NGL Recovery Optimization Calculator
Material balance model using GPSA liquid yield factors (Table 23-2) for cryogenic and refrigeration-based NGL recovery. Calculates liquid yields, GPM content, residue gas properties, Wobbe Index, and frac spread economics.
Feed Gas Composition
MMSCFD
mol%
mol%
mol%
mol%
Est. GPM: 3.27 (Rich)
Balance assumed to be methane + inerts
Operating Mode
Turboexpander + External Refrigeration
Cryogenic operation: -120°F to -150°F demethanizer. Typical for petrochemical feedstock markets. GSP or RSV process.
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%
%
Product Pricing (Mont Belvieu basis)
$/gal
$/gal
$/gal
$/gal
$/MMBtu
Leave at 0 for volume-only calculation
📚 Learn the Theory
Understand NGL recovery processes, cryogenic plant design, and optimization strategies
Frac Spread: NGL value minus shrinkage gas value - key economics driver
Ethane Rejection: Common when C₂ price < 35% of propane value
Mode Flexibility: Plants designed for 2-3 operating modes add optionality value
Operating Cost: ~$0.08-0.20/gal NGL for cryogenic plants (fuel + power)
Rule of Thumb: Rich gas (>3 GPM) typically justifies turboexpander; lean gas (<1.5 GPM) may favor JT/refrigeration only or bypass.
Technical Notes
Calculation Methodology
Material balance using GPSA liquid yield factors to estimate NGL production from specified recovery targets. Conversion from gas volume (MSCF) to liquid volume (gallons):
GPD = MMSCFD × 1000 × mol% × Rec% × gal/MSCF
where gal/MSCF = (1000/379.49) × MW / ρliquid
Assumptions & Limitations
Ideal gas molar volume: 379.49 SCF/lbmol @ 60°F, 14.696 psia
Feed gas balance assumed to be methane (no N₂/CO₂ correction)
Butanes modeled as 40/60 iC₄/nC₄ mix (GPSA typical)
C₅+ recovery fixed at 99.9%
Heating values are gross (HHV) basis per GPA 2145
Liquid densities @ 60°F from GPSA Table 23-2
References
GPSA (SI)
GPA Standard 2145 - Physical Constants
Campbell, J.M., "Gas Conditioning and Processing", Vol. 2
Arnold & Stewart, "Surface Production Operations", Vol. 2