Background: Chicken manure is a difficult substrate for anaerobic digestion, due to its
high content of nitrogen and sulphur. Nitrogen (Ammonia) and Sulphur (H2S) inhibit the digestion
process. In this paper an analysis is made of the methods to mitigate the effect of nitrogen and sulphur
on the anaerobic digestion of chicken manure.
Methods: A literature study was made on additives, that reduce the negative effects of nitrogen and
sulphur. The data of a biogas plant in Thüringen (Germany) using chicken manure together with
swine manure, cattle manure and maize silage are analysed. This installation operates with a total solids
concentration [TS] of the substrate of 190 kg/m3
and a total nitrogen concentration [TKN] of the
effluent of 9.3 kg/m3. number of additives, which reduce these negative effects, are discussed.
Results: The plant in Thüringen could use more chicken manure and could have higher TS loading,
when the pumps between primary and secondary reactors are replaced. Capacity of the plant can be
increased by 15 %. The data of the plant in Thuringen (Germany) are compared with design data of a
plant in the Dnepropetrovsk oblast (Ukraine). There is an option for this latter plant to recycle part of
the effluent, when a nitrogen mitigating additive is used. Capacity could be increased by 25 %, when
the total solids loading of the Thuringen plant is adopted.
Conclusion: Chicken manure is economically digested in together with swine manure, cattle manure
and maize silage. The contribution of the chicken manure to the biogas yield can be increased by 15
%, when pumps be- tween primary and secondary reactors are exchanged.
Power of the plant in the Dnepropetrovsk oblast can be increased by 25 % or more of the liquid fraction
of the effluent can be recycled, when iron containing compounds are used.