Process Simulation and Integration of Methanol

Production

3rd Year Chemical Engineering Research Project

By: Aaron McClean

Introduction

Welcome to this Presentation on the Simulation and Integration of a Methanol Production Process

The Project in Brief

The Project Involves the Simulation of a conventional methanol process using Aspen simulation software. Using stream data obtained from the simulation and Process Integration techniques, a maximum energy recovery system is then designed

Three Project Objectives

• Development of a Methanol Production Process

• Simulation of the Methanol Production Process using Aspen Plus

• Carryout Process Integration on the Methanol Process to gain a Maximum Energy Recovery system

Development of a Methanol Production Process

• Research into various routes for the production of methanol

• Process selection

• Producing a Flow Diagram of the Process

• Collecting information on the physical properties and characteristics of the Process

Process Flow Diagram

This diagram shows the main sections in Methanol Production

Combustion

Natural Gas

Synthesis Gas

Reaction

Crude Methanol

Distillation

Oxygen

Steam

Methanol

Process Sections

• Partial Combustion of Natural Gas to produce Synthesis Gas

• Conversion of Synthesis Gas to Methanol

• Purification of Crude Methanol by Distillation

Partial Combustion of Natural Gas to produce Synthesis Gas

• Natural Gas composed of 80% Methane, 15% Ethane and 5% Propane• Partial Combustion Reaction

• Water Shift reaction

Natural Gas + H2O CO + 3H2

CO + H2O CO2 + H2

Natural Gas + O2 CO + H2

Conversion of Synthesis Gas to Methanol

• Methanol Conversion Reactions

CO + 2H2 CH3OH

2CO + 4H2 CH3OCH3 + H2O

CO2 + H2 CO + H2O

Process Diagram

Simulation of the Methanol Production Process using Aspen

Plus

• Aspen Plus is a Computer Simulation Package for Chemical Processes

• It is Primarily used as a labour and time saving tool

• It is still only a tool, and does not replace the knowledge required by the Process Engineer

Aspen Plus User Interface

Aspen Plus User Interface

Methanol Process Simulation

Process Integration

• What is Process Integration?

• What does Process Integration involve?

• Why carry out Process Integration?

What is Process Integration• Process Integration is the optimisation of a

Chemical Process to produce a Maximum energy recovery system

Cool

Cool

Heat

Heat

R eactor

FEED

FEEDREC YCLE

PRODUCT

BYPRODU CT

What does Process Integration involve?

• Pinch Technology

• What is a Pinch Analysis?

• What is required for the analysis?

• How is an analysis performed?

What is a Pinch Analysis?• Linking streams that need heating to those that need cooling

REACTOR

PRODUCT

COOLING

REAC. OUT

COOLING

FEED

HEATING

RECYCLE

HEATING

220 °

210 °

210 °

50 °

270 °

60 °

160 °

160 °

2500

3200

3520

1980

130 °

Cool

Cool

Heat

Heat

What is a Pinch Analysis?

• What is meant by the Pinch

REACTOR

FEEDSTEAM

STEAMRECYCLE

PRODUCT

DistillationColumn

DISTVAP

CW

REAC.OUT

880

19801220

1620

2640

160°

160°

130°

220°

220°

210°

210° 270°

149°

178°

50°

60°

160°180°

Above PinchBelow Pinch

What is meant by the Pinch

• The Composite Curve

Q Hm in

Q Cm in

T

H

Pinch(Cold)

P inch(Hot)

The Composite Curve

No Name Tsupply

Ttarget H

1

2

Product

Reac. Out

220

270

60

160

3520

1980

No Name Tsupply

Ttarget H

3

4

Feed

Recycle

50

160

210

210

3200

2500

160°

60°

220°

270°

Product

3520 1980

Reac. Out

T

H

CP = 22CP =

18 210°

160°

50° 3200 2500

Feed

Recycle

CP = 50

CP = 20

T

H

The Composite Curve

200 °

250 °

150 °

50 °

0°

100 °

Qcmin= 800

Hot Composite

Curve

Cold Composite

Curve

Tmin= 20

°

Hot Utility Target QHMIN = 1000

Cold Utility Target QCMIN = 800

QHMIN = 1000

Creating a heat exchanger network

210° 160° 50°

220° 180° 60°80°

210° 190° 177.6°

235.6°

160°

270° 180° 160°

Product

Feed

RecycleH

C

C

880

440

360

22001000

6201000

Q = 1000Hmin Q = 800Cmin

Reac. Out

Driving force plot

T

Tcold composite

Driving Force Plot

Representation of driving forcesfor vertical heat transfer

a b Tmin

Driving Force plot used to check the use of exchangersT

TC

CP

1

2

0.5

Why carry out Process Integration?

H H H

C

C

C

H = 1000

H = 1000

H = 1000

H = 1000

H = 1000

H = 1000

Steam(100ºC )

Cooling water(20º-40ºC)

40º 40º 40º

50º100º

100º

100º

50º

50º

20º20º20º

H = 1000

H = 1000

H = 1000

40º 40º 40º

50º100º

100º

100º

50º

50º

20º20º20º

Tota l H eat Transferred = 6000kWrea = 112m ² A

T o t a l H e a t T r a n s f e r r e d = 3 0 0 0 k Wr e a = 6 9 m ² A

N o In teg ra tion In teg ra tion

Process Costs Reduced

Process Integration on Methanol Process

Summary•Aspen Plus is a great tool for the development of chemical processes or carrying out analysis on existing processes

•Process Integration gives a reduction in the amount of Energy required in the process

•Pinch Technology can be used to reduce the number of Heat Exchangers required

Thank You for your time and patience

• Please feel free to ask questions or give feed back on this presentation