Anaerobic Digestion (AD)
Anaerobic digestion refers to the biological breakdown of organic material in the absence of oxygen. It is a net energy-producing process as it generates substantial quantities of 'biogas' which consists mainly of methane and carbon dioxide. Biogas is then used as a fuel to produce both electrical energy and heat. Excess renewable electricity can then be exported to the national grid, or for use within your own facilities. By using biogas as a fuel the system is displacing the use of fossil fuels, thereby reducing the emissions of carbon dioxide into the atmosphere.
A wet anaerobic digestion plant from HAASE can typically take material from numerous sources of organic food stock such as:-
- Farm by-products (pig slurry, manure etc)
- Source separated food waste
- Food processing waste
- Abattoir waste
- Energy crops and silage
Wet AD
Wet anaerobic digestion has developed to be the state-of-the-art process for bio-waste treatment and stabilisation in Europe. In direct contrast to composting, it is performed in the absence of air, which offers numerous benefits such as:-
- Low energy requirement – high value electrical renewable energy exported to the grid (when biogas produced is utilised with a CHP plant)
- Carbon neutral – extracts volatile carbon and methane for energy production
- Low space requirement (build upward rather than out)
- Little or no water required after start-up, a closed loop process
- Low operating cost; low manpower requirement, low maintenance requirement - piping and pumping
- Less expensive than composting for plants larger than 50,000t/a
- Closed, hygienic, very low odour process with significantly less foul air to treat than aerobic systems
- After-treatment stage produces a high quality end product
- Sustainable technology with one of the highest deliverable BMW diversion rates
- Can be used to expand local renewable energy production via use of energy crops like maize or fodder beat.
Reference list
Click here to download a PDF reference list.