Based on experience and knowledge gained from application of the highly-effective Zimpro® wet air oxidation (WAO) technology, Siemens has developed an electro-oxidation process to address the needs of refinery and petrochemical spent caustic treatment. This new process – Zimpro® electro-oxidation – uses electrically conductive boron doped diamond (BDD) electrodes, enabling efficient oxidation of organic and inorganic compounds that are dissolved in spent caustic. The system’s flexible, modular design is capable of treating highly-contaminated spent caustic streams typically generated by both refineries and petrochemical plants in producing clean fuels and chemicals. Treatment using Zimpro electro-oxidation produces an effluent that is amenable to traditional wastewater treatment processes.
The Zimpro electro-oxidation technology performs oxidation in a unique way, using electricity passed across BDD electrodes to produce oxidation reactions at near-ambient conditions. The oxidation potential is very high, allowing for polishing to end-of-pipe requirements in the wastewater plant. Unlike other advanced oxidation processes, no strong and expensive oxidizing chemicals are required to be stored on- site, and the oxidation reactions only occur when electricity is applied to the electrodes.