Producing Mechanisms Of Low-boiling Organic Acid From Auto-Atalyzed Ethanol-H₂O Pulping

Previous studies generally considered that reed Auto-Atalyzed Ethanol-H2O Pulping fully demonstrated the advantages of solvent pulping. But there was no unified understanding about organic acidcatalysis was how to produce in reed Auto-Atalyzed Ethanol-H2O Pulping process. Therefore, the study of reed auto catalyzed ethanol pulping process "system acid environment" -- the organic acids types, content and generating reasons, could provide the theoretical basis for optimizing the cooking process.In the process of research:Firstly, used model method:production of cellulose, the main degradation of sugar and lignin in raw materials generation situation of organic acids in ethanol water solution of cooking were represented by absorbent cotton, D-glucose, D-xylose and homemade lignin. Secondly, studied the changes in acid environment of reed cooking liquor with ethanol water solution during cooking. Finally, used formic acid, acetic acid to simulate the formic acid, acetic acid influence of the system acid environment.In the process of research:but also on formic acid, acetic acid, levulinic acid, furfural,5-HMF generation means were studied, found a way to accurately quantify furfural, 5-hydroxymethyl furfural of their content in mixture, and used FT-IR,1H-NMR,13C-NMR and so on advanced means of comparison and analysis of the structure before and after the change of model compounds of cooking. The cellulose could not occur chemical reaction alone, lignin was chemical reaction more intense, side chain fractured, consumption of relatively large amount of ethanol, formic acid, acetic acid and laevulin acid etc. organic acids, acetic acid production was large among them, the research results were very different from before; D-xylose generated to formic acid, acetic acid and furfural etc. degradation products, formic acid was through the "D-xylose?furfural?formic acid" path generation; D-glucose generated to formic acid, acetic acid and levulinic acid etc.degradation products,5-HMF and formic acid were the result of "glucose ? 5-HMF ? levulinic acid+ formic acid" path generation. Model in the cooking process, lignin side chain broken, structure of lignin unit C-C bond was relatively stable, and the Ely stable, but the ether bond breaks. Monosaccharide oxygen ring type structure part was damaged, and there was a corresponding containing baldheads and acids produced.Research also obtained, in the ethanol water solution cooking process, D-xylose had a large number of furfural production D-glucose also had a mall amount of furfural was generated, homemade lignin generated less, cotton production could be ignored. Xylose was converted to furfural, glucose was converted to 5-HMF,5-HMF further into furfural. UV spectrophotometer (UV) qualitative and quantitative furfural and 5-HMF was more reliable detection method.Ethanol water solution in the process of cooking Reed, different cooking stages had formic acid, acetic acid and levulinic acid generation. The content relationship between different organic acids:acetic acid> levulinic acid> formic acid. The system acidity dependsed mainly on the formic acid.