ASPEN PLUSChao Miao

04.25.2013

INTRODUCTION In industry complicated problems are often not

solved by hand for two reasons: Human error and time constraints.

Aspen can be a very powerful tool for a Chemical Engineer in a variety of fields

oil and gas production, refining, chemical processing, environmental studies, power generation

INTRODUCTION

Aspen Tech was born out a joint research project between the MIT and DOE—an Advanced System for Process Engineering (ASPEN) Project.

Aspen Plus is a process modeling tool for conceptual design, optimization, and performance monitoring for chemical processes. Aspen Plus is a core element of AspenTech’s Process Engineering applications.

Some other tools offered by Aspen One: Dynamic Simulation, Heat exchanger design, Production planning, interface with Microsoft excel (Workbook).

INTRODUCTION A process model can be defined as an engineering system's "blue print.” The process model is a complete layout of the engineering system

including the following:

1. Flowsheet The flowsheet shows one or more inlet streams entering into the system

and continues through the process, illustrating all intermediate unit operations and the interconnecting streams.

The flowsheet also indicates all product streams. Each stream and unit operation is labeled and identified. 

2. Chemical Componentsall chemical components from the necessary reactants and products, to steam and cooling water. 

3. Operating ConditionsAll unit operations in the process model are kept under particular operating conditions (i.e., temperature, pressure, size).

THE STRUCTURE OF A PROCESS SIMULATOR

Component Database

Thermodynamic Model Solver

Flowsheet Builder

Unit Operation Block Solver

Data Output Generator

Flowsheet Solver

Basic Computational Elements in Process Simulator

Select Chemical Components

Select Thermodynamic

Model

Input Topology of Flowsheet

Select Units and Select Feed

stream properties

Select Equipment Parameters

Select Output Display Options

Sequence of Input Steps for a Simulation Problem

Select Convergence

Criteria and Run Simulation

Turton, Bailie, Whiting, Shaeiwitz, “Analysis, Synthesis, and Design of Chemical Processes”, Second Edition, 2003

INTRODUCTION

To solve this problem, we need:Material balancesEnergy balances

What is the composition of stream PRODUCT?

GETTING STARTED

GETTING STARTED

ASPEN ACCESS

NAVIGATING THE ASPEN WINDOWS

Toolbar Feature

Equipment Model Library

Stream Library

Status Bar Simulation Status

Next Button

STATUS INDICATOR

SET UPMost of the commonly used Setup information is entered on the Setup Specifications Global sheet:

• Flowsheet title to be used on reports

• Run type

• Input and output units

• Valid phases (e.g. vapor-liquid or vapor-liquid-liquid)

• Ambient pressure

Stream report options are located on the Setup ReportOptions Stream sheet.

SET UP SPECIFICATIONS FORMS

COMPONENTS

• Use the Components Specifications form to specify all the components required for the simulation.

• If available, physical property parameters for eachcomponent are retrieved from databanks.

• Pure component databanks contain parameters such as molecular weight, critical properties, etc. The databank search order is specified on the Databanks sheet.

• The Find button can be used to search for components.

COMPONENTS

ENTERING COMPONENTS

• The Component ID is used to identify the component in simulation inputs and results.

• Each Component ID can be associated with a databankcomponent as either:Formula: Chemical formula of component (e.g., C6H6)Component Name: Full name of component (e.g.,BENZENE)

• Databank components can be searched for using the Find button.Search using component name, formula, component class, molecular weight, boiling point, or CAS number. All components containing specified items will be listed.

FIND

PURE COMPONENT DATABANKS

PROPERTIES• Use the Properties Specifications form to specify the physical property methods to be used in the simulation.

• Property methods are a collection of models and methods used to describe pure component and mixture behavior.

• Choosing the right physical properties is critical for obtaining reliable simulation results.

• Selecting a Process Type will narrow the number of methods available.

PROPERTIES SPECIFICATIONS FORM

STREAMS

• Use Stream Input forms to specify the feed streamconditions and composition.

• To specify stream conditions enter two of the following:1. Temperature2. Pressure3. Vapor Fraction

• To specify stream composition enter either:1. Total stream flow and component fractions2. Individual component flows

STREAMS INPUT FORM

BLOCKS

• Each Block Input or Block Setup form specifies operating conditions and equipment specifications for the unit operation model.

