Research On The Degradation Of Lignocellulose By Hydrodynamic Cavitation

The components separation of corn strover was reported and treatment through two methods was reported. and the various components of the isolated structure and surface morphology analysis, discussed under each method, the basic principle of separation of lignocellulose, and the optimum technological conditions, the purity and recovery rate of each composition.It was covered that corn stover was decomposed in alkaline solvent system which consist of NaOH-H2O2 and the corn stover compositions were separated by means of acid precipitation and ethanol extraction. It was confirmed that in alkali solution the main residue by post-treatment was primarily cellulose, the filter liquor after the acid sediment was lignin, the solid after the anhydrous ethanol extraction of the liquor was hemicellulose. The best dissolution conditions were obtained by single-element tests, which is as follows: the concertration of H2O2 is 5%, the concertration of NaOH is 1%, dissolution temperature 60℃, dissolution time 3.0 h, the ratio of liquid to solid 30 mL/g. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) were utilized to identify the ingredients’structure, the cellulose recovery yield can achieve to 84.2% and lignin recovery yield after acid precipitation is about 66.6%, the hemicellulose recovery yield after ethanol extraction is about 96.7%. After recycling the solvent 4 times,the cellulose yield can achieve to 82.7% and lignin yield after acid precipitation is about 67.6%, the hemicellulose yield after anhydrous ethanol extraction is about 97.4%.The lignocellulose separation of corn stover was studied by hydrodynamic cavitation, Corn store was immersed into different solution of H2O, NaOH, NaOH/H2O2. Single-factor experiment method was employed to investigate the effect of the solution, dissolution time, dissolution temperature on structural features of the cellulose separated. The best parameters of pre-treatment were obtained:H2O2-NaOH solution, H2O2 concentration of 5%, NaOH concentration of 1%, the cellulose recovery yield is 75%. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) were employed to identify the structure of the components separated.A novel method of degradation of chitosan, by hydrodynamic cavitation using an orifice plate, was investigated. The effects of original concentration, pH, treatment time and geometry of the orifice plate on the degradation of chitosan were evaluated. It was found that the degradation of chitosan solution was dependent on initial concentration of chitosan solution, solution pH, treatment time the geometry of the orifice plate. To determine the optimum degrading condition was:chitosan solution concentration of 0.5 g/L concentration solution, the pH of the solution was 4.4, reaction time is 3 hours and the orifice geometry for a large number of holes, smaller hole diameter. Structures of the degraded products were characterized with Fourier-transform infrared spectra (FT-IR) and X-ray diffraction (XRD). The present study conclusively establishes that hydrodynamic cavitation can be effectively used for the degradation of chitosan.