Difference between Colourless and Straw yellow Jet A-1 properties

-

Difference between Colourless and Straw yellow Jet A-1 properties


 As given in last blog article normally colour of Jet A-1 is either colourless, straw/yellow or a very little shade of blue, pink or red. Reason for each colour was explained in the article.

Colour of Aviation turbine fuel depends upon a) composition of crude oil & 2) Refinery processes used in refining the crude.  (Read in detail How the Aviation turbine fuel colour is colourless or straw/Yellow? ).

In this article we deal with differences between Colourless and straw yellow coloured fuel properties.

1.  Straight Run product 


Straight run product is referred as Jet A-1 obtained straight from Atmospheric distillation unit in refinery or derived from natural Gases condensate liquids.

Such Jet A-1 consist of natural original hydrocarbons of crude oil or natural Gases condensate liquids as existing in the earth and separated from it by only physical processes. Since no chemical reactions involved in this, the hydrocarbons are most stable. 

Colour of such hydrocarbon depends upon the original colour of hydrocarbons from the earth. If the source contains some coloured Nitrogen/Sulphur compounds then Jet A-1 will also have this straw yellow colour. Otherwise, if absence the colour will be towards colourless.

The biggest advantages of this coloured Nitrogen/sulphur species are - a) these are polar compounds having higher lubricity value, higher electrical conductivity, and these compounds acts as self reacting towards natural storage oxidation protecting the other Jet A-1 hydrocarbons that is bulk of the product from oxidation degradation.

 The above para explain clearly that such Jet A-1 does not need anti-oxidant and Lubricity improver additives (LIA).  The product is very good towards elastomers of fuel handling systems in field as well as aircraft- increasing elastomer life and thus protecting from fuel leak from material failure ( O-ring, gaskets etc).

 The disadvantage seems - appearance due to pale yellow/straw colour is disliked as  customers/operators think of fuel contamination erroneously. More education by Quality Assurance group is desired in such situation. Further in very long storage, such fuel will become more darker in yellow colour due to natural oxidation, however, this does not affect the fuel properties and its performance adversely.  

List of all blog articles on Petroleum QC  by RJ Patel.

2 Hydroprocessed Jet A-1 



 Usually to increase the Jet A-1 yield to meet the product demand, besides Atmospheric distillation, other secondary refining processes like hydroprossesing /hydrotreating/hydrofinishing of suitable streams from Vacuum distillation unit etc are involved in JEt A-1 production. As explained in last article,  many chemical changes occur in such refining processes, including colour which will be colourless.

 The colourless product, if hydro-treatment done properly, will remain colourless for very very long period. The author once kept one hydroprocessed batch Jet A-1 and evaluated Colour and key properties like colour, Existing Gum, distillation, PONA  etc and found that the colour  remain unaffected even after 5 years.

 Also, it is seen, if hydro processing not done properly ie. if hydrogen quantity used is less or hydrogen quality is not as desired,  Jet A-1 produced is unstable towards many properties like  Colour, storage stability etc. This is more true , if the refiner has used  unusually some cracked products from FCC etc to increase availability of more quantity of product to market.

 Since hydroprocessing removes Nitrogen and Sulphur compounds greatly, the product obtained lacks the good properties listed and therefore need of adequate dose of additives ( anti-oxidants, LIA etc) are necessary to achieve the performance properties.

 Further, manufacturing of hydroprocessed Jet A-1 is much more expensive than ADU straight run product as running product thru secondary units, time taken, costly hydrogen and catalysts used. Cost further increase due to mandatory additive requirement to enhance fuel performance.

 Key Words:

Colourless Jet A-1,  Hydro-treatment, Hydro-processing, ADU, FCC, LIA, anti-oxidants,  Existent Gum.

Visit to my blog https://rjpatelioc-petroleum.blogspot.com for similar other work related to Petroleum Product QC. Some of following links may be useful:

List of all articles on Petroleum QC upto 06 Apr 2019 by author.


