Gases Solubility Water

Overview

Engineering reference data for Gases Solubility Water in combustion engineering.

Key Formulas

Heat Release

$Q = \dot{m} \cdot HV$

Fuel energy release rate.

Air-Fuel Ratio

$AF = \frac{m_{air}}{m_{fuel}}$

Mass of air per mass of fuel.

Excess Air

$EA = \frac{O_2}{21 - O_2} \times 100\%$

From flue gas oxygen measurement.

Variables

Gases Covered

The following gases have solubility data available in water:

Important Notes on Partial Pressure

For gases in mixtures (e.g., oxygen in air), use the partial pressure of the individual gas rather than total system pressure.

Example: Air at 1 atm contains approximately 20% oxygen by volume. The effective partial pressure for oxygen solubility calculations is:

$p_{O_2} = 0.20 \times 101.325 \text{ kPa} = 20.27 \text{ kPa}$

This relationship follows from Dalton's Law of Partial Pressures:

$p_i = y_i \cdot P_{total}$

where $y_i$ is the mole fraction of gas $i$ in the mixture.

General Solubility Trends

• Gas solubility in water decreases with increasing temperature (opposite to most solids)
• Solubility increases with increasing pressure (Henry's Law)
• Polar gases (NH₃, SO₂, CO₂) show higher solubility due to chemical reactions with water
• Non-polar gases (N₂, O₂, Ar, He) have lower solubility

Data Conditions

All solubility values are referenced to 1 atmosphere (101.325 kPa) total pressure at saturation. Data covers temperatures from 0°C to approximately 100°C depending on the specific gas.

References

• Original Source