Refining process units monitoring 1

[sheiko]

I would like to know what operating variables process engineers do (or should) monitor in your refineries, in order to follow the performances of the following units:
1- Atmospheric distillation
2- Semi-regenerative catalytic reforming
3- Naphta HDT
4- Kerosene HDS
5- Gasoil HDS
Thanks

"We don't believe things because they are true, things are true because we believe them."

 

[sottocutaneo]

I think that the answer to your question is more or less one thousand of paramters. MAy be that you must specify the question

 

[sheiko]

Ok.
So may I know the most critical operating conditions for each of the above mentionned units?

"We don't believe things because they are true, things are true because we believe them."

 

[owg]

Get to know the operators well, and help them whenever you can.

HAZOP at

http://www.curryhydrocarbons.ca

 

[RefinerLink]

1. Heat Exchanger train fouling, fractionation efficiency, stream cutpoints
2. Severity of operation, feed sulfur, feed PONA, MCP / Cyclohexane split, runlength, operating pressure
3. reactor exotherm, product sulfur & nitrogen, catalyst aging rate
4. reactor exotherm, product sulfur & nitrogen, catalyst aging rate, hydrogen partial pressure
5. product sulfur & nitrogen, catalyst aging rate, hydrogen partial pressure
6. product sulfur & nitrogen, catalyst aging rate, hydrogen partial pressure, aromatic saturation

For additional tips on Oil Refinery operations, you can read up on additional content on RefinerLink.com

 

[sheiko]

Thanks refinerlink

I do know your eponym website I it is really helpful.

As for your tips, what is MCP? Reactor exotherm?

Also you have 6 items while I had 5. So I am bit lost. Could you please clarify?

"We don't believe things because they are true, things are true because we believe them."

 

[mpsmps]

Making reference to semirigen reforming, as follows has to be monitored:
- DWAIT, delta beeing expected weight average reactors inlet temperature vs actual. Parameters ( RON, Naphthenes, aromatics, LHSV) have to be normalized, catalyst suppliers provide General operating manual where normalization is well explained; This parameter is able to predict end of cycle and to show upsets if any;
- Selectivity, the meaning being the difference between expected C5+ yield and actual; even here normalization is required in order to take in account different feeds and severity;
In general, HCl in recycle gas (traces) and debuta overhead (traces X3)monitoring is necessary as well as recycle gas water content (15-25 ppmv). Subsequently water and chloride injection.
Cl on cat can be monitored even considering ex RX's light ends ratio C1+C2/C3+C4 (molar), the ratio to be considered correct if near to 1+/-0,1. If lower too Cl or H2O injection.
For possible f/e exchangers leakage I utilize the ratio metilcyclohexane/1t2dimetilcyclopentane, warning if ratio is higher than 1.7

 

[RefinerLink]

Sheiko,

MCP is Methyl-Cycle Pentane. The separation between this molecule and cyclohexane is an important one for optimizing reformer feed quality. MCP does not reform well, while cyclohexane does.

Reactor exotherm is how much temperature gain occurs across your reactor. It's also known as reactor DT (delta temperature), but as hydrotreating processes are net exothermic, many refer to the reactor DT as reactor exotherm. For processes that are net endothermic (i.e. reforming), some call it reactor endotherm as opposed to net DT.

As for listing 6 items, you can replace item 5 with item 6 completely. I added an extra line accidentally.

regards,