1. Robert Cox, IPIECA, United Kingdom
Improving water management in refining operations: minimizing consumption and maximizing re-use
Mudumbai Venkatesh
Vice President
AECOM, USA
Robert Cox, IPIECA, United Kingdom
Forum 22 – Managing Water in Upstream and Downstream Operations

2. Who we are:
AECOM is an international engineering company operating worldwide specializing in professional, technical & management services including refinery water and wastewater treatment.
IPIECA is a global oil and gas industry association for environmental and social issues

3. Outline of Presentation
Introduction
Refinery Water Balance
Raw Water uses in the Refinery
Management of Wastewater
Refinery Wastewater Treatment
Water Reuse
Zero Liquid Discharge

4. Introduction Critical shortages of water in many parts of the world
Refineries use a significant amount of water when compared to other industries
Critical shortages of water in many parts of the world
Refineries are trying to minimize water usage and maximize recycle/reuse

5. Refinery Water Balance

6. Raw Water Users in the Refinery
Process Water
Wash Water
Boiler Feed Water - Makeup
Cooling Water - Makeup
Potable Water
Fire Water
Utility Water

7. Wastewater - Desalter
Desalter - First unit operation - used to wash naturally occurring salts in the crude to protect downstream equipment
Wash water - 5 to 8% of crude throughput
Drilling muds are also periodically purged
Operating pH in the Desalter should be 7 or lower to prevent formation of excessive emulsions
Results on discharges of excessive hydrocarbons - loss of crude, slop creation

8. Wastewater - Desalter Desalter Wash Water Sources
Fresh water
Boiler Feed Water
Crude Tower Overhead
Vacuum tower Overhead
Stripped Sour Water
Stripped Sour Water is best choice - results in significant savings in water usage

9. Wastewater - Sour Water
Sour Water - Stripping Steam condenses and absorbs H2S and NH3
High Performance Strippers - <1ppm H2S and <30ppm NH3
Stripped sour water is an ideal candidate for recycle within the refinery
Phenolic Sour Water - Cat Crackers and Cokers
Non-Phenolic Sour Water-Other producers

10. Wastewater - Sour Water
Stripped phenolic SW should be processed in a separate stripper and preferentially used for Desalter makeup
Up to 90% of phenol will be extracted into the crude - lowering phenol load to WWT
Remaining stripped SW should also be used in the Deslater if possible - excess should be discharged to WWT

11. Wastewater Tank Bottom Draws
Crude Tanks, Gasoline Tanks, Slop Tanks
Crude Tank Draw - example

12. Wastewater - Spent Caustic
Hydrocarbon product streams are washed with caustic to remove acidic compounds such as sulfides, organic acids, etc
Spent caustic is purged from the system
Phenolic spent caustic can be sent offsite for recovery (high odour stream)
Sulfidic SC can be treated in the WWTP
High TAN crudes produce naphthenic spent caustic - toxic to biological systems

13. Refinery Wastewater Treatment
Wastewater Segregation
High TDS - Desalter Effluent, Tank BS&W, Spent Caustic
Low TDS - Stripped Sour Water, Storm water, Miscellaneous WW
Two parallel trains of treatment

14. Water Reuse
Potential Users - Desalter Makeup, Coker quench water, cutting water, Flare seal water, FCC scrubber, Hydrotreaters, BFW and Cooling Tower Makeup, Potable water, Fire Water, Utility water
Reuse non-contaminated storm water
Treated refinery wastewater
Treated municipal wastewater from outside sources

15. Technologies for Upgrade
Suitability of technology is site specific and should be evaluated case-by-case
Criteria for Evaluation
Prior application in refineries for water reuse
Ability to consistently achieve product specification
Operability & Flexibility
Capital & Operating Costs
Plot Space Requirements

16. Water Reuse Technologies - Ion Exchange

17. Water Reuse Technologies -UF/RO

18. Water Reuse Technologies - UF/EDR

19. Water Reuse Technologies - ZLD

20. Document is available at www.ipieca.org

21. Thank you for your attention Questions???
Contact Information
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