生物脱硫固定床反应器中的Fe^(2+)氧化动力学

Kinetics of oxidation of Fe^(2+) in fixed-bed bioreactor for biodesulfurization

生物脱硫技术中,Fe2+氧化速率是制约整个脱硫工艺效率的关键因素。以两种尺寸的木屑作为固定化载体,分析了反应器中Fe2+氧化动力学。根据所推导的Fe2+氧化动力学方程,对Fe2+浓度随时间衰减的实验值进行非线性拟合分析,确定了反应器分别采用两种载体在最优通气速率下的Fe2+氧化反应级数,并分析了木屑载体(b)的氧化动力学参数对通气速率的变化规律。采用所确定的反应级数,根据连续操作下的动力学方程及Fe2+转化率随稀释率变化的关系确定了连续操作下的反应速率常数分别为0.9698h-1·(g·L-1)0.1666、0.9042h-1·(g·L-1)0.1135。动力学曲线与真实值之间的相关系数R2均在0.99以上,具有良好的预测性。

The rate of oxidation of ferrous iron in bio-oxidation reactor is the key factor constraining the entire biodesulfurizaion process. Wood chips of two different sizes were used as the immobiliazation carriers of Thiobacillus ferrooxidans, and the kinetics of oxidation of ferrous iron conducted by the biofilm was analyzed. According to the kinetic equation deduced, the data of ferrous iron concentration varying with reaction time was analyzed by the method of non-linear fitting. Thereby the reaction orders were obtained, when two different carders worked respectively at the optimal aeration rate. And the relationship between the kinetic parameters and the aeration rate were investigated when wood chips （b） was used as the carrier. According to the reaction orders obtained and the data of conversion of ferrous iron varying with the dilution rate under continuous operation, the reaction rate constants in the kinetic equation deducted were obtained by the method of linear fitting as follows, 0.9698h^-1·（g·L^-1）^0.1666、0.9042h^-1·（g·L^-1）^0.1135. The correlation coefficients between prediction model and experimental data were all higher than 0.99, indicating that the kinetic model was suitable for prediction.