Optimal Design of a Sustainable Extraction Process for the Treatment of Acidic Wastewater

The wastewater from the fluid catalytic cracking refinery is difficult to treat because of its high organic and oil content. A sustainable extraction process is designed to treat the wastewater. In this process, oil is first separated from wastewater to facilitate further removal of phenol from wastewater. The purification process of oil phase makes use of parazole to extract phenol from oil and wastewater to back-extract parazole, while the purification process of water phase makes use of Methyl Butyl Ketone (MBK) to extract phenol from wastewater followed by distillation recycling of MBK. The extraction mechanism is explained by molecular simulation from micro-level. Compared to traditional extraction operations, this treatment process reduces the make-up of extractant greatly and is sustainable. Subsequently, the extraction process is optimised by sensitivity analysis and Heat Integration with Aspen Plus software. The simulation result exhibits high purity of disposed oil and wastewater (up to 99.50 % and 99.99 %) and a great reduction of energy consumption, utility cost, and CO2 emission. Finally, one control scheme is designed for this process after its anti-disturbance ability is verified with Aspen Dynamics software.