A small-scale biogas digester model for hen manure treatment: Evaluation and suggestions

In this case study, a small-scale biogas plant in treatment of manure wastes was proposed for a hen farm (Dortler Farm on Ankara Highway in Corum city of Turkey) selected as model pilot plant. A fixed-dome Chinese model biogas reactor (FDCMBR) having a digester volume of 280 m super(3) was found to be appropriate in treatment of hen manure wastes. Calculations based on design criteria and literature data were presented. The proposed biogas plant was designed for local possibilities, and low cost conditions based on local information and experimental studies given in the literature. In Corum city, the total daily biogas production (about 7625 m super(3) day super(-1)) can be provided from individual biogas plants, operating at 58 active hen farms having different waste loads. By considering the population of Corum city (161000 people), this total production was estimated to compensate the daily requirements of 290 families (5 members) including heating, cooking, cooling and lighting. The number of people who make use of this biogas energy (1452 people) was found to be equal to approximately 1% of the total population of Corum city. In this case study, revenues and expenditures (R&E) were also estimated for the proposed FDCMBR. The R&E analysis showed that revenues that can be provided from selling of stabilized manure were estimated to be 15500 per year. This value was found to be nearly equal to total operating and construction expenditures of the proposed biogas plant Moreover, results of some experimental studies including projection criteria were also presented. More importantly, this case study is expected to provide a useful background and a scientific contribution in manure management for rural areas of Turkey.