Oily Water Separation On Board Ships. 5

[Lis]

I am carrying out a research project into new methods for separating oil and water, as found in machinery space bilges on board ships.

I am currently researching technologies used shore-side and evaluating their potential for use at sea. I am particularly interested in ozonation, UV exposure, biotechnologies, electrocoagulation, chemical additives, ultrafiltration and dissolved air flotation.

If anybody has any information or experience with any of these, or any other technologies, and would be willing to answer a few specific questions in this area, could you please let me know by replying to this thread.

Many thanks,

Lisa Wooderson.

 

[EngineeringManger]

Dear Ms. Lisa Wooderson,

WOW - you sure have collected a lot of high technology solutions to solve the problem - and a few can be simply ruled out due to space limitations and others to cost and still others for the use of strong oxidants - I for one would not like to work in a confined space where the risk of exposure to Ozone (OSHA PEL†: TWA 0.1 ppm (0.2 mg/m3)).

One point that is not made clear is that the "oils" are a combination of many different type - an unfortunate fact is that fuel oil is blended for calorific value and not for beauty, hence it can contain both mineral and vegetable oils and it is the latter which create the environmental problem.

I have never given the problem much thought, but a suitable (and low cost) technology would be to treat the oily water with a suitable surfactant (to break the emulsion) and then process it with an approved separator. There are some excellent oil/water separators available – the “Bilge Master ®” is one such unit worth considering - it works on the coalescing principle - with auto backwash operation( made somewhere in the USA).

Absorption (activated carbons and the like) will quickly clog (ave. available area is about 1300 to 1800 m2/g)but is micro pored and the media closest to the inflow will fill and render it U/S.

If you would like additional information please feel free to contact me direct at engineering@envirocontrol.com

Best Regards with your technology research - Allen

 

[moltenmetal]

If you're interested in a system that someone else has already put into service, have a look at

http://www.hydroxyl.com

. They can offer entire packages plus information about the advanced oxidation options you were originally considering.

 

[alanr]

Lis,

I was pointed to this site by friend Tony.

I have been involved in the design Marine & Industrial Oily Water Separators ( gravity and Membrane)since the early eighties and have had good success using membranes with pre-filtration ahead of them.

What is it specifically that you want to know and why?

ATB,

Alan Russell

 

[Hewlett]

To save some work for your separation equipment and increase overall separating efficiency, you might want to consider a tank skimming device, like the sludgebuoy:

http://www.sludgebuoy.com/html/

They also deliver computerized loggers that can be set up to log from a lot of different equipment.

 

[ivanhoe374]

depending on how low the levels required are you may want to look at this technology

http://www.mycelx.com/products/marine/default.asp

 

[netherhay]

I have only just come across this thread so please forgive a rather late contribution.

UK company Flight Refuelling Ltd - Fluid Systems manufacture a ceramic membrane bilge water separator system certified to MEPC.107(49)

While the MEPC stipulates 15ppm, the system is consistently operated at better than 5ppm. There are no chemical additives or disposable filter elements or stockings to rewind, so no contact between operator and fluid - no dermatitis claims.

Equipment is supplied to UK Royal Navy for new build Type 45 frigates and also as retro fit on Type 23 destroyers currently undergoing refit program. This system is currently military and so is shock and vibration qualified, EMC, etc.

A commercial marine adaptation of this system is currently being manufactured.

A larger shoreside adaptation has also been installed at Faslane, Scotland, to process bilge water from shore side storage - clean water discharged straight to sea and concentrated oils retained.

 

[sumihar]

Dear All,
I just join with this discussion and I would like to ask regarding the ceramic membrane as Netherhay mention.
Could you tell me how is the membrane characteristic you said produce 5 ppm ? Do you have the website of that company or someone that I could contact?

I have other request for Nosey. Would yu like to send me also the paper from Mare's Tail ? By the way I can not find the application of ultrasonic in the website of Cyclotech (

http://www.cyclotech.com)

and Merpro (

http://www.merpro.com).

Do you have some contacts also which I can get more information ?

Best regards,
Sumihar

 

[hprorelis]

Orelis (Novasep group) produce ceramic and organic membrane used for oil/water separation
Ceramic membrane are already used on ferry for bilge water treatment - Orelis organic membrane are installed on cruise liner QM2
Feel free to contact me if you need information
Best regards
Herve PRADELLE

 

[netherhay]

Sumihar,

You can contact the company via the website:

http://www.flight-refuelling.com

You need the Fluid Systems Division at Factory 3, recently integrated into the company but not represented on the site as yet - persistance may be required!

In the most basic terms, the bilge water is circulated around a loop that contains a cermaic membrane. Clean water permeates through the ceramic membrane and is discharged overboard. The contaminated water is retained in the loop and, when a sufficient concentration of oil has been reached, is diverted to a sullage tank.

The equipment is fully certified by Lloyds to MEPC.107(49), the latest and most stringent MARPOL standard, and is operated by the Royal Navy at a maximum overboard discharge of 5ppm.

 

[appy1]

I read separion of oli and water by CPI that is corrugated plate interceptor. This is very effective method where oil separates at top which can be scimmed off and oil free water can be further treated by bilogical treatment method.
The oliy water to CPI comes from underflow-overflow arrangements where due to differences in densities, most of the oil can be separated.

 

[Muggle]

Lis,
suggest you contact Ed Gardyne at Environmental Processes Ltd in Scotland (edgardyne@environmentalprocesses.com) - they've been doing work for Petrofac/Shell/Bp on oil-water seperation for some months now - supercoagualting the oil for removal for refining, then reduction of the remaining THc/Aromatics for direct discharge to the ocean - meeting EU 2007-2009 standards. No secondary waste stream to handle - small units for oil platforms, barges, barge washout, etc.
Tell him Dave at Aquatic Technologies sent you - they've beaten out several major competitors for this type of treatment - lower O&M, lower capitol cost, etc. -

Dave

 

[graciecat]

My understanding is that the bilgewater problem has already been solved by a small American company through the use of an oil extractor and polishing filters that brings the IMO cocktail down to below 5 ppm's. They have found a way to increase the oil droplets and break the emulsion. I don't believe the unit is very widely known at this time. I do know that the inventor was Hal Alper. I will research more and post again.