Abstract
For the design and development of a high performance methane fermentor, the anaerobic fluidized bed fermentor was evaluated in order to determine the characteristics of this fermentor. The obtained results are summarized as follows:
1. When the fermentor was operated at less than a 0.38 dilution rate (D, 1/day), more than a 85% substrate (acetate) removal ratio could be observed. When D was over 0.38, the value of sludge retention time (SRT, days) was less than 10 days and the substrate removal ratio decreased.
2. When the fermentor was controlled at a high D, the methane microbes retained on the support media were reduced and consequently the microbes in the mixed liquor increased. As a result, the SRT of the fermentor was decreased.
3. Using the kinetic model modified here, growth characteristics such as μ (1/day) and YG (mg/mg) of the methane fermentation process were determined. These values indicated that methane microbes contained in the fermentor showed relatively low substrate consumption and growth rates. On the other hand, the concetration of methane microbes in the fermentor was high. This might be one reason for the higher performance of the fermentor.
4. It was suggested that high performance of methane fermentor with a high concentration of methane microbes even if the activity of the methane microbes was relatively low.
