Experimental Research On Wet Oxidation Pretreatment Of Straw

Biomass is renewable energy source, with zero net carbon dioxide emission. Because of extensive sources and great economic benefits, research on comprehensive utilization of biomass is of great significance on China Energy Strategy.Aimed to get a method of maximizing the utilization of biomass, especially for that with high moisture content, study focus on feasibility analysis about pretreatment of biomass using wet oxidation. Wheat straw was chosen as research material. By virtue of IR-spectra, elements determined and Mass Spectrometry, the effect of temperature, retention time, alkaline Na2CO3 and wheat straw concentration on the quantity and performance of reaction products is explored. It reveals three-phase product distribution, element contents and ratio of carbon to nitrogen in the solid products.Based on the relationship between calorific value and CHNs, a multiple linear regression model was developed, in which CHNs are variables and calorific is function. Compared with that of the wheat straw without pretreatment, there is no positive linear correlation between the CHNs and the high heat value. The models can provide important evidences for calculation and prediction in Research of products.In addition, variation of biomass ingredient pretreated by using wet oxidation was discussed with Thermo-gravimetric Analysis Technique. It is found that the initial temperature of heat decomposition is higher(310℃), and the weight loss rate becomes larger. Combined with some investigation of biomass pyrolysis by simultaneous thermal analyzer, we infer that the solid residue mainly contains cellulose, with the hemicellulose almost being oxidized and dissolved. The optimum conditions to deal with 6g/L wheat straw pretreated by using wet oxidation are the following, the delignification and solubilization of hemicelluloses take place in the first 10 min, and the temperature is 190℃with 6g/L Na2CO3 used. In the process, the reaction of wet oxidation occupies a leading position, which is accompany with pyrolysis, bond breaking of ether and ester, dehydration, condensed reaction, and etc.According to the theoretical research of pretreatment of wheat straw using wet oxidation, the paper puts forward a batch reactor system and a continuous reactor system, and also explains economical evaluation of the process. The cost of ethanol fermentation will be reduced by 109.08 yuan if the process is used.The wet oxidation technology, which is easy to operate and control, can convert biomass into one of new resources with high affiliated value. It is helpful to increase employment chances and Promote in the construction of the new socialist countryside.In conclusion, this study with a view to the theoretic to solve the problems of biomass with high moisture content, which provides fresh thoughts in New technology for biomass recycling use. The wet oxidation pretreatment, a promising technique, can not only dispose the pollutant but also make the biomass reduce. There will be a bright market future applying wet oxidation technology in biomass disposal on a large scale.