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The construction and operation of a low‐cost poultry waste digester
Author(s) -
Steinsberger Scott C.,
Shih Jason C. H.
Publication year - 1984
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260260520
Subject(s) - biogas , waste management , environmental science , methane , municipal solid waste , anaerobic digestion , biogas production , pulp and paper industry , waste treatment , engineering , chemistry , organic chemistry
A simple and low‐cost poultry waste digester (PWD) was constructed to treat the waste from 4000 caged laying hens on University Research Unit No. 2 at North Carolina State University. The system was built basically of a plastic lining with insulation, a heating system, a hot‐water tank, and other metering equipment. It was operated at 50°C and pH 7.5–8.0. The initiation of methane production was achieved using the indigenous microflora in the poultry waste. At an optimal loading rate (7.5 kg volatile solids/m 3 day), the PWD produced biogas (55% methane) at a rate of 4.0 m 3 /m 3 day. The PWD was biologically stable and able to tolerate temporary overloads and shutdowns. A higher loading rate failed to maintain a high gas production rate and caused drops in methane content and pH value. Under optimal conditions, a positive energy balance was demonstrated with a net surplus of 50.6% of the gross energy. For methane production, the PWD system was proved to be technically feasible. The simple design and inexpensive materials used for this model could significantly reduce the cost of digestion compared to more conventional systems. More studies are needed to determine the durability, the required maintenance of the system, and the most economical method of biogas and solid residue utilization.