Steady-state methane digester

In a field digester these steady-state values would also be affected by the fact that most of the volatile acids and cations (NH4 ) would be generated internally with some carbon dioxide being produced by the acid-producing bacteria. Acids other than acetic are also formed, and it is of interest to compare the steady state conditions for other volatile acids with those of acetic. The formulas for converting propionic and butyric acids to microorganisms, methane, and carbon dioxide are given in Equations 32 and 33. 

Representative data from Run 1. which did not achieve steady state, as previously mentioned, are shown in Table V. This represents the baseline run without added nutrients. It was found that to maintain pH in the 6.8-7.2 range, 72 meq NaOH// of feed slurry was required this raised the sodium ion concentration in the digester to about 1670 mg//. Overall, the results of Run I were poor. The methane yield, volatile solids reduction, and energy recovery efficiency as methane in the product gas were low, and the volatile acids concentration in the digester effluent was high. 

Steady-state performance of conventional high-rate mesophilic digestion of the biomass-waste blend at the baseline loading and detention time is presented in Table I. The methane yields from replicate baseline runs ranged... 

Table VI. STEADY-STATE PERFORMANCE OF CONTINUOUSLY FED MESOPHILIC PACKED-BED METHANE DIGESTER...

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