Anaerobic Digestion Systems
Transform organic waste into renewable energy with our advanced anaerobic digestion technology. From initial design to ongoing optimization — we deliver complete biogas solutions that maximise energy output while minimising environmental impact.
Why Choose Anaerobic Digestion?
Biogas production isn't just environmentally responsible — it's economically smart. Our systems typically achieve 85-92% methane recovery rates, generating substantial returns on investment.
Get Your System QuoteProcess Overview & Technology
Pre-Treatment Stage
Organic materials undergo careful preparation. Size reduction, pH balancing, and contaminant removal ensure optimal digestion conditions. This stage typically increases biogas yield by 12-18%.
Anaerobic Fermentation
Bacteria break down organic matter in oxygen-free environments. Temperature control (35-55°C) and retention times (15-30 days) are precisely managed for maximum methane production.
Biogas Capture & Purification
Raw biogas (55-70% methane) undergoes purification to remove CO₂, H₂S, and moisture. Our systems achieve 95%+ methane purity for direct grid injection or CHP generation.
What makes anaerobic digestion particularly attractive? The process generates multiple revenue streams. Beyond biogas sales, digestate provides high-quality fertiliser — often worth £15-25 per tonne. Gate fees for waste acceptance create additional income (typically £30-80 per tonne, depending on material type).
Modern AD plants operate as integrated systems. Heat recovery from CHP units maintains digester temperatures, reducing external energy requirements by 40-60%. Automated feeding systems ensure consistent organic loading rates — crucial for maintaining stable biogas production.
Plant Management & Operations
Daily Operations Excellence
Successful AD plants require meticulous daily management. Our operators monitor pH levels (6.8-7.2 optimal), volatile fatty acid concentrations, and alkalinity ratios. Small deviations can reduce biogas output by 15-25% within days.
Feeding schedules follow precise protocols. Overloading digesters causes acid accumulation and process inhibition. Our systems typically process 85-120 tonnes per day (depending on plant capacity), with organic loading rates maintained between 2-4 kg VS/m³/day.
Performance Tracking
Real-time monitoring of gas composition, flow rates, and energy output.
Preventive Maintenance
Scheduled equipment inspections prevent costly breakdowns and production losses.
Laboratory Analysis
Regular testing ensures optimal biological conditions and early problem detection.
Process Optimization
Continuous improvements based on performance data and operational experience.
Temperature control proves critical — mesophilic digesters (35-40°C) offer stability, while thermophilic operation (50-55°C) increases biogas production by 20-30% but requires more energy input. Economic analysis determines the optimal approach for each site.
Digestate management often determines project viability. Quality digestate commands premium prices, but contamination (particularly plastics or heavy metals) severely reduces marketability. Our pre-treatment systems eliminate 98%+ of contaminants.
Methane Monitoring & Gas Quality
Methane concentration directly impacts revenue — every percentage point matters. Grid injection requires 95%+ methane content, while CHP systems operate efficiently at 60%+ concentrations. Our monitoring systems track composition in real-time, alerting operators to deviations within minutes.
Continuous Analysis
Gas chromatography systems monitor CH₄, CO₂, H₂S, and NH₃ concentrations every 15 minutes. Early detection prevents process upsets and maintains optimal production conditions.
Safety Systems
Methane leak detection and flare systems ensure safe operations. Automated shutdown procedures activate when gas concentrations exceed safe limits (typically 25% LEL).
Revenue Optimization
Gas upgrading systems increase methane content from 60-65% to 95%+. This transformation can double the value per cubic metre of biogas produced.
Hydrogen sulphide removal prevents corrosion and meets gas quality standards. Iron chloride dosing or biological scrubbing reduces H₂S from 3,000-5,000 ppm to <10 ppm. This investment pays for itself through reduced maintenance costs and extended equipment life.
Siloxane removal becomes essential for CHP applications. These compounds (from personal care products) cause engine damage if not removed. Activated carbon systems eliminate 99%+ of siloxanes, protecting expensive generator sets.
Efficiency Metrics & Performance Indicators
Key Performance Indicators
How do you measure AD plant success? Multiple metrics provide the complete picture. Biogas yield (m³/tonne VS added) indicates biological efficiency. Electrical efficiency (kWh/m³ biogas) measures energy conversion performance. Availability (operational hours/total hours) tracks reliability.
- Specific biogas production: 450-650 m³/tonne VS
- Organic loading rate: 2.5-4.0 kg VS/m³/day
- Hydraulic retention time: 20-35 days
- Plant availability: 95%+ annually
- Methane content: 60-70% (raw biogas)
- Digestate dry matter: 6-8% typically
Economic performance matters most to investors. Levelised cost of electricity (LCOE) compares favourably with other renewables — typically £45-85/MWh for well-managed plants. Payback periods range from 8-14 years, depending on feedstock costs and revenue streams.
Benchmarking Excellence
Top-performing plants achieve remarkable results. Danish facilities average 92% plant availability with biogas yields exceeding 600 m³/tonne VS. German plants demonstrate consistent electrical efficiencies above 42%.
Continuous Improvement
Performance optimization never stops. Advanced process control systems use machine learning to predict optimal feeding schedules. Predictive maintenance reduces unplanned downtime by 35-50%.
Financial Performance Metrics
Revenue streams vary significantly by location and market conditions. UK Renewable Heat Incentive payments historically provided £2.80-4.50/MWh thermal. Feed-in tariffs for electricity generation ranged from £8-15/MWh (plus wholesale prices). Gate fees for waste acceptance often exceed energy revenues.
Capital Costs
£3,500-6,000 per kW installed capacity (including infrastructure, pre-treatment, and gas upgrading systems).
Operating Costs
£15-25/MWh generated (including labour, maintenance, insurance, and consumables).
Revenue Potential
£65-120/MWh total revenue (energy sales plus gate fees, RHI payments, and digestate sales).
Payback Period
8-14 years typically (varying with feedstock costs, energy prices, and support mechanisms).
Risk factors affect project viability. Feedstock price volatility can impact margins significantly — long-term contracts provide stability but may limit upside potential. Regulatory changes (particularly support scheme modifications) create uncertainty. Technical risks include equipment failures and process upsets.
Ready to Develop Your Anaerobic Digestion Project?
From feasibility studies to full-scale plant development — we provide complete anaerobic digestion solutions. Our team has delivered projects ranging from 250kW farm-scale plants to 5MW industrial facilities.
What We Deliver
- Comprehensive feasibility assessments
- Process design and optimization
- Equipment procurement and installation
- Commissioning and performance testing
- Operations training and support
- Long-term maintenance contracts