Fuel Additives: Emulsify water or demulsify?
 

OK so I've spent the last 2 hours going through all the threads on here and other forums about the various benefits and detractions of using fuel additives for water emulsification vs. water demulsification.

Having been trained as an organic chemist, I know what the differences are between emulsification and demulsification. I also know that my Cat 1R-0750 and Baldwin PF 7977 fuel filters have predominantly cellulose-based media, which are excellent in absorbing free water (which is probably why I have never seen free water come out of the stock fuel filter bowl when I drain it every week). I also know that the filters trap water in their media because algae grows on the Baldwin filter, and I can see it (it looks black-that's algae)-and algae only grows at the diesel-water interface.

The big question with emulsifiers is what happens to a water/diesel emulsion when it's pressurized to 30,000 lbs and then exposed to the shearing effect and heat that occurs in an injector. I don't know of any research that has looked at that emulsion being maintained in that environment. Does it accelerate injector wear? Internal fuel line rust?

On the flipside, has anyone ever had injector line issues or injector issues because of demulsified water with using demulsifiers such as Stanadyne or Racor? Theory would argue that it's best to demulsify, so that water doesn't enter the injection circuit at all. But has anyone ever had to have an expensive fuel system service because they used a demulsifier that pulled water out after the fuel passed through the filter?[nonono]

Any comments or thoughts are appreciated.

I never had water do any damage but I believe in demulsification so hopefully the filter catches it. I've dumped some ugly junk out of the filter housing. Craig

Thanks Craig-this is the kind of information I'm looking for. Appreciate you posting ;)

A little off topic here, but i thought algae had to have sun light to grow?

What looks like algae may be in fact asphaltene.

Asphaltene is a chemical problem inherent in diesel fuel and not biological contamination.

http://www.cumminsfiltration.com/htm...asph_cond.html

Sorry for the topic stray, i just did some research on this for a friend of mine.

From what I've read, the engine manufacturers recommend demulsifiers. (Thinking back to a GM service bulletin.) They want the water to drop out of the fuel so the separator can deal with it. So it seems your concerns on the emulsion's behavior in the pressure and heat are justified.

I have seen the result of a truck having enough water in the fuel that it overwhelmed the separator and damaged the injectors. Not sure if he was using any additive at all, and I couldn't say if either type would have changed the outcome in that case.

Just my .02

Being a marine engine tech for over 25 yrs I have never heard of an engine manufacturer recommended an emulsifier. They all recommended fuel water separators. Reason being that the fuel system is lubricated by FUEL with proper lubricity. Water is a poor lubricant. It will also separate inside the system once the engine is turned off causing corrosion, & leaving deposits behind. I have actually seen emulsified fuel cause injector pump damage after sitting for the winter. Algae, & mineral deposits don't flow through small orifices well.

Additives are a waste (all additives). They are completely unnecessary. Save your money, environment, and time by not draining your bowl every week. This is also completely unnecessary and just wastes good fuel. If you accumulate water in your bowl, the sensor will let you know.

I think "loving our trucks to death" is a disease. I had it once too but helped myself get back to reality. People get way too deep and worry about/create problems that really don't exist. Just run quality filters/fluids and perform regular maintenance. Probably not what you wanted to hear but it is the truth nonetheless.

Thanks guys for your input! Robtackett-in some ways I agree with you, but the reason I wanted to know is that I have a 40 gallon aux tank in the bed of my truck-and since in the summer I usually drive my '71 Lincoln around, that fuel ends up sitting there a while before it gets burned. I want to make sure that any water that it accumulates doesn't cause injector damage.

As for algae vs. asphaltenes, it may very well be asphaltenes-but algae doesn't need sunlight to grow. Some algae do, but not all-and the algae that grow in diesel fuel systems definitely does not need sunlight (it uses the hydrocarbons in the fuel as a food source, instead of the products of photosynthesis).

Anyone else have any in depth knowledge of emulsifiers vs. demulsifiers?

And again, thanks to everyone for their input!

When your truck is sitting for a while, you might want to have your aux tank completely full or completely empty to help with condensation. I think, for your situation, your money would be better spent to have some filtration/water separation on that aux tank if you don't already. Your fuel would be getting double filtered and it would put your mind to ease with the water.

Over half a million miles on my rigs and I've never opened the filter drain even once.
I'm still waiting for the WIF light, which I know works, to come on.
None of the 14 tractors on my farm and my semi even have drains.

I agree additives are a waste except for anti-gel in the winter depending on your location.

All diesel fuel contains asphaltines that turn the filter black.
Diesel algae is mainly a concern in coastal and topical areas.
In much of the US low humidity or low temperatures don't allow it to get started or survive.

Infidel, has your trucks ever had a fuel filter change?[laugh] But seriously, your info is on the money. I do know the WIF light works on my '92. Filled up with some bad fuel and had to pull over along side the road to open the valve. After three times of starting and stopping/repeating, it went away and I've never had it come on again. The system worked like it was designed and caused no harm to the injectors.

I use my fuel pressure gauge to indicate when to change the filter.
I usually go from 30-50k miles but went 72k on one filter change.
All depends on your fuel sources. In my diesel dependent agricultural area anyone selling dirty or watered down fuel would be run out of town.

Infidel-I have to admit, I share your experience-85K miles so far on mine, and I've never once seen water in the bowl.

Has anyone on here that has used demulsifiers had a fuel system problem from using them? Like water separating in the injector lines and the rust? I would think that if that happened you would've had unbelieveably bad fuel, but I've heard of it happening before-which is why I ask . . .

I'm not worried about it. If I stored my truck or had a large fuel tank I'd consider worrying though.


Injectors seem to go at around 200K on my particular model. Rebuild them for $1,100 and get them installed for $350.



I'll just keep my fuel reciepts for insurance incase of some idiot fuel station.



I do like to see people like A - 2 - Z and bcfitz do research on the subject. They seem to know what they are talking about.
I'd like to have someone also test stores to see which is best/worse.

Some time ago the Japanese did some research of using emulsified diesel fuel. Don't know what ever became of it.