Plant Design Presentation - Current Version

Design of a High Production Volume Benzyl Chloride Manufacturing Plant

CSChE Conference 2014

UNIVERSITY OF OTTAWA DEPARTMENT OF CHEMICAL AND BIOLOGICAL ENGINEERING

FOR SNC LAVALIN PLANT DESIGN COMPETITION

Ryan Bekeris Martin Dussault Matthew Hudder Robert Tyssen

Acknowledgements

• Special thanks is given to Dr. Jules Thibault and Joanne GamageMcEvoy, of the University of Ottawa Department of Chemical and Biological Engineering, for their assistance, advice, and support over the course of this project.

• Additional thanks to all members of the uOttawa Department of Chemical and Biological Engineering for their unmatched professionalism, for challenging us, and for providing us with the tools and expertise necessary to succeed as engineers.

2

Project Objectives

• Design a high production volume benzyl chloride manufacturing plant

• Minimize capital and operating costs, and maximize profitability and process feasibility

• Emphasis on a safe, highly selective, and energy efficient process

3

Presentation Outline

1. Introduction

2. Process description

3. Economics

4. Process optimization

5. Safety considerations

6. Project summary and conclusions

4

INTRODUCTION

5

Introduction > Benzyl Chloride

• Colourless liquid with a pungent odour

ρ = 1.10 g/cm MM = 126.58 g/mol

Tb = 179°C

• Primarily used as a starting material for other syntheses

• Benzyl alcohol (solvent; ester precursor)

• Butyl benzyl phthalate (PVC plasticizer)

• Quaternary ammonium salts

• Phenylacetic acid

6

Introduction > Market Growth and Demand

• Global demand of 400,000 metric tonnes per year

• Global consumption growth of 4% per year

• Increased North American imports from Europe/Asia

7

Introduction > Facility Location

• Positioned near Co-op Refinery Complex

• Toluene supply, consumer market, industrialized location

8

$250k for 10 acres of undeveloped land

Introduction > Market Projections

• Toluene global price index:

9

Introduction > Market Projections

• Peak in toluene prices – correlated to crude oil and naphtha prices

• Decline in toluene price predicted over several months

• Gross material profit increase of 44%

• Economic analysis performed using peak toluene prices

10

Introduction > Reaction pathway

• Photo-chlorination of toluene

• Most economical pathway, with highest yield and selectivity, and least hazardous materials

11

Benzyl Chloride

Main product can further chlorinate to produce unwanted benzal chloride (left), and benzotrichloride (right)

Introduction > Hazards

• Many chemicals in the process are hazardous

• High emphasis on process safety and control

• Consideration for materials of construction• Hastelloy® B nickel alloy provides high corrosion resistance

12

Toluene Chlorine HCl Bn. Clx (x = 1, 2, 3)

Flammable YES YES

Explosive YES YES

Corrosive YES YES YES

Irritant YES YES YES YES

Poisonous YES YES YES YES

PROCESS DESCRIPTION AND PLANT LAYOUT

13

Process Description > Overall Process

14

Toluene

Feed Preparation

ReactorsLight Ends

Removal via Distillation

Product Purification

via Distillation

Toluene Removal via

Flash

HCl Removal via

Absorption

Chlorine Recylce

Toluene Recycle

HCl (aq) 36 wt%

Benzyl Chloride

Organic Wastes

Chlorine

Acid Feedwater

Stream Mass Flow

Toluene Feed 77.5 kt/year

Chlorine Feed 62.0 kt/year

Acid Feedwater 61.2 kt/year

Benzyl Chloride Product 96.2 kt/year

HCl (aq) Product 93.1 kt/year

Organic Wastes 11.4 kt/year* Mass balance assumes operation 50 weeks per year

Process Description > Overall Process

15

R-100 R-101 R-102 R-103

E-100

E-101

T-100

C-101C-100

P-100 A/B

K-100 A/B

T-100 Cond.

T-100 Reboil.T-101

T-101 Cond.

T-101 Reboil.

