AN INTRODUCTION TO ASPEN Plus AT CITY COLLEGE

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1 AN INTRODUCTION TO ASPEN Plus AT CITY COLLEGE Prepared by I. H. RINARD Department of Chemical Engineering November 1997 (Revised October 1999) ASPEN Plus provided by Aspen Technology, Inc. Cambridge, Massachusetts 10/18/99 ASPEN Introduction 1

2 WHAT IS ASPEN? A computer program for steady-state process simulation (a.k.a. process Flowsheeting) Developed for the simulation of Chemical & Petrochemical Processes Coal-based Processes Petroleum Refining Polymer Processes One of many commercially available flowsheeting programs such as PRO II (Simulation Sciences) HYSIM (Hyprotech) ChemCad (Chemstation) 10/18/99 ASPEN Introduction 2

3 HOW DOES ASPEN WORK? Basic unit is the BLOCK model Unit operations (Distillation Columns, Reactors, etc.) Related operations such as piping User assembles flowsheet model by selecting and connecting appropriate Block models and specifying Block model parameters ASPEN solves sequentially for output streams given input streams and Block model parameters 10/18/99 ASPEN Introduction 3

4 BLOCK MODEL Input Streams Output Streams Model Parameters Physical Properties 10/18/99 ASPEN Introduction 4

5 Process Flow Sheet St8 C-1 St7 P-1 St6 St9 St1 M-1 St3 St4 E-1 St5 R-1 V-1 St2 Item ASPEN # Name Model M-1: Feed Mixer MIXER R-1: Reactor RSTOIC E-1: Condenser HEATER V-1: Flash Drum FLASH2 C-1: Compressor COMPR P-1: Purge Point FSEP St10 10/18/99 ASPEN Introduction 5

6 MAJOR COMPONENTS OF ASPEN Unit operations (BLOCK) model library Physical properties system Physical properties models (density, enthalpy, VLE, etc.) Pure component and binary pair databases Estimation capability for missing values Flow sheet convergence capability for recycle processes Control capability (Design Specs) 10/18/99 ASPEN Introduction 6

7 USEFUL FEATURES IN ASPEN Sensitivity analysis Cost estimation and profitability evaluation Optimization Process flow diagram generation Physical properties data regression 10/18/99 ASPEN Introduction 7

8 ASPEN BLOCK MODEL LIBRARY I Mixers and Splitters MIXER - Adds two or more streams together FSPLIT - Splits a stream into two or more SEP - Separates a stream component by component Flashes and Heaters FLASH2 - Two outlet flash FLASH3 - Three outlet flash HEATER - Heater/cooler HEATX - Two stream heat exchanger MHEATX - Multistream heat exchanger DECANTER - Liquid-liquid decanter 10/18/99 ASPEN Introduction 8

9 ASPEN BLOCK MODEL LIBRARY II Reactors RSTOIC - Stoichiometric reactor RYIELD - Yield reactor REQUIL - Equilibrium reactor RGIBBS - Equilibrium reactor RCSTR - CST reactor (requires kinetic model) RPLUG - Plug flow reactor (requires kinetic model) RBATCH - Batch reactor (requires kinetic model) 10/18/99 ASPEN Introduction 9

10 ASPEN BLOCK MODEL LIBRARY III Separators DISTIL - Shortcut distillation design DISTWU - Shortcut distillation rating RADFRAC - Rigorous distillation EXTRACT - Rigorous liquid-liquid extraction RATEFRAC - Rate-based distillation* BATCHFRAC - Batch distillation * PETROFRAC - Rigorous distillation for petroleum * Requires special license 10/18/99 ASPEN Introduction 10

11 ASPEN BLOCK MODEL LIBRARY IV Solids Processing CYCLONE - cyclone separator VSCRUB - Venturi scrubber CRYSTALLIZER - Mixed suspension mixed product removal crystallizer CRUSHER - Solids crusher SCREEN - Solids separator FABL - Fabric filter HYCYC - Hydrocyclone CFUGE - Centrifuge FILTER - Rotary vacuum filter SWASH - Single-stage solids washer 10/18/99 ASPEN Introduction 11

12 ASPEN BLOCK MODEL LIBRARY V Fluid Movers COMPR - Compressor/turbine MCOMPR - Multistage compressor/turbine PUMP - Pump/hydraulic Piping PIPELINE - Multiple segment pipe PIPE - Single segment pipe VALVE - Valve 10/18/99 ASPEN Introduction 12

13 ASPEN PHYSICAL PROPERTIES SYSTEM I What is an Option Set? A collection of methods used by ASPEN to evaluate thermodynamic properties such as enthalpy, density, and K-values as well as transport properties such as viscosity Some available Option Sets / K-value Method IDEAL - Ideal gas/ Raoult s Law & Henry s Law RK-SOAVE - Redlich-Kwong-Soave EOS PENG-ROB - Peng-Robinson EOS WILSON - RK/Wilson NRTL UNIFAC UNIQUAC - RK/NRTL - RK/UNIFAC - RK/UNIQUAC 10/18/99 ASPEN Introduction 13

14 ASPEN PHYSICAL PROPERTIES SYSTEM II Databanks PURECOMP - parameters for 1550 (mostly organic) cpds INORGANIC - data for 2450 (mostly inorganic ) cpds AQUEOUS SOLIDS - data for 900 ionic species - data for 3314solid cpds COMBUST - special databank for high temperature, gas phase calculations (59 cpds and free radicals) 10/18/99 ASPEN Introduction 14

15 ASPEN PHYSICAL PROPERTIES SYSTEM III WHAT IF THE DATA IS NOT IN THE DATABANK? PROVIDE THE MISSING DATA - PROPS DATA Capability REGRESS RAW DATA - Data Regression Capability ESTIMATE THE MISSING DATA Pure Components VLE and LLE - UNIFAC COMPONENT NAMING AND FORMULAS [Cn1Hn2On3Nn4Othern5]-nx, nx for isomers Example: Acetaldehyde: C2H4O-1 Ethylene Oxide: C2H4O-2 10/18/99 ASPEN Introduction 15

16 USING ASPEN THREE STEPS 1) Use the Model Manager to specify the problem 2) Run the problem 3) Analyze and report the results MODEL MANAGER To start from a Sun station, type APLUS Select equipment BLOCK models - drag and drop on work area Click and connect BLOCK models with streams Pull down forms menus and fill out 10/18/99 ASPEN Introduction 16

17 ASPEN SPECIFICATION FORMS 1) TITLE - Specify title for current problem 2) COMPONENTS - Specify what chemical components are to be included in the simulation 3) PROPERTIES - Specify what Option Set (or Sets) is to be used 4) BLOCKS - Provide specification data for each block included in the simulation [one form per BLOCK] 5) STREAMS - Specify each stream entering the flow sheet from OSBL, also any important recycle streams. Must specify state, composition and flow rate of the stream. These forms are required. Other forms to invoke other ASPEN capabilities are optional. 10/18/99 ASPEN Introduction 17