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COMSATS INSTITUTE OF INFORMATION TECHNOLOGY DECLARATION OF THESIS / UNDERGRADUATE PROJECT PAPER AND COPYRIGHT

Author’s full name: S.M. Hamza Raza Zaidi

Title

DDP-FA13-BEC-101/LHR

M. Meesam Ijaz

DDP-FA11-BEC-135/LHR

Zaki-ullah

DDP-FA13-BEC-115/LHR

M.Bilal Aslam

DDP-FA13-BEC-059/LHR

Wajeeh-ur-Rehman

DDP-FA13-BEC-109/LHR

: Production of 1500 ton/yr of cyclohexanone by phenol

BBGHJJBGHJBJHJH hydrogenation process Academic Session :

2013-2017

I declare that this thesis is classified as: CONFIDENTIAL

(Contains confidential information under the Official Secret Act 1972) *

RESTRICTED

(Contains restricted information as specified by the organization where research/ project was done) *

OPEN ACCESS

I agree that my thesis to be published as online open access (full text)

I acknowledged that COMSATS Institute of Information Technology reserves the right as follows: 1. The thesis is the property of COMSATS Institute of Information Technology. 2. The Library of COMSATS Institute of Information Technology has the right to make copies for research only. 3. The Library has the right to make copies of the thesis for academic exchange. Certified by

SIGNATURE OF LEADER

SIGNATURE OF SUPERVISOR

S.M. Hamza Raza Zaidi

Dr. Maria Mustafa

LEADER NAME

Date:

24thMay,

2017

NAME OF SUPERVISOR

Date :24th May, 2017

SUPERVISOR’S DECLARATION

“I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms of scope and quality for the award of the degree of Bachelor of Chemical Engineering”

Signature

:

Name of Supervisor :

Dr.Maria Mustafa

Date

24th May, 2017

:

PART A - Confirmation of Cooperation * It is certified that this thesis research project was undertaken through cooperation between _______________________ and _______________________ Endorsed by: Signature

:

Name

:

Post

:

Date:

(Official Seal) * If the thesis / project involves collaboration. PART B - For Official Use only This thesis has been examined and recognized by: Name and Address of External Examiner:

Name and Address of Examiner

Other Supervisor (if any)

Approved by the Head of the department: Signature:

Date:

PRODUCTION OF 1500TON/YR OF CYCLOHEXANONE FROM PHENOL HYDROHENATION PROCESS

S.M. HAMZA RAZA ZAIDI

DDP-FA13-BEC-101/LHR

M.MEESAM IJAZ

DDP-FA13-BEC-135/LHR

ZAKI-ULLAH

DDP-FA13-BEC-115/LHR

M.BILAL ASLAM

DDP-FA13-BEC-059/LHR

WAJEEH-UR-REHMAN

DDP-FA13-BEC-109/LHR

This report is submitted in partial fulfillment of The requirements for the award of the degree of Bachelor of Science in Chemical Engineering

Department of Chemical Engineering COMSATS Institute of Information Technology

MAY 2017

We declare that this report entitled “Production of 1500 ton/yr of cyclohexanone from phenol hydrogenation process”is the result of our own research except as cited in the references. The report has not been accepted for any degree and is not concurrently submitted in candidature of any other degree.

Signature: .................................

Signature: ..................................

Name:

Name:

S.M. Hamza Raza Zaidi

M. Meesam Ijaz

Signature:

Signature: .................................

Name:

Name:

Zaki-Ullah

Signature: .................................. Name:

Date:

Wajeeh-ur-Rehman

24th MAY, 2017

M. Bilal Aslam

v

DEDICATION

“This is dedicated to our Parents, Respected Teachers and to loving fellows who help us to complete this Project”

vi

ACKNOWLEDGEMENTS

All praises to the Almighty Allah, who provided us with the strength to accomplish this final year project and for His countless blessings on us. All respects are for His Holy Prophet (PBUH), whose teachings are the true source of knowledge and guidance for whole mankind. Before anybody else, we hanks our parents, who have always been a source of moral support and the driving force behind whatever we do. They have been a constant source of support-emotional, moral and of course, we are thankful to Dr. Maria Mustafa for her worthy discussions, encouragement and inspiring guidance that enable us to complete this report. We are sincerely grateful to all the faculty members; their informal support and encouragement has been indispensable.

vii

ABSRACT

Cyclohexanone is a valuable chemical and it is used to form caprolactam and adipic acid which are used to production of nylon 6,6 and nylon 6. Cyclohexanone is used as a solvent in paints and dyes, coatings, pharmaceuticals, adhesives and as an intermediate. Production of cyclohexanone is done by phenol hydrogenation which gives 98% purity of cyclohexanone. The raw materials required to produce cyclohexanone are available in Pakistan and could be easily got from our side the country. In this design thesis report, there is an introduction which gives a brief overview of proposed process along with its major applications, material and energy balance on every equipment of the process, design of process equipments, instrumentation is done on every equipment to get a better control of process and to overcome the disturbances in the process, cost estimation, a plant location is also proposed and HAZOP study of plant is also done.

