Inlet diverters and oil collectors in distillation columns for reducing COD and BOD5 in biodiesel plants

Wastewater from the biodiesel process contains oil and methanol, requiring treatment to reduce chemical oxygen demand (COD) and biological oxygen demand (BOD5). Chemical separation can generate additional waste, so innovative methods like gravity separators are essential. This research uses an inlet diverter and oil collector at the distillation column bottom to treat wastewater effectively. The results show COD and BOD5 values of 210 mg/L and 80 mg/L, respectively, with percentage of removal was ±70 % and ±60 %, respectively, with 96.2 % oil recovery. Gas chromatography (GC) analysis found 2.6 % methanol and minimal impurities. This method effectively separates water-methanol-oil mixtures, making it suitable for biodiesel plants.