Catalytic behaviour of mesoporous metal phosphates in the gas-phase glycerol transformation

Continuous Flow Upgrading of Selected C2-C6 Platform Chemicals Derived from Biomass

The ever increasing industrial production of commodity and specialty chemicals inexorably depletes the finite primary fossil resources available on Earth. The forecast of population growth over the next 3 decades is a very strong incentive for the identification of alternative primary resources other than petro-based ones. In contrast with fossil resources, renewable biomass is a virtually inexhaustible reservoir of chemical building blocks. Shifting the current industrial paradigm from almost exclusively petro-based resources to alternative bio-based raw materials requires more than vibrant political messages; it requires a profound revision of the concepts and technologies on which industrial chemical processes rely. Only a small fraction of molecules extracted from biomass bears significant chemical and commercial potentials to be considered as ubiquitous chemical platforms upon which a new, bio-based industry can thrive. Owing to its inherent assets in terms of unique process experience, scalability, and reduced environmental footprint, flow chemistry arguably has a major role to play in this context. This review covers a selection of C₂ to C₆ bio-based chemical platforms with existing commercial markets including polyols (ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, xylitol, and sorbitol), furanoids (furfural and 5-hydroxymethylfurfural) and carboxylic acids (lactic acid, succinic acid, fumaric acid, malic acid, itaconic acid, and levulinic acid). The aim of this review is to illustrate the various aspects of upgrading bio-based platform molecules toward commodity or specialty chemicals using new process concepts that fall under the umbrella of continuous flow technology and that could change the future perspectives of biorefineries.

VAlPOs as Efficient Catalysts for Glycerol Conversion to Methanol

The catalytic activity of a series of vanadium aluminophosphates catalysts prepared by sol-gel method followed by combustion of the obtained gel was evaluated in glycerol conversion towards methanol. The materials were characterized by several techniques such as X-ray diffraction (XRD), UV-vis, Fourier-transform infrared (FTIR), Raman and X-ray photoelectron (XPS) spectroscopies. The amount of vanadium incorporated in aluminophosphates framework played an important role in the catalytic activity, while in the products distribution the key role is played by the vanadium oxidation state on the surface. The sample that contains a large amount of V4+ has the highest selectivity towards methanol. On the sample with the lowest vanadium loading the oxidation path to dihydroxyacetone is predominant. The catalyst with higher content of tetrahedral isolated vanadium species, such V5APO, is less active in breaking the C–C bonds in the glycerol molecule than the one containing polymeric species.