| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Gas flow | 50 | MMSCFD | Standard-day basis |
| H2S inlet / outlet | 1500 / 4 | ppmv | Pipeline-style target |
| CO2 inlet / outlet | 80000 / 2000 | ppmv | Partial removal |
| Solvent | MDEA | — | Selective sweetening typical |
| Amine concentration | 40 | wt% | Common strength range |
| Lean / rich loading | 0.10 / 0.45 | mol/mol | Defines working capacity |
| Density | 1050 | kg/m³ | Depends on strength and temperature |
| Safety factor | 15 | % | Design margin for uncertainties |
- Enter gas flow and inlet/outlet targets for H2S and CO2.
- Select a solvent and set concentration and molecular weight.
- Choose lean and rich loadings to reflect your operating window.
- Confirm density and add a safety factor for design conservatism.
- Click Calculate to view circulation, mass rates, and removal basis.
- Export the report using the CSV or PDF buttons.
Process Objective and Design Basis
Gas sweetening removes acid gases, mainly hydrogen sulfide and carbon dioxide, to meet pipeline, export, or plant protection limits. This calculator uses standard-condition molar conversion and target ppm reductions to estimate how many moles of acid gas must be absorbed each day.
Solvent Selection and Strength
Amines differ in reactivity and selectivity. Faster-reacting solvents can reduce absorber height, while selective solvents can prioritize H2S over CO2. Solution strength affects viscosity, corrosion tendency, and working capacity; the concentration field converts required amine mass into an overall solution circulation rate.
Loading Window and Working Capacity
Lean and rich loadings define the usable “capacity” of the solvent loop. The difference between rich and lean loading represents the net molar pickup per mole of amine. A wider loading window reduces required circulation, but must remain realistic for regenerator performance and thermal stability.
Circulation Rate Interpretation
The recommended circulation is a screening value for pump sizing, line sizing, and early equipment checks. It does not replace hydraulic design or equilibrium modeling. Use the safety factor to cover uncertainties in inlet composition swings, solvent degradation, foaming, or conservative outlet specifications.
Example Case Walkthrough
Example data for a preliminary scenario:
- Gas flow: 50 MMSCFD
- H2S: 1500 ppmv in, 4 ppmv out
- CO2: 80000 ppmv in, 2000 ppmv out
- Solvent: MDEA, 40 wt%, density 1050 kg/m³
- Lean/Rich loading: 0.10 / 0.45 mol/mol, safety factor 15%
For this case, the screening acid gas removal is about 198 kmol/hr and the recommended circulation is about 185 m³/hr. Use these outputs to compare scenarios, then confirm with process simulation, materials review, and vendor hydraulic limits.
FAQs
It estimates the solvent circulation rate needed to absorb the specified H2S and CO2 removal, based on standard gas molar flow and the selected loading window.
Gas treating specifications are commonly expressed as parts per million by volume. The model converts ppmv differences to a mole fraction for a quick molar removal estimate.
Use plant history, licensor guidance, or simulation results. The rich minus lean difference represents working capacity; too wide may be unrealistic for regeneration or corrosion control.
Not in this screening method. They are captured for reporting. Detailed design should include equilibrium, kinetics, and hydraulics that depend strongly on temperature and pressure.
It covers uncertainties such as composition swings, solvent aging, foaming tendency, and conservative outlet limits. It also provides margin for pump and control stability.
This tool is tuned for amine-type chemical absorption using a loading window. Physical solvent systems require different property models and should be evaluated with dedicated correlations or simulation.
Verify absorber hydraulics, contact efficiency, regenerator heat duty, corrosion limits, reclaiming strategy, and downstream dehydration or sulfur recovery constraints before finalizing equipment sizes.