Treatment options are essentially about waste and energy; both are key factors affecting operational profitability. To contextualise;
- Each kilogram of chicken meat delivered to the customer produces a combined waste stream in excess of 16 kg (including wastewater)
- Every aspect of the poultry production and supply chain requires energy. We estimate this energy requirement, excluding feed production, to be approximately 16MJ per kg carcase weight
Broiler farms require energy for;
- Feeding & drinking equipment (pumps & augers)
- Climate control including associated production management systems which can include both heating and cooling systems.
Energy costs constitute a significant portion, often over half, of cash expenses (non-feed costs) for poultry producers (Cunningham, 2008).
Successful treatment of broiler farm waste has to address the following challenges;
- Poultry waste presents itself as a major risk factor and maintaining bio-security is a major concern of poultry farmers. Effective waste management programmes should be designed to reduce the spread of various pathogens and diseases within the farm and to all other farms and processing facilities.
Poultry farm waste is comprised of broiler litter (manure & bedding material) and on-farm mortalities, each requiring separate treatment protocols;
- Chicken manure is a demanding substrate for further processing due to high ammonia, nitrogen and sulphur levels. Combustion of chicken manure can result in NOX and SOX emissions. Anaerobic digestion of chicken manure needs to address the low Carbon: Nitrogen ratio (7:1) which is deficient in carbon molecules for quality biogas production. The presence of heavy metals can be an inhibiting factor in biological treatments.
- Bedding materials can contain high lignin levels that breakdown very slowly in nature and which can be inhibitory to biological processing.
- Mortalities are a major source of pathogens requiring quick and effective treatment to prevent spreading of diseases.
The Selectra approach is to implement farm-specific sustainable architecture as each broiler/layer farm has unique operating conditions and diverse needs. Furthermore consideration must be given the fact that farm operations normally consume less energy than what is recovered through H2E anaerobic digestion system. Other system benefits include enzymatic pre-treatment to reduce lignin to sugars thereby facilitating the digestion of bedding material, treated bedding material provides carbon to correct the Carbon: Nitrogen ratio, and alkaline hydrolysis for processing of mortalities.