GPSA Ch. 16
| Parameter | Typical Range |
|---|---|
| Column Pressure | 75–200 psig |
| Reboiler Temperature | 250–400°F |
| Theoretical Stages | 6–14 |
| Tray Efficiency | 45–65% |
| C₁ in Bottoms Spec | 0.5–2.0 mol% |
| Dissolved Gas Loading | 3–15 SCF/gal |
Column Diameter (Souders-Brown):
Where CSB depends on tray spacing. Design velocity = Uflood × flood fraction. Column cross-section sized for overhead vapor traffic.
Function: The rich-oil demethanizer strips dissolved methane and ethane from absorber rich oil. Overhead vapors (primarily C₁/C₂) are returned to the absorber or fuel system. Bottoms (demethanized rich oil) proceed to the oil purification still for NGL recovery.
Understand rich-oil demethanizer design, reboiler selection, and stripping optimization
The rich-oil demethanizer strips dissolved methane and ethane from rich absorption oil to produce NGL-laden oil for downstream fractionation. It is a key column in lean oil absorption plants per GPSA Ch. 16.
Stripping efficiency measures the percentage of dissolved methane removed from the rich oil. The calculator uses tray-by-tray equilibrium calculations to determine the required number of trays and reboiler duty for target methane removal.
The calculator sizes columns based on typical parameters including rich oil flow rate, dissolved gas composition, column pressure, tray spacing, and reboiler temperature. Results include diameter, tray count, and overhead gas rate per GPSA Ch. 16.
Rich-oil demethanizer columns are designed per ASME Section VIII for pressure containment and GPSA Ch. 16 for process sizing. The calculator estimates vessel weight based on column dimensions and design pressure.