Question

(15)3. You are to provide an assessment of potential energy production from a local farm which is considering an anaerobic digester to treat its wastes. has 52 cattle, 75 pigs, and 955 hens. Assuming 1 m3 of biogas has 20 MJ energy value and would give 1.7 kWh of electricity, estimate the annual energy value and electricity production from this farm using the information given below The farm Feedstock No of animal to produce 1 tonne/day Biogas yield (m3/tonne feedstock) 25 Cattle slurry Pig slurry Laying hen litter 20 40 250 300 8.000-9,000 26 50 100 How much money (S/year) can be saved by generating electricity from the captured biogass if the cost of purchased electricity is $0.075/kWh.

Answer 1

9iven data animals in a farm Number of Cattle = 52 Pigs = 75 hens = 9S5 AsSuming 1 m of bigjas 2oMJ enenay 1.1Kwh of electricity FYon the given table Catte slury: 20-4o Auma will pYachuce 1 bonne/day will pYoduce 1 tonne ASSume 4o 1 will produce 1 tonne 40 5a cate will praduce 5Qx 4o 1.3 tonne/day Produces S bijaj 1tonne feed slock[ catteslu 1.3 Lonne PYodu ces 25x1.3 3a.5 i/day Pig slury 250-300 Animay 1tonne/day ABume 1 tonne 1 tonne 300 1 15 Pias 75 300 o. as tunne/day 26m biesas 4 Lonn e feed stuck O.a5 tonne O 25X a6 6.5 m/day

hen LiHen Similanly 1 tone/doy 9000 955 hens 1xq55 9000 =7 a 10 tonne/day 50-100 e m 1 tonne feedshck tonne 1aom biogaj O.10 tanne = 10. 6 Total Biogas 3a.S 65+ 10.6 49.6 Som/day 18 a5o m of biogaj year Annual enengy Value 18 aSO X 20 365 000 MJ of enenay Amaual elecbicity 18aSo X 1.7 31 oas kwh of electicity Momey Saved:- 310a5 x O O15 23 36.815 23a yean