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9 Reactors

9.1 CSTR/General Reactors..................................................................3

9.1.1 Adding a CSTR/General Reactors................................................4

9.2 CSTR/General Reactors Property View...........................................6

9.2.1 Design Tab..............................................................................69.2.2 Conversion Reactor Reactions Tab.............................................109.2.3 CSTR Reactions Tab................................................................179.2.4 Equilibrium Reactor Reactions Tab ............................................229.2.5 Gibbs Reactor Reactions Tab....................................................289.2.6 Rating Tab.............................................................................329.2.7 Worksheet Tab.......................................................................369.2.8 Dynamics Tab........................................................................37

9.3 Yield Shift Reactor.......................................................................42

9.3.1 Yield Shift Reactor Property View..............................................459.3.2 Design Tab............................................................................469.3.3 Model Config Tab....................................................................489.3.4 Composition Shift Tab.............................................................519.3.5 Property Shift Tab ..................................................................649.3.6 Worksheet Tab.......................................................................719.3.7 Dynamics Tab........................................................................72

9.4 Plug Flow Reactor (PFR)..............................................................73

9.4.1 Adding a Plug Flow Reactor (PFR).............................................74

9.5 Plug Flow Reactor (PFR) Property View.......................................75

9.5.1 PFR Design Tab......................................................................769.5.2 Reactions Tab........................................................................849.5.3 Rating tab.............................................................................929.5.4 Work Sheet Tab......................................................................95

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9.5.5 Performance Tab .....................................................................959.5.6 Dynamics Tab.........................................................................98

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9.1 CSTR/General Reactors

With the exception of the Plug Flow Reactor (PFR), all of the reactor operations share the same basic property view. The primary differences are the functions of the reaction type (conversion, kinetic, equilibrium, heterogeneous catalytic or simple rate) associated with each reactor. As opposed to a separator or general reactor with an attached reaction set, specific reactor operations can only support one particular reaction type. For instance, a conversion reactor only functions properly with conversion reactions attached. If you try to attach an equilibrium or a kinetic reaction to a conversion reactor, an error message appears. The GIBBS reactor is unique in that it can function with or without a reaction set.

You have a great deal of flexibility in defining and grouping reactions. You can:

Define the reactions inside the Basis Manager, group them into a set and then attach the set to your reactor.

Create reactions in the Reaction Package in the main flowsheet, group them into a set, and attach the set to the reactor.

Create reactions and reaction sets in the Basis Environment and make changes in the Main Environment's Reaction Package.

Regardless of the approach, the reactions you define are visible to the entire flowsheet, i.e., a reaction set can be attached to more than one reactor.

However, there are some subtleties of which you must be aware. When you make a modification to a reaction via a reactor, the change is only seen locally, in that particular reactor. Modifications made to a reaction in the Basis Environment or in the Reaction Package are automatically reflected in every reactor using the reaction set, provided you have not made changes locally. Local changes are always retained.

Refer to Chapter 5 - Reactions of the HYSYS Simulation Basis guide or Section 5.3 - Reaction Package of the HYSYS User Guide for details on installing reactions and Reaction Sets.

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To override local changes and return the global parameters to a reaction, you must press the DELETE key when the cursor is in the cell which contains the local change.

The four reactors which share common property views include:

CSTR (Continuous-Stirred Tank Reactor) GIBBS Reactor Equilibrium Reactor Conversion Reactor Yield Shift Reactor

The last four reactors are referred to as General Reactors. In order to avoid redundancy, CSTR, Gibbs, Equilibrium, and Conversion reactor operations are discussed co-currently. In areas of the property view where there are differences, such as the Reactions tab, the differences are clearly noted.

The Yield Shift and PFR have a different property view from the other reactors. As a result it is discussed in Section 9.3 - Yield Shift Reactor and Section 9.4 - Plug Flow Reactor (PFR).

9.1.1 Adding a CSTR/General Reactors

There are two ways that you can add a reactor operation to your simulation:

1. In the Flowsheet menu, click the Add Operation command. The UnitOps view appears.

2. Click the Reactors radio button.

3. From the list of available unit operations, select the reactor type you want to add: Cont. Stirred Tank Reactor, Conversion Reactor, Equilibrium Reactor, Gibbs Reactor, or Yield Shift Reactor.

4. Click the Add button. The CSTR or General Reactor property view appears.

OR

To remove local changes, move to the appropriate cell and press the DELETE key.

You can also add a reactor by clicking the F12 hot key.

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1. In the Flowsheet menu, click the Palette command. The Object Palette appears.

2. Do one of the following:

continuous-stirred tank reactor, double-click the CSTR icon. The CSTR property view appears.

OR

For Conversion, Equilibrium, Gibbs, and Yield Shift reactors, click the General Reactors icon to open the General Reactors object palette. In the General Reactors object palette, double-click on the appropriate reactor operation icon.

You can also open the Object Palette by clicking the F4 hot key.

CSTR icon

General Reactors icon

General Reactors object palette

Conversion Reactors icon

Equilibrium Reactors icon

Gibbs Reactor icon

Yield Shift Reactors icon

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The property view for the selected general reactor operation appears.

9.2 CSTR/General Reactors Property View

The CSTR and General Reactors property view contains the following tabs:

Design Reactions Rating Worksheet Dynamics

To ignore the reactor operation entirely during calculations, click the Ignored checkbox. HYSYS disregards the operation entirely until you restore it to an active state.

9.2.1 Design TabThe Design tab contains several pages, which are briefly described in the table below.

Page Description

Connections Connects the feed, product, and energy streams to the reactor. For more information, refer to the section below.

Parameters Sets heat transfer and pressure drop parameters for the reactor. For more information, refer to the section on the Parameters Page.

User Variables

Enables you to create and implement your own user variables for the current operation.

For more information refer to Section 1.3.3 - User Variables Page/Tab.

Notes Allows you to add relevant comments which are exclusively associated with the unit operation.

For more information on the Notes page, refer to Section 1.3.2 - Notes Page/Tab.

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Connections PageThe Connections page, is the same for both the CSTR and the General Reactors.

The Connections page consists of the following objects described in the table below.

Object Input Required

Name Contains the name of the reactor. You can edit the name of the reactor at any time by typing in a new name in the Name field.

Inlets / Feed Streams

Connects a single feed or multiple feed streams to the reactor. You can either type in the name of the stream or if you have pre-defined your stream select it from the drop-down list.

Vapour Outlet Connects the vapour product stream to the reactor. You can either type in the name of the stream or if you have pre-defined your stream select it from the drop-down list.

Liquid Outlet / Product Stream

Connects the liquid product stream to the reactor. You can either type in the name of the stream or if you have pre-defined your stream select it from the drop-down list.

Energy (Optional)

Connects or creates an energy stream if one is required for the operation.

Fluid Package Enables you to select a fluid package to be associated to the reactor.

At least one product stream is required.

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Parameters PageThe Parameters page allows you to specify the pressure drop, vessel volume, duty, and solving behaviour.

Object Description

Delta P / Pressure Drop

Contains the pressure drop across the vessel. The pressure drop is defined as:

(9.1)

where:

P = vessel pressure

P = pressure of vapour product stream

P = pressure of liquid product s