-Temperature around 3 deg C, - Density Conversion from observed temperature to 15 C without use of ASTM Table

    
  

Comments

Post a Comment

Popular posts from this blog

- Excel Formula-Density Conversion to 15 deg C, table ASTM 53 B - 1980,

-
Image
- Excel Formula-Density Conversion to 15 deg C,  table ASTM 53 B - 1980,    Excel sheet giving the Density 15 deg C figures from given observed Density and observed temperature for petroleum product as derived from ASTM tables 53 B. Density conversion to 15 deg C matches exactly with the ASTM conversion tables 1980. Lists of Android/iOs Apps developed on Petroleum Calculation - see here.      (These apps convert Density/API gravity exactly as per ASTM tables 5a, 5b, 6a, 6b, 23a,23b, 24a,24b, 53a,53b, 54a,54b to standard temperature 15 C,  20 C and 60 F.)   Example:  Observed density is 792 kg/Cu. M and observed temperature is 29 deg C. Corresponding 15 deg C for this set of data comes 802.2  kg/Cu. M Excel Worksheet - green color cells  observed density and observed sample temperature are variables and Red color digits are the answer - density at 15 deg C.  Apps developed on Petroleum Calculations - see here. ...
Read more

- Temperature around 15 deg C, - Density Conversion for Petroleum Products from observed temperature to 15 C without use of ASTM Table (1980 series)

-
- Temperature around 15 deg C,    - Density Conversion for Petroleum Products from observed temperature to 15 C without use of  ASTM Table List of all blog articles on Petroleum QC  by RJ Patel. Lists of Android/iOs Apps developed on Petroleum Calculation - see here.      (These apps convert exactly as per ASTM tables 5a, 5b, 6a, 6b, 23a,23b, 24a,24b, 53a,53b, 54a,54b to standard temperature 15 C,  20 C and 60 F.) One follower from Kiev, Ukraine  has requested the formula for the subject conversion. The post gives a simple way to convert Density of petroleum products from ambient temperature  ( say 15 +/-7  deg C  )  to density at 15 Deg C, in line with ASTM table 53B,  without using these table and in the field with simple calculation. See my earlier post dated 18 Dec 2016, for detail description of the procedure explained there. For areas in Norther Europe,  Canada,  Russia,...
Read more

Density conversion to any temperature say 20 C, 15 C or any desired temperature from any observed temp

-
Image
Density conversion to any temperature say 20 C, 15 C or any desired temperature from any observed temp Some of the countries like Russian block follow standard temperature 20 deg C as compared to Commonwealth countries which have standard temperature 15 deg C.  The calculator developed for conversion of Density from observed temperature to 20C or 15C or any desired temperature is thus very handy.   It may be noted that the calculator is for finished petroleum products and uses ASTM tables 1952 version for this conversion. For Excel Worksheet you may contact by email to  rjpatelioc2014@gmail.com and specify your clear requirement as per the title of this post. Follow me on twitter @RJPatel13 to get notification when my new post is available in my blog. Author's Profile List of all blog articles on Petroleum QC  by RJ Patel.
Read more

Android/iOS apps for Petroleum Calculation

-
List of Android/iOS apps on Petroleum Calculation  App for Jet A-1 Density Conversion to 15 deg C as per ASTM 53B  App for Aviation products Density Conversion to 20 deg C as per ASTM 53B     App for Petroleum Products Density Conversion to 15 Deg C as per ASTM 53B  App for Gasoline - Diesel for Density Conversion to 20 Deg C as per ASTM 53B     App for Crude Oil Density Conversion as per ASTM 53A and Volume correction as per ASTM 54A  Crude Oil  API Gravity Conversion  to 60 deg F and Volume Calculation App as per  Petroleum tables ASTM 5A and 6A Petroleum Products API Gravity Conversion  to 60 deg F and Volume Calculation App as per  Petroleum tables ASTM 5B and 6B.   LPG density Conversion from observed temperature to 15 C and also to 20 C.   An App for Calculation of Vapor pressure of Liquefied Petroleum (LP) Gases from Compositional Analysis based on ASTM D2598.    An ...
Read more