[Hedewandro Lucredi]

Do you have any site or paper thats describes your system ?

[Hedewandro Lucredi]

If one of the two wet compressor gas suction valves that relieves to the flare to open incorrectly with the compressor running is there a risk of air entrainment from the regenerator to the main fractionator? Is there any risk of damage to these equipment like fractionator, compressor, etc ?

[Hedewandro Lucredi]

Sorry. It is a Ortoflow C

[Hedewandro Lucredi]

Our FCCU is an orthoflow and modified for external risers. The reactor gases go to the main fractionator. From the top after condensation the gases go to the compressor. In the event of a compressor failure, there are two valves (one redundant from another) that relieve gases to the flare. These valves are not the anti-surge valve of the compressor. Today the failure mode of these valves is a stationary failure and the other failure closes. We want to transform the failure closes to failure opens. What are the problems for the process? What is the typical failure mode for these valves?

[Hedewandro Lucredi]

Besides Veolia process anybody knows any other company to treat sludge to inject in DCU ?
We intend to reduce our sludge generation to minimum.

[Hedewandro Lucredi]

Thanks a lot. Please if you have the Mitch Moloney presentation available I will appreciate.

[Hedewandro Lucredi]

The problem to send to DCU heater is Emissions increase a lot . In the past we sent to the heater, besides emissions sometimes there are some liquid carryover. This gas was sent to a specific burner and sometimes plugged this burner. As you write there are some risks

[Hedewandro Lucredi]

The sulfur formed is elemental. The temperature of the treating system is +/- 45 C. The oxygen has a excess because the treatment required that

[Hedewandro Lucredi]

The water used to dilute the caustic (NaOH) is industrial water, so there is high hardness. We analysed the deposits. 15%-20% is caustic, +/- 10 % is sulphur and lot o iron (corrosion deposits)

[Hedewandro Lucredi]

We usually have a huge corrosion in the wall on the top section of main tower, above LGOk. Is there any technique that is possible to measure the wall thickness of the main tower running ? In our case we stopped the tower, cooled down and measured the wall thickness by ultrasom. We also we are using the technique Pulsed eddy current testing with the main tower in operation. Are this technique reliable to measure the wall thickness of the main tower in operation ? It seems that the corrosion on the tower wall is from HCl formed on the top . How do we detect this before the tower damage occurred ?

[Hedewandro Lucredi]

Mike. Thanks for the answer. In the past we had a lot of problem with salts in the gas compressor that produced vibration. We wash a lot and did not solve the problem. During the maintenance we opened the compressor and we observed that a little piece of metal screen inside it. This metal screen was from the second stage filter that it was broken.

[Hedewandro Lucredi]

We do not have this kind of depressure system in our FCCU gas recovery system. Do you have this system ? Is it by tower or overall ? We intend to send the gas to the flare. We are concerned about some emergency in this area.

[Hedewandro Lucredi]

You are right. During the DCU start up we needed to improve the pipe suports because the bottom tower pipe was vibrating. The problem was solved.

[Hedewandro Lucredi]

What about if we recycle the sour water to upstream of the top heat exchanger of the main tower ? In this case the sour water can be send to SWS using the fracionator top vessel ? What about the champagne effect (releasing of the contaminants by despressuring) and its effects in the recovery gás section (corrosion, amine degradation, etc) ?

[Hedewandro Lucredi]

If I inject the FLO (flushing oil) that is cold immediately after the heater shutdown and the heaters are still hot is there any risk of leaking in some flange, mule ears, etc because the temperature ?

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