Aspen间歇精馏模拟教程

Aspen间歇精馏模拟教程

Use this Getting Started section to become familiar with the steps to set up a batch simulation using Aspen Batch Modeler.

You will be modeling a system to recover methanol from a mixture of methanol and water.

The objective is to separate methanol from the mixture with a purity of 99%. This mixture is not ideal given the polarity of the molecules; therefore, for a working pressure of 1atm, you will choose NRTL to model its physical properties.

There are four steps in this process. Click a step to go the instructions for the step.

Step 1 – Set up the Properties for Aspen Batch Modeler

Step 2 – Enter structural data and specifications for the Aspen Batch Modeler block Step 3 – Enter Operating Steps

Step 4 – Run the simulation and view the results

Step 1 - Set up the Properties for Aspen Batch Modeler

We want to define a Properties file that has the following defined.

Components Property Method

Water NRTL

Methanol

To define this Properties file, follow the steps below.

To set up the Problem Definition file from within Aspen Batch Modeler:

1. Start Aspen Batch Modeler.

2. On the Species form, click Edit Using Aspen Properties.

This will start Aspen Properties.

3. Enter the Components:

Component ID Component name Formula WATER WATER H2O METHANOL METHANOL CH4O

Tip: You can use the Next button

4. Click the Next button Properties Specifications form.

5. On the Properties Specifications form, in the Property method field, select NRTL. Tip: Clicking the pull-down arrow on the field and typing N (the first letter of the property method name) takes you to the right choice much faster than just scrolling down the long list.

6. Click Next

You are taken to the binary parameters forms, where you can view the binary parameters that will be used for Properties Calculations.

7. Click Next

You are prompted to click one of the options shown below.

8. There is no need for further input, so click OK to run the property setup.

9. Close Aspen Properties by clicking File | Exit.

You are prompted with the following:

10. Click Yes to save the file.

The Property setup is now complete.

Step 2 - Enter structural data and specifications for the Aspen Batch Modeler block

The column has been designed as follows:

Configuration

10 Stages (this includes eight trays, condenser and pot)

Vapor-liquid separation

Pot Geometry

Elliptical head

1m diameter

volume of 1m3

Overhead

Total Condenser

Distillate mole flow rate = 4.5kmol/hr

Reflux drum is present

(no need to enter dimension because we are defining fixed pressure profile/holdups; therefore reflux holdup will be entered)

Pressure/Holdups

Pressure profile is fixed

Condenser pressure 1.01325 bar

Column Pressure Drop 0.1 bar

Holdups

Reflux Drum liquid holdup: 0.02 m3

Stage holdup: 0.005 m3

Heat Transfer

Duty: 150 kW

Receivers

One receiver for liquid distillate

Initial condition: total reflux

Initial Conditions

Initial Charge

18kmol of material

Component mole fraction

Methanol: 0.4