Study On Hydrodeoxygenation Performance Of MoNi/USY Catalysts

The technique key to the production of second generation biodiesel from animal and vegetable fats hydrodeoxygenation?HDO?is the development of suitable catalysts.Most of the supported hydrodeoxygenation catalysts have the disadvantages of low hydrodeoxygenation activity and poor hydrothermal stability.Therefore,the development of hydrodeoxygenation catalyst with high activity and good hydrothermal stability has become the focus of biodiesel research.Microporous USY molecular sieves has a large specific surface area and good hydrothermal stability,and are widely used in reactions such as catalytic cracking and alkane isomerization.However,if USY are used for the support of hydrodeoxygenation catalyst for animal and vegetable fats,it has to be modified with alkali to introduce mesopores for it having suitable pore structure and acidity,thereby improving the catalytic activity of the catalysts.In this paper,USY were modified by treatment of inorganic base NaOH and organic base triethanolamine?TEA?,respectively,and using modified USY as the support MoNi/USY hydrodeoxygenation catalysts were prepared.The effects of modification conditions on the properties of USY and HDO Performance of MoNi/USY catalysts were investigated.The experimental results of the effects of modification conditions on HDO Performance of MoNi/USY catalysts indicated that the suitable conditions for NaOH modification of USY were as follows,NaOH concentration 0.1mol/L,treatment time 2h,treatment temperature 85?;the suitable conditions of TEA modification of USY were as follows,TEA concentration 0.2mol/L,treatment time 3h,treatment temperature 75?.The results of the supports characterized by XRD,N₂ adsorption-desorption,NH₃-TPD,Py-IR indicated that alkali modification changed USY pore structure and acid properties,and in comparison with the USY modified by NaOH,USY modified by TEA had bigger pore diameter,more B acid and L acid content.Using the modified USY as the support for the hydrodeoxygenation catalyst for jatropha curcas oil,the TEA modification of USY was better than the NaOH modification of USY.After hydrothermal treatment,MoNi/USY catalyst exhibied a high hydrodeoxygenation activity,indicating that the catalyst has high hydrothermal stability.Using the USY modified with TEA as the support,suitable active component loading and Mo/Ni molar ratio were 35%and n?Mo?/n?Ni?=0.4,respectively.The experimental results of the effects of promoters on HDO Performance of MoNi/USY catalysts indicated that the hydrodeoxygenation activity of the catalysts was improved significantly by the15%citric acid?CA?addition?CA mass/support mass?.The results of XRD and NH₃-TPD showed that the CA addition enhanced the active components dispersion and changed the acidity of the catalysts.The addition of P was no improvement to the hydrodeoxygenation activity of the catalysts.