Research On Hydrothermal Process Of Algriculture Wastes

Our country is a large agricultural nation and produces a large amount of agricultural wastes. As a newly technology, hydrothermal process in treating agricultural wastes is hot researched on producing bio-oil, organic acids, H₂ and Biological fertilizer. However, research on its transform pathway is very scarce. The paper, took Shanghai science committee scientific research plan project "Organnic waste hydrothermal Resources Research" a part, is mainly research on hydrothermal process using maize straw and wood flour as target model.The reactors in the research are a 6mL tubular reactor and a salt bath stove with independent design. The concrete reaction pathway is putting certain particle size and certain amout of reactant, certain amount of water or hydrogen peroxide solution into tubular reactor, then seal, vibrate and put it into salt bath. When hypothesis time arrived, take out tubular reactor rapidly and put it into cooling water to cease the reaction. The research uses instrument such as infrared spectrum, HPLC, TOC, GC/MS, ultimate analysis doing analysis. We try to research product C distributions, the residual structure, the reducible sugar output, the ethanoic acid output change through changing reactant quality, the reaction time, the reaction temperature, the reactant particle size, the oxidant amount used, the water volume added.The experimental study indicated the reaction temperature, the reaction time, the oxidant amount used have remarkable impact on the product C distribution. However, the weight of reactant, the volumn of water added, the particle size of reactant have slice impact on the product C distribution. Increasing reaction temperature can stimulate the velocity of hydrothermal reaction and accumulate carbon in liquid phase. Increasing residual time can stimulate carbon transformation from solid phase to liquid phase and gas phase. Adding oxidant can stimulate carbon transformation from solid phase to gas phase, meanwhile the amount of cabon in liquid phase remain constant. The reaction temperature, the reaction time, the oxidant amount used have remarkable impact on enhancing the reducible sugar and the ethanoic acid output. Increasing reaction temperature, adding oxidant or increasing residual time can remarkably enhance the reducible sugar and the ethanoic acid output. However when addition exceeds threshold, the reducible sugar and the ethanoic acid output will decrease. From IR spectrum and SEM observation, we can find residue structure changed remarkably during hydrothermal process. During the temperature rising from 250 to 374℃, the vibration adsorbance of phenyl increase remarkably. The -OH, the -COOH, the disassimilation area beta-key transformed from solid phase to liquid phase.