A Technical Experiment on Biogas Production from Small-Scale Dairy Farm

Abstract

The key objective of this study was to evaluate the economic feasibility of producing biogas from privately-owned dairy farm in the North of Jordan. This experiment did not adopt Best-Available- Technology (BAT) but rather traditional unit manufactured with minimized costs through install ing locally produced materials to avoid economic burden on the farmers’ production costs. A ther mophilic biodigester unit was built sub-surface with 22 m 3 capacity (15 m 3 manure tank plus 7 m 3 biogas holder) in a relatively small scale dairy farm. The daily feed was about 500 liter of cow slurry (150 - 200 liter cow manure) and the remaining were production liquids. The retention time was approximately 25 - 30 days and the seasonal temperature measured was about 18 ° C - 20 ° C. The unit was thermally insulated; therefore, the temperature fluctuation was slightly around +/ - 3 ° C. The daily biogas production was estimated at 7 m 3 equivalent to 4 kg of Liquefied Petro leum Gas (LPG) or 11 (12.5 kg) LPG cylinders per month worth US$140. The methane percentage was 60% in relatively warm temperature (18 ° C - 20 ° C) and approximately 56% in colder temper ature