drop into water

Re-Refinery Used Oil | Sour Water Treated with Hydrogen Peroxide

In North America, approximately 1 billion gallons of used oil are collected annually from generators such as quick lubes, truck fleets, and manufacturers.  Several companies have begun the process of re-refining this hydrocarbon-rich waste product.  Re-refining allows the lubricating oil to be repeatedly re-used as a higher value product.

Re-refining involves operations which will separate and remove contaminants in the used oil so that this oil becomes suitable for reuse. The re-refining process is much like that of a traditional refinery with similar waste treatment requirements.  Such was the case for a major used oil re-refinery facility in the mid-west.  They had a “sour water” treatment system that was not performing as designed, resulting in operational problems and safety concerns.  Sour water is hydrogen sulfide rich wastewater water that is generated from a variety of sources including hydrotreaters, reformers and hydrocrackers.

Hydrogen peroxide has been shown to be a convenient, cost effective and environmentally friendly part of hydrogen sulfide gas scrubbing technologies.  Scrubbing of hydrogen sulfide using sodium hydroxide and hydrogen peroxide is a well-established technology.

A typical scrubbing solution consists of dilute sodium hydroxide to which enough hydrogen peroxide is added to react with the hydrogen sulfide according to the equation:

4H2O2 + H2 H2SO4 + 4H2O

The above reaction predominates at pH > 9.2, and yields soluble sulfate as the reaction product. The stoichiometry calls for 4.25 lbs H2O2 per lb S 2 and it is not unusual for reaction efficiencies to approach 100%, provided that the hydrogen peroxide is added in a controlled fashion and the reaction medium is thoroughly mixed.

Enough sodium hydroxide must be present to neutralize the sulfuric acid formed according to the equation:

2NaOH + H2SO4  Na2SO4 + 2H2O

This indicates that for each weight part of hydrogen sulfide, approximately 2½ weight parts of sodium hydroxide are needed.

USP Technologies provides a full scope of supply (chemicals, equipment and services) to support emergency and ongoing applications for hydrogen peroxide and a range of water and wastewater treatment chemicals.

USP Technologies

1375 Peachtree Street NE, Suite 300 N

Atlanta, GA 30309

Toll-free (877) 346-4262

Phone (404) 352-6070

 View a Map

USP - Canada

3020 Gore Road

London, Ontario N5V 4T7

Toll-free (877) 346-4262

Phone (404) 352-6070

 View a Map

Contact Us

Our sales engineers are ready to help you find the right solution. Fill out the form to connect with your local USP Technologies representative.
  • This field is for validation purposes and should be left unchanged.

Sign Up For Our Newsletter

Subscribe for exclusive news, products, innovations, events and educational resources sent right to your inbox.

  • This field is for validation purposes and should be left unchanged.