balances m&e rutinas operaciones diseño de equipos simulaciÓn equilibrio fases reacción...
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Balances M&E
Rutinas operaciones
Diseño de Equipos
SIMULACIÓN
Equilibrio Fases
ReacciónPropiedades
Termodinámicas
CÁLCULO PROPIEDADES
Propiedades Transporte
Propiedades Intermedias
Relaciones Termodinámicas
ECUACIONES
Ecuaciones numéricas
Variables de operación(xi, P, T, V)
Propiedades Puros
PARÁMETROS
Parámetros de mezclas
Escalares
Función T
Binarios
Ternarios
Valores ExperimentalesRegresión
Base de datos
Usuario
Estimación
Models (Routes)
Models
Major
Subordinate
CÁLCULO DE PROPIEDADES FÍSICAS EN UN SIMULADOR ANÁLISIS
Intermediate
How does the Property Method calculate a specific property?
The properties used in the simulation are classified into categories depending on how they are evaluated:
Some general concepts:
1. MODELS
2. METHODS
3. ROUTES
How does the Property Method calculate a specific property?
The properties used in the simulation are classified into categories depending on how they are evaluated:
1. MODELS: models calculate properties by direct use of an empirical expression or a theoretical model. For example:
GAMMA: liquid mixture activity coefficients.Possible MODELS: GMRENON: NRTL original
GMUFAC: UNIFAC
GMUFDMD: UNIFAC, modif. Dormund
.... (up to 32 MODELS)
2. METHODS: in this case the property is evaluated using a thermodynamic expression where required properties are evaluated with MODELS. Different thermodynamic expressions (METHODS) may be available to evaluate a specific property.
For example, four METHODS are available to evaluate the enthalpy of a liquid mixture (HLMX) :
METHOD 1: Empiric expressionHLMX = f(T, P, x_i, parámetros)
METHOD 2: From the ideal liquid mixture enthalpy (Hi*L) y the excess
enthalpy (HEX).HLMX = Σxi Hi
*L + HEX
METHOD 3: From ideal gas mixture enthalpy (Hmig) and departure
enthalpy (Hdepart):HLMX = Hm
ig + Hdepart
METHOD 4: ElectrolytesHLMX = f(xTRUE)
How does the Property Method calculate a specific property?
The properties used in the simulation are classified into categories depending on how they are evaluated:
3. ROUTES: The group of specific METHOD and MODELS selected to evaluate a property is named a ROUTE.
How does the Property Method calculate a specific property?
The properties used in the simulation are classified into categories depending on how they are evaluated:
Types of properties depending on their use and how they are calculated:
MAJOR: Are those properties required for calculations by unit operation models. They ere evaluated according to ROUTES, and may depend on other MAJOR, SUBORDINATE and INTERMEDIATE properties .
Properties: PHI, H, G, S, V, MU, K, D, SIGMA (Pure and mixtures)
SUBORDINATE: these properties are also calculated using ROUTES, but are not directly required for unit operation model calculations. They are used to calculate MAJOR properties.
Ex.: HLXS (excess enthalpy), ...
INTERMEDIATE: calculated by MODELS, they are used to calculate MAJOR and SUBORDINATE properties.
Ex.: GAMMA (activity coefficients),...
How does the Property Method calculate a specific property?
Property Method
• Property Method: a collection of methods and models to evaluate physical properties and phase equilibrium.
• The first step is choosing the appropriate property method.
Select a Property Model
• Template, General with metric units.•/Data /Setup: Run Type Property Analysys• /Data /Components: METHANOL, WATER• /Data /Properties: Base Method NRTL
FlowsheetProperty
EstimationProperty Analysis
Data Regression
Assay data analysis
Flowsheet simulation
Property constant estimation (PCES)
Properties tables calculation
Experimental data correlation
Oil fractions characterization
• /Properties / Property Methods /NRTL: Routes , Select HLMX, View
View a ROUTE description
Descripción en ENERGIA LIBRE NRTL.docx
• /Properties / Property Methods /NRTL: Models , Select GMRENON
Check a MODEL
F1
EJERCICIO: Explicar la ruta para calcular la entalpía molar de un componente puro en fase líquida cuando se selecciona el Property Package NRTL, con una mezcla Methanol+Agua
Property Method Selection
• Main characteristic: phase equilibria calculation. Classification:
• IDEAL• EOS (PR, RK, BWR,....)• Activity coefficient (NRTL, UNIFAC, ...)• Electrolites (ELECNRTL, PITZER)• Special methods (AMINES, STEAMNBS,...)
• Selection: Help
1
2
3
More about Property Methods ... APrSystem Help: /Data /Properties [F1]
Separation of a mixture of methanol + water in an atmospheric column:
Open a new file (General with metric units) and define components (METHANOL, WATER) and Property Method (NRTL).
Polar ?
Electrolyte ?
Yes
P < 10 bar ?
No
ij ?
Yes
LL ?
Yes
Wilson, NRTL, UNIQAC
No
Model Parameters
Reid,Prausnitz y Pooling, The Properties of Gases & Liquids, 4th Ed, Cap. 8, p. 380-1.
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