Coal gasification condensate water: Thermodynamic modeling of gas quench effluent

The partial oxidation products from a coal gasification process may contain substantial quantities of tars, phenols, ammonia, H₂S, CO, CO₂, H₂, and water vapor. Cooling below the dew point produces condensate water which must be treated before it can be reused or discharged into the environment. A rigorous computer model based on equilibrium thermodynamics has been developed to predict gas and condensate composition for one or more quench steps. Recycle as well as addition of fresh water to one or more stages has been included. Condensate quantities and composition as a function of quenching temperature are calculated for three gasification conditions. A flow diagram for multi‐stage effluent treatment before reuse or discharge is proposed.