生物气生成的化学动力学模型及其应用——以柴达木盆地为例

针对国内外评价生物气资源量普遍采用的微生物厌氧发酵法中不能反映生气期的不足,本文从化学动力学角度出发,首先建立有机质生成生物气的化学动力学模型并结合实验条件下生物气产率数据,标定了地质样品的化学动力学参数。在此基础上,考虑菌体浓度和温度对动力学参数的影响,将所标定的动力学参数在柴达木盆地进行初步应用,结果表明柴达木盆地生物气生成速率随埋深先增大后减小,速率最大值对应的深度约为600m,与前人(戴金星等,2003)研究结论相近,说明根据实验室产气率数据标定所建立的动力学模型在考虑了菌体浓度和温度对动力学参数影响之后可以用来定量评价生物气生成期。

Chemical Kinetic Model of Biogenic Gas and Its Application in the Qaidam Basin

The anaerobic fermentation method, which was used in biogenic gas resource appraisal, failed to reflect or describe the gas generation period. In consideration of this tough problem, a chemical kinetic model of biogenic gas generated from organic matter is constructed according to chemical kinetic theory, and the kinetic parameters are calibrated with the data of simulation experiment. On the base of this, taking the influence of bacterium concentration and temperature on the kinetic parameters into consideration, the initial application of the chemical kinetic model in the Qaidam Basin shows that the biogenic gas generation rate increases with the buried depth firstly, and then decreases when it reaches to the maximum (corresponding to a buried depth of 600 m). This conclusion is similar to the previous study result, so this model can be used to appraise the biogenic gas generation period.