Selective Production of Acrylic Acid from Glycerol Through a Single-stage Gas Phase Catalytic Oxydehydration over Vanadium-incorporated Zeolite Beta Catalysts

The manufacture of acrylic acid from glycerol presents an intriguing alternative for this molecule, which has significant industrial importance. A surplus of glycerol was produced as waste during the transesterification process as a result of the increase in biodiesel production. The key difficulty is finding a catalyst that can catalyze a certain oxydehydration reaction to produce acrylic acid while maintaining an appropriate balance between acid and metal sites. For the conversion of glycerol to acrylic acid, metal loaded zeolites, heteropoly acids, metal oxides, and phosphates have all been successfully investigated. In a fixed bed reactor run between 280 and 360 degrees C, several vanadium (V) integrated zeolite beta (V-beta) catalysts with variable V loadings (0.6-5.0 wt%) were synthesized and tested for the gas-phase glycerol oxydehydration process. It has been demonstrated that vanadium is essential for transforming the intermediate acrolein molecule into acrylic acid. The V-2.5-beta catalyst had the best acrylic acid selectivity (39%) due to its adequate pore diameter (130 angstrom), and moderate acidity (1.13 mmol/g). Loss of accessible Bronsted acid sites and increased COx generation were linked to worse activity at greater V loading. The effects of feed glycerol-oxygen ratio and reaction temperature (280-360 degrees C) were satisfactorily proven. The glycerol conversion improved and the acrylic acid selectivity peaked at 340 degrees C. The alkaline treatment and small internal pore diameters to reduce the deposition of carbonaceous deposits made the V-2.5-beta catalyst an extremely active and selective catalyst for the reaction that also showed good stability over time. [GRAPHICS] .