• Some unit operation models require additional specification forms

• All unit operation models have optional information forms (e.g. BlockOptions form).

BLOCK FORM

START THE RUN

Select Control Panel from the View menu or press the Next button to be prompted.

The simulation can be executed when all required forms are complete.

The Next button will take you to any incomplete forms.

REVIEWING RESULTS• History file or Control Panel Messages Contains any generated errors or warningsSelect History or Control Panel on the View menu to display the History file or the Control Panel

• Stream ResultsContains stream conditions and compositionsFor all streams (/Data/Results Summary/Streams)For individual streams (bring up the stream folder inthe Data Browser and select the Results form)

• Block ResultsContains calculated block operating conditions (bringup the block folder in the Data Browser and select the Results form)

UNIT OPERATION MODEL TYPE

• Mixers/Splitters • Separators • Heat Exchangers • Columns • Reactors • Pressure Changers • Manipulators • Solids • User Models

SEPARATORS

PROBLEM DESCRIPTION

Perform a Flash Calculation for the following stream:

Molar Composition:Ethane: 40%Propane: 40%n-Butane: 20%

Pressure: 15 barTemperature: 25 CelsiusFlow: 100 kmol/hr

CREATING A FLASH PROCESS To place a unit operation (or piece of

equipment) into the flowsheet window, select it from the Equipment Model Library and then click on the flowsheet window where you would like the piece of equipment to appear.

Required Stream

Optional Stream

CREATING A FLASH PROCESS Streams can be added by clicking on the

process flowsheet where you would like the stream to begin and clicking again where you would like the stream to end

SOME ASPEN FEATURES

Color Code:- Red: Information is required / simulation has

finished with errors- Blue: Everything is ok.- Yellow: Input Information has changed /

simulation has finished with warnings.

Next Button:Displays the next required input specification

Next Button

SET UP

SPECIFICATION OF CHEMICAL COMPONENTS

SELECTION OF PHYSICAL PROPERTY MODEL

Peng Robinson: This property method is comparable to the RK-SOAVE property method. It is recommended for gas-processing, refinery, and petrochemical applications. Sample applications include gas plants, crude towers, and ethylene plants.

SELECTION OF FEED STREAM PROPERTIES

SELECTION OF EQUIPMENT PARAMETERS Pressure = 0 means no pressure drop

through the equipment. Heat Duty = 0 means no Heat is added to the

equipment.

RUNNING

VERIFY YOUR RESULTS

VERIFY YOUR RESULTS

REACTORS

REACTORS

PROBLEM DESCRIPTION

Aspen Plus will be used with benzene pyrolysis reaction in a plug flow reactor

REACTION KINETICS

EXPERIMENT DATA

PARAMETER VALUES

FLOWSHEET

FLOWSHEET

FLOWSHEET

FLOWSHEET

SET UP INPUT FORM

SET UP INPUT FORM

COMPONENT INPUT

COMPONENT INPUT

PROPERTY INPUT FORM

STREAM INPUT FORM

REACTOR INPUT FORM

PHYSICAL DIMENSION OF REACTION

INFORMATION FOR REACTIONS

INFORMATION FOR REACTIONS

REACTIONS INPUT FORM

REACTIONS INPUT FORM

REACTIONS INPUT FORM

REACTIONS INPUT FORM

REACTIONS KINETICS INPUT FORM

REACTIONS KINETICS INPUT FORM

REACTIONS KINETICS INPUT FORM

REACTIONS KINETICS INPUT FORM

RUNNING

RESULTSExperiment data

Simulation data

PROBLEM DESCRIPTION

The feed shown in the diagram above will consist of 50 lbmol/hr of Methanol and 50 lbmol/hr of water. A purity of 95% is desired in both thebottoms and distillate product streams using a reflux ratio of 1.5.

FLOWSHEET

FLOWSHEET

FLOWSHEET

SETUP

COMPONENT

PROPERTIES

STREAMS

DISTILLATOR

DISTILLATOR

DISTILLATOR

RUNNING

RESULTS

Thank you