E-102 E-103 V-105

E-104 E-105

E-106 E-107

E-108

P-101 A/B

LPS

LPS

RW

CW RW

CW RW

CW

HPS

CW

HPS

CW RF

Toluene

Chlorine

Benzyl Chloride

Organic Waste

Water

HCl (aq)

Process Description > Feed Preparation

16

E-100

E-101

TolueneFeed

P-101 A/B

TolueneRecycle

LPS

LPS

ChlorineRecycle

ChlorineFeed

1 2

4 5

3

6

7

8

9

To Reactor

To Reactor

Process Description > Reactors

• Approximately 30% single-pass conversion of toluene

• Overall benzyl chloride yield is approximately 94%

17

R-100 R-101 R-102 R-103 P-101 A/B

K-100 A/B

PreparedChlorine

PreparedToluene

ProductPurification

1

2

3

4

5

6

7

Process Description > Reactors

Bubble column reactor

18

hliq = D = 1.4 m εgas = 0.3

4 identical reactors

Process Description > Separation

19

T-100

C-101C-100

T-100 Cond.

T-100 Reboil.T-101

T-101 Cond.

T-101 Reboil.

E-102 E-103 V-105

E-104 E-105

E-106 E-107

E-108

RW

CW RW

CW RW

CW

HPS

CW

HPS

CW RF

From Reactor

Toluene to Recycle

Benzyl Chloride

Organic Wastes

Chlorine to Recycle

HCl (aq) 36 wt%

Acid Feedwater

Process Description > Separation

Falling Film

Absorption

20

Δhabs ≈ 75 kJ/kmol @ 25°C

Tb = 58°C for 36 wt% HCl acid

Process Description > Plant Layout

21

R-102R-101 R-103R-100

K-100

T-100T-101

V-105

C-100

C-101

P-100P-101

V-104

V-102

V-100

V-101

Office SpaceCafeteria

Shipping and Receiving

Laboratory

Parking Lot

V-103

V-106

Machine Shop

Warehouse

V-101

V-101

V-101

V-101

V-101

V-101

Reagent Loading Location

Product Loading Location

Pip

e R

ack

Pipe Rack

Pip

e R

ack

E-100

E-101

E-102 + E-103

T-100 Condenser

T-100 Reboile

r

T-101 Condense

r

T-101 Reboiler

E-104 + E-105

E-106 + E-107

E-108

Overhead Piping

Vehicle Loading

Zone

Control Room

ECONOMIC ANALYSIS

22

Economic Analysis > Capital Expenses (CAPEX)

Capital Expenses – $96.6 million USD + $250k for land

23

Storage Tanks (30 day capacity)

83%

Heat Exchangers2%

Absorption Columns

2%

Distillation Columns

7%

Reactors3%

Pumps + Compressors

3%

Economic Analysis > Operating Expenses (OPEX)

Operating Expenses – $264 million USD per year

24

Toluene Feed38%

Chlorine Feed30%Utilities

2%

Waste Treatment

2%

Other Direct Manufacturing

6%

Fixed Manufacturing

6%

General Manufacturing

16%

Economic Analysis > Profitability and Cash Flow

25

-200

-150

-100

-50

0

50

100

150

200

250

0 2 4 6 8 10 12 14

Cas

h F

low

($ M

illio

ns)

Time (years)

Non-Discounted Discounted

Operation

*

Construction

CCP = $224.6m

NPV = $102.5m

PBP = 2.78 years

DPBP = 3.30 years

DCFROR = 17.7%

* (6% interest rate for DCF)

Economic Analysis > Raw Material Price Case Study

• Current prices: 1.29 USD/kg toluene

1.30 USD/kg chlorine

26

-600

-400

-200

0

200

400

600

0 50 100 150 200

Net

Pre

sent

Val

ue

($ M

illio

n)

Percentage of Current Price (%)

Toluene Chlorine

Economic Analysis > Products Price Case Study

• Current prices: 2.69 USD/kg benzyl chloride

0.28 USD/kg hydrochloric acid

27

-1000

-500

0

500

1000

1500

0 50 100 150 200

Net

Pre

sent

Val

ue

($ M

illio

n)

