Oily Water Treatment

The API separator is normally the first, and arguably most important wastewater treatment step in oil and gas refineries and petrochemicals. The API separator is a gravity separation device that works on the principle of Stokes Law, which defines the rise velocity of an oil particle based on its density and size. Typically, the difference between the specific gravity of oil to be separated and water is much closer than the specific gravity of the suspended solids and water. Therefore, the design of the API separator is based on the difference in the specific gravity of the oil to be separated and the wastewater. If this design criterion is followed, the majority of suspended solids will settle in the unit. Once the oil and suspended solids are removed from the wastewater in the API separator, the middle phase, water, is then sent on for further treatment in most refinery wastewater treatment plants.

Denaco Group can design, fabricate and commission API units for all ranges of flows in both concrete and steel/carbon steel types.

API and CPI units cannot remove oil particles completely. For more reduction of oil contents, DAF units should be used. Dissolved Air Floatation (DAF) duty is about removing tiniest oily parts of waste water by means of air particles. This process can be done with/without aid of chemical Coagulants. Chemicals are mixed with waste water through flocculation pipes. The suspended matter is finally removed from surface by skimmer.

In the oil and gas industry, sometimes dissolved gas flotation (DGF) units used instead of DAF units due to prevent the explosion risk. Nitrogen gas is used instead of air in DGF to separate oil contents.

Denaco Group can design, fabricate and commission DAF units for all ranges of flows in both concrete and steel/carbon steel types.