Effects of Reaction Conditions on Synthesis of Butadiene from Formaldehyde and Propylene

This study investigated the effects of reaction conditions in a one-step gas-phase synthesis of butadiene from formaldehyde and propylene over a SiO2-supported silicotungstic heteropoly acid catalyst. The physicochemical properties of the catalyst were examined by X-ray fluorescence spectroscopy, low-temperature nitrogen adsorption, XRD, SEM, and NH3–TPD. It was found that, with increase in reaction temperature, the yield of butadiene passes through its maximum. Increasing the WHSV of the reactant feed lowers the formaldehyde conversion and enhances the butadiene selectivity. Raising the propylene to formaldehyde molar ratio increases the formaldehyde conversion, with the butadiene selectivity passing through its maximum. Finally, diluting the reactants with an inert gas barely affects the process performance.