Percentage of Current Price (%)

Benzyl Chloride Hydrochloric Acid

PROCESS OPTIMIZATION

28

Process Optimization > Heat Integration

• Minimize external utility requirements by exchanging heat between process streams

29

-50

0

50

100

150

200

250

-60

-10

40

90

140

190

240

0 1 2 3 4 5 6 7 8

Ho

t St

ream

Tem

pe

ratu

re (

°C)

Co

ld S

tre

am T

emp

era

ture

(°C

)

Stream ID

Cold Stream

Hot Stream

Process Optimization > Heat Integration

• Approx. 1500 kW of heat exchange between streams

• Eliminate low-pressure steam requirements

• 63% less refrigerant required, 90% less cooling water

• $8.63 million in operating savings over 10 years

30

4

6

5

7

1 32

110°C 7.31°C

RF

180°C

CW RW

CW RW

RW

210.7°C

50°C

-15°C

25°C

25°C

25°C

45°C

45°C

67.9°C

94°C

-2.69°C 21.89°C 25°C

80°C 80°C 50°C

125.9°C

66.4°C

1008 kW

213 kW198 kW

59 kW

Process Optimization > T-101 Product Recovery

31

T-100

C-101C-100

T-100 Cond.

T-100 Reboil.T-101

T-101 Cond.

T-101 Reboil.

E-102 E-103 V-105

E-104 E-105

E-106 E-107

E-108

RW

CW RW

CW RW

CW

HPS

CW

HPS

CW RF

From Reactor

Toluene to Recycle

Benzyl Chloride

Organic Wastes

Chlorine to Recycle

HCl (aq) 36 wt%

Acid Feedwater

Process Optimization > T-101 Product Recovery

• The change in fixed capital investment and utility requirements is insignificant when product recovery is increased

• $6000 reduction due to smaller E-106 and E-107

• Waste treatment costs were significantly reduced by increasing product recovery

• Approximately $2 million per year in savings

32

PROCESS SAFETY

33

Process Safety > Hazard and Operability Study (HAZOP)

• HAZOP technique used to identify and evaluate potential for hazards of the equipment in the process

• Serves to protect plant personnel, nearby residents, environment and wildlife, and the investment itself

• Results in rigorous safety measures and emergency plans

• Study conducted on the reactor and distillation column

• Chosen for their high complexity and the high throughput of the material they must process

• Ideally a HAZOP study would have been conducted for every piece of equipment

34

• The HAZOP evaluations conducted identified variations in inlet and outlet flow rates to be the most likely cause of an incident for both units

• Additional equipment inspection and maintenance of related piping and valves reduces the probability of this event occurring

• Operation can continue during a repair or blockage if backup valves and pumps/compressors are used

• A feed or cooling water supply shortage can be temporarily addressed by the 30 day supply capacity

35

Process Safety > Hazard and Operability Study (HAZOP)

• In addition to HAZOP studies, process wide hazards were identified. To address such hazards:

• Overestimation of corrosion allowance and design pressure

• Anticipated liquid level surges in vessels

• Minimize ignition sources and ensure a well ventilated area

• The reaction pathway was chosen in part for its moderate operating conditions

• Maximum process temperature = 210.7oC

• Maximum process pressure = 200 kPa

36

Process Safety > Safety Features

• Glass, Hastelloy® B and electroless nickel plating were considered for their high corrosion resistance

• Hastelloy® B selected based on cost, conductivity and yield strength

37

Process Safety > Materials of construction

Material of Construction

Material Type Bulk Material CostThermal

Conductivity[W/m·K]

Yield Strength [MPa]

Electroless Nickel Plating

Ni coated carbon steel

420 USD/mm·m2 80 -Varies with substrate

700 - Varies with substrate

Hastelloy® B® Nickel Alloy 18 - 20 USD/kg 12.1 375 - 400

SiO2 Glass Glass 1-2 USD/kg 0.2 - 0.73 70

SUMMARY AND CONCLUSIONS

38

100 kt/year

95% selectivity

High emphasis on safety and green engineering

Highly optimized

CAPEX of $96 million

OPEX of $264 million/year

NPV of $103 million (18% DCFROR in 10 years)

Summary and Conclusions

39

Thank you for listening!Questions?

