3procesossimplesaspen.pptx

7/29/2019 3PROCESOSSIMPLESASPEN.pptx

1/25

Procesos Simples

Ing. Harvey Andrs MilquezUniversidad de la Sabana

2011


2/25

Ejemplo (Introduction toChemical Engineering

Computing) Problema 5.1


3/25

Ejemplo (Introduction toChemical Engineering

Computing)


4/25

Desarrollo

HIDROGEN

TOLUENE

B1

ALREACT


5/25

Componentes y PaqueteTerm. Tolueno, benceno, xileno, trimetil

benceno, hidrogeno, metano. NRTL-RK


6/25

Corrientes

Hidrogeno: Se tienen que definir 4variables. T=20C, P=1atm, FlujoMolar= 70 kmol/h composicin solo

H2. Tolueno: T=20C, P=1atm, Flujo

Molar= 10 kmol/h composicin solo

Tolueno.


7/25

Reactor de Estequeomtrico

ALREACT

SALREACT

B2

nicamente requiere la estequiometria de la reaccin y laconversin


8/25


Especificaciones del equipo: Presin: 1 bar.

Temperatura: 20 C

Reacciones: New.


9/25

Reactor de EstequeomtricoReaccin 1

Ingresen las dems


10/25


As se debe ver


11/25

Separadores

Sep combina corrientes y separa elresultado en dos o mas corrientes deacuerdo a las consideraciones decada componente dadas por elusuario.

Este equipo no es real, es unaherramienta si los procesos deseparacin no son importantes o paralimitar el tiempo de proceso.


12/25

Separador 1

SALREACT

B4

4

5

Hidrogeno: 1Metano: 1


13/25

M

H

B5

4

Separador 2

Hidrogeno: 1


14/25

Separador 3

5

B3B

2

Benceno: 1


15/25

2

T

X

B6

Separador 4

Tolueno : 1

Cual es la cantidad de hidrogeno que sale por la corriente H?


16/25

HIDROGEN

TOLUENE

ALREACT

SALREACT

4

5

H

M

B1B2

B4

B5

B3B

2

B6

T

X

As debe quedar


17/25

Reciclos

Se hace necesario realizar un reciclotanto del tolueno como del hidrogenoque sale al final del proceso, sin

embargo, como dice el enunciado larelacin hidrogeno/tolueno se debemantener en 7.

Si cerramos el proceso, ponemos elreciclo, la simulacin funciona?


18/25

Reciclos

Debe modificarse el flujo de entradade hidrogeno o de tolueno para quese mantenga la relacin H/T.


19/25

Design SpecA design specification sets the value of a variable that Aspen Plus would otherwise calculate. For example, you maywant to specify a product stream purity or the permissible amount of an impurity in a recycle stream. For each designspecification, you identify a block input variable, process feed stream variable, or other simulation input to be

manipulated (adjusted) to meet the specification. For example, you might manipulate a purge rate to control the levelof impurities in a recycle stream. Design specifications can be used to simulate the steady state effect of a feedbackcontroller.

When you use a design specification, you specify a desired value for a flowsheet variable or some function offlowsheet variables. The flowsheet variables used in a design specification are called sampled variables. For eachdesign specification, you must also select a block input variable or process feed stream variable to be adjusted tosatisfy the design specification. This variable is called the manipulated variable.

The design specification achieves its objective by manipulating an input variable specified by the user. Quantities thatare calculated during the simulation should not be varied directly. For example, the stream flow rate of a recyclestream cannot be varied; however, the split fraction of an FSplit block where the recycle stream is an outlet can bevaried. A design specification can only manipulate the value of one input variable.

Design specifications create loops that must be solved iteratively. By default Aspen Plus generates and sequences aconvergence block for each design specification. You can override the default by entering your own convergencespecifications.

The value of the manipulated variable that is provided in the Stream or Block input is used as the initial estimate.

