Aspen Tutorial Terry A. Ring ChEN 4253

Process Simulation Software Steady State Process Simulation AspenPlus ProMax ChemCad Hysis HySim ProSim CADSim OLI Process Simulator KemSimp Chemical Workbench Code Ascend IV Dynamic Process Simulation Aspen Dynamics CADSim Simulation Solutions, Inc.

Types of Simulators ProMax Equation Based Aspen Solves block by block Aspen Puts all equations into one Matrix equation Solves all Mass and Energy Balances at once

* * Basic Elements of a Simulation Program Thermodynamics Numerical Methods Thermodynamics Other Subjects : Solid Mechanics, Manufacturing Science Economics * - Reaction Engineering, Mass Transfer, Heat Transfer, Fluid Mechanics Towler and Sinnott , “Chemical Engineering Design : Principles , Practice, Economics of Plant and Process Design” , Elsevier (2008)

Aspen Aspects of Aspen Next Button Many units that perform a given function Degrees of Freedom are chosen for you Setup for kinetic reactions are tricky Accounts for particle sizes Simple block models Automatic Plant Costing (Aspen Economics)

Steps to Run Aspen (Left Hand Bar) Wiring up Process Title Components Thermopackage Process Flow Sheet Feed Stream Unit Specifications Fixed degrees of freedom Run Results Report

ThermoPackage Choice Questions for ThermoPackage Choice Are the components? Polar Non-Polar System Pressures? P< 10 atm - ideal gas Interaction Parameters Available?

Eric Carlson’s Recommendations Figure 1 Non-electrolyte See Figure 2 E? Polar Electrolyte Electrolyte NRTL Or Pizer Real Peng-Robinson, Redlich-Kwong-Soave, Lee-Kesler-Plocker All Non-polar R? Chao-Seader, Grayson-Streed or Braun K-10 Polarity Pseudo & Real Real or pseudocomponents P? R? P? Pressure Vacuum Braun K-10 or ideal E? Electrolytes

Figure 2 LL? ij? P? LL? ij? Yes NRTL, UNIQUAC and their variances Yes WILSON, NRTL, UNIQUAC and their variances ij? (See also Figure 3) P < 10 bar No Yes No UNIFAC LLE P? LL? Polar Non-electrolytes P > 10 bar No UNIFAC and its extensions Schwartentruber-Renon PR or SRK with WS PR or SRK with MHV2 LL? Yes Liquid/Liquid ij? P? Pressure No PSRK PR or SRK with MHV2 ij? Interaction Parameters Available

Figure 3 DP? Wilson, NRTL, UNIQUAC, or UNIFAC with special EOS for Hexamers Figure 3 Hexamers DP? Yes Wilson, NRTL, UNIQUAC, UNIFAC with Hayden O’Connell or Northnagel EOS Dimers VAP? Wilson NRTL UNIQUAC UNIFAC Wilson, NRTL, UNIQUAC, or UNIFAC* with ideal Gas or RK EOS No VAP? Vapor Phase Association UNIFAC* and its Extensions DP? Degrees of Polymerizatiom

Bob Seader’s Recommendations  

Bob Seader’s Recommendations Yes Figure 4 PSRK HC? Hydrocarbons PC? Yes LG? Light gases No E? Electrolyte See Figure 5 Yes LG? Yes PC? Organic Polar Compound See Figure 6 No PC? HC? No See Figure 5 No Yes Modified NRTL E? No Special: e.g., Sour Water (NH3, CO2, H2S, H2O) Aqueous amine solution with CO2 and H2S

Figure 5 P? T? BP? Critical PR Cryogenic Narrow or wide Non-Critical PR, BWRS T? HC and/ or LG Non- Cryogenic BP? SRK, PR Very wide BP? Boiling point range of compound LKP T? Temperature region P? Pressure region

Figure 6 PPS? BIP? Yes NRTL, UNIQUAC Available No PC with HC Wilson Not Available BIP? Binary Interaction Parameters UNIFAC PPS? Possible Phase Splitting

Hyprotech Recommendations  

ProMax Guidance (5 more pages like this) Model Pure Binary Mixture VLE VLLE Notes EOS (Equation of State) SRK (Soave Redlich Kwong) ● Gas Processing with No Methanol, Refinery Distillation Peng-Robinson Gas Processing with No Methanol SRK Polar Gas Processing with Methanol or NMP Peng-Robinson Polar Lee-Kesler Light Hydrocarbon Systems with H2S and CO2, No 2nd Liquid Phase Tillner-Roth and Friend NH3 + H2O Ammonia Absorption Refrigeration, Ammonia and/or Water Only

Problem-1 Problem 5.12 Alternatives in preparing a feed. A process under design requires that 100 lbmol/hr of toluene at 70F and 20 psia be brought to 450 F and 75 psia. Flow sheets using Peng-Robinson Boil-Superheat-Compress Pump to 75 psi-Boil-Superheat Which process uses the most energy?

Design Spec What Then How (WtH) What do I want to specify? What do I want to vary to control it?

Which System has the most Energy? Moving from To, Po to Tf, Pf STATE PROPERTY Enthalpy change is the same if the end points are the same. Why is Boil then Compress not suggested? Heuristic 43

Problem -2 Use Gibbs Minimization reactor in Aspen to determine the products of reaction at 10 atm and 200 C. Feed equimolar in CO and H2

Sensitivity Analysis Produces Table of Results using a Do Loop to vary one (or more variables) What Then How

Problem 3 Use Equilibrium Reactor to determine reactor conversion for methanol reaction at 10 atm and 200C Use sensitivity analysis to determine reactor conversion at a suite of temperatures

Problem -4 Determine the resulting equilibrium at 10 atm and 200 C using an equilibrium reactor in Aspen with both of the reactions listed.

Problem 5 Vapor-Liquid Equilibrium 40mole% Ethanol – water

Problem 6 Liquid-Liquid Equilibria Polar - polar

Problem 7 Liquid-Liquid Equilibria Polar - non-polar

Problem 8 Multiple component phase equilibria Methane – 0.1 mole fraction Ethane – 0.2 Propane- 0.3 Butane- 0.3 Methyl ethyl keytone -0.1 10 atm, 10°C Use Ideal and Peng Robinson Thermo Pkg. Compare results

Example-9 Distillation/Flash Methanol – Water 100 lbmole/hr Flash at 90C, 1 atm Distillation R=2 BoilUp Ratio=3