Size circulation rates for amine systems with confidence. Convert gas flows, ppm targets, and loadings. Produce clear outputs for design checks, reporting, and approvals.
| Case | Gas flow | H2S (in→out) | CO2 (in→out) | Amine | Lean→Rich | Safety | Result (approx.) |
|---|---|---|---|---|---|---|---|
| A | 25 MMSCFD | 1200→10 ppmv | 20000→5000 ppmv | MDEA 40 wt% | 0.10→0.45 | 10% | ~10–14 m³/h |
| B | 8,000 Nm³/h | 300→5 ppmv | 0→0 ppmv | MEA 30 wt% | 0.12→0.38 | 5% | ~2–4 m³/h |
The calculator estimates solution circulation from removed acid gas and available loading swing.
Amine circulation is the liquid flow that carries reactive amine through the absorber and regenerator loop. Adequate flow provides contact area and reaction capacity to capture H2S and CO2, meet outlet limits, and maintain stable temperature profiles. Oversizing increases pumping, heating, and cooling duties and can aggravate entrainment, while undersizing often shows up as rising outlet ppmv during load swings, foaming, or temperature upset. A calculated baseline helps set a controllable operating window.
Sizing begins with a defensible gas flow basis and acid‑gas concentrations. Use metered inlet flow at the stated temperature and pressure basis, then enter inlet and target outlet ppmv for H2S and CO2. Confirm solvent wt% from lab checks, and verify density near operating temperature. Molecular weight and density govern the conversion from molar requirement to volumetric circulation. When data are uncertain, use conservative targets and document assumptions.
Lean and rich loadings define the available working capacity: Δloading = rich − lean (mol acid per mol amine). A larger swing reduces required circulation, but may be limited by corrosion, heat stable salts, or regenerator constraints. Stage efficiency represents real mass‑transfer performance and tray or packing condition, including maldistribution and channeling. Conservative efficiency values help prevent optimistic under‑circulating designs, especially when internals are aged or fouled.
Circulation rate influences absorber hydraulics, regenerator heat duty, and pump power. Higher flow increases liquid traffic and pressure drop, but can improve wetting and short‑term removal during upsets. Use pump screening to relate differential pressure and flow to power, then check available head and margin. Apply a safety factor to cover fouling, temperature variation, antifoam use, and potential future capacity or tighter specifications.
After choosing a design flow, validate against plant data. Compare predicted rich loading with lab samples, check temperature bulges, and trend filter differential pressure. If outlet specs drift, investigate solvent strength, contamination, foaming tendency, and regenerator performance before simply increasing circulation. Review make‑up rate and reclaiming history, because degraded solvent reduces effective capacity. Routine sampling and operator logs support timely adjustments.
Gas flow, inlet acid‑gas ppmv, outlet targets, loading swing, and stage efficiency drive the required molar removal capacity. Solution wt% and density mainly affect how that molar requirement converts to a volumetric flow.
Use recent operating lab data for both streams, preferably averaged over stable periods. If you lack samples, start with typical vendor ranges for your solvent and refine after you collect plant measurements.
Absorbers rarely achieve ideal contact. Efficiency accounts for packing wetting, tray condition, maldistribution, and mass‑transfer limits. Using a conservative value reduces the risk of underestimating circulation during real operation.
Not always. More flow can improve wetting and capacity, but it can also increase pressure drop, entrainment, and energy use. If you already have good loading swing and temperature profile, root causes may be elsewhere.
For early design, 10–25% is common to cover variability, fouling, and future debottlenecking. For steady, well‑characterized units, a smaller factor may be justified with good monitoring and control history.
No. It is a screening estimate based on your assumed differential pressure and efficiency. Final selection must use detailed hydraulic calculations, NPSH checks, equipment curves, and site‑specific piping losses.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.