Design of Nickel Supported on Water-Tolerant Nb2O5 Catalysts for the Hydrotreating of Lignin Streams Obtained from Lignin-First Biorefining

• Main Authors: Glauco F. Leal, Sérgio Lima, Inês Graça, Heloise Carrer, Dean H. Barrett, Erico Teixeira-Neto, Antonio Aprigio S. Curvelo, Cristiane B. Rodella, Roberto Rinaldi
• Format: Article
• Language: English
• Published: Elsevier 2019-05-01
• Series: iScience
• Online Access: http://www.sciencedirect.com/science/article/pii/S2589004219301440

Summary: In biomass conversion, Nb2O5 has attracted increasing attention as a catalyst support presenting water-tolerant Lewis acid sites. Herein, we address the design of Ni/Nb2O5 catalysts for hydrotreating of lignin to hydrocarbons. To optimize the balance between acidic and hydrogenating properties, the catalysts were first evaluated in the hydrotreating of diphenyl ether. The best catalyst candidate was further explored in the conversion of lignin oil obtained by catalytic upstream biorefining of poplar. As primary products, cycloalkanes were obtained, demonstrating the potential of Ni/Nb2O5 catalysts for the lignin-to-fuels route. However, the Lewis acidity of Nb2O5 also catalyzes coke formation via lignin species condensation. Thereby, an acidity threshold should be found so that dehydration reactions essential to the hydrotreatment are not affected, but the condensation of lignin species prevented. This article provides a critical “beginning-to-end” analysis of aspects crucial to the catalyst design to produce lignin biofuels. : Catalysis; Biofuel; Energy Materials Subject Areas: Catalysis, Biofuel, Energy Materials