UNIVERSITY OF OTTAWA DEPARTMENT OF CHEMICAL AND BIOLOGICAL ENGINEERING

FOR SNC LAVALIN PLANT DESIGN COMPETITION

Ryan Bekeris Martin Dussault Matthew Hudder Robert Tyssen

APPENDIX

41

• Pseudo-first-order reaction kinetics to represent the rate of production of organic species (liquid-phase mole fraction basis):

• Increased benzyl chloride (RCl) generation yields higher rates of production of undesired RCl2 and RCl3

Appendix > Reactor Design

42

𝑑𝑥𝑅𝐻

𝑑𝑡= −𝑘1,𝑝𝑠𝑒𝑢 𝑥𝑅𝐻

𝑑𝑥𝑅𝐶𝑙

𝑑𝑡= 𝑘1,𝑝𝑠𝑒𝑢 𝑥𝑅𝐻 − 𝑘2,𝑝𝑠𝑒𝑢 𝑥𝑅𝐶𝑙

𝑑𝑥𝑅𝐶𝑙2

𝑑𝑡= 𝑘2,𝑝𝑠𝑒𝑢 𝑥𝑅𝐶𝑙 − 𝑘3,𝑝𝑠𝑒𝑢 𝑥𝑅𝐶𝑙2

𝑑𝑥𝑅𝐶𝑙3

𝑑𝑡= 𝑘3,𝑝𝑠𝑒𝑢 𝑥𝑅𝐶𝑙2


• Reaction progression at 80°C

• Assume pure toluene in feed liquid-phase and toluene is limiting reagent

43

0

0.2

0.4

0.6

0.8

1

1.2

0 0.05 0.1 0.15 0.2 0.25 0.3

Mo

le F

ract

ion

Residence Time [hr]

RH

RCl

RCl2

RCl3


• Benzyl chloride yield vs. toluene conversion

• Limit toluene conversion to 30 percent

• 93% benzyl chloride selectivity; temperature independent

44

0

0.2

0.4

0.6

0.8

1

1.2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

YR

Cl/

RH

Toluene Fractional Conversion

60C

80C

100C


• Arrhenius plots for rate constants:

• Temperature change yields roughly equal proportional changes in k1, k2, and k3

45

ln(k1) = -2916/T + 12.23R² = 0.975

ln(k2) = -3104/T + 10.89R² = 0.986

ln(k3)= -3677/T + 10.59R² = 0.992

-2

-1

0

1

2

3

4

5

2.80E-03 2.90E-03 3.00E-03 3.10E-03 3.20E-03

ln(k

[h

r-1])

Temperature-1 [K-1]

k1

k2

k3


• Estimation of gas-holdup:

• Properties obtained from HYSYS simulation

• Extended NRTL – Virial vapour estimation – UNIFAC VLE

• Obtain εg as a function of superficial gas velocity (Ug)

46

𝜀𝑔 = 0.672𝑓 𝑈𝑔𝜇𝑙

𝜍

0.578

𝜇𝑙

4𝑔

𝜌𝑙𝜍3

−0.134

𝜌𝑔

𝜌 𝑙

0.062

𝜇𝑔

𝜇𝑙

0.107

Property Value Units for Equation

µl 3.145 x 10-3 g/cm·s

µg 1.335 x 10-4 g/cm·s

ρl 8.983 x 10-1 g/cm3

ρg 1.801 x 10-3 g/cm3

σ 24.14 cm/s2


• Want to operate near εg = 0.3; get Ug = 0.2 m/s

• εg increases with pressure – operate at ~1 atm

• Vg = 4434 m3/h – split to 4 reactors (D = 1.4m)

47

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

εg

Superficial Gas Velocity [m/s]


• Four reactors gives sufficiently low Ug and maintains enough volume to allow proper phase contact, liquid agitation, and lighting equipment.

