Tribrid-Bioreactor™ · COD basis
Enter your flow and COD strength to see the biogas, water, carbon, and compliance-risk value of treating that stream on site instead of discharging or hauling it.
Typical F&B COD: brewery 25–70k · dairy 40–130k · food processing 30–95k · rendering 60–150k
Share of influent COD converted in the digester. 85–92% is typical for soluble F&B streams.
Hauling, treatment, and discharge fees at base rate
Delivered price of the fuel biogas displaces
Ratios are typical ranges. A lab COD test on your own stream beats any conversion factor.
Treating on site transfers discharge-permit responsibility and removes your exposure to strength-based surcharges and violation penalties.
Current frequency of COD, TSS, or pH discharge violations
Extra fees for high-strength load above permit limits
EPA and state penalties commonly land between $10k and $100k per incident
Applies a 50% risk premium for heightened regulatory scrutiny
Same annual CO₂ reduction
If the biogas runs a CHP engine
Working on a COD basis removes a conversion step. Methane yield follows directly from chemical oxygen demand by stoichiometry — 1 kg of methane exerts 4 kg of COD — so every kilogram of COD destroyed produces 0.25 kg of CH₄, or 0.35 Nm³ at standard conditions. No empirical BOD correlation sits in the middle.
| Term | Value | Basis |
|---|---|---|
| COD load | gal/d × mg/L × 8.34 ÷ 10⁶ | Pounds of COD per day |
| Methane yield | 0.25 kg CH₄ / kg COD | Stoichiometric; equals 0.35 Nm³/kg |
| Capture factor | 0.92 | Net of cell synthesis and methane dissolved in the effluent |
| Methane heating value | 55.5 MJ/kg (HHV) | Matches how US gas is priced |
| Biogas methane content | 70% | Typical for a high-rate reactor on soluble COD |
| Water recovery | 95% | Treated effluent available for reuse |
| Displaced gas carbon | 53.06 kg CO₂/MMBtu | EPA factor for natural gas |
| Per-vehicle carbon | 4.6 t CO₂/yr | EPA typical passenger vehicle |
| CHP conversion | 36% electrical, 10,500 kWh/home | Engine efficiency; EIA average US household |
The carbon figure counts only the fossil gas the biogas displaces. Avoided hauling miles, avoided aeration power, and avoided fugitive methane from lagoons or holding tanks are all real and none of them are counted here, so treat the number as a floor. Surcharges are applied to base disposal cost as an increment, so they are not double-counted against disposal savings. Every output is a planning estimate — a site-specific engineering study supersedes it.
Estimates only. Actual yields depend on COD biodegradability, temperature, FOG and solids content, nutrient balance, and inhibitory compounds in your stream.
PurposeEnergy is an established US-based renewable fuels and biogas specialist focused on waste solutions for the food and beverage industries. Over the last 15 years, PurposeEnergy has developed, owned, and operated multiple projects that convert organic waste streams to biogas for use in industrial processes, conversion to renewable electricity or refinement to Renewable Natural Gas (“RNG”). PurposeEnergy is a portfolio company of Quinbrook.
