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与液态发酵相比,甜高粱秆固态发酵制燃料乙醇具有能耗低、工艺设备简单和排放废物少等优点,近年来引起人们越来越多的注意。发酵动力学是工业放大过程中设计、操作和模拟优化的基础,文中基于实验室自行筛选的高效酵母菌株TSH-SC-1,对甜高粱秆分批固态发酵制乙醇的动力学进行了研究。根据固态发酵实验结果,分别采用Logistic方程、Leudeking-Piret方程和类似Luedeking-Piret方程,建立了描述固态发酵过程中菌体生长、底物消耗和产物生成的动力学模型方程,并利用最小二乘法对模型参数进行非线性拟合。结果表明,酒精作为酵母厌氧呼吸的能量代谢副产物,与菌体生长速率和菌体浓度都有关系,最大比生长速率为0.331/h,维持常数为0.0127g(糖分)/[g(菌体干重).h]。模型预测值和实验值有良好的拟合性,菌体生长、糖分消耗、乙醇生成3条曲线的相关指数R2分别为0.83,0.996和0.994。表明该动力学模型可以较好地定量描述基于TSH-SC-1菌株的甜高粱秆乙醇固态发酵过程,对指导其下一步过程放大和生产具有实际意义。
Compared with liquid fermentation, the solid state fermentation of sweet sorghum straw fuel ethanol has the advantages of low energy consumption, simple process equipment and less waste discharge, attracting more and more attention in recent years. Fermentation kinetics is the basis of design, operation and simulation optimization in industrial amplification. The kinetics of batch solid-state fermentation of ethanol from sweet sorghum straw was studied based on highly efficient yeast strain TSH-SC-1 screened by laboratory. According to the results of solid-state fermentation, the kinetic model equations describing the growth, substrate consumption and product formation in solid-state fermentation were established by Logistic equation, Leudeking-Piret equation and similar Luedeking-Piret equation respectively. Non-linear fit to model parameters. The results showed that alcohol as a byproduct of energy metabolism in anaerobic respiration of yeast was related to the growth rate of mycelia and the concentration of mycelium. The maximum specific growth rate was 0.331 / h and the retention constant was 0.0127g / g Body dry weight) .h]. The model predictive value and the experimental value have a good fit, the correlation index R2 of the three curves of cell growth, sugar consumption and ethanol production were 0.83, 0.996 and 0.994 respectively. The kinetic model can be used to quantitatively describe the solid-state fermentation of ethanol from sweet sorghum stalks based on TSH-SC-1 strain. This kinetic model has practical significance in guiding the amplification and production of the next step.