Which simulation software
Which simulation software
(OP)
Hi,
Which simulation software is considered the best and most accurate for crude refining ? Hysys, Chemcad, Pro II, Design II .. ?
Did anyone try to cross check the simulation with manual calculation ?
Which simulation software is considered the best and most accurate for crude refining ? Hysys, Chemcad, Pro II, Design II .. ?
Did anyone try to cross check the simulation with manual calculation ?





RE: Which simulation software
The main difference today would be in features, user friendlyness, cost and number of users.
Best regards
Morten
RE: Which simulation software
Aspen Plus is one of the most user-unfriendly softwares (for my taste), while ChemCAD and Design II are more like academic purpose software. I do not have experience with Pro/II.
Also include ProMax and VMGSim in your evaluation list. Bot are rated high in process industry. VMGSim comes from the original Hyprotech team, developers of HYSYS.
Best regards,
RE: Which simulation software
I useually do a hand calculation first before using a simulation. Not a tray by tray ect, but generalized tables/charts. I may use a simple energy or mass balance to get an idea of what is going on. This allows me to give the simulator a good set of initial guesses or where recycles are and how big.
I consider WinSim the best bang for the buck. It isn't as pretty as the others, but you have to love the cost and ease of use, yeah, once you get to know its tricks. The same is true with them all. So much for the commercial.
Morten is also with me on this, "it isn't the software that makes a simulation, its the user."
RE: Which simulation software
I also like winsim - unfortunately as a consultant i have to go with that package that my clients prefer - and here it seems like HYSYS has the larger userbase. One of our major cliens hwoever uses winsim - and therefore we (still) have licenses for winsim.
Best regards
Morten
RE: Which simulation software
I'm not a power user, but I keep an eye open for people with questions in that forum along with the other simulators.
RE: Which simulation software
Since the basis of distillation is vaporization, the simulation software should be able to provide the phase change of crude correctly.
I don't know if it is possible for people who have access to different simulation software to try to find how much of a specific crude is vaporized at specific conditions, for example the heater outlet conditions or the flash zone conditions, for a crude they already know about. It is possible to do the hand calculations cross checking with known crude such as the crude provided in the example shown in Watkins book "Petroleum Refinery Distillation".
The manual calculation of the crude Equilibrium Flash Vaporization curve provides a certain % vaporization at heater outlet conditions, if the simulator is able to provide similar result, then it is a good starting point for its accuracy.
Would anyone try that ?
RE: Which simulation software
Cost difference....well that depends what deal you can prize out of them.
RE: Which simulation software
You hint that you have been able to get a discount on Aspen products. I usually dont stop untill i get some discout - in some cases up to 50% - but with Aspen i couldnt get anything.
Best regards
Morten
RE: Which simulation software
It was not my decision to convert to Aspen. I think it was the company's need for access to a polymers package...namely Polymers Plus from Aspen.
My (admittedly cynical and simplistic) view is that Aspen was written by scientists for scientists and SimSci was written by engineers for engineers.
Best wishes
Geordie87
RE: Which simulation software
RE: Which simulation software
Bulk Gravity : 36.3 oAPI
Light end analysis per 100 barrels
bbl
C2H6 0.1
C3H8 0.9
iC4H10 1.4
nC4H10 2.3
iC5H12 2.1
nC5H12 1.8
TBP distillation of crude , Temperature in oF
Vol.% TBP
5 62
10 144
20 255
30 344
40 437
50 531
60 623
70 717
80 819
85 897
I asked a friend who has access to Chemcad in a university to check the % vaporized provided by the simulator, comparing with the manual calculation it was very far and can't be accepted.
Would anyone try other software and share the results ?
Thanks ...
RE: Which simulation software
Sorry for not providing the conditions to check for % vaporized
Watkins made his illustration for the crude distillation at the following conditions
Heater outlet
T = 700 oF, P = 35 psia
Flash Zone conditions
T = 695 oF , P = 25 psia
The heater outlet conditions are the main checking case, since the % vaporized at flash zone is affected by presence of stripping steam.
RE: Which simulation software
I would check the assumptions in the manual method - is it possible that the simulator with an appropriate equation of state is going to be more accurate than a (presumably short cut) hand calculation? I would also ask your friend what property method they used for the calculation.
RE: Which simulation software
Stream Name Heater in Heater out
Thermo Method Option Esso Esso
Vapor Fraction 0.0227614 0.9143195
Temperature F 215 700
Pressure psia 35 25
Enthalpy btu/hr -85367587.1 384706965
Entropy btu/R/hr 1740.185 524631
Vapor Density lb/ft3 0.3099071 0.3084775
Density lb/ft3 48.31416 48.48441
Specific Gravity60F@STP 0.8561347 0.9722873
Vapor Cp btu/lbmol/R 29.22838 98.73733
Vapor Cv btu/lbmol/R 26.97994 96.5664
Liquid 1 Cp btu/lbmol/R 96.96243 387.37642
Vapor Viscosity cP 0.0096158 0.0124019
Liquid 1 Viscosity cP 1.1053 1.60212
Vapor Thermal Conductivity
btu/ft/hr/F 0.0159779 0.028927
Liquid 1 Thermal Conductivity
btu/ft/hr/F 0.0676442 0.0391321
Vapor Flowrate mmscf/day@STP 1.4213 57.09321
Liquid Flowrate gal/min@STP 2884.44235 625.47441
Molecular Weight 181.5572 181.5572
Molar Flowrate lbmol/hr 6857.1946 6857.1946
Mass Flowrate lb/hr 1244973.051 1244973.051
Note: All Liquid 1 Phase calculations exclude Free Water
RE: Which simulation software
My knowledge so far concerning crude distillation is that using the TBP curve to construct the EFV curve of the whole crude at heater outlet conditions and flash zone is the first step for successful distillation calculations, because it will give the actual % vaporized. Creating EFV is a manual method, but it is the only known method (as far as I know). I presume that the simulators do not have other ways to create the EFV.
Since my only available option is Chemcad, I was informed it doesn't provide EFV curve, but the % vaporized calculated by it should be close to what Watkins calculated since he used the only known method for creating EFV, otherwise the built in method in Chemcad for crude phase change won't be accurate enough.
To dcasto
Thanks, it seems you took a practial step, which software did you use ?
I think you should try the heater outlet conditions at pressure = 30 psia, it will give you slightly lower % vaporized, as the 25 psia is at flash zone and in this case you can't compare your results to the manual results obtained by Watkins since he used stripping steam which will give more vaporization than dry conditions.
In all cases, I think you arrived at about the same results which were obtained by Chemcad, the % vapor you got is much higher (much much higher) than the actual EFV curve results.