Preparation of platform chemicals by hydrothermal conversion of citrus peel in Choline Chloride/Carboxylic acid based deep eutectic solvent
In order to explore the potential of fruit peel waste conversion to produce high-value platform chemicals,the hydrothermal conversion of citrus peel to furfural(FF)and 5-hydrox-ymethylfurfural(5-HMF)was conducted in the choline chloride(ChCl)/carboxylic acid based deep eutectic solvents(DES)system.Conclusions can be drawn from experiments in xylose and glucose:The carboxylic acid performance was ranked lactic acid>acetic acid>glycolic acid.The optimal molar ratio of choline chloride to carboxylic was 1∶2.The optimal water content of solvent system was 20%.The effects of temperature and time on citrus peel conversion were studied based on the optimized operating conditions.Since the pectin component in the citrus peel was mainly converted to 5-HMF in DES,the yield of the peel converted to 5-HMF was significantly higher than that of FF.The maximum mass yield of 5-HMF from citrus peel was 8.6%(molar yield was 43.1%).The maximum mass yield of furfural reached 2.4%(molar yield was 19.1%).
deep eutectic solventcitrus peelhydrothermal conversion5-hydroxymethylfurfuralfurfural