Bioglycerol-to-Propylene Routes: From Fundamental Catalysis to Process Design and Marketing

Bioglycerol-to-propylene (GTP) routes are undergoing major developments in terms of both fundamental catalysis and process design on the way to becoming a connecting bridge between the biorefinery and polyolefin industries. This review starts introducing some GTP routes-related market potentialities and continues discussing significant mechanistic, kinetic, and engineering developments in GTP catalysis involving high-temperature, multistep, tandem, and single-step hydrodeoxygenation strategies. It highlights the main advances made in the design of efficient catalysts and in the elucidation of their active sites, thereby shedding light on state-of-the art preparation, functionalization, and characterization methods. The GTP mechanisms are also assessed over versatile metallic, acid, and bifunctional catalysts' surfaces to discover which C-O bond is removed and which C=C bond is formed. GTP configurations are discussed as a function of the thermodynamic and operating conditions affecting catalysts' reactivity, selectivity, and stability. They are also compared using various qualitative and quantitative criteria such as process configuration, severity of operating conditions, energy consumption, sustainability assessment, and propylene production. We thus intend to provide a broad overview of GTP catalysis for inducing new opportunities in the biorefinery-to-olefins field.