Q & A > Question Details
We were producing Aviation Turbine Fuel (ATF) by desulphurising 140-240 deg. cut kerosene through a Kerosene Hydro Desulphurisation Unit (KHDS). The electrical conductivity of ATF was maintained around 300 pS/m by injecting antistatic additive (Stadis 450) at a concentration of 1mg./lit in the product. Two years back we started producing ATF through the ATF Merox unit as well and are injecting Stadis 450 at the same rate from Merox Unit. But when the percentage of ATF produced from Merox Unit is going up to around 60% the conductivity of ATF drops down to around 150 pS/m (the marketing company require a minimum of 200 pS/m, even though the specification is 50-450 pS/m in ATF). What could the reasons for the drop in conductivity?
 
Answers
21/07/2020 A: Carlos Mendiondo, CHM Consult, Carloshugomendiondo@gamil.com
The conductivity in your kero could be associated with naphthenic acidity which is removed by caustic as sodium naphthenates at the oil-water interface in the separator.
09/07/2016 A: Mainak Sarkar, Indianoil Corporation Ltd, sarkarm@indianoil.in
With NaOH in ATF, the conductivity should go up? But here conductivity is dropped.
To solve the problem you have to check:
Conductivity of Merox ATF and KHDS ATF separately.
If decrease in conductivity is due to Merox ATF, you will have to further investigate conductivity at inlet and outlet of Clay column, salt column etc.
19/09/2007 A: Amarjit Bakshi, Refining Hydrocarbon Technologies LLC, abakshi@rhtgulfcoast.com
Carry over of caustic from Merox unit will effect the conductivity of the jet fuel, so you need to check how well your Merox unit working and if you can wash the Merox product to remove the caustic which should solve your problem.
It will be good idea to have additional KHDS unit which will produce dry product and cleaner solution. RHT LLC can provide KHDS unit for your other stream which is being routed through Merox unit.......