The Study of Saccharides Hydrolysis to Levulinic Acid
|Course||Of Food Science|
|Keywords||Levulinic acid Ultrasound - microwave synergistic Corn starch Glucose Dynamics Suppression|
The levulinate having good reaction activity , is an important compound of green platform . Equipment corrosion problems exist in the acid hydrolysis process under high temperature and pressure conditions , the use of normal temperature and pressure conditions for the preparation of levulinic acid , glucose hydrolysis reaction kinetics , and inhibition of ketone rot black substance produced by the hydrolysis process . Using ultrasound - Microwave collaborative methods to generate levulinic acid comparison of different carbohydrate hydrolysis . The study found that the rate of single- glycohydrolase generated levulinate its conformation . Oligosaccharide or polysaccharide hydrolysis rate of levulinic acid is generated with its own structure and hydrolysis rate of monosaccharides and monosaccharides conformation . Corn starch prepared from levulinic acid , using a central composite design test optimization optimum conditions : microwave power 100 W, reaction time 90 min , the concentration of hydrochloric acid 4.5 mol / L, liquid to solid ratio of 15:1 ( mL : g), levulinic acid was 23.17%. Study liquid to solid ratio , the concentration of hydrochloric acid , the reaction temperature kinetics of the hydrolysis reaction of glucose . Series of liquid to solid ratio can be controlled reaction kinetics : greater than 30:1 (mL: g) as a reaction , is less than 30:1 (mL: g) zero order reaction . The initial reaction rate is positively correlated with the concentration of hydrochloric acid linear . Glucose conversion rate and the rate of formation of the levulinic acid with the reaction temperature is significantly increased . Glucose decomposition reaction activation energy of 110.63 kJ / mol, levulinic acid to generate the activation energy of the reaction was 161.41 kJ / mol . Using ketone inhibition of glucose in the hydrolysis process rot the black material research ketone rot Black was inhibition rate and yield of levulinic acid . Simultaneously adding 5% (L: L) of acetone and 5% (L: L) of 2 - butanone, the effect of suppressing the rot black material preferably , the reaction time of 24 h, to achieve the maximum inhibition rate 27.52% ; at 21 h levulinic acid yield is 28.93% . In addition, two ketone was added so that the levulinate generate the activation energy of the reaction to a decrease of 16.28 kJ / mol , conducive to the generation of the levulinate . The addition of sodium chloride can play play activation of hydrochloric acid catalyst , promote the generation of the decomposition of glucose and levulinic acid , glucose decomposition reaction activation energy is reduced from 13.413 kJ / mol , and the levulinic acid formation reaction of the activation energy decreases 23.896 kJ / mol.