Izvorni znanstveni članak
Zootechnical and economic aspects of producing biogas out of pig manure
Davor Kralik
Zdravko Tolušić
Igor Kralik
Ivana Majkovčan
Sažetak
Pig manure that was used in the research was obtained on two farms situated near Osijek. The first farm used grid floor system (grid floor), so the amount of manure dry matter was low due to high amount of technological waters used for rinsing the drainage canals.The amount of 3.8% dry matter (DM) was conditioned at 10% of dry matter by adding solid separated component. The second farm used deep litter system (DL) and provided significantly higher amount of dry matter, 19.56%. By adding water, DM concentration was reduced to 10%. The average dynamics of producing biogas out of deep litter (DL) substrates was 232.75 ml/day, and out of grid floor substrates it was 105.25 ml/day. The most intensive production was achieved with deep litter substrates in the period from 5th to 35th day of anaerobic fermentation, when the average daily amount of produced gas reached 472.44 ml. Pig manure from grid floor had weaker intensity of biogas production. The most intensive biogas production was achieved from 2nd to 21st day, with average daily amount of 390.92 ml. Total biogas produced out of 500 ml of pig manure with 10% DM during an 80-day anaerobic fermentation was 18.768 ml (DL), and total biogas produced out of 500 ml pig manure from grid floor with 10% DM was 8.415 ml. By testing daily amounts of biogas and total biogas produced, statistically highly significant difference were determined (p<0.001), which led to a conclusion that deep litter pig manure was more favorable for biogas production. The research has proved that it is possible to produce 6.1 kWh of electric energy out of 1 m3 of biogas. Pig farms spend great amounts of electric and heating energy. The farm with grid floors spends yearly 984200 KW of electric energy and 433512 m3 of earth gas. Building plants for biogas production within farms enables usage of manure as a source of energy, thus producing their own energy affecting resulting in lower production costs.
Ključne riječi
biogas; deep litter; keeping system; economic aspects; pig manure
Hrčak ID:
4498
URI
Datum izdavanja:
10.7.2006.
Posjeta: 2.782 *