Free ammonia in biogas: calculation, thresholds and mitigation
Co-digestion multiplies profitability but introduces dynamic uncertainty. The first risk is not total ammoniacal nitrogen (TAN): it is the free NH3 fraction. It is governed by the pKa 9.25 equilibrium, modulated by pH and temperature. A digester that incorporates pig slurry, WWTP sludge or poultry by-products without auditing the mixture works with an inhibition variable […]