Digesters & Biogas Systems
CM Aquatechnik supplies anaerobic sludge digesters for stabilisation of primary and secondary sludge with simultaneous biogas (methane) production. Available in fixed-cover, floating-cover, and membra
Technical Specifications
| Digester Types | Fixed-cover CSTR · floating-cover · gas-holder |
| Capacity | 100 – 50,000 m³ digester volume |
| Retention Time (HRT) | 15 – 25 days |
| Temperature | Mesophilic 32–38 °C · thermophilic 50–55 °C |
| Biogas Yield | 0.4 – 0.5 m³ biogas / kg VS destroyed |
| Biogas Composition | CH₄ 60–70% · CO₂ 30–40% |
| VS Reduction | 45 – 65% |
| Biogas Utilisation | CHP engine · boiler · flare |
| Electrical Output (CHP) | 1 – 5,000 kW (plant size dependent) |
| Standards | CE · ATEX · DVGW · DIN EN 12255 |
Key Features
- Biogas recovery reduces net energy cost of sludge treatment to near zero
- CHP engine generates electricity and heat from biogas — revenue from energy
- VS destruction of 50–60% reduces final sludge disposal volume and cost
- Floating-cover digester allows variable gas storage with constant pressure
- ATEX-certified gas handling and electrical equipment throughout
- Complete system: digester, mixer, heat exchanger, gas storage, CHP, flare
Applications
- Municipal WWTP sludge stabilisation
- Industrial sludge anaerobic digestion
- Food waste co-digestion (FW + sludge)
- Agricultural slurry and manure digestion
- Brewery and distillery by-product digestion
- Energy-neutral WWTP design
Product Overview
CM Aquatechnik supplies anaerobic sludge digesters for stabilisation of primary and secondary sludge with simultaneous biogas (methane) production. Available in fixed-cover, floating-cover, and membrane-cover CSTR (completely stirred tank reactor) configurations. Biogas collection and utilisation systems for CHP (combined heat and power) generation or safe flaring are supplied as complete systems.
Frequently asked questions
How is a sludge digester sized?
Digester volume is determined mainly by the daily sludge volume and the required hydraulic retention time, typically 15–25 days, together with the organic load and the selected temperature regime. Our systems cover digester volumes from 100 to 50,000 m³.
Should I choose mesophilic or thermophilic digestion?
Mesophilic digestion at 32–38 °C is the most widely used regime because it is stable and comparatively easy to operate. Thermophilic digestion at 50–55 °C accelerates the biological processes but requires more heat and closer process control, so the choice depends on sludge type, energy balance and treatment objectives.
How much biogas can be expected and how is it used?
Biogas yield is typically 0.4–0.5 m³ per kg of volatile solids destroyed, with a methane content of 60–70%. The gas can be used in a CHP engine to generate electricity and heat, in a boiler for process heating, or safely flared when it is not required.
What information do you need for a quotation?
Please provide the sludge types and daily quantities in m³/day, their dry solids and volatile solids content, any co-substrates such as food waste, your preferred temperature regime and cover type, and the intended biogas utilisation (CHP, boiler or flare). Send us your requirements and we will prepare a proposal within 48 hours.
