You are beginner in Hysys ? we will show you :)

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.............

Aspen HYSYS contain tow systems

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 

	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:

-          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.