What is the purpose of testing for sulfides in the oily wastewater from the distillation column of a hydrogenation unit?

This issue is indeed easy to confuse; let me try to analyze it: Testing for sulfides in the oily wastewater from the fractionator reflux tank is primarily intended to monitor corrosion risks — hydrogen sulfide and sulfides can cause acidic corrosion in aqueous environments, especially affecting carbon steel components in the tower top and condensation systems. Furthermore, if there is a wastewater treatment unit downstream, the sulfide concentration will also affect the efficiency of biological treatment. Furthermore, the gasoline and diesel products produced by some hydrogenation units have specific requirements regarding sulfur content, and the sulfides present in the wastewater from the reflux tanks may indicate issues with the separation efficiency of the distillation system or the degree of reaction that takes place upstream. However, the specific purpose will depend on the design of your equipment and the process control parameters. It is recommended to refer to your unit’s process sheets or consult the equipment engineers to confirm this.

The core purpose of testing for sulfides in the oily wastewater from the distillation towers of hydrogenation units is to monitor the degree of reaction and the risk of ammonium salt formation, to guide the operation of the acidic water stripping unit, to prevent equipment corrosion and hydrogen sulfide poisoning incidents, and to ensure compliance with environmental emission standards.