Design of an acidic sulfonated mesoporous carbon catalyst for the synthesis of butyl levulinate from levulinic acid

Abstract

In this work, the ordered mesoporous carbon CMK‐8 which has some advantages, including large specific pore volume, high surface area, and also its tunable pore size, was synthesized, then functionalized with various sulfonic acid groups and utilized as a heterogeneous catalyst in the esterification reaction of levulinic acid (LA) into n‐butyl levulinate (BL). The prepared catalysts were characterized using Fourier transformed‐infrared spectroscopy, N2 adsorption–desorption, small‐angle X‐ray diffraction analysis, elemental analysis, transmission electron microscopy, field emission scanning electron microscope, thermal gravimetric analysis, energy dispersive X‐ray spectroscopy, and elemental mapping. The important parameters such as reaction temperature, reaction time, catalyst amount, and LA to n‐BuOH molar ratio were investigated by Taguchi experimental design. Maximum BL yield (75.1%) and LA conversion (95%) were obtained with CMK‐8‐SO3H catalyst under optimum reaction conditions: reaction temperature 130°C, reaction time 10 h, catalyst dosage 0.015 g, and LA to n‐BuOH molar ratio 1:10. Among the entire parameters, LA to n‐BuOH molar ratio followed by the reaction temperature, catalyst concentration, and reaction time have the most influence on BL yield. Finally, the regeneration and reusability of the CMK‐8‐SO3H catalyst were studied, and the recovered catalyst showed high stability and activity after four runs.

Efficient Utilization of Biomass Hydrolysis Residues in Preparing a Metal/Acid Bifunctional Catalyst for Butyl Levulinate Hydrogenation to γ-Valerolactone

“…The selectivity of GVL reached the maximum of 92.9% at 180 °C, but decreased gradually with an increase in the reaction temperature to 220 °C due to the further transformation of GVL to some byproducts . Moreover, BL conversion was also decreased, which might be caused by the esterification between butanol and levulinic acid . It is well known that there is much more dissolved hydrogen in the reaction solvent at higher hydrogen pressure, which is beneficial for the conversion of BL .…”

“…50 Moreover, BL conversion was also decreased, which might be caused by the esterification between butanol and levulinic acid. 51 It is well known that there is much more dissolved hydrogen in the reaction solvent at higher hydrogen pressure, which is beneficial for the conversion of BL. 52 Therefore, the initial hydrogen pressure from 0.5 to 5.0 MPa was then investigated over the 20Sn1RuB/CBSA-SB catalyst at 180 °C.…”

Catalytic Esterification of Levulinic Acid into the Biofuel n-Butyl Levulinate over Nanosized TiO2 Particles

“…Hence, the development of green and environmentally friendly, benign heterogeneous catalysts for the synthesis of LEs from LA would be highly desirable and required [ 26 , 27 ]. Recently, various heterogeneous catalysts including zirconium phosphate [ 28 ], sulfonated mesoporous carbon [ 29 ], methane sulfonic acid [ 30 ], ion-exchange resins [ 31 ], sulfonic acid-functionalized materials [ 32 , 33 , 34 ], heteropolyacids [ 35 , 36 , 37 ], and biocatalysts [ 38 , 39 ] have been employed to catalytic LA to produce LEs. However, some heterogeneous catalysts often suffer from the complex catalyst preparation process, the severe leaching of catalytic active species, and an unstable catalyst structure during the esterification reaction process, which limits their use in practical applications.…”