Designs of linear-quadratic regression models for facile conversion of carbohydrate into high value (5-(ethoxymethyl)furan-2-carboxaldehyde) fuel chemical

Abstract

In this design, the swift synthesis of 5-(ethoxymethyl)furan-2-carboxaldehyde (EMF) was systematically investigated via ultrasound-assisted isomerization-dehydration-etherification of carbohydrate-derived glucose in the presence of ethanol and tetrahydrofuran as well as zinc oxide nanorod-doped sulfonic-glycerol-carbon microsphere catalyst (Zn-SO3H-GR-carbon). The catalyst was easily synthesized via in-situ hydrothermal carbonization with sulfonation and followed by trapping with zinc oxide nonorod. The physicochemical properties of as-synthesized catalyst were studied in details. A combination of linear regression model with 2k factorial design exhibited three significant parameters for EMF production which were in the order of catalyst amount > reaction time > reaction temperature. A maximum yield of EMF (86.3%) was successfully obtained from an actual experiment with Box-Behnken design (R2 > 0.95 and 1.3% error from quadratic regression model), providing the optimum conditions: catalyst amount (62 mg), reaction time (72 min), reaction temperature (106 °C) and tetrahydrofuran amount (250 mmol). Moreover, the long-term reusability for 20 cycles based on EMF yield was found in Zn-SO3H-GR-carbon catalyst after regeneration. This research was expected that all useful information for ultrasonic-assisted EMF production from glucose over efficient catalyst could be further applied in industrial practices.