48

R-100 R-101 R-102 R-103

Chlorine

Prepped

Toluene

Prepped

Off gas

Liquid

Products


• Primary and secondary reactions are highly exothermic

• ΔH1 = -1.2 x 105; ΔH2 = -9.8 x 104; ΔH3 = -1.2 x 105 [kJ/mol]

• 30 percent conversion of a 323.9 kmol/h toluene feed

• 3252 kW of cooling required

• Cooling water (Cp = 4.18 kJ/kg·K) – temp range 30 – 45°C

• Obtain a cooling water requirement of 52 kg/s

• Total for all reactors – divide roughly equally

49


50

Reactor PerformanceTemperature 80°C Organic Outlet CompPressure 101.3 kPa Toluene 0.71 Pass Toluene Conversion 30% Benzyl Chloride 0.2813Benzyl Chloride Selectivity 93.8% Benzal Chloride 0.0185Gas-Holdup 0.3 Benzotrichloride 0.0002

Reactor SizingSingle Reactor Diameter 1.4 m Working Volume 2.16 m3

Single Reactor Height 2.8 m Wall Thickness 8.45 mmSingle Reactor Volume 4.32 m3 Construction Material Hastelloy® B®Liquid Height In Reactor 1.4 m Number of Identical

Reactors4

Lighting ConfigurationNumber of Lights 9 Lamp Diameter 1.27 cmLight Source Fluorescent Lamp Height 1.4 mLighting Volume Per Reactor 6.126 x 10-3 m3 Lamp Well Thickness 6.09 mm

Cooling Utility RequirementTotal Cooling Duty 3250.1 kW UA (Total) 77.27 kW/KUtility Choice Cooling Water UA (Per Reactor) 19.32 kW/KTotal Utility Requirement 51.95 kg/s

Appendix > Distillation Column Design

• Fenske equation to find minimum number of trays (4.79):

• Underwood equations to find minimum reflux ratio (0.218):

• Theoretical number of trays at 100% tray efficiency:

51

𝑁𝑚𝑖𝑛 = log

𝑥𝐿𝐾𝑥𝐻𝐾

𝐷 𝑥𝐻𝐾𝑥𝐿𝐾

𝐵

log 𝛼𝐿𝐾 𝐻𝐾 𝐴𝑣𝑒

𝛼𝑖𝑥𝑖,𝐹

𝛼𝑖 − 𝜃= 1 − 𝑞

𝑛

𝑖=1

𝑅𝑚𝑖𝑛 + 1 = 𝛼𝑖𝑥𝑖,𝐹

𝛼𝑖 − 𝜃

𝑛

𝑖=1

𝑁 − 𝑁𝑚𝑖𝑛

𝑁 + 1= 0.75 1 −

𝑅 − 𝑅𝑚𝑖𝑛

𝑅 + 1

0.566


• 1.5Rmin selected as operating conditions, to balance operating costs with capital costs:

52

0

2

4

6

8

10

12

14

16

18

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Nu

mb

er o

f Tra

ys (N

theo

reti

cal)

Reflux Ratio (R)


• Optimal feed tray selected using Kirkbride method (8):

• Actual number of trays using separation efficiency (18):

• Column diameter using empirical correlations (2.23m):

