[Hedewandro Lucredi]

How can I measure the suspended solids in the water decoking ? Any specific method ? The coke fines is decanted in the water. And the other contaminants ? Is there any spec ? We analyse chloride, NH3 and H2S in the water.

[Hedewandro Lucredi]

We have the same problem. The solution is to control the blowdown flare flowrate and with small step in order to reduce the mix of streams

[Hedewandro Lucredi]

The OEM for the WGC is from Germany (huge company). So, the naphta injection is not continuous? The OEM recommend a continuous injection. We have this experience with no injection starts the vibration. After we start the injection the vibration decreased. Do you know any paper that has more information about this injection or even in this site ?

[Hedewandro Lucredi]

Evan
As I told, we process all liquid flare from our refinery in our DCU and this liquid is not from our DCU only. We process +/- 0.7 % related with the feed rate. We need to discover all point from all refinery unit in order to check any leakage to flare that would be possible to produce “liquid” in the blowdown flare.

[Hedewandro Lucredi]

We are studying to send to blowdown this flare liquid, but we already sent recovered oil from API to this systems and oil from SWS also. Your ideia to put sensitive TI/PI is good or even using infrared , but I am concerned how to measure the flowrate in the BL (battery limit) of each unit. We need to do a “mass balance” of this liquid from each unit to flare. Also, if you have any ideia I will appreciate.

[Hedewandro Lucredi]

We are having problems with our isolation valves. In the last 3 years the maintenance increase a lot. There are in these isolation valves constant leaking. So, we are decoking a drum and the others drum are receiving water water leaking from the isolation valve.
We observe in these isolation valves in its internal like a erosion. Very hard erosion. Some part of the metal disappear. What is it ? Erosion by fines ? How can I measure this coke fines ? Is it corrosion ?

[Hedewandro Lucredi]

Hi Evan
What do you mean when you refer to this rule of thumb ? Is it 1 lb/1000 bbl of the comercial NALCO EC 9019A product or the PDMS that it contains ? And this rule applies perfectly to the 100.000 cST or what ? Thank you

[Hedewandro Lucredi]

Evans. Thanks. The water wash flow rate in our case is by design +/- 3 %. What is it the problem if I have low water flow rate ? Corrosion ? Amine degradation ?We try to control pH in the sour water at +/- 7 to 8. Do we need to follow the same conditions like FCCU related with water wash ?

[Hedewandro Lucredi]

Evan. Our target is < 2%, but our “spec” is < 3 %. We are running between 2 a 3 %. What do you meaning 3 % is more “normal”. Less than 2 % require more naphta circulation to the absorber. So, to reach < 2 % is it profitable in terms of energy ?

[Hedewandro Lucredi]

Evan

We do not have methodology to measure COS in liquid stream . Do you have ? Probably the best solution is what you have told before, remove the stream (like residue) and analyse the LPG COS.

[Hedewandro Lucredi]

Thanks Even
Our propylene unit has a splitter and a final poliment reactor. We produce chemical grade propylene with purity above 99.5 % and the spec is less than 20 ppt of COS. In the final poliment reactor the design was made to treat less than 570 ppt. We have only amine (DEA) and regenerative caustic treatment for coker LPG. Our feedstock (crude oil) change a lot, but we do not observe any reduction in the COS coker LPG yet. What do we need to reduce the COS in the feedstock ? Is it not change the crude oil or even stop to inject offshore residue in the distillation unit ?

[Hedewandro Lucredi]

Thanks Evan. We are finding numbers of COS at non treated Coker LPG of 200,000 ppb up 1,800,000. We are processing a lot of by products in the DCU, like API sludge in the blowdown, flare condensate and Fuel gás from gasoline hydrotreater in the main tower vessel. Also, in the distillation unit we are processing residue from of shore tanks (heavy and light products).

[Hedewandro Lucredi]

The feed is the same quality. The drum purge durations is +/- 4 volumes. The PDMS is 100,000.00 cSt and the rate is 3 ppm based on the feed. What is your experience with the feed quality ? How can I measure it? And our purge duration ? Any suggestion ?

[Hedewandro Lucredi]

Regards. If have more information I will appreciate

[Hedewandro Lucredi]

We have a similar system with sprinklers on the top of the drums with fire detector. The problem with the fire detector is because some of them are located near some hot place. Because that, the sprinklers opened in the past. Nowadays we located outside of this place and there is no problem.
The fire dector is the standard with liquid inside a glass.
All this sprinkler is only to protect the man during a fire.

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