10 calculators for biogas feedstock yield, cleanup, upgrading, pipeline injection, and credit economics — built for engineers developing landfill, dairy, WWTP, and food-waste RNG projects.
10 calculators · 4 engineering guides · LandGEM v3.03 · IPCC 2019 Tier-2 · AGA Report 4A · CARB LCFS · EPA RFS 40 CFR 80.1426
EPA LandGEM first-order decay summation for annual landfill methane generation, peak-year rate, captured CH₄ for RNG, and NMOC mass flux.
Anaerobic-digester biogas yield with LCFS avoided-baseline credit, volatile solids loading, and methane potential per IPCC Tier-2 method.
WWTP and food-waste anaerobic digester biogas yield with Class A/B biosolids assessment and Liu correlation for volatile solids destruction.
Dry-media H₂S scavenger bed sizing for biogas cleanup, breakthrough capacity, and bed life calculation to meet pipeline spec.
Silicon-basis activated carbon and silica gel bed sizing to remove D4/D5 siloxanes from landfill and WWTP biogas for engine/turbine protection.
Pressure swing adsorption sizing for biogas upgrading to pipeline RNG (≥96% CH₄), methane recovery, and bed cycle design.
Polymer membrane sizing with specific-area method for polyimide, cellulose acetate, and polysulfone technologies. Includes methane slip estimate.
Gas-quality blending for tariff compliance with Wobbe Index, HHV, specific gravity, and methane number per AGA 4A.
CARB LCFS pathway carbon intensity scoring for RNG (dairy, landfill, WWTP, food waste). Tier-2 method with avoided emissions credits.
Stacked-revenue project DCF for D3 RIN + LCFS + brown gas market stack. NPV, IRR, simple payback, and sensitivity analysis.
First-order decay and volatile-solids methods set RNG project capacity.
Pipeline-spec gas: ≥96% CH₄, <4 ppm H₂S, low siloxane.
Stacked D3 RIN + LCFS revenue drives RNG project economics.
Feedstock characterization for landfill, dairy manure, WWTP, and food-waste digesters — methane yield models per LandGEM, IPCC 2019, and EPA AgSTAR.
H₂S scavenger sizing (iron sponge, SulfaTreat), siloxane removal (coal GAC), and moisture/VOC pretreatment per GPSA §21.
Biogas CO₂ upgrading compared — PSA vs membrane vs amine vs water scrubbing on methane recovery, slip, compression power, and capex/opex.
Stacked D3 RIN (RFS2), CARB LCFS, and pipeline-tariff revenue; 2024 LCFS amendments and NPV / IRR drivers explained.