53

log 𝑁𝐷

𝑁𝐵 = 0.206 log

𝐵

𝐷

𝑥𝐻𝐾 ,𝐹

𝑥𝐿𝐾,𝐹

𝑥𝐿𝐾,𝐵

𝑥𝐻𝐾 ,𝐷

2

𝑁𝑎𝑐𝑡𝑢𝑎𝑙 =𝑁𝑡𝑕𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙

𝜀

𝐷𝑡 = 4𝐺

𝑓𝑈𝑓 𝜋 1 −2𝐴𝑑𝐴𝑇

𝜌𝐺


54

Parameter Value Parameter Value

Feed Molar Flow (kgmole/h) 444.75 Toluene Recovery 0.995

Distillate Molar Flow (kgmole/h) 344.92 Benzyl Chloride Recovery 0.995

Bottoms Molar Flow (kgmole/h) 99.83 Average Volatility 5.92

Condenser Temperature (°C) 111 Reboiler Temperature (°C) 209

Condenser Pressure (kPa) 150 Reboiler Pressure (kPa) 200

Nmin 4.79 Nactual 18

Rmin 0.218 Ractual 0.327

Uf (m/s) 0.729 єactual 0.75

Hc (m) 13.3 Dt (m) 2.23

Tray Type Sieve Column Type Fractional

Main Construction Material Hastelloy B Secondary Material Carbon Steel

Condenser Duty (kJ/h) -2.47 ∙ 106 Reboiler Duty (kJ/h) 1.57 ∙ 107

Condenser Area (m2) 11.21 Reboiler Area (m2) 387.7

Total Module Costs ($USD) 3.04 million

Appendix > Falling Film Absorber

• Design Equation Utilized:

• linearized-coupled mass and heat transfer model:

55

𝑑𝜔𝑠𝑏

𝑑𝐴= −𝐾𝑒𝑓𝜌𝑠

𝜔𝑎𝑣𝑔2

𝑀1 𝜔𝑠𝑏 − 𝑎 + 𝑏𝑇𝑠𝑏

𝑑𝑇𝑠𝑏

𝑑𝐴= 𝐾𝑒𝑓𝜌𝑠

𝑐𝑤𝜔𝑎𝑣𝑔2

𝑀1𝑐𝑠+

𝑖𝑣𝑠𝑀𝑠𝑐𝑠

𝜔𝑠𝑏 − 𝑎 + 𝑏𝑇𝑠𝑏 − 𝑈𝑏𝑤

𝑀𝑠𝑐𝑠 𝑇𝑠𝑏 − 𝑇𝑤

𝑁𝐴 =0.00122𝐷𝐺

𝑃𝑜𝑝𝑀1.75𝜇

𝑃𝑎𝑚 𝐴

Appendix > Falling Film Absorber

56

• HCl and Cl2 solubility in water

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0

10

20

30

40

50

60

70

80

90

0 20 40 60 80 100 120

Solu

bili

ty o

f Cl2

[gC

l2/g

H2O

]

Solu

bili

ty o

f H

Cl[

gHC

l/gH

2O]

Temperature [°C]

HCl

Cl2

Appendix > Plant Layout

57

• Equipment spacing used for plant layout

Equipment Distance (m)K-100 and E-100 10E-100 and E-101 1E-101 and R-100 2.4R-100 and R-101 3R-101 and R-102 3R-102 and R-103 3R-103 and E-102 + E-103 2.4E-102 + E-103 and V-105 2.4V-104 and C-100 3C-100 and E-108 2.4E-108 and C-101 2.4P-100 and T-100 4.5T-100 and T-100 reboiler 2.4T-100 reboiler and T-101 2.4T-101 and T-101 reboiler 2.4T-101 reboiler and E-104 + E-105 1E-104 + E-105 and E-106 + E-107 1

Appendix > Control Strategy Example (P&ID)

58

Appendix > Reaction Pathway Selection

• Potential alternative pathway:

• Blanc chloromethylation of benzene

• Reagent Price

59

𝐶6𝐻6 + 𝐶𝐻2𝑂 + 𝐻𝐶𝑙 𝑍𝑛𝐶 𝑙2 𝐶7𝐻7𝐶𝑙 + 𝐻2𝑂

Compound Price (USD/kg)Benzene 1.43Formaldehyde 1.10Hydrogen Chloride 3.87Zinc Chloride (Granular) 106.1

Appendix > Heat Integration

• Heat Integration

• By exchanging heat between process streams, can reduce the amount of external utility (ex. Steam, cooling water, etc.) that is required

