8 replies to this topic

[Kat]

Hi all,
I am using the H&MB which is the Hysys simulation results from other guy. There are two set of data: Start of run (SOR) and End of run (EOR).
What do the SOR and EOR exactly mean and why they are needed?
There are some differences between these 2 sets. Which set of data should be used for design case?
Thanks

[Zauberberg]

Both.

This may be discussed further depending on which type of equipment is in question, but in general these two conditions (SOR, EOR) mean the following: minimum and maximum design duty that a particular piece of equipment needs to be designed for.

SOR conditions refer to the new equipment, or to the conditions after turnaround when performance parameters have been fully, or almost fully restored. For a fired heater, for example, this corresponds to the minimum quantity of fuel that needs to be burnt in order to achieve desired process duty. EOR conditions refer to the partially fouled heater, both from process side (e.g. coking) and flue gas side (e.g. fuel ash deposits). Both these factors cause the amount of fuel per unit of duty to increase, due to fouling. EOR conditions in this case refer to the maximum quantity of fuel that needs to be burnt in order to achieve desired duty.

It is very important to emphasize which equipment, and in what configuration, is in question when you speak about SOR/EOR conditions. Just to give you a flavor of this issue: in the same fired heater example, if upstream of the heater is a heat exchanger train that normally fouls by time, for the EOR conditions now you have to consider another factor apart from fouling of the heater itself - and that is lower heater inlet temperature due to fouled heat exchangers, which calls for even higher fuel consumption for the same heater outlet temperature.

Edited by Zauberberg, 13 December 2010 - 06:13 PM.

[djack77494]

This nomenclature is also common in reacting systems. I am familiar with reactions catalyzed with solid catalysts. Over time, the catalyst is deactivated by the impurities present, and so the extent of the reaction gradually falls. At some point, you cannot tolerate any further decrease in performance and you must replace or regenerate the catalyst. Just before you do this is called the "End of Run" condition. Same principle as that described by Zauberberg, just different specifics.

[Kat]

thank you very much for your valuable explanation.
One more thing: how to get Start of Run and End of Run? Is the Start of Run the input before I run simulation and End of Run is the output from simulation?

Edited by Kat, 05 January 2011 - 01:32 PM.

[DB Shah]

thank you very much for your valuable explanation.
One more thing: how to get Start of Run and End of Run? Is the Start of Run the input before I run simulation and End of Run is the output from simulation?

"Run" referred in SOR/EOR does not imply to simulation "run". SOR & EOR are two different sets of operating conditions.
SOR or BOR = Start/Begning of Run ie when the catalyst or equipment is fresh
EOR = End of Run ie when the catalyst is decayed or the equipment is fouled or has lost its efficiency.

For eg-
If you consider a Methanol plant, when you charge a fresh catalyst conversion is maximum and purge from the loop is minimum. Reactor temperature are also lower. With respect to time catalyst starts to deactivate and production drops. Purge from the loop increases. Typically for a methanol plant catalyst charge is replaced after 3 ~ 4 years. (Replacement of catalyst is an economic decision ie if you replace catalyst, production increases but at a cost of catalyst and downtime to replace catalyst)

Now to ans your initial question - "Which set of data should be used for design case?"
When you design the plant it is designed for both the cases. SOR does not means "max" or "min" of all parameters. As given in above eg at SOR production is max but purge flow is minimum. Similarly at EOR production is low but reactor temperature is high, purge draw is high. Hence if you consider SOR case - down stream units of the reactor (heat recovery & purification units) should be able to handle the highest production level. At EOR the reactor feed heaters and purge gas units should be able to handle highest duty.

If you are still in doubt, indicate the equipment/configuratio you are working on, maybe we will be able to explain in better way.

[Kat]

"Run" referred in SOR/EOR does not imply to simulation "run". SOR & EOR are two different sets of operating conditions.
SOR or BOR = Start/Begning of Run ie when the catalyst or equipment is fresh
EOR = End of Run ie when the catalyst is decayed or the equipment is fouled or has lost its efficiency.

For eg-
If you consider a Methanol plant, when you charge a fresh catalyst conversion is maximum and purge from the loop is minimum. Reactor temperature are also lower. With respect to time catalyst starts to deactivate and production drops. Purge from the loop increases. Typically for a methanol plant catalyst charge is replaced after 3 ~ 4 years. (Replacement of catalyst is an economic decision ie if you replace catalyst, production increases but at a cost of catalyst and downtime to replace catalyst)

Now to ans your initial question - "Which set of data should be used for design case?"
When you design the plant it is designed for both the cases. SOR does not means "max" or "min" of all parameters. As given in above eg at SOR production is max but purge flow is minimum. Similarly at EOR production is low but reactor temperature is high, purge draw is high. Hence if you consider SOR case - down stream units of the reactor (heat recovery & purification units) should be able to handle the highest production level. At EOR the reactor feed heaters and purge gas units should be able to handle highest duty.

If you are still in doubt, indicate the equipment/configuratio you are working on, maybe we will be able to explain in better way.

Thanks Shah,
I am working on the unit similar to UOP Unionfining. You can find it in UOP Unionfining
To this particular configuration, how can I get SOR and EOR?
What should be the possible conditions for EOR? If the SOR in this case is the decay of catalyst in the reactor, how can I simulate it?
Warm regards

Edited by Kat, 06 January 2011 - 05:23 PM.

[DB Shah]

SOR is start of run or Begning of run with fresh catalyst, EOR is end of run when catalyst decays/deactivates.
This detail can be obtained by catalyst supplier, you cannot simulate it. For a given quality of feed stream catalyst supplier guarantee performance when catalyst are fresh ie SOR condition, when catalyst deactivates (EOR) and will also give expected pertiod during which catlayst deactivates. Catalyst supplier simulates the reactor for both this cases and will provide heat and mass balance around the reactor for both the cases.

[Kat]

SOR is start of run or Begning of run with fresh catalyst, EOR is end of run when catalyst decays/deactivates.
This detail can be obtained by catalyst supplier, you cannot simulate it. For a given quality of feed stream catalyst supplier guarantee performance when catalyst are fresh ie SOR condition, when catalyst deactivates (EOR) and will also give expected pertiod during which catlayst deactivates. Catalyst supplier simulates the reactor for both this cases and will provide heat and mass balance around the reactor for both the cases.

Thanks Shah,
the process that I am working on is not a licensed process, it is a small testing unit therefore I simulate the reactor as a flash drum with (reaction) temperature and pressure. How can I do SOR and EOR in this case?
Another thing, I have only the experiment data with different feedstock for this testing unit, should I use the experimental results to validate simulation, or in other words, use simulation to reproduce the experimental data?

[Kat]

Hi all,
One question regarding the input data for EOR: which kinds of specific process data do I need to simulate EOR case for diesel hydrotreating?
Should I use the same simulation file for SOR and change the operating conditions (for example deactivated catalyst) to have EOR?
Thanks,

Edited by Kat, 13 January 2011 - 04:49 PM.