Study On Glucose Production From Rhizome Residues Of Acanthopanax By Acid Hydrolysis

This paper discusses the best hydrolysis process of producing glucose with Acanthopanax roots residues as raw material by a two-step hydrolysis method. First, the pre-hydrolysis conditions are studied, the optimal pre-hydrolysis conditions of concentrate sulfuric acid72%, hydrolysis temperature30℃, hydrolysis time1h, solid-liquid ratio1:9. Then the pre-hydrolysis solution is diluted to different sulfuric acid concentration, hydrolysed by the method of high temperature reflow heating in different conditions. And based on the best single factor results through the single factor experiment of secondary hydrolysis of cellulose, the optimal results of orthogonal experiments are obtained:dilute sulfuric acid concentration of12%, hydrolysis temperature of110℃, hydrolysis time of40min, with the highest yield of glucose of83.96%.Using microwave heating method instead of traditional high temperature reflow heating method to select better way of secondary heat hydrolysis, the pretreatment of microwave auxiliary secondary dilute sulfuric acid hydrolysis is similar to that of former hydrolysis method. Then it is followed by the study of hydrolysis production in the condition of three different acid concentrations6%,9%,12%with different microwave power and time. And the orthogonal experiment design is based on the single factor test results, and the optimal condition for microwave auxiliary secondary dilute sulfuric acid hydrolysis is sulfuric acid concentration of12%, microwave power of350w and microwave time of30min. with maximum glucose yield of85.91%, which is a little higher than that of high temperature heating method. Therefore, due to the shorter reaction time and easier to operate with higher glucose yield, microwave heating method is considered to be more suitable for the secondary hydrolysis process.The sugar acid hydrolysis solution prepared under the optimal acid hydrolysis process is used for the research of the sulfuric acid recycling by the technology of diffusion dialysis membrane separation. The results show that the innovative method can effectively separate the acid and sugar with high sulfuric acid recovery and sugar recovery which are both above90%. Then, the off-sulfuric acid hydrolysis liquid is used as the saccharification liquid of raw material liquid for the study of the decolorization process. After the treatment of the saccharification liquid, it is scanned in the200nm-700nm wavelength to get the greatest absorption peak of the coloured substances in the liquid, and the result is282nm. The decolorization rate of the sample is determined under this wavelength, and the loss rate of glucose is used as the index to measure the effect of decolorization process. Four factors of concentration of activated carbon, bleaching time, bleaching temperature, initial pH value are concluded in the single factor experiment, based on which a further orthogonal test is designed to obtain the optimal process conditions:activated carbon of5.5%, bleaching time of40min, bleaching temperature of40℃, initial pH value of6with approximately94%decolorization rate and15%glucose keeping rate. Finally, the prepared glucose was analysised by qualitative methods under the detection of FTIR, HPLC and LC-MS.