viii

TABLE OF CONTENTS

CHAPTER

1

2

TITLE

PAGE

SUPERVISOR’S DECLARATION

i

DEDICATION

v

ACKNOWLEDGEMENTS

vi

ABSRACT

vii

TABLE OF CONTENTS

viii

LIST OF TABLES

xii

LIST OF FIGURES

xiv

LIST OF APPENDCIES

xv

INTRODUCTION

2

1.1 Cyclohexanone

2

1.2 Applications and Consumption of Cyclohexanone

2

1.3 Manufacturing Processes for Production of Cyclohexanone

3

1.3.1

Cyclohexane oxidation process

3

1.3.2

Phenol hydrogenation process

4

PROCESS DESCRIPTION

2

2.1 Process selection

2

2.2 Raw material

7

ix 2.3 Process flow diagram Explanation

3

4

5

8

MATERIAL BALANCE

14

3.1 Capacity

15

3.2 Backward Balance

15

3.3 Forward Material Balance

17

3.4 Overall balance

29

ENERYGY BALANCE

30

4.1 Heat Balance around Mixer 1

32

4.2 Energy balance around heat exchanger 1

33

4.3 Energy balance around heat exchanger 2

34

4.4 Heat balance around Reactor 1

35

4.5 Energy balance around heat exchanger 3

36

4.6 Energy balance around heat exchanger 4

37

4.7 Energy balance around heat exchanger 5

38

4.8 Energy balance around condenser of distillation column 1

38

4.9 Energy balance around re-boiler of distillation column 1

39

4.10 Energy balance around condenser of distillation column 2

40

4.11 Energy balance around reboiler of distillation column 2

41

4.12 Energy balance around heat exchanger 6

42

4.13 Energy balance around heat exchanger 7

42

4.14 Energy balance around heat exchanger 8

44

4.15 Energy balance around reactor no.2

45

4.16 Energy balance around heat exchanger 9

46

4.17 Energy balance around heat exchanger 10

47

4.18 Energy balance around heat exchanger 11

47

EQUIPMENT DESIGNING

49

5.1 Fixed bed catalytic reactors

49

x

6

5.2 Types of fixed bed catalytic reactors

49

5.3 Reactor type selection

50

5.4 Design of reactor 1

51

5.4.1

Tube side calculations

52

5.4.2

Shell side calculations

54

5.5 Separator Flash tank

59

5.6 Design Steps for Vertical Tank Separator

61

5.7 Design of vertical flash tank

62

5.8 Distillation column Design (DC-2)

66

5.9 Selection of packed and Plate column

66

5.10 Design calculation steps for distillation column

67

5.11 Design calculations

68

5.12 Diameter calculations

71

5.13 Height of the column

73

5.14 Plate Design

74

5.15 Reactor Selection Criteria

78

5.16 Design of reactor 2

78

5.16.1 Tube side calculations

80

5.16.2 Shell side calculations

83

5.17 Double Pipe Heat Exchanger

88

5.18 Design Calculation of double pipe heat exchanger

89

5.19 Selection of Pumps

93

INSTRUMENTATION & PROCESS CONTROL

96

6.1 Introduction

96

6.2 Instrumentation and process Control on Reactor 1

98

6.3 Instrumentation and Process Control on Heat exchanger

100

6.4 Instrumentation and Process Control on Distillation column

101

6.5 Instrumentation and Process Control Reactor 2

103

6.6 Instrumentation on Flash tank separator

104

xi

7

8

9

COST ESTIMATION

105

7.1 Equipment costing

106

7.2 Fixed capital investment

108

7.2.1

Direct plant cost

108

7.2.2

Indirect Cost

109

7.3 Production Cost

110

7.4 General expenses

112

7.5 Annual revenue

112

7.6 Payback period

113

HAZOP STUDY

114

8.1 HAZOP Study on Reactor

114

8.2 HAZOP Study on Heat Exchanger

117

8.3 HAZOP Study on DC-2

118

PLANT LOCATION

119

9.1 Cyclohexanone Plant Location Selection

119

9.1.1

Raw materials availability

120

9.1.2

Markets

121

9.1.3

Energy Availability

121

9.1.4

Climate

121

9.1.5

Transportation Facilities

122

9.1.6

Taxation and legal restrictions

122

9.1.7

Waste Disposal

123

9.1.8

Labor supply

123

9.1.9

Conclusion

123

APPENDICES (A-K)

124

REFERENCES

140

xii

LIST OF TABLES

TABLE NO.

TITLE

PAGE

1.1

Physical properties of cyclohexanone

2

2.1

HAZID Study of Cyclohexanone Chemical Plant

12

3.1

Material Balance on Reactor 1

19

3.2

Unit conversion of feed and product flow rates (Kmol/hr to Kg/hr)

19

3.3

Feed specification in separator 1

20

3.4

Gas out stream flow rates from separator 1

20

3.5

Liquid out stream flow rates from separator 1

21

3.6

Flow rates at Gas junction point

21

3.7

Inlet of feed to DC-1

22

3.8

Distillate from DC-1

23

3.9

Bottom Product from DC-1

23

3.10

Mixer 1 outlet stream

23

3.11

Flow-rates at reactor 2

25

3.12

Unit conversion from kmol/hr to kg/hr for rector 2

25

3.13

Feed inlet for Separator 2

26

3.14

Gas from separator 2 to retreatment plant

26

3.15

Recycle stream for cyclohexanone purification from separator 2

26

3.16

Feed for DC-2

27

3.17

Feed to DC-2

27

3.18

Distillate from DC-2

28

3.19

Bottom product from DC-2

28

3.20

Over-all material balance

29

4.1

Utilities for Medium pressure steam

31

4.2

Utilities for Low pressure stream

31

xiii 4.3

Utilities for Dowtherm

31

4.4

Utilities for Chilled water

32

4.5

Utilities for cooling water

32

4.6

Heat specification for Mixer

33

4.7

Heat specification for HX-1

33

4.8

Heat specification for HX-2

34

4.9

Heat specifications for Reactor 1

35

4.10

Heat specification for HX-3

36

4.11

Heat specification for HX-4

37

4.12

Heat specification for HX-5

38

4.13

Heat specification for DC-1

38

4.14

Heat specification for DC-2

40

4.15

Heat specification for HX-6

42

4.16

Heat specification for HX-7

43

4.17

Heat specification for HX-8

44

4.18

Heat specification for Reactor 2

45

4.19

Heat specification for HX-9

46

4.20

Heat specification for HX-10

47

4.21

Heat specification for HX-11

48

5.1

Fixed Bed Catalytic Reactors Classifications

50

5.2

Specification sheet of multi tubular fixed bed reactor-1

58

5.3

Specification sheet of separator

65

5.4

Composition data for DC-2

68

5.5

Streams condition of DC-2

68

5.6

Specification sheet for Distillation column

77

5.7

Specification sheet of multi tubular fixed bed reactor

87

5.8

Physical properties of streams

91

8.1

Hazop Study on reactor

114

8.2

HAZOP Study on Heat Exchanger

117

8.3

HAZOP study on DC-2

118

xiv

LIST OF FIGURES

FIGURE NO.

TITLE

PAGE

2.1

Production of Cyclohexanone by Phenol hydrogenation

9

3.1

Block Diagram for material Balance

14

5.1

Number of theoretical plates

70

5.2

Power calculation for Centrifugal pump by Aspen

95

6.1

Ratio control system on Mixer

98

6.2

Instrumentation on Reactor 1

99

6.3

Instrumentation on HX-11

100

6.4

Instrumentation on DC-2

102

6.5

Instrumentation on reactor 2

103

6.6

Instrumentation on Sep 1

104

8.1

HAZOP action plan on reactor

116

xv

LIST OF APPENDCIES

APPENDIX

TITLE

PAGE

A

Specific Heat

125

B

Flooding velocity, sieve plate (Vol-6)

126

C

Relation between downcomer area and weir length ( Vol 6)

127

D

Weep-Point correlation (vol 6)

128

E

Discharge coefficient, sieve plate (Vol 6)

129

F

Value of constant K

130

G

Value of HLLL

130

H

Shell-bundle clearance (Vol 6)

131

I

Temperature Co-relation factor (VOL 6)

132

J

Cost estimation

133

K

Energy Balance

137

CHAPTER 1

1 INTRODUCTION

1.1 Cyclohexanone

Cyclohexanone (C6H10O) is a six-carbon cyclic molecule with the ketone functional group. It is a colorless oily liquid with an acetone like smell. Cyclohexanone is a hazardous material. It is less dense than water with a pleasant odor. Flash point of cyclohexanone is 43.8°C and vapors of cyclohexanone heavier than air. Majority of cyclohexanone consumed in the production of precursors to nylon 6, 6 and nylon 6. 50% of cyclohexanone is used to produce the adipic acid which is the precursor to produce nylon 6, 6. For this application, the KA oil is oxidized with nitric acid, and the other 50% supply is converted to oxime in the presence of sulfuric acid catalyst, the oxime rearranges to caprolactam, which is a precursor for nylon 6. Additional uses include spot remover,

degreasing

of

metals,

polishes,

and

lubricating

oil

additives.

