine, are explored in a multiphase system. By tuning the relative volume of the immiscible water/hydrocarbon phases and the concentration of the aqueous solution, quantitative conversion of LA can be achieved with formation of γ-valerolactone (GVL) or N-(cyclohexylmethyl)pyrrolidone in >95 and 88 % selectivity, respectively.

Abstract

At 60–150 °C and 15–35 bar H2, two model reactions of levulinic acid (LA), hydrogenation and reductive amination with cyclohexylamine, were explored in a multiphase system composed of an aqueous solution of reactants, a hydrocarbon, and commercial 5 % Ru/C as a heterogeneous catalyst. By tuning the relative volume of the immiscible water/hydrocarbon phases and the concentration of the aqueous solution, a quantitative conversion of LA was achieved with formation of γ-valerolactone or N-(cyclohexylmethyl)pyrrolidone in >95 and 88 % selectivity, respectively. Additionally, the catalyst could be segregated in the hydrocarbon phase and recycled in an effective semi-continuous protocol. Under such conditions, formic acid additive affected the reactivity of LA through a competitive adsorption on the catalyst surface. This effect was crucial to improve selectivity for the reductive amination process. The comparison of 5 % Ru/C with a series of carbon supports demonstrated that the segregation phenomenon in the hydrocarbon phase, never previously reported, was pH-dependent and effective for samples displaying a moderate surface acidity.

Conflict of interest

The authors declare no conflict of interest.