Hello everyone peace, be upon you
This blog is made for people who want to learn how to use
Aspen HYSYS, this one is used for simulation of process like oil and gas,
polymers.............
1- Static mode (Steady state mode)
2- Dynamic mode
We will start with the steady and we will show you how to converge the system, then finishing by dynamic mode.
First in your simulation that you want to make it when
you enter to hysys you have to pick your components after that, you have to
pick your fluid package and i will give you some examples how you choose your
fluid package, because it's very important for your simulation to converge.
Fluid package means
states equations or thermodynamic model the different fluid package and their use :
System type
|
recommended model
|
Atmospheric
distillation (Topping)
|
PR
|
Dehydration TEG
|
PR
|
Hard water
|
PR, sour PR
|
Cryogenic and Gas
Treatment
|
PR, PRSV
|
Separating Air
|
PR, PRSV
|
Under Vacuum Column
|
PR, PR Option, GS
(<10 mmHg)
|
H2 High System
|
PR, ZJ or GS
|
Tank System
|
PR, PR Option
|
Water Vapor
|
Stream package, CS or
GS
|
Chemical System
|
Model of activity,
PRSV
|
Hydrate Inhibitor
|
PR
|
Alkylation at HF
|
PRSV, NRTL
|
Dehydration TEG With
Aramotic
|
PR, Amine package
|
Systems of
Hydrocarbure When The Solubility of Water is Important
|
KAbadi Danner
|
The success
of the simulation depends on the choice of the thermodynamic model, because the
model is established for a fluid class and a domain of pressure and
temperature conditions recommended using
assumptions and practices suppositions.
The most recommended
equation for hydrocarbon systems is the equation PR (PENG ROBINSON) because it
correctly solves the problems with balance and allows predicting liquid
densities more in line with real values than other equations..
Now we start our simulation with all steps that I mentioned them (new case,
components, and choose the appropriate fluid package) we enter to simulation environment :
After that we take our material stream (the blue
arrow), now for this step, we have to converge this one and if we do it, all
simulation will be very easy, so how we can converge the material stream?
Materiel stream needs
four things to converge:
- Temperature or Vapor fraction
- Pressure or Vapor fraction
- The quantity (molar flow, mass flow…)
- Compositions of stream.
Example :
We have stream
(C3, iC4, nC4, C5, C6, C11)
Initial
conditions
P = 1000 KP =
10 bar
T = 82 °C
Molar flow = 200
kmole/h
Compositions are :
C6 = 4,166 e-002
C5 = 8,33e-002
nC4 = 0, 25
iC4 = 0,375
C3 = 4,16e-002
C11=0,208
Notice :
The total of compositions must be one (1)
∑X’i = 1 or ∑Xi = 1
X’i: molar fraction
Xi : mass fraction
And if you notice the color of the stream (1 to 1’), it shows you how the stream get converged (change the color for sky blue to blue)
Now we did the most important step, we have the stream; let us explore equipment or apparatus used in simulation.
In HYSYS, we have many apparatus (exchangers, separators, valves, pumps, compressors, columns……..) we will explore them one by one.
But i found the most important we have learn it and we have focus on it is the Distillation column (the rectification column):
Exercice for distillation column:
We have tow streams
Notice :
The total of compositions must be one (1)
∑X’i = 1 or ∑Xi = 1
X’i: molar fraction
Xi : mass fraction
And if you notice the color of the stream (1 to 1’), it shows you how the stream get converged (change the color for sky blue to blue)
Now we did the most important step, we have the stream; let us explore equipment or apparatus used in simulation.
In HYSYS, we have many apparatus (exchangers, separators, valves, pumps, compressors, columns……..) we will explore them one by one.
But i found the most important we have learn it and we have focus on it is the Distillation column (the rectification column):
Exercice for distillation column:
We have tow streams
Stream 1
|
Stream 2
| |
Compositions
|
X’L,i
|
X’L,i
|
% Molar
|
% Molar
| |
C2
|
0,01305
|
0,00483
|
C3
|
0,55177
|
0,09186
|
iC4
|
0,10943
|
0,03941
|
nC4
|
0,16454
|
0,07576
|
iC5
|
0,05847
|
0,05854
|
nC5
|
0,04402
|
0,05307
|
nC6
|
0,03661
|
0,1105
|
nC7
|
0,01555
|
0,12236
|
nC8
|
0,00533
|
0,12063
|
nC9
|
0,00103
|
0,08335
|
nC10
|
0,00016
|
0,05187
|
nC11
|
0,00003
|
0,03645
|
nC12 +
|
0,00001
|
0,15137
|
Total
|
1
|
1
|
T (°C)
|
97
|
188,8
|
P (bar)
|
15,5
|
15,5
|
Molar flow (kmol/h)
|
737,96
|
256,75
|
Our objective in this exercise is to converge the distillation column
for getting the stream products (LPG, condensate)
Now in the distillation column after successful converged of the inlet streams;
We have to give:
We have to give:
-
definition (names) for
the products streams (materials and energy)
-
the number of stages of
column
-
The pressure of all the
areas of column (condenser, the top of column, the bottom of column, and the
reboiler)
After that, we skip the other setting, because HYSYS will calculate them
At the moment we enter to the dashboard of the column we have to pick the specifications of
products streams (LPG, condensate)
In LPG : the fraction of iC5 max = 0.005 %
And the condensate: TVR = 10 psia = 68.95 KPa (TVR: Ried vapor pressure)
After successful converged the distillation column, we will make video to present it more
properly and clearly.
