[Hedewandro Lucredi]

Another related question. If we do not have utilities (steam, electric, instrument air), but we have FLO (Flushing oil) from a off site pump. Can we use FLO to inject in the heaters after the shutdown ? Are there any problem related with flange leaking, heater coking and so on ? We have in our heaters a smal pipe (1 1/2 in) that inject FLO in the furnace header. We can inject in each heater pass because I think the flowrate is not enough for the overall heater pass, or is better to inject in all pass equaly. The FLO temperature is +/- 30 Celsius.

[Hedewandro Lucredi]

Mr Kimbrell. Thanks for the answer. You help me a lot.

[Hedewandro Lucredi]

In order to avoid the operator goes to the drum bottom during the drum opening to pinned the bottom unheading valve opened, we intend to improve the SIS interlock that we do not need to do this operation. What is the risk of this proposal ? Damage to the automatic bottom drum valve ? Damage to the decoking drim stem ? Is this proposal (operate de drum bottom unheading opened with no pinned) usual ?

[Hedewandro Lucredi]

Thanks Mike. The company that we contracted there is no experience before with pigging but they contracted some experience people, but besides that we had problem.

[Hedewandro Lucredi]

We still have benzene at light naphtha. It seems to be from the feed more lighter than usually is. How can I reduce the benzene in the light naphtha ? What are the process variables that affects benzene in the naphtha?

[Hedewandro Lucredi]

Thanks. It is very helpful

[Hedewandro Lucredi]

We opened the transfer line between heater and coke drum. We found the line all plugged with hard coke. Now we will open the heater coil and hydro-blastering the coils.

[Hedewandro Lucredi]

Now we are opening the transfer line between the heater and coke drum. We are concerned if the hydro-blaster can removes any oil inside the heater coils or any initial coke. Can hydro-blaster remove oil and any initial coke inside the heaters coil ?

[Hedewandro Lucredi]

We are studying with the heaters “cold” (no burners and pilot on) inject steam and with infrared device see any local hot or cold in order to detect the exact point where is the coke in the coil.

[Hedewandro Lucredi]

Thanks. I will check that.

[Hedewandro Lucredi]

Thanks Mike. Very helpful

[Hedewandro Lucredi]

We observed coking in the radiant section of the heaters. As I told we observed a increase in the skin temperature of 15-20 degrees celsius in a day. It is to much, the regular number is 0.5-0.7 degrees celsius a day

[Hedewandro Lucredi]

Thanks for your answer. In order to remove CO2 in the propylene unit we increased the steam and reduces the pressure in the deetanizer tower. It seems do not remove the CO2 enough. This tower remove the lighter streams on the top (ethane, CO2, etc) and the bottom have propane/propylene, but it seems do not remove enough the CO2. The propane/propylene stream in the tower bottom still have 2-3 ppm of CO2 and produces propylene with CO2. How can I improve this tower to remove more CO2 ?

[Hedewandro Lucredi]

Good discussion. How Can I predict when I need to stop the FCCU turbo expander related with catalyst loss from regenerator ? During the FCCU regular campaign there is a loss catalyst from the regenerator to turbo expander and it increase. What do I need to measure in order to shutdown the turbo expander if the loss catalyst reach a determined point ? We need to know this point to protect the turbo expander from FCCU loss catalist.

[Hedewandro Lucredi]

We also replaced LCO to Heavy naphtha in the compressor washing pallets. I have read that the best FCC stream would be light naphtha. What is the recommended product to inject in the FCCU wet gas compressor ?

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