Phase equilibrium measurement, thermodynamics modeling and process simulation for extraction of phenols from coal chemical wastewater with methyl propyl ketone

Abstract The extraction of phenols from coal chemical industry wastewater with methyl propyl ketone was studied in this work by experimental determination and process simulation. Phenol and hydroquinone were separately selected as the representatives of phenolic pollutants in the phenols-containing coal chemical industry wastewater. The liquid–liquid phase equilibrium data for methyl propyl ketone + phenol + hydroquinone + water quaternary system were measured at 40 °C and 101.3 kPa. The NRTL and UNIQUAC models were used to correlate the experimental data to achieve binary interaction parameters. The process simulation for the extraction of phenols from coal chemical industry wastewater with methyl propyl ketone was developed to obtain optimized operation parameters with the binary interaction parameters fitted from the experiment. The simulation results show that, the concentration of total phenols in the coal chemical industry wastewater could be reduced from 12,700 mg L −1 to 313 mg L −1 in the stream of the bottom in the stripping column, which is suitable for further biochemical treatment of the wastewater. The extraction solvent could be recycled through the distillation column and the stripping column. The crude phenols would be as by product in the phenols extraction and solvent recovery.