Abstract:
The two-phase bench scale digester system to optimize the bio gasification process was
successfully fabricated. The system comprised two main reactors, namely, hydrolysis
(acidification) and methanation reactors. The reactor performance was evaluated in terms
o f its efficiency for biogas production using rice straw for about two months and it was
found that biogas production increased by -10% over the conventional dry batch reactor
system. The maximum biogas production was 2.6 L/kg on the 30th day in the two-phase
reactor system. Total gas production over 62 days was 81 L/kg and 74 L/kg, for two-phase
reactor system and the dry batch reactor system, respectively. Further optimization o f gas
production in terms o f gas quality (with increased methane) and quantity could easily be
achieved by controlling the operating parameters o f the system since the three processes
involved in the anaerobic process are separated to two anaerobic chambers. The nutritive
value o f the digested material (anaerobically digested straw) was evaluated and N, P and
K percentages were increased in digested straw. However, no significant increase in yield
was observed in the field trial conducted with okra for the evaluation o f digested material
as organic manure
