沼气产生的两步一级反应耦合模型

根据有机物厌氧产生沼气的生化机理，假设沼气通过两步相互衔接的一级反应生成，即复杂有机物的水解酸化反应和简单有机酸的产气反应.根据假设，建立了基于两步一级反应耦合的沼气产气率与产气量随时间变化的数学模型.该模型用统一的数学公式对沼气产气率随时间变化的倒“U”形曲线进行了解释，指出这一过程是两步相互衔接的一级反应相互作用的结果.已知有机物质量，通过拟合或根据经验得出K值后，利用该模型可解出任一时刻有机物的产气率、产气量、最大产气率及其发生的时间.拟合表明，两步反应的反应常数趋于相等.利用该模型可导出已有的Scholl Canyon模型，并可对Palos Verdes模型和Sheldon Arleta模型的经验假设进行解释. 

Methane Production Model of Two-Stage First-Order Kinetics Reaction

According to the bio-chemical mechanism of methane production, it is assumed that methane is formed from organic matters through two linked first-order reactions, which are called the hydrolyzing-acidifying reaction and the gas forming reaction. Based on this assumption, a new model for methane production quantity and rate variation vs time was developed, which could be called a two linkedfirst-order reaction model. This model can explain the upside-down U shape graph of methane production rate vs time by one consecutive function, pointing out that the shape is due to the interaction of two stage first-order reactions.The model can give analytic result of gas production rate and total produced gas quantity at any time and the exact maximum gas production rate value and when it happens. By simulation with the experiment, it shows that the parameter of each reaction stage tends to be equal. Scholl Canyon model can be concluded from this model. And the assumptions made in Palos Verdes and Sheldon Arleta models can also be explained by this model.