Providing a good estimate for the manipulated variable will help the design specification converge in fewer iterations.This is especially important for large flowsheets with several interrelated design specifications.

The objective of the specification is that it equals the calculated value (Specified Value - Calculated Value = 0). Thespecification can be any valid Fortran expression involving one or more flowsheet quantities. Specifications must alsohave a tolerance within which the objective function relation must be satisfied. Therefore, the actual equation that mustbe satisfied is

| Specified Value - Calculated Value | < Tolerance

There are no results associated directly with a specification other than whether the objective function equation wassatisfied or not. The final value of the manipulated an/or sampled variables can be viewed directly on the appropriate


20/25

Design Spec


21/25

Design Spec


22/25

Design Spec


23/25

Reciclo

Str eam I D 2 4 5 ALREA CT B H HI DRO GENM SALREA CT T TOLU ENE X

Temp eratu r e C 2 0 ,0 2 0 ,0 2 0 ,0 8 ,2 2 0 ,0 2 0 ,0 2 0 ,0 2 0 ,0 2 0 ,0 2 0 ,0 2 0 ,0 2 0 ,0

Pr essu re b ar 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0

Vap o r Fr ac 0 ,0 0 0 1 ,0 0 0 0 ,0 0 0 0 ,8 8 8 0 ,0 0 0 1 ,0 0 0 1 ,0 0 0 1 ,0 0 0 0 ,9 0 7 0 ,0 0 0 0 ,0 0 0 0 ,0 0 0

Mo le F lo w k mo l/h r 1 2 ,1 8 8 1 2 0 ,3 9 9 1 7 ,2 0 0 1 3 7 ,5 9 9 5 ,0 1 2 1 2 0 ,3 7 5 0 ,0 2 4 0 ,0 2 4 1 3 7 ,5 9 9 7 ,2 0 0 1 0 ,0 0 0 4 ,9 8 8

Mass F lo w k g /h r 1 1 9 2 ,9 5 8 2 4 3 ,0 4 8 1 5 8 4 ,4 6 7 1 8 2 7 ,5 1 4 3 9 1 ,5 0 9 2 4 2 ,6 6 1 0 ,0 4 9 0 ,3 8 6 1 8 2 7 ,5 1 4 6 6 3 ,3 9 9 9 2 1 ,4 0 5 5 2 9 ,5 5 9

Vo lu me Flo w cu m/h r 1 ,3 7 7 2 9 3 6 ,3 2 2 1 ,8 2 9 2 8 6 2 ,2 2 2 0 ,4 4 6 2 9 3 5 ,7 3 5 0 ,5 8 7 0 ,5 8 6 3 0 4 5 ,4 8 3 0 ,7 6 3 1 ,0 6 0 0 ,6 1 2

En th alp y MMk cal/h r - 0 ,0 1 0 - 0 ,0 0 5 0 ,0 4 6 0 ,0 4 3 0 ,0 5 8 - 0 ,0 0 4 > - 0 ,0 0 1 > - 0 ,0 0 1 0 ,0 8 1 0 ,0 2 0 0 ,0 2 7 - 0 ,0 3 0

Mo le F lo w k mo l/h r

TOLUEN E 7 ,2 0 0 7 ,2 0 0 1 7 ,2 0 0 7 ,2 0 0 7 ,2 0 0 1 0 ,0 0 0

BENZENE 5 ,0 1 2 5 ,0 1 2 5 ,0 1 2

XYLEN E 4 ,9 8 8 4 ,9 8 8 4 ,9 8 8 4 ,9 8 8

3METBENZ

HI DROG EN 1 2 0 ,3 7 5 1 2 0 ,3 9 9 1 2 0 ,3 7 5 0 ,0 2 4 1 2 0 ,3 7 5

METHA NE 0 ,0 2 4 0 ,0 2 4 0 ,0 2 4


24/25

Tarea Reciclos


25/25

Tarea Reciclos

3procesossimplesaspen.pptx

Documents