viscosity of water in HFO

[DYV1973]

LS,

In the moment we are examining a problem with the viscosity of HFO with water added for NOx reduction. The water is added in the supply line to the mixing tank of the fuel system. With the viscosity control we find that we need a higher temperature for the same viscosity setpoint, when compared to the same HFO without water.
Does anyone know what will be the effect of water on the viscosity of HFO (as I expected that it would be less, but the measurement gives higher values).

Thanks,
DYV

 

[kenvlach]

It forms an emulsion, so the viscosity is higher. See
Viscosity of crude-water emulsion?
thread135-120558

 

[jmw]

for a particular emulsion of 380cst fuel with water, where with 5% water the viscosity is 8cst at 150degC, the increasing water content causes an increasing viscosity:9cst for 10%, 12cst for 18%, 18cst for 25% water.


JMW

http://www.ViscoAnalyser.com

 

[MASE81]

I know that mixing the two can cause problems. Warsila avoids this by using a method called Direct Water Injection, whereby water is injected at high pressure directly in to the cylinder.
Rgds,
RKK

http://wwww.rkkimmons.com

 

[DYV1973]

Thanks for your replies. But I have one more question. The water will be added usely in the supply to the mixing tank (except for the Wartsila system as described by RKK). Will the emulsion of water/HFO stay stable in the circulation, and what will be the effect of the higher temperature. Do we run the risk of separation of water and oil in the mixing tank? Is there any proven effect of having a homogenizer in the system (besides the statements of the manufacturers), or is it necessary to add an emulsifying additive?

Thanks,
DYV

 

[orenda1168]

You'll need to deal with the fact that the emulsion and optimum water droplet size (roughly <10 micron - >0.2 micron) will not remain stable, i.e the water phase will coalesce, if the mix is recirculated at an elevated temperature without application of an emulsifying additive specifically identified as suitable for your HFO/water blend. A homogenizer operating other than for production of the initial emulsion and preferred droplet size range runs the risk of forming non-optimum water droplet size, particularly with introduction of an emulsifier.

You might contact Exxon Chemicals as they had several suitable emulsifiers for this purpose some years ago (mid- 1980's) under the Corexit trade name, the chemistry for which is probably still available.

Orenda