Jet A1 Flash & Freezing Point

[engineergoki]

Hi everyone,

I have just started working as Lab Supervisor in Fuel Lab. after my graduation in July.
I have a jet A1 sample with flash point of 78C(corrected to atmosphere pressure).This was unusual for me so I did distillation, it meets our specification(%10 recovery--Max 205 C End point Max 300 C ).Distillation result: %10 recovery--202 and End point 242 C. So have can I decide that this product is good to purchase?
Another issue is about freezing point, when I run freezing point test I don't get any cloudy appearance, I had some crystals on the top layer as suspended at -50 C.
How can I identify this crystal as water crystal or hydro carbon crystal? By the definition of freezing point it should be hydrocarbon crystal but what happens to dissolved water in sample?(As far as I know FSII depress freezing point of water to -43 C, and Jet A1 doesn't have FSII, do refineries use another type of icing inhibitor?)

The product came from a different supplier,management asking me if it is good to buy and I don't have so much experience (4 months) so wanted to take advise on this issue.Thank you so much.

 

[BigInch]

"Technical Review Aviation Fuels", by Chevron,

Jet A is used in the United States while most of the rest of the world uses Jet A-1. The important difference between the two fuels is that Jet A-1 has a lower maximum freezing point than Jet A (Jet A: –40°C, Jet A-1: –47°C). The lower freezing point makes Jet A-1 more suitable for long international flights, especially on polar routes during the winter.

The lower freezing point comes at a price. Other variables being constant, a refinery can produce a few percent more Jet A than Jet A-1 because the higher freezing point allows the incorporation of more higher boiling components, which in turn, permits the use of a broader distillation cut. The choice of Jet A for use in the United States is driven by concerns about fuel price and availability. Many years of experience have shown that Jet A is suitable for use in the United States, especially for domestic flights.

Maybe you have Jet B

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[EmmanuelTop]

http://www.chevronglobalaviation.com/docs/aviation_tech_review.pdf

 

[BigInch]

That's the one. I lost the link. Thanks EmmanuelTop.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[engineergoki]

Thank you everyone,
EmmanuelTop thank you for useful link.
However I need a specific answer about flash point,
I have never seen a max spec. for flash point, all specs are min like min 38 C for JP8 or min 60C for JP5.
What should we think if flash point is higher than expected?
I am sure that product also is not contaminated by heavier products like diesel.

 

[BigInch]

Kero max flash is 72C


BP Jet A
petroleum distillate blended
from kerosine fractions having a freezing
point below –40ºC and a flash point above 38ºC.

BP Jet A-1
petroleum distillate blended
from kerosine fractions having a freezing
point below -47ºC and a flash point above 38ºC.


BP's "Typical Properties" are,
Total acidity, mg KOH/g below 0.010
Aromatics, % vol 23.4
Total sulphur, % mass 0.07
Mercaptan, % mass 0.0005
Distillation Fuel recovered
10% vol at ºC 185
50% vol at ºC 211
90% vol at ºC 245
Final boiling point, ºC 280
Residue, % vol 1.0
Loss, % vol 0
Flash point, ºC 51.1
Density at 15ºC, kg/m3 820
Fluidity
Freezing point, ºC -51
Viscosity at -20ºC, mm2/s 5.2
Combustion
Specific energy, net, MJ/kg 43.02
Smoke point, mm 19.5
Naphthalenes, % vol 2.9

For military use, BP Jet A-1 additionally
conforms to the UK Specification Def Stan
91-87 and US Specification MIL-T-83133
(JP-8) and contains static dissipator
additive, corrosion inhibitor and fuel system
icing inhibitor.

I suggest you look at these to see if there is a max for JA

BP Jet A-1 BP Jet A-1 (FSII)
(Civil) (Military)
NATO Code No F-35 F-34
UK Joint Serv. AVTUR AVTUR/FSII
British Def Stan 91-91 Def Stan 91-87
US Military – Mil-T-83133 (JP-8)
ASTM D1655 Jet A-1) –



**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/