Solvent‐Free Hydrogenation of Squalene Using Parts per Million Levels of Palladium Supported on Carbon Nanotubes: Shift from Batch Reactor to Continuous‐Flow System. Issue 19 (25th August 2022)

• Record Type: Journal Article
• Authors: Guicheret, Boris; Vanoye, Laurent; Rivera‐Cárcamo, Camila; de Bellefon, Claude; Serp, Philippe; Philippe, Régis; Favre‐Réguillon, Alain
• Is Part Of: ChemSusChem. Volume 15:Issue 19(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-25
• Subjects: heterogeneous catalysis -- hydrogenation -- nanotubes -- palladium -- terpenoids; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202200916
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: The transition from batch catalytic processes to continuous flow processes requires highly active and stable catalysts that still need to be developed. The preparation and characterization of catalysts where palladium single atoms and nanoparticles are simultaneously present on carbon nanotubes were recently reported by us. These catalysts are considerably more active than commercial or previously described catalysts for the liquid phase hydrogenation of terpenes. Herein is shown that under solvent‐free conditions, squalene (SQE) could be converted into squalane (SQA, >98 %) using only 300 ppm of Pd in less than 1.4 h at 20 bar H2 and 120 °C. Catalyst stability was assessed in a lab‐scale flow reactor, and long‐term experiments led to turnover number (TON) higher than 300000 without any detectable loss in the activity. Then, the implementation of this catalyst in a commercial intensified continuous‐flow milli‐reactor pilot was achieved. High purity SQA (>98 %) could be obtained by continuous hydrogenation of solvent‐free SQE at 180 °C and 30 bar H2 with a contact time below 15 min. A production capacity of 3.6 kg per day of SQA could be obtained with an effective reactor volume ( V R ) of 43.2 mL for this complex 3 phase reaction. Large‐scale production can now be foreseen thanks to seamless scale‐up provided by the continuous flow pilot supplier. Abstract : Less but more : Solvent‐free total hydrogenation of highly unsaturated squalene into squalane is achieved in batch in less than 2 h using Pd‐supported catalyst on carbon nanotubes bearing both Pd nanoparticles and Pd single atoms at 20 bar H2 and 120 °C using 300 ppm Pd. Implementation of this catalyst in a commercial continuous flow pilot was successfully achieved, and a turnover number higher than 300000 was demonstrated.