Simulation of Process Steady-state in Livestock Waste Methanogenesis

A predictive indicator of process steady-state is an invaluable tool in operating sensitive biological processes such as anaerobic methanogenesis. Nitrogen ratio (NR), the ratio of total Kjeldahl nitrogen (TKN-N) entering an anaerobic fermenter to the TKN-N leaving the fermenter (TKNin/TKNout), has been established as a reliable indicator of fermenter steady-state (Cobb and Hill, 1990). The methanogenesis model developed by Hill (1982) and subsequently modified by Hill and Bolte (1987) and Hill and Cobb (1993) has been updated to include nitrogen balances for TKN-N and organic nitrogen (ON-N) in order to calculate NR.