• Summary of streams requiring heating and cooling:

60

Stream Name ID mCp (kW/°C) Tin (°C) Tout (°C) Q (kW)

Toluene to Reactor Heater 1 14.589 -2.69 80.00 1206.32

Chlorine Mixed Feed 2 1.015 21.89 80.00 59.00

HCl Acid Feedwater 3 8.504 25.00 50.00 212.60

T-100 Distillate 4 9.812 110.00 -15.00 -1226.49

T-101 Distillate 5 3.673 180.00 25.00 -569.31

T-101 Bottoms 6 0.505 210.70 25.00 -93.86

Hydrochloric Acid Product 7 9.614 50.00 25.00 -240.36


• Utility outlet temperature limits

• Total utility requirements for process stream heating and cooling

61

Utility Heating/Cooling Outlet Temperature Limit (°C)Low Pressure Steam (LPS) Heating 150 - 160 (maximum)Cooling Water (CW) Cooling 45 (minimum)Refrigerated Water (RW) Cooling -5 (minimum)Refrigerant (RF) Cooling -5 and colder

Utility Heating/Cooling Duty (kW)Low Pressure Steam (LPS) Heating 1478Cooling Water (CW) Cooling 1217Refrigerated Water (RW) Cooling 324Refrigerant (RF) Cooling 589


• Cold stream temperature-enthalpy diagram

• Energy required per temperature change

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0

200

400

600

800

1000

1200

1400

1600

-10 0 10 20 30 40 50 60 70 80 90

Hea

t Tr

ansf

erre

d (

kW)

Temperature (°C)


• Hot stream temperature-enthalpy diagram

• Energy released per temperature change

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-2500

-2000

-1500

-1000

-500

0

-50 0 50 100 150 200 250

Hea

t Tr

ansf

erre

d (

kW)

Temperature (°C)


• Combined temperature-enthalpy diagrams

• A total of 1478 kW of energy can be shared between process streams. (652 kW utility cooling required)

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-1000

-500

0

500

1000

1500

2000

-50 0 50 100 150 200 250

Hea

t Tr

ansf

erre

d (

kW)

Temperature (°C)

Pinch Barrier

1478 kW

652 kW


• Can now design heat exchange network

• Can eliminate heating and reduce cooling requirements

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C

4

6

5

7

2

1

3

80°C

80°C

50°C

-2.69°C

21.89°C

25°C

C

C

C

C = Cold Utility

110°C

180°C

210.7°C

-15°C

25°C

25°C

50°C 25°C

66.4°C

7.31°C

1008 kW

125.9°C

213 kW

67.9°C

198 kW

59 kW

94°C

80°C

50°C

218 kW

158 kW

35 kW

241 kW


• Summary of new utility requirements

• Note: Cooling water numbers refer to process stream cooling only

• Annual savings:

• LP Steam: $655k; Cooling Water: $12.4k; Refrigerant: $196k

• Save $8.6 million after 10 years of plant operation

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Utility Heating/Cooling New Duty (kW) Decrease (kW)Low Pressure Steam Heating 0 1478Cooling Water Cooling 109 1108Refrigerated Water Cooling 324 0Refrigerant Cooling 219 370

Appendix > Green Engineering Principles

1. Design process inputs and outputs to be as inherently nonhazardous as possible.2. Prevent waste, rather than treating/cleaning waste after it is formed.3. Minimize energy and material consumption for separation and purification

processes.4. Maximize energy/space/time efficiency of processes, products, and systems.5. Process should be output-pulled instead of input-pushed.6. Added complexity to a process or material is an investment with respect to design

choices on recycle/reuse.7. Focus on making processes durable; not immortal.8. Reduce designs with unnecessary capacity (i.e. "one size fits all").9. Reduce material diversity in multi-component products to promote disassembly

and to retain value.10. Design processes such that material and energy streams are integrated and

interconnected.11. Products and processes should be designed to have maximum commercial

performance.12. Use of renewable materials and energy, over depleting sources.

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Plant Design Presentation - Current Version

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