초록
<P><B>Abstract</B></P> <P>This study investigated methods to optimize the process conditions for preparing levulinic acid (LA) using magnetic ferric oxide/SO<SUB>4</SUB> <SUP>2</SUP>- biomass-based solid acid, to catalyze pyrolysis of corn straw using response surface methodology (RSM). The measured parameters were quality of liquid-solid ratio (QLSR), catalyst dosage (CDe), hydrolysis temperature (HT) and hydrolyzation duration (HD). The mathematical model of the quadratic polynomial of LA had a P-value less than 0.005, and the loss of quasi P-value was less than 0.01; the <I>R<SUP>2</SUP> </I> value of 0.9969 indicates that the model was highly significant. The coefficient of variation was 3.02% (<10%), indicating that the model had high reliability. The optimal process conditions for preparing LA were determined by analyzing the three-dimensional surface and contour plots with a regression model equation. Using the Box-Behnken design to optimize the process conditions, the most favorable values of QLSR, CDe, HT and HD were 17.2:1 (V/W, mL:g), 3 g, 249.66 °C, and 67.3 min, respectively. Under optimized conditions, the maximum yield of LA was 23.17%, compared to the predicted value of 23.05%; the relative deviation between the two methods was 0.12%, indicating good repeatability. This study demonstrates that using RSM to optimize the conditions of LA preparation is feasible and has a very good application value.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Levulinic acid(LA) was synthesized by catalytic pyrolysis of corn straw. </LI> <LI> Using response surface method to optimize the conditions of LA preparation is feasible. </LI> <LI> Magnetic solid acid cataklyst was used to catalyze the pyrolysis of corn straw. </LI> <LI> Magnetic solid acid catalyst showed high catalytic activity and stability. </LI> <LI> Levulinic acid has a higher yield and utilization value. </LI> </UL> </P>