Example Data Table
| Component | Inlet (ppmv) | Outlet (ppmv) | Flow (MMSCFD) | Spec (ppmv) | Expected efficiency |
|---|---|---|---|---|---|
| H₂S | 250 | 4 | 12 | 10 | 98.40% |
| CO₂ | 2.50 | 0.30 | 18 | 0.50 | 88.00% |
| H₂O | 1200 | 50 | 6 | 100 | 95.83% |
| NH₃ | 35 | 2 | 2 | 5 | 94.29% |
| SO₂ | 80 | 6 | 9 | 10 | 92.50% |
These examples are illustrative only; real performance depends on solvent, contactor design, operating conditions, and equilibrium limits.
Formula Used
- Operating-flow estimate: Qoper ≈ Qstd × (Toper/Tstd) × (Pstd/Poper) using ideal gas.
- Solvent-to-gas ratio: gal/MMSCF ≈ (gpm × 1440) / MMSCFD.
- Overall stage efficiency: E ≈ Ntheoretical / Nactual × 100.
How to Use This Calculator
- Select Single case for one operating point, or Batch dataset for multiple lines.
- Choose the component. For Custom, enter a molecular weight.
- Enter inlet/outlet concentrations in the selected unit and add an optional specification.
- Provide the gas flow rate and its unit. Optional pressure/temperature adds an operating-flow estimate.
- Optional solvent circulation and stage counts add ratio and stage-efficiency indicators.
- Press Submit. Use export buttons to download CSV or PDF.
Efficiency as a performance indicator
Removal efficiency summarizes how much of a target contaminant is reduced across a treating step. For amine sweetening, dehydration, or scavenger beds, it compares inlet and outlet quality at the same basis. High efficiency does not always mean compliance if the inlet is high; likewise, modest efficiency can be acceptable when the inlet is near the limit. Use the calculator to pair efficiency with a specification check.
Concentration basis and specification context
Gas treating specifications are written in ppmv for trace contaminants and in mol% for bulk gases. This calculator accepts both and converts to a ppmv-equivalent view to help you compare cases. Keep sampling and lab uncertainty in mind; very low outlet values can be near analyzer detection limits. When reviewing results, confirm that inlet and outlet measurements represent the same operating period, pressure, and temperature conditions.
Mass removal estimates for inventories and reporting
The removed-mass estimate combines the mole-fraction drop with the standard gas molar flow and the selected molecular weight. Converting to kg/day supports solvent loading checks, scavenger replacement planning, and emissions accounting. Because standard flow is used, the estimate is most reliable when the flow measurement is referenced to standard conditions. If you also enter operating pressure and temperature, the tool reports an operating-flow estimate to support hydraulic comparisons.
Solvent circulation and contactor effectiveness clues
When solvent circulation is available, the calculated gal/MMSCF ratio provides normalization across throughput changes. It is not a design guarantee, but it helps flag step changes that often correlate with foaming, channeling, or degraded solvent quality. The optional stage metric, Ntheoretical/Nactual, gives an overall efficiency indicator for tray or packing performance and can complement differential pressure and temperature profile observations.
Batch runs for trending and audits
Batch mode is useful for daily reports, unit surveillance over time, or before-and-after comparisons following a turnaround. Weighted efficiency is emphasized because it reflects contaminant removed relative to the inlet load, not just an arithmetic average. Review outliers for analyzer drift, unstable flow, or short-circuiting events. If conditions vary widely, segment the dataset by operating regime so the trend reflects process behavior rather than mixed operating states.
FAQs
1) What does the calculator call “efficiency”?
It is the percent reduction from inlet to outlet: (Cin − Cout) / Cin × 100. It summarizes performance, but the outlet value and the required specification still determine compliance.
2) Can I enter concentrations in mol% instead of ppmv?
Yes. Select mol% as the concentration unit and enter Cin, Cout, and any specification on the same basis. The tool also shows ppmv-equivalent values for quick comparison.
3) How is removed mass in kg/day estimated?
The tool converts standard gas flow to mol/day, multiplies by the mole-fraction drop, then applies molecular weight. It is an estimate for screening and reporting, not a substitute for full material balance.
4) Why do I see an operating-flow estimate?
If you provide operating pressure and temperature, the calculator adjusts the standard flow using an ideal-gas relationship. This helps compare hydraulics or contactor loading at actual conditions.
5) What does the solvent-to-gas ratio tell me?
It normalizes solvent circulation against throughput as gal/MMSCF. Use it for trending, detecting step changes, and comparing days. It does not guarantee capacity without equilibrium and mass-transfer checks.
6) Why use weighted efficiency in batch mode?
Weighted efficiency reflects contaminant removed relative to the inlet load across varying flows. It avoids giving small-flow points the same influence as high-flow points, which is helpful for surveillance datasets.