3. Results and Discussion
3.1 Biogas production in batch process
In this study, the chemical properties of pineapple
peel were analyzed in order to investigate the biogas generation potential of raw material (Table 1).
The accumulative gas recorded for 30 days with original pH (4.6) by using microorganism from sewage sludge was shown in Fig. 1. (Other seed microorganism was not made the system to generate gas, so the result was not shown). At present system, the acidogenesis process was occurred within 8 days of the experiment which appeared pH was lowest. After that the pH was gradually higher while the gas formation was noticeably accumulated for 20 days. However, less efficiency resulting from fewer amounts of total gas and methane were detected at this initial pH because of high content in both acid value and carbon to nitrogen ratio. This condition was not suitable for methane formation bacteria to grow up [4].