In the last 10 years, we have successfully installed over two dozen spent caustic wet oxidation systems, with capacities varying from 0.5 to 18.5 m3/h (2 to 81 gpm). Our systems are the industry standard and are included in many of the new world-scale ethylene plants.
In the petroleum and petrochemical industries, spent caustic liquors typically come from two main sources:
These spent caustic streams are a significant odor source as well as disruptive to the operation of a biotreatment facility. In addition, the Chemical Oxygen Demand (COD) load in spent caustic is usually very high (10,000 - 100,000 mg/l), and the contaminants in spent caustic typically include sodium carbonate, sodium sulfides, mercaptans, phenols, and emulsified hydrocarbons.
Wet air oxidation is commonly used for treating spent caustics. Depending upon specific contaminants and treatment objectives, spent caustic wet air oxidation systems can be divided into three ranges of operation: