The Study On The Effect Of The Degradation Of Sugar And Lignin On The Acidity Of The System In Ethanol-water Cooking Liquor

As a relatively clean chemical pulping method,ethanol-water pulping has been paid more and more attention in recent years.In the process of ethanol-water extraction,the primary wall of fibrous cells is destroyed.In the case of stronger cooking reaction,some lignin is dissolved from secondary wall of fiber,and other components such as carbohydrates,resins,inorganic salts and so on are also partly removed.Therefore,the pulp is usually cellulose content.During the pulping process,the acid released from the hydrolysis of raw materials can catalyze the pulping,that is,the acid that catalyzes is not added,but is produced by the hydrolysis of raw materials in the process of pulping.Therefore,the organic acids produced in the extraction process are entered into the extraction solution,providing acidity for the system and promoting the fragmentation of lignin into the pulp.However,in previous studies,it was found that with the change of temperature of ethanol-water extract,the p H value of solution changed greatly.So the content of organic acid changed,affecting the dissolution of lignin in raw material,and finally,the energy consumption of slurry would be affected.At present,few studies on effects of dissolved lignin for an organic acid ethanol-water solvent extraction process.Aiming at the characteristics of reed ethanol water extract,this study explored the change rule of lignin and degrading sugar(glucose as an example)to the acidity of ethanol water extraction.Firstly,the p H value of the distillates of the reed ethanol-water extracting was studied in this experiment.With the decrease of temperature,the fraction of the p H value of the solution increased significantly.The p H value of the solution is not sensitive to the time of action after the alcohol lignin is dissolved in the distillate.With the increase of the concentration of dissolved Ethanol Lignin,the ionizing effect of Ethanol Lignin on the ionization of [H+] in the distillate solution was more obvious.When glucose was dissolved in the distillate,glucose increased the inhibitory effect on [H+] when the temperature increased to 60 degrees Celsius.With the increase of glucose content,the inhibition increased,but the higher the glucose concentration was,the better it was.When the amount of glucose is up to 0.05 g,the inhibitory effect is greatly reduced.And the infrared analysis of the characteristic temperature is carried out to explore the strength of the hydrogen bond.Secondly,the p H value of the distillates of the reed ethanol-water extract by the mixing of glucose and ethanol lignin was studied in the experiment.The results showed that the inhibition of glucose was enhanced at a lower and higher temperature.At high temperature,the increase of the concentration of Ethanol Lignin will increase the inhibitory effect on [H+].After more than 60 degrees Celsius,glucose inhibited [H+],and ethanol lignin inhibited it after 70 degrees Celsius.However,the inhibition of glucose and lignin weakened at intermediate temperature.According to the analysis of lignin chemical structure functional groups,it is conjectures that the carbonyl group of its functional groups will form hydrogen bonds with the hydrogen ions of organic acids in the fractions,and inhibit the release of [H+].Therefore,the anthraquinone containing quinone structure was used as a model,and the effect of anthraquinone and Ethanol Lignin on the p H value of the distillate solution was compared.As a result of the addition of anthraquinone,the p H value of the solution increased as a whole,indicating that anthraquinone has a strong inhibitory effect on [H+],and the higher the concentration,the stronger the inhibition effect.Compared with ethanolic lignin,the inhibition of [H+] was stronger than that of ethanolic lignin.Thirdly,the acidity of the reed ethanol water extraction solution itself was studied.With the decrease of the temperature of the extract,the p H value of the solution also increased obviously.And the infrared analysis of the characteristic temperature is carried out to explore the strength of the hydrogen bond.Finally,the change of the p H value of the distillates of the reed ethanol water extract was tested.The quinone structure of phenol was dissolved in the distillate solution,and the change of p H value was not obvious,which just proved the experiment.