Q & A > Question Details
I work on CDU/ VDU plant as a process engineer . We commissioned performance of the feasibility study concerning revamp of the vacuum system. It appears that we may achieve different vacuum at the top of the vacuum column with different solutions, so we have to consider the best option in terms of the yields of the fractions.
Is it possible to simulate in Sulzers proprietary application SULCOL how the yields will change from the vacuum column
1. when I set various pressures at the top of the column (without modification to vacuum column)
2. when I change the structured beds from current structured packing Mellapack to Mellapack Plus or other.
I would be very grateful for some information with regard to technical capabilities of this program or maybe some recommendations for other free software of this kind.
26/09/2012 A: Celso Pajaro, Sulzer Chemtech, celso.pajaro@sulzer.com
Sulcol will allow you to predict the presure drop of the packed bed at different conditions; however Sulcol does not predict the chimney tray pressure drop which can be significant.
The pressure drop calculations will allow you to estimate the column pressure profile that should be input in a distillation simulation software (PROII, Hysys) this will allow to estimate the column yields.
25/09/2012 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Most people use their regular distillation simulation program, along with a set of HETPs for different packings. Vary the pressure from case to case and vary the number of theoretical stages from case to case. Solve to the same 95% points from case to case. Examine the different yields.
25/09/2012 A: Rajkumar Chate, Sulzer, rajkumar.chate@sulzer.com
Please keep in mind that Sulcol is not a process simulator and it is tool used for hydraulics design/rating of column internals. With sulcol you can do the rating of existing packing.
Regarding changes in packing from melapak to mellapakplus definately you will have some advantages in terms of capacity and efficiency, mellapackplus have higher capacity than melapak due to its change in corrogation angle.
I will redommend to do following
You might be having the test run data now with you, based on this data prepare a simulatio model in any process simulator PRO II/Hysys/Unisim/Petrosim/Chemcad then match all the plant run data with your simulation model, generate the vapor liquid loadings in the tower then use this vapor liquid traffice for hydrualics (rating of existing internals, in you case you have mentioned mellapak) and chek the capacity limitation.
Please keep in mind that Sulcol is the tool used for hydraulics design only and you can not do any process design with this tool. Also there is a KG tower used for same purpose and you can download it from the KG website.