How is the mass of moisture in the syngas at the outlet of the gasifier calculated?

There is a conversion factor; the water-vapor ratio is 1.3–1.5, and it can also be calculated based on saturated steam. The corresponding saturated vapor pressure is determined based on the outlet temperature; the saturated vapor pressure divided by the outlet pressure gives the steam content!

The theoretical basis is that the water vapor in the syngas at this time is the saturated vapor at that temperature; knowing the flow rate of the syngas also allows for calculation.

Moisture content: 1. The moisture content in the syngas is determined, as a volume percentage, either using an on-line syngas analyzer or through manual analysis. Alternatively, based on the temperature at the syngas outlet, a table can be consulted to find the saturated vapor pressure of water at that temperature; the ratio of this pressure to the total pressure of the syngas represents the volume ratio (mole ratio) of water. 2. Flow meters are installed at both the syngas outlet and the exit of the carbon scrubber to measure the total flow rate of the crude syngas. 3. Using the values from 1 and 2, the volume of water can be calculated; usually, this value is already expressed in terms of standard volumetric flow rate. 4. The standard volumetric flow rate is then converted into a mass flow rate. Usually, the flow rate of the purified active gas can also be used to infer the moisture content.

These calculations based on saturated vapor pressure and molar mass are merely rough reference values. The compressibility factor of the gas also needs to be taken into account for corrections