TS-content
Daily gas production
Specific gas production
Gas utilization
250 m³/d
0.6 m³/m³ Vd
MWM gas-powered
motor-generator set
15 kWel
Operating time
Power generation
22 h/d
270 kWh/d
4-8%
450 m³/d
0.55 m³/m³ Vd
Deutz gas-powered
motor generator set
32 kWel, with exhaust heat recovery for heating
water
10 h/d
245 kWh/d
Combination gas-oil burner for steam sterilizer, 130-
355 kW
1Fluctuation due to seasonal factors (rainy/dry season)
Slaughterhouses
The proper disposal of paunch and intestinal contents (fecal matter), dung and urine and, in some
cases, blood and offal is not always ensured in slaughterhouses. Such residues can be put to good
use in a biogas plant, since:
- the energy demand and the substrate incidence are extensively parallel and usually involve
short distances for transportation;
- the biogas technique is more cost-efffcient and yields more energy than aerobic processes, so
that most slaughterhouses could cover their own energy demand with such a plant.
Slaughterhouses in developing countries span a wide size range. Consequently, various techniques
are needed for treating and/or disposing of waste materials and wastewater. While little experience
has been gained to date in connection with the disposal of slaughterhouse wastes via biogas
technology, the following assessment can nonetheless be arrived at:
- Small, village-scale slaughterhouses
in which 50 - 100 animals are slaughtered each week can make use of simple agricultural biogas
plants like those discussed in chapter 5 for disposing of all offal and other residues, and the
digested slurry can be used as agricultural fertilizer.
The main problem in such plants is the formation of a thick layer of scum made up of the contents of
paunches and fecal matter. For that reason, and in order to achieve good hygiene, retention times
of 100 days or more are considered practical.
- Medium-sized slaughterhouses (200-500 slaughterings per week)
Here, too, biogas plants are able to provide complete disposal, although large-scale types like those
used in Ferkessedougou are required. Sometimes, it is a good idea to separate the solid wastes
from the wastewater and possibly compost the solids.
- Large-scale slaughterhouses
Most such slaughterhouses are quite similar to those found in European cities and are usually
located in urban areas. Consequently, proper waste disposal and wastewater purification call for
integrated concepts in line with European standards.
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