GPSA Ch. 1
| Component | BP (°F) | FP (°F) | Tc (°F) |
|---|---|---|---|
| Methane | -258.7 | -296.5 | -116.7 |
| Ethane | -127.5 | -297.0 | 90.1 |
| Propane | -43.7 | -305.8 | 206.2 |
| n-Butane | 31.1 | -217.0 | 305.7 |
| n-Pentane | 96.9 | -201.5 | 385.7 |
| n-Hexane | 155.7 | -139.6 | 453.7 |
| Water | 212.0 | 32.0 | 705.4 |
| CO₂ | -109.3 | -69.9 | 87.9 |
| H₂S | -76.5 | -121.9 | 212.7 |
Clausius-Clapeyron Equation:
Relates vapor pressure to temperature using the heat of vaporization. Assumes constant ΔHvap over the temperature range. Used for pressure-adjusted boiling point estimation.
Raoult's Law (Mixture Bubble Point):
At the bubble point, the sum of each component's mole fraction times its K-value equals unity. K-values are estimated from the ratio of pure-component vapor pressure to system pressure.
The calculator uses the Clausius-Clapeyron equation to estimate how boiling points shift with pressure. This relates vapor pressure to temperature using the heat of vaporization, per GPSA Ch. 1.
Bubble point is the temperature at which the first vapor bubble forms from a liquid mixture, while dew point is where the first liquid droplet condenses from a vapor mixture. Both are calculated using Raoult's Law for ideal mixtures.
The calculator includes pure component data for methane, ethane, propane, isobutane, n-butane, isopentane, n-pentane, and heavier hydrocarbons. Normal boiling points and freezing points are per GPSA Ch. 1 reference data.
Freezing points determine the minimum safe operating temperature to avoid solid formation (freeze-out) in cryogenic heat exchangers and columns. Heavier hydrocarbons like benzene can freeze and plug equipment at cryogenic conditions.