Dairy shed and animal waste
Typically a mix of partially digested grain, sand, grass, urine and faeces, the stream responds well to high rate anaerobic digestion and dairy shed waste. Material from pad or barn fed cattle will record a higher methane gas yield and reduced solid waste. In-vessel reactors have a number of advantages over ponds primarily due to reduced sludge generation, elimination of rafting and increased methane gas.
The need for land to be out of service because of pond requirements is eliminated.
- Gas created may be used for electricity generation and heat recovery (cogeneration)
- Electricity plus heat plus chilling (tri-generation)
- Enhanced cellulose digestion (more energy recovered) is a feature of sonication.
- Improved nutrient management on irrigated pastures as sonication will reduce nitrogen load.
- Treated water is particularly suitable for wash-down purposes.
- Significant odour reduction as waste is enclosed and normally fugitive gas is contained as part of the energy recovery feature.
- Reduced methane to atmosphere – a good environmental outcome