Design and simulation of sour water unit: A case study of port Harcourt refining company
Michael Anemka Nabula, Kenneth Dagde and Patience Ikenyiri
The simulation of a 35.0m3/hr sour water plant model using aspen hysys process simulator was carried out using 3 different fluids; steam, kerosene and naphtha, respectively. The major equipment in the plant model are: 3-phase separator, heat exchanger and absorber tower. The results of the parameter obtained from aspen HYSYS were presented in terms of material balance, Energy balance, sizing and costing. The material balance result in terms of composition (mole fraction) obtained from the absorber outlet stream for treated water were constant for naphtha and kerosene plants showing 0.0248, 0.0004, 0.9748 and 0.0000 for NH3, H2S, H2O and oil, respectively while that of steam plant gave 0.0296, 0.0004, 0.9699 and 0.0000 for NH3, H2S, H2O and oil, respectively. The result in terms of material balance shows total elimination of oil from sour water with 97.48% recovery of water, 0.04% reduced rate of H2S and 2.48% reduced rate of NH3. The energy requirement of each plant model in terms of heat duty (kJ/hr) for heater and heat exchanger for steam, kerosene and naphtha plant models were also examined. Steam plant heat duty for heater and heat exchangers gave: 6.798 x 106 KJ/hr and 8.031 x 106 KJ/hr, respectively, kerosene plant heat duty for heater and heat exchanger were 8.031 x 106 KJ/hr and 2.067 x 107 KJ/hr, respectively, naphtha plant heat duty for heater and heat exchanger were 8.031 x 106 KJ/hr and 1.238 x 107 KJ/hr, respectively. Sizing results of major equipment such as 3-phase separator, heat exchanger and absorber column for steam, kerosene and naphtha plant were obtained from aspen HYSYS simulation along with cost analysis.