2

1.2

Applications and Consumption of Cyclohexanone

Cyclohexanone is used to form caprolactam and adipic acid which are used to produce of nylon 6,6 and nylon 6. Cyclohexanone is used as solvents in paints and dyes, coatings, pharmaceuticals, adhesives and as an intermediate. In Pakistan, Cyclohexanone is majorly imported from other countries Like China, USA to fulfill the industrial requirements. The major importers of cyclohexanone in Pakistan are Berger Paints Limited, Swat Agro Chemicals, Al-Mehran Chemicals and many sub groups. Table 1.1: Physical properties of cyclohexanone Freezing point

-312 oC

Density

0.947 g/Ml

Odor

Sweet acetone like

Heat of vaporization

3.8x105 J/kg

Melting point

-47 oC

Boiling point

155.6 oC

Refractive index

1.447

Viscosity at 25 oC

2.02 cp

Flammable limit in air

1.1% – 9.4%

Critical temperature

356 oC

Critical pressure

38 atm

Vapour pressure at 20 oC

5 mmHg

3

1.3 Manufacturing Processes for Production of Cyclohexanone

There are two main processes to produce Cyclohexanone: 

Cyclohexane oxidation process



Phenol hydrogenation process [1]

1.3.1

Cyclohexane oxidation process

Benzene hydrogenation is first step that gives cyclohexane and this cyclohexane is oxidized to give cyclohexanone and cyclohexanol, oxidation process might be catalytic or non-catalytic oxidation. Catalytic Oxidation Cobalt salt is used as a catalyst with temperature, pressure condition of 125 -165 °C and 0.8 – 1.5 MPa for oxidation of liquid phase cyclohexane. [2] Ni

Co

C6H6 + 3H2 → C6H12 + O2 → C6H10O + H2O Limitations This process easily generates number of oxidation by-products thus have low rate of conversion ( 3 sec. so, result is satisfactory No of Holes Area of one hole  1.964  10 5 Number of Holes = Hole Area / Area of one hole No. of holes 

0.0129 = 657 1.964  10 5

77 Table 5.6: Specification sheet for Distillation column SPECIFICATION SHEET OF DISTILLATION COLUMN Identification Item

Distillation Column

Item #

DC-2

Type

Sieve Tray Function

The separation of CYCLOHEXANONE FROM CYCLOHEXANOL Design data No. of trays

23

Operating Pressure

0.066 Bar

Operating Temperature

74 °C

Tray spacing

6 mm

Tray thickness

7 mm

Height

12.66 m

Diameter (top)

0.60 m

Diameter (Bottom)

0.33 m

Reflux ratio

2.13

Hole size

7 mm

Liquid density

888.2 Kg/m3

Vapor density

0.23 Kg/m3

No. of holes

657

Pressure drop

113.17 mm liquid

Efficiency

39 %

78

5.15 Reactor Selection Criteria

Appropriate Reactor is selected based on Following Criteria 

Phase Based Selection (Homogenous and Multiphase Reactors)



Mode of operation like batch, continuous mixed concurrent and counter current.



High Heat Transfer Required.

Reactor type selection After considering different classifications of fixed bed catalytic reactors given above we decided that the most suitable reactor for this process is multi tubular fixed bed reactor. As the dehydrogenation of cyclohexanol is in vapor phase and highly endothermic. If temperature rise from 330o C the hot spot will occur in the reactor. To overcome this issue and make reaction isothermal high heat transfer is required so a thermal agent Dow-therm is used as a hot media which provide efficient heat transfer and make process isothermal at 330oC.Multi-tublar reactor deals both liquid and vapor phase but with different alignment. [6]

5.16 Design of reactor 2

Cyclohexanol Dehydrogenation to Cyclohexanone Where A (mol / g h) =9.4 × 108 E (kj/mol) = 108 k=A

× exp(

𝐸 𝑅𝑇

).

79 KC=2.68 × 10-9 Kb= 3.43× 10Kd= 34.7 × 10-9 By using the kinetic data and given Mole fractions for 80%conversionusing the kinetic model given below a graph is generated at different temperatures for cyclohexanol dehydrogenation to cyclohexanone in the presence of zinc oxide catalyst. [17] Kinetic Model 𝐾.Kd(Yd−.

YbYc ) Ky

-r3 =(1+𝐾𝑏𝑌𝑏+𝐾𝑐𝑌𝑐+𝐾𝑑𝑌𝑑)2 Operating Temperature = To = 330oC Operating Pressure = Po = 2 bar Conversion = X = 0.8 Density of catalyst particles = 5606kg/m3 Bed void fraction = ε = 0.574

[17]

ρB= ρc(1- ε) ρB=2388.15 kg / m3

∑

X

Ra

∆x/ra

0.1

0.007

14.285

0.2

0.0057

17.543

0.3

0.0038

26.315

0.4

0.0022

45.454

0.5

0.0018

55.555

0.6

0.0012

83.333

0.7

0.0008

125

0.8

0.0003

333.333

∆𝐱

kg hr = 700.82 kmol 𝐫𝐚

For Weight of Catalyst following Equation is used FAO= 2.1660

kmol hr

80 X dX

W = FAO ∫0

−r′A

W = FAO ×∑

∆𝐱 𝐫𝐚

kg hr

W = 700.82 kmol ×2.1660

kmol hr

W = 1518.03 kg Weight of catalyst catalyst bulk density 1518.03 kg 2388.15 kg / m3

= volume of reactor

= volume of reactor

Volume of reactor = V = 0.6356 m3 Volume of reactor = V = 635.6 liters

5.16.1 Tube side calculations

The volume of reactor is equal to the volume of tubes in multi tubular fixed reactor because reaction takes place in catalyst filled tubes. Diameter of catalyst particle = DP = 4 mm

[6]

Diameter of catalyst particle = DP= 0.004 mm The tube diameter should be such that the 8-10 catalyst particles can be placed in the tube along the tube diameter. Tube OD = 0.0508 m Tube ID = 0.0447 m Area of single tube =AS = 0.00157 m2 For multi tubular fixed bed reactor sizing Height of tube

Ratio = Diameter of catalyst particle=

𝐻 𝐷𝑝

≥ 100 [18]

81 𝐻 𝐷𝑝

= 300

H = DP × 300 Height of tube = H = 0.004 × 300 = 1.2 m Volume of tube = π r2 L = As × L Volume of tube = VT = 0.001884 m3

Number of tubes Number of tubes required = Nt = =

Volume of reactor volume of tube

[11]

0.6356 0.001884

= 338 tubes AS for single tube = 0.00157 m2 Total surface area available of all tubes = AS×Nt= 0.00157 m2 ×338 = 0.529 m2 Total Flow Area = Af = 0.00157 m2 × 329 = 0.5151 m2 For tubes bundle square pitch is selected Pitch = Pt = 1.25 ODTube

[8]

= 1.25 × 0.0508m = 0.0635 m Using tube bundle diameter relation Nt

DB= d0 (𝑘1)1/n1

[11]

k1= 0.319 n1 = 2.142 DB = Bundle diameter Do = tube outside diameter = 0.0508m DB= 1.311 m

Tube Side Heat Transfer Coefficient By using LEVA correlation for heat transfer coefficient, which relates with the heat transfer through a packed bed reactor. [19]

82 G = mass flow rate = 476.26 kg/hr m2 µ = viscosity = 0.01539 c poise µ = viscosity = 0.00001539 kg/s m µ = viscosity = 0.055404 kg/h m Dp∗G Rep = µ

=

0.004 m∗ 489.69 kg/hr m2 0.042408 kg/h m

Rep = 34.38 As Rep is in the Range of Relation given below hi =

K Do

× 0.813* (Rep)0.9 * e -6 *DP/ Do

where k = thermal conductivity = 0.05277 W/mk Do = tube outside diameter = 0.0508 m DP= Diameter of catalyst particle = 0.004 m Hence hi = 32.69 W /m2k Tube ID hio = hi × Tube OD

hio = 28.81 W /m2k

Tube Side Pressure Drop Using Ergun equation for pressure drop calculations ∆𝑃 150𝜇𝑉𝑜 (1 − 𝜀)2 1.75𝑝𝑔 𝑉𝑜2 1 − 𝜀 = + 𝐿 𝐷𝑝2 𝜀3 𝐷𝑝 𝜀3 where ε

= void fraction = 0.574

Dp = diameter of catalyst particles =0.004m µ = viscosity of vapors = 0.055404 kg/hr m m = Mass Flow rate in = 252.28 kg / hr ρg= density of vapors = 4.031kg/ m3

V=

Mass flow Rate density of vapors

=

252.28 kg / hr 4.031 kg/ m3

= 62.58 m3/hr. = 0.01738 m3/s

83

Vo= superficial velocity=

Volumetric flow Rate Flow Area tubes

=

0.01738 m3/s 0.5297 m2

= 0.032819 m/s

H = Height of the tube = 1.2 m ΔP =pressure drop Hence Pressure drop =ΔP = 630.97 Pa = 0.0063 bar

5.16.2 Shell side calculations

For shell diameter, Ds Clearance =Pitch – Tube OD = 0.0635-0.0508 = 0.0127 m So, Shell diameter =Ds = DB + Clearance Ds= 1.311 m + 0.0127 m = 1.3242 m For Height of shell we assume 10 % percent allowance from top and bottom of tubes Height of shell = Hs = 0.2 HTube + HTube Hs = 1.44 m

Reynolds Number De × G Re = µ

Equivalent diameter = De =

84 De = 0.03615 m Utility stream used is Dowtherm P = 6.29 bar Inlet temperature of Thermal Fluid = Ti = 360oC Outlet temperature of Thermal Fluid = To = 337oC Average Temperature = Tavg = 348.5oC Temperature difference = ΔT = 23oC Heat capacity of Dowtherm = Cpavg = 2.4025 kJ/ kgoC As Qreq= m× Cp×ΔT Qreq= 36000 Kj/hr 36000 = m×(2.4025) ×(23) m = 650.63 kg/ hr Now Log mean temperature difference LMTD =

(ΔT2 – ΔT1) 2.303 log (

ΔT2 ) ΔT1

ΔT2 = hot fluid temperature in –cold temperature out = 360-330 =30oC ΔT1=hot fluid temperature out- cold fluid temperature in = 337-330 ΔT2= 7oC LMTD = 15.80 Cross sectional area of shell side =As =Dshell ×Baffle spacing × Baffle spacing = 0.2× Dshell

[9]

= 0.2262 m So, As= 1.3242 ×0.2262 ×

0.0127 0.0635

As= 0.07014 m2 Mass Flow rate of Dowtherm = 650.63 kg/ hr

Clearance Pitch

85 Mass flow rate per unit area = G =

650.63 kg/ hr 0.07014 m2

= 9275.32 kg/h m2 = 2.576 kg/s m2

Viscosity of Dowtherm = µ = 0.178 c poise = 0.000178 kg/ms Thermal conductivity of Dowtherm = k = 0.08615 w/.m.k Hence Reynolds no = Re =

Prandtl no = Pr =

0.03615 m ×2.576 kg/s m2

𝐶𝑝 µ 𝑘

0.000178 kg/m s

= 523.38

kJ kg ×0.000178 ×1000 kgC ms

2.4025

=

0.08615 w/.m.k

= 4.9639

Shell Side Heat Transfer Coefficient Shell side heat transfer coefficient hs = 0.36 ×

𝑘 𝐷𝑒

×(Re)^0.55×(Pr)^0.33

where Viscosity of Dowtherm = µ = 0.000178 kg/m s Thermal conductivity of Dowtherm = k = 0.08615 w/.m.k Equivalent diameter =De = 0.03615 m Thermal Fluid mass flow rate per unit area = G = 2.576 kg/s m2 Hence, hs = 45.53 W/m2 k

Design Overall Heat Transfer Coefficient Assuming dirt factor =Rd= 0.003 m2 k/W 1 Ud 1 Ud

1

1

= ho +hio+Rd 1

1

= 45.53 +28.81 + 0.003

Ud =16.76 W/m2 k

Clean Overall Heat Transfer Coefficient hio×ho

Uc = hio+ho 45.53×28.81

Uc =45.53+28.81 Uc = 17.64 W/m2 k

86 Uc –Ud

Corrected Dirt Factor = Rd= Uc×Ud Rd4 = 0.003 m2 k/W

Thickness of Shell Consider a cylindrical shell. The choice of material is depending upon the reactants that we are dealing in reactor. Stainless steel 304 is preferred. Cc = 1mm for thermal oil For cylindrical shell Thickness of shell = t = Radius of shell = r =

P× r S×Ej−0.6P

𝑆ℎ𝑒𝑙𝑙 𝐼𝑑 2

+Cc

[11]

= 0.6621 m

For Carbon steel Joint efficiency = Ej = 0.85 Operating pressure = 100 kPa Maximum pressure = 79006.72 kPa Allowable corrosion resistance = 0.002 m After Applying Formula given above which is satisfying our conditions Thickness of shell = t = 0.00236 m = 2.36 mm

87 Table 5.7: Specification sheet of multi tubular fixed bed reactor SPECIFICATION SHEET OF MULTI TUBULAR FIXED BED REACTOR Identification Item

Reactor

Type

Multi tubular fixed bed reactor Function

Dehydrogenation of Cyclohexanol to Cyclohexanone Design data Length of single tube

1.2 m

Diameter of single tube

0.0508 m

No. of tubes

338

Operating Pressure

2 Bar

Operating Temperature

330 °C

Pressure drop

0.0063 bar

Volume of reactor

0.6365 m3

Catalyst

Zinc Oxide

Tube side heat transfer coefficient

28.81W /m2k

Utility stream

Dowtherm (Thermal Fluid)

Shell side heat transfer coefficient

45.53 W/m2 k

Overall design heat transfer coefficient

16.76 W/m2 k

Overall clean heat transfer coefficient

17.64W/m2 k

Shell Height

1.44 m

Shell diameter

1.3242 m

Thickness of shell

0.00236 m

Material of Construction

Carbon Steel

88

5.17 Double Pipe Heat Exchanger

A heat exchanger is a heat transfer device that is used for transfer of internal thermal energy between two or more fluids available at different temperatures. Heat Exchangers are used in the process, power, petroleum, transportation, air conditioning, refrigeration, cryogenic, heat recovery, alternate fuels & other industries. Most common type of heat exchanger used in chemical industries are, shell and tube heat exchanger, double pipe exchanger, plate and frame exchanger and Plate-Fin exchangers.

Heat exchanger selection criteria 

Material of construction



Operating temperature & pressure



Flow rates



Flow arrangements



Performance parameters (thermal effectiveness & pressure drops)



Fouling tendencies



Types & phases of fluids



Overall economy



Fabrication technique



Intended application

Double pipe heat exchanger The working principle of double pipe heat exchanger is based on the law of conservation of heat. As by law of nature heat tends to flow from higher potential to lower potential. It tends to equalize the temperature of both streams. But physical barrier of good conductor prevents the both streams from physical mixing and allows only heat to flow from one to other. Double pipe exchangers are usually assembled in 12-, 15-, or 20-ft effective lengths. When hairpins are employed more than 20ft, the inner pipe tends to sag and touch the outer pipe causing a poor flow distribution in the annulus. The

89 double-pipe exchanger is very flexible: vaporization, condensation, or single-phase convection can be carried out in either channel. The exchanger can be designed for very high pressures or temperatures if required. By proper selection of diameters and flow arrangements, a wide variety of flow rates can be handled.

5.18 Design Calculation of double pipe heat exchanger

The purpose of this equipment is to heat the process stream (cyclohexanone +cyclohexanol) to the required temperature. Assumed Calculations: A=

𝑄 𝑈 ∗ ∆𝑇

Assume U = 45 W/m2OC Q = 29090 kJ/Kg A = 2.578 m2 (27.66 ft2) As the area is not much big so we will use Double Pipe Heat Exchanger.

Inner pipe Side (steam) Inlet temperature = 1350C Outlet temperature = 1350C m (flow rate of steam) = 13.43 Annulus side (process stream) Inlet temperature = 33oC Outlet temperature = 90oC m (flow rate of process stream ) = 213.19

𝑘𝑔 ℎ𝑟.

𝑘𝑔 ℎ𝑟.

90 Selection of diameters As velocity in double pipe is usually 1 to 2m/s for low viscosity fluids (Edward Cao) Assume V = 1 m/s at (flow area) = ms / ρv at = 0.000008 m2 Di = √4at/π Di = 0.00319 m (0.12569 inch) Nearest pipe size (inner pipe) Nominal size = 1/8 inch Di = 0.269 inch Do = 0.405 inch at = πDi2 /4 at = 0.000366 m2 v = ms / ρat v = 1.785 m/s Outer pipe (Annulus) Nominal size = 1/2 inch Di = 0.622 inch Do = 0.84 inch 3.14 ∗ (D2o − D2i ) aa = 4 aa = 0.0001129 m2 v = mp / ρaa v =0.5785 m/s

Calculation of LMTD LMTD =

∆𝑇1 − ∆𝑇2 ∆𝑇1

ln(∆𝑇2)

LMTD = 69.66 oC

91 Table 5.8: Physical properties of streams PHYSICAL PROPRTIES

INNER PIPE

ANNULUS

saturated steam

Process stream

Viscosity µ (cp)

0.0133

1.589

Thermal Conductivity(k) (w/mk)

0.368

0.1369

heat capacity(Cp) (kj/kg k)

2.19

1.9792

Density ρ(kg/m3)

931

906

Calculation of heat transfer coefficient Assume L =6m (Edward Cao) (Annulus) Equivalent Diameter Dequivalent = (Do2- Di2)/ Di Dequivalent = 0.01398 m Reynolds Number Re =

De ρ𝑣 μ

R e = 4613.81

Pr =

Cp ∗ μ 𝑘

Pr = 22.97 𝑘

ℎ𝑜 = 1.86 𝐷𝑒𝑞 [𝑅𝑒𝑃𝑟

𝐷𝑒𝑞 0.33 ] 𝐿

ho = 55.23 j/sm2k Inner pipe (saturated steam) Di = 0.269 inch

R et =

Di ρ𝑣 μ

R et = 8536

92

Pr =

Cp ∗ μ 𝑘

Pr = 20.39 µ

𝑘

ℎ𝑖 = 0.023Ret0.8pr0.33{µ}0.14𝐷𝑖 µ

{µ}0.14 = 1 hi = 1500 j/sm2k ℎ𝑖𝑜 = ℎ𝑖

𝐷𝑖 𝐷𝑜

hio = 996.29j/sm2k tw = 60 so no effect on hi and hio µ

{µ}0.14 = 1.149 ho = 48.04j/sm2k 1

1

U = [ho + hio + Rf]-1 U = 44 J/sm2k Required Area A = Q/U∆T A = 2.60 m2 (28ft2) Required Length Required Length = Surface Area/0.106Ft L =80.74m (264 linear ft) Hairpin = 13.45 Hairpin = 14 Actual length = 84m (275ft) Actual Area will be: Actual Length * 0.106

Actual Area (A) = 2.70m2 (29.15ft2)

This area is close to the assumed calculation area (2.57m2) so we can move for next calculation.

Pressure Drop (Annulus) 1) De’ = (Do – Di)

93 De’ = 0.0055 Ft. Re’a = De’ ρ𝑣 /µ Re’a = 1819.46 f = 16/(Re’a) f = 0.0087 𝐿

∆𝑃 = 4𝑓 𝐷′𝑒𝑞

ρ𝑣2 µ 0.25 {µ} 2

∆𝑃 = 64436.72N/m2 (0.644bar)

Inner Pipe Rep = 4277 f = 0.0035 + 0.246 /(Rep)0.42 f = 0.030 ∆𝑃 = 4𝑓

𝐿 ρ𝑣2 𝐷𝑖 2

∆𝑃 = 67000 N/m2 (0.67bar)

5.19 Selection of Pumps

Mostly the pumps that used industrially are categorized into two types 1. Dynamic pumps such as centrifugal pumps 2. Positive displacement pumps such as diaphragm and reciprocating pumps Selection of the right pump is purely based upon the process conditions

94 1. Nature of fluid In nature of fluid we basically check the liquid viscosity, temperature, specific gravity, vapor pressure and concentration like if viscosity of fluid is high we use the pump of higher power, if temperature is high then we more towards the pump that has better material of construction. In our system, we are using Phenol, cyclohexanone, cyclohexanol these are corrosive fluids so to pump that fluid a pump that is required must have better material of construction (corrosion resisting). 2. Flow rate We must have a flow rate to select a pump. This is measured in Gallons per minute and in m3 / h For Height 10 m usually one stage centrifugal pumps, vortex pumps are used and if height between 10 to 100 m then one stage centrifugal pumps, Piston and screw pumps are used In our system flow rate is less than 10 m3/h and if flow rate is less than 10 m3/h then 

Dynamic pumps such as one stage centrifugal pumps are used



Positive displacement such as piston, screw and plunger pups are used

3. Pump Inlet conditions Select a pump on the basis on suction and discharge head. Use pump that has Net positive suction head available is greater than Net positive suction head required considering frictional losses like valves, sudden expansion and contraction 4. Power Source available Pump is a fluid handling device worked both electrically and mechanically. If we move towards electrical part of the pump that is motor so we must careful about the source of electricity and fluctuations on which that motor work so source of electricity is a major issue before selecting a pump.

95 5. Plant operation This factor is basically deals with the importance of pump that how and for which critical application we are using pump. If situation is critical then heavy duty and less expensive (in sense of Maintenance) pumps are used. Pump power is calculated by using aspen hysys without calculating NPSH and frictional losses. Pump after separator 1 and before distillation column 1 

One stage centrifugal pump is used because we want to pump fluid at certain height which is less than 10 m and Flow rate is also less than 10 m3/h

Inlet pressure = 1 bar Outlet pressure = 1.62 bar

Figure 5.2

Power calculation for Centrifugal pump by Aspen

1 and 2 are process streams at inlet and outlet pressure while 3 is energy stream like how much power is required to run the motor which pump the fluid with respect to conditions. Delta P relates at how much pressure difference pump is creating and at which efficiency it is working.

CHAPTER 6

6 INSTRUMENTATION & PROCESS CONTROL

6.1 Introduction

Instrumentation and process control is a basic and essential system in modern industry. Manual systems are replaced by automated control systems which are supported by various instruments for work. Almost all chemical plant is automated, major equipments like reactors, heat exchangers and distillation column etc. must be operated under IPC to run system or process smoothly without any loss. There are certain requirements that must be fulfilled under instrumentation and process control during the operation of chemical plant. Requirements are as following

97

Safety Working in a chemical plant safety is a major factor that should be considered very strictly whether it is a safety of worker or equipment. It is obvious to maintain all equipment condition like temperature, pressure and concentration within allowable limits for smooth running of process.

Product specification Proper instrumentation must be installed to achieve high quality product with accurate quantity as well. Indicators, measuring tools or meters, high efficiency transducers should be installed.

Environment regulation There are many toxic chemicals that are effluent through chemical plant, every chemical plant has some allowable limit to discharge waste to environment. To ensure that limit flow rate and concentration of waste should be maintain by using high efficiency instrumentation over piping system.

Operational constraint Every equipment has some specification and limitation which must be follow very strictly. According to operation equipments have some constraints that may cause problem if these are not be measured and considered accurately.

Economics When safety is maintained and product quality and quantity is maintained than overall profit through plant will add to revenue from plant and hence the economy of chemical plant will improve this is done only when there will be proper and accurate IPC. Three steps of point that should instrumentation has to satisfy in overall chemical plant 1. Suppress external disturbances that may cause deviation of process from normal path. 2. Stability of chemical process should be maintained. 3. Optimized the operations that are necessary t to run chemical plant smoothly.

98

6.2 Instrumentation and process Control on Reactor 1

Plug flow multi-tubular reactor is installed for hydrogenation of phenol at 150 o

C. Hydrogenation reaction is exothermic process which may cause problem in

production of product; reaction takes place inside the tube bundle where particles of platinum catalyst are supported on silica gel. Because of reaction between hydrogen and phenol heat is generated that may slower down selectivity and conversion. To maintain temperature of tube bundle at 150 oC (optimum temperature) cooling water is passed through shell side of reactor so that heat exchange may occur. Ratio between H2 and phenol must be maintained before entering in the reactor at 3:1, for this reason ratio control system is installed.

Figure 6.1

Ratio control system on Mixer

99 Auctioneering control system is installed over reactor to maintain the temperature of reactor. In PFR reaction occurs through the length and temperature also changes w.r.t length of reactor. Multiple temperature measuring sensors are installed on the different points on surface of tube bundle within the reactor which sense highest deviated temperature and signal through auctioneering system will be sent to controller. Controller will compare value with sent point and according to generated error it will send signal to final control element to change the valve opening.

Figure 6.2

Instrumentation on Reactor 1

100

6.3 Instrumentation and Process Control on Heat exchanger

Double pipe heat exchanger raise temperature from 33 oC to 90 oC of process stream containing cyclohexanone and cyclohexanol by using steam. Steam is passed from inner pipe and process stream is at annulus side. Disturbance may cause by flow rate and temperature of process stream. Objective is to maintain temperature of process stream at 90 oC at out let of the heat exchanger. Feed forward control system is installed over the heat exchanger to maintain this temperature; disturbances will be calculated before entering in the heat exchanger by using flow meter and temperature sensors and sent to the controller where value is compared with set point and controller will send signal to final control element to change the opening of valve to manipulate flow-rate of steam.

Figure 6.3

Instrumentation on HX-11

101

6.4 Instrumentation and Process Control on Distillation column

Operation of distillation column is to separate out binary mixture having component cyclohexanone and cyclohexanol. Cyclohexanone is vaporized from top and condensed and cyclohexanol is a bottom product which will sent for dehydrogenation. Feed flow-rate may cause disturbance in the operation of distillation column hence it is important to maintain inlet feed flow-rate to the distillation column, feed forward control system is installed at inlet stream of column so that disturbance may suppress before entering the column. Level of reflux drum must be maintained as condensed Vapour of cyclohexanone are collected in it, for this purpose feed backward control system is installed over the reflux drum so that after occurrence of disturbance level is measure by level measuring sensor and signal send to level controller where value is compared with set point and flow rate of distillate will be controlled by opening or closing the valve. Reflux flow rate is also controlled by valve that receives data of concentration from distillate. Temperature of bottom stream is also to maintain at certain temperature so enough steam should pass through the reboiler hence flow-rate of steam is adjusted before entering the system feed forward control system. Bottom level should also be control so that lower plate may not sink in it level is measured and flow rate of bottom product will be manipulated by changing opening of valve.

102

Figure 6.4

Instrumentation on DC-2

103

6.5 Instrumentation and Process Control Reactor 2

Dehydrogenation of cyclohexanone is take place in plug flow shell and tube type reactor. As dehydrogenation is endothermic process heat is required to follow the reaction in forward path. Heating media is introduced into the system as utility. Aim is to maintain the temperature of reactor at 330 oC so that reaction may give desired results.

Figure 6.5

Instrumentation on reactor 2

104

6.6 Instrumentation on Flash tank separator

Feed backward control system is installed to maintain the liquid level in flash tank. Liquid outlet flow rate will be controlled by final control element (valve) which receive signal from level controller. In controller, optimum liquid level is set as a set point and according to the measurement from level sensor controller will generate signal and send to final control element to manipulate the flow rate.

Figure 6.6

Instrumentation on Sep 1

CHAPTER 7

7 COST ESTIMATION

Chemical plant is installed and run to earn money and to develop business. Cost is a major factor that should be considered while designing a chemical plant, more the economical process result in more profit and benefit to entire chemical industry. Cost is estimated for future production and to optimize the process cost for availing benefits and profit. Major costs that must be calculated are 

Total purchased equipment cost



Installation cost



Fixed capital investment



Total capital investment



Production cost of product



General expenses Once money is invested to a business it should be recovered as soon as possible to

earn profit from business. Time in which a business return invested money is known as payback period which should not be greater than 5 years.

106

7.1 Equipment costing

Reactor 1 (Hydrogenation Reactor) [11] Type: Plug flow reactor (Multi-tubular) Surface area: 28.61 m2 Purchased cost in 2000: $6000 × 3 × 0.96 ×1.92 = $ 33230.76

Appendix J

𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟

Present cost = original cost × 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 Cost Index in 2002 = 390.6

(Peter and Timmerhaus 5th Ed)

Cost index in 2016 = 536.5

Appendix J

Present cost = $ 45643.38

Reactor 2 (Dehydrogenation Reactor) Type: PFR (Multi-tubular) Surface area: 64.37 m2 Purchased cost: $9000× 3× 0.98 × 1.92 = $50884.62 𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟

Present cost = original cost × 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 Cost index in 2002 = 390.6 Cost index in 2016 = 536.5 Present cost =$ 69891.44 Total cost of Reactors = $115534.83

Distillation column Column Diameter = 0.6 m Column Height = 12.66 m Number of plates = 23 Column purchased cost = $ 220000 × 1 × 1 = $220000 Per plate purchased cost = $300 × 23 × 1 = $ 6900 𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟

Present cost = original cost × 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 Cost index in 2002 = 390.6

107 Cost index in 2016 = 536.5 Present cost of plates = $ 9477.34 Present cost of column = $ 302176.13 Total cost = $ 311653.48 2 distillation columns are installed so cost for 2 distillation columns = $ 623306.96

Heat exchanger Type: Double Pipe Surface area: 2.60 m2 Purchased cost = $ 2100 Present cost = original cost ×

𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑

Cost index in 2002 = 390.6 Cost index in 2016 = 536.5 Present cost = $2884.40 15 heat exchangers are installed Total cost = $ 43266.12

Separator Type: Flash tank separator Height = 2.01 m Diameter = 1.06 m Purchased cost = $6000 × 1×1 = $ 6000 𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟

Present cost = original cost × 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 Cost index in 2002 = 390.6 Cost index in 2016 = 536.5 Present cost = 8241.68 2 separators are installed Total cost of separator = $16482.33

Pump Type: centrifugal pump Number of pumps = 9 Total Purchased cost = $24660

108 𝐶𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑝𝑟𝑒𝑠𝑒𝑛𝑡 𝑦𝑒𝑎𝑟

Present cost = original cost × 𝑐𝑜𝑠𝑡 𝑖𝑛𝑑𝑒𝑥 𝑎𝑡 𝑦𝑒𝑎𝑟 𝑜𝑓 𝑜𝑟𝑔𝑖𝑛𝑎𝑙 𝑐𝑜𝑠𝑡 𝑜𝑏𝑡𝑎𝑖𝑛𝑒𝑑 Cost index in 2002 = 390.6 Cost index in 2016 = 536.5 Present cost = $ 33871.19

Mixer Present purchased cost = $2110 2 mixers are installed Total present purchased cost = $ 4220

Total Purchased equipment cost Total purchased equipment cost = Sum of all equipment costs = $ 810987.92 Purchased equipment delivery = 10 % of total purchased equipment cost = $ 81098.79

7.2 Fixed capital investment

7.2.1

Direct plant cost

Installation cost Equipment installation cost is varying between 22-55 % of purchased equipment cost hence 40 % is selected = $ 324395.16 Piping and labor cost = 68% of total purchased equipment cost

109 =$551471.78

Electric System Cost = 20 % of total purchased equipment cost = $ 162197.58 Instrumentation and control cost = 26% of total purchased equipment cost = $210856.85 Building cost = 45 % of total purchased equipment cost for new site = $ 364944.56 Yard Improvements = 15% of total equipment purchased cost = $ 121648.18 Services Facilities Cost = 55% of total equipment purchased cost = $ 446043.35 Health & safety and Environment function = 15% of total equipment purchased cost = $121648.18 Land Cost = 5% of total equipment purchased cost = $ 40549.39

Engineering and supervision = 30% of total equipment purchased cost = $243296.37 Direct plant cost = sum of all above cost = $ 3479138.18

7.2.2

Indirect Cost

Construction Expenses = 10 % of direct plant cost = $ 347913.81

110 Contractor fee

= 3% of direct plant cost = $ 104374.14

Legal expense

= 2% of direct plant cost = $ 69582.76

Contingencies = 8% of direct plant cost = $ 834993.16 Indirect plant cost = sum of all cost = $834993.16 Fixed capital investment = sum of direct plant cost and indirect plant cost = $ 4279339.96 Working capital Cost vary between 10-20% of fixed capital investment, 15% is selected = $ 641900.99 Total Capital Investment = sum of fixed capital investment and working capital cost = $ 4921240.95

7.3 Production Cost

Raw materials Phenol Price = $ 1.28/kg Consumption = 4456.14 kg/day Cost of phenol = $5703.86/day

Hydrogen Price = $ 2.2/kg Consumption = 286.12 kg/day Cost of Hydrogen = $ 629.47/day Total Raw Material Cost = $ 6333.34/day Transportation Cost = 10 of raw material cost = $ 633.3

111

Operating labor Cost Production = 4524.60 kg/day Employee work hours = 25 hr/day Average wages of skilled and non-skilled labor = $30/hr Operating labor cost = $1030.15/day Operating supervision and clerical Cost = 15% of labor cost = $154.52/day Maintenance and repairs Cost = 10% of total equipment purchased cost = $222.19/day Operating Supplies = 15% of maintenance and repair cost = $33.32/day

Plant overhead cost It is estimated between 50-70% of maintenance, operating labor and operating supervision, 60 % is selected as an estimate = $ 844.11/day

Utilities Utilities cost is 15% of total production cost so let ‘x’ be the total production cost = 0.15x

Patent and Royalties Patent and royalties can be estimated as 2% of total production cost = 0.02x

Fixed charges Fixed charges can be assumed as 15% of total production cost = 0.15x

112

7.4 General expenses

Distribution and Marketing Distribution and marketing cost is 10% of total production cost = 0.10x Research and Development Research and development cost is 5% of total production cost = 0.05x Administrative cost Administrative cost is estimated from range between 15-25% of operating labor cost so 20% is assumed = $206.02/day

Total Production cost Total product cost is sum of all the above costs Total production cost = 9456.84 +0.47x 9456.84 +0.47x = x x = $ 17843.09/day Total production = 4524.60 kg/day Product cost =

𝑇𝑜𝑡𝑎𝑙 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑐𝑜𝑠𝑡 𝑡𝑜𝑡𝑎𝑙 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑖𝑜𝑛

= $3.94/kg

7.5 Annual revenue

Market value of Product = $5/kg Annual revenue = (product cost – market value) × total production × 330 = $1577269.41/year

113

7.6 Payback period

𝑇𝑜𝑡𝑎𝑙 𝑐𝑎𝑝𝑖𝑡𝑎𝑙 𝑖𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡

Payback period =

𝐴𝑛𝑛𝑢𝑎𝑙 𝑟𝑒𝑣𝑒𝑛𝑢𝑒

= 3.12 yr

CHAPTER 8

8 HAZOP STUDY

8.1 HAZOP Study on Reactor

Table 8.1: Hazop Study on reactor Study no. 1.

Parameter Level

Guide Word No

Possible Causes

Consequences

Blockage or leakaging in pipelines-1 inlet, pump 101 Malfunctions

Pipeline-1 may explode. Hazardous chemicals release in the atmosphere

Action Required Examine the inlet pipeline-1 carefully, follow maintenance procedures carefully

115 More

2.

3.

Increased flow of streams, failure of control valve-1, pump 101 Malfunctions Blockage or leakaging in pipelines-1 inlet, pump 101 Malfunctions

Reaction will Install level not proceed sensors and flow effectively, meters, alarms overflow in the reactor Less Pipelines may Same as for no explode. Hazardous chemicals release in the atmosphere Reverse Blockage in outlet Products will Examine the pipeline-2. failure not obtain at equipments, of control valve-4, the outlet, install check pump 103 choking of the valve-4 Malfunctions system Temperatur More Decreased Hot spots Use temperature e flowrate of cooling occur in the controller, do water, failure of reactor, maintenance of control valve-2, specifications control valve-2 pump 102 and Malfunctions composition of product changes, reactor may explode Less Excessive flowrate Reactions will Install of cooling water, condition will temperature failure of control not satisfy, sensors, use valve-2, pump 102 undesired flow controller, Malfunctions products will do maintenance obtain of control valve2 Pressure More Blockage of outlet Reactor may Open pressure pipeline-2, high explode, toxic relief valve R-1, inlet flowrates, chemicals will install pressure failure of control release in the sensors, safety valve-4, pump 103 atmosphere alarms, check Malfunctions control valve-4

116

Figure 8.1

HAZOP action plan on reactor

117

8.2 HAZOP Study on Heat Exchanger

Table 8.2: HAZOP Study on Heat Exchanger Study

Parameter

no. 1.

Temperature

Guide

Possible

Word

Causes

Less

More

Consequences

Action Required

Increased flow

Undesired

Decrease the

of cooling

cooling, desired

flowrate of cooling

water, Control

temperature not

water. install

valve failure

achieved.

temperature sensors

Decreased

High

Increase the

flowrate of

temperature

flowrate of cooling

cooling water,

rise, cooling

water, install safety

control valve

will not occur

alarms and

failure No

temperature sensors

Blockage of

Cooling will

Remove blockages

pipelines, inlet

not happen

in pipelines, do

cooling water

proper maintenance

valve fail to

of control valve

open 2.

Process

As

Leakages in

Proper heating

Proper maintenance

fluid

well as

pipelines

or cooling will

required

not take place. equipment will corrode

118

8.3 HAZOP Study on DC-2

Table 8.3: HAZOP study on DC-2 No. of

Parameter

Study 1.

Temperature

Guide

Possible

Consequences

Action Required

word

Causes

More

Less feed

Pressure buildup in

Temperature

in the

column, column

controllers, safety

column

may explode,

alarms

desired components will not obtain Less

Malfuncti

Desired

Proper

oning of

components will

maintenance of

reboiler

not separate out,

reboiler, install

undesired product

temperature controllers

2.

Pressure

More

Failure of

Column may

Critically examine

pressure

explode, distillation

pressure relief

relief

will not happen

valves and vents,

valves

high pressure alarms

3.

Level

More

Failure of

Reboiler will not

Install level

level

work properly,

sensors and high

controller

flooding

level indicator alarms

Less

Failure of

Reboiler will not

Install level

level

work properly

sensors and high

controller

level indicator alarms

CHAPTER 9

9 PLANT LOCATION

9.1 Cyclohexanone Plant Location Selection

The geographical location of the final plant can have strong influence on the success of the industrial venture. Considerable care must be exercised in selecting the plant site, and many different factors must be considered. Primarily the plant must be located where the minimum cost of production and distribution can be obtained but, other factors such as room for expansion and safe living conditions for plant operation as well as the surrounding community are also important. The location of the plant can also have a crucial effect on the profitability of a project. The following factors should be considered in selecting a plant site.

120 

Raw materials availability



Markets



Energy availability



Climate



Transportation facilities



Water supply



Waste disposal



Labor supply



Taxation and legal restrictions



Flood and fire protection



Community factors

The project on which we are working is the production of Cyclohexanone. In Pakistan, this plant can most probably be installed in the region of Sindh. This is so because of the major easy access of raw materials and water, energy availability, suitable climate and good transportation facilities in this whole region. But the best suitable location for the plant is “Hyderabad District of Sindh province, Sindh”. Taking in consideration all the critical factors the selection of this specific location is described below.

9.1.1

Raw materials availability

Raw material required for cyclohexanone production is Phenol and hydrogen gas. Phenol is not available in Pakistan as per our requirements. So, phenol will be imported from foreign Countries like china etc. using Karachi sea port to meet our requirements. So, raw material will be easily available viaQassim Port, Karachi.

121 9.1.2

Markets

There is a huge market of chemicals in this region mainly Punjab and Sindh so the plant will be perfectly located to launch its product in the market at minimum transportation costs.

9.1.3

Energy Availability

The natural gas from Mari Petroleum Company can be utilized to fulfill the demands of the plant.

9.1.4

Climate

Climate has a special influence on the revenue generation because If the plant is in a cold climate, costs may be increased due to construction of protective shelters around the equipment. If the plant is in hot climate, then special cooling tower air-conditioning equipment may be required. If there is excessive humidity or extremes of hot or cold weather, then it will cause serious effect on the economic operation of a plant.

122 The weather in the region remains moderate but temperatures in summer can go up to 40 degree Celsius but it has no major influence on the process of the production.

9.1.5

Transportation Facilities

Rail tracks, roads, and highways are the common need for transportation of products and raw materials. Possibility of canal, river, lake, or ocean transport must be considered. In this region,the plant site has access to the national highway (N5) passes through the region and the area is connected by railways so the possess very good transportation facilities. Water supply The region has enough usable ground water which can be utilized for the plant.

9.1.6

Taxation and legal restrictions

The site selected for the plant is a developing industrial area so the taxation in the area would be lower than compared to other locations

123 9.1.7

Waste Disposal

It is a major issue in any industry because in recent years many legal restrictions have been placed on the methods for disposing of waste materials from the process industries. So, the site selected for a plant should have adequate capacity and facilities for correct waste disposal. So, the permissible tolerance levels for various methods of waste disposal should be considered carefully, and attention should be given to potential requirement for additional waste treatment facilities. Although the site has no major canal or river nearby to dump the waste, the waste can be disposed by other means.

9.1.8

Labor supply

Labor is an important assert of any industry Hyderabad city have population that can work in industrial environment. Engineer and lower staff is available for running plant.

9.1.9

Conclusion

Considering all the described factors the site location of the plant is very suitable in every aspect which will ensure that the plant will be economical and profitable.

APPENDICES (A-K)

125

Appendix A: Specific Heat Stream

Specific heat (kJ/kmol°C)

1

184.8

2

190.8

3

214.4

3a

68.11

5

58.04

6

155.6

7

175.8

8

154.1

10

204.9

11

221.6

11.01

15.4

11.02

223.3

12

293.4

13

223.3

13.1

227.6

15

245.6

16

192.4

16.01

152

17

199.9

18

241.2

19

156.2

20

138.4

21

126.2

22

182.9

23

206.7

Values are calculated using Aspen-hysis software.

126

DESIGNING CHART Appendix B: Flooding velocity, sieve plate (Vol-6)

127 Appendix C: Relation between downcomer area and weir length ( Vol 6)

128 Appendix D: Weep-Point correlation (vol 6)

129 Appendix E: Discharge coefficient, sieve plate (Vol 6)

130 Appendix F: Value of constant K

Appendix G: Value of HLLL

131 Appendix H: Shell-bundle clearance (Vol 6)

132 Appendix I: Temperature Co-relation factor (VOL 6)

133 Appendix J: Cost estimation

134

135

136

137 Appendix K: Aspen Hysis methods Selection of components

Use appropriate Fluid package by using Method assistant Step 1 Go to method assistant

138

Selection of process

139 Go to simulation and add temperature, pressure, composition from material balance and calculate properties like specific heat dew point bubble point by varying vapor phase 1 and 0 Data entry

Compositions

Properties chart

140

REFERENCES

1. Report on “Synthesis Process of Cyclohexanone and Cyclohexanol” Manufacturing Method and Technology Retrieved 27 October 2016 from http://www.technologyx.net/C07C/200610050682.htm 2. Van Geem, P. C., & van den Brink, F. T. (1990). U.S. Patent No. 4,927,974. Washington, DC: U.S. Patent and Trademark Office. 3. Parton, R. F. M. J., & Tinge, J. T. (2013). U.S. Patent No. 8,389,773. Washington, DC: U.S. Patent and Trademark Office. 4. Duggan, R. J., Murray, E. J., & Winstrom, L. O. (1963). U.S. Patent No. 3,076,810. Washington, DC: U.S. Patent and Trademark Office 5. Hancil , V. , Beranek , L. , Kinetics of consecutive catalytic reactions: hydrogenation of phenol on platinum catalyst 6. Dimians, A. C., & Bildea, C. S. (n.d.). Ch 5: Pheno Hydrogenation to Cyclohexanone. In Chemical Process Design. Wiley-VCH. 7. Albright, L. F. (n.d.). Albright's Chemical Engineering Handbook. 8. Kern, D. Q. (2011). Process heat transfer. Tokyo: McGraw-Hill. 9. Coulson, J. M., & Richardson, J. F. (1979). Chemical engineering (Vol. 6). Oxford: Pergamon Press. 10. Stankiewicz, A. (1989). Advances in modelling and design of multitubular fixedbed reactors. Chemical Engineering & Technology - CET, 12(1), 113-130. doi:10.1002/ceat.270120117 11. Peters, M. S., Timmerhaus, K. D., & West, R. E. (2006). Plant design and economics for chemical engineers (5th ed.). Boston: McGraw-Hill. 12. Sulzer Chemtechk, Gas/Liquid Separation Technology 13. Xiuli Wangk, Advanced Natural Gas Engineering, Houston, Texas: 2009 14. Perry, R. H. Hand book of Chemical Engineering. 8th edition. New York, Toronto: 1999. 15. Skogestad, S. (2009). Chemical and energy process engineering. CRC press.

141 16. Coulson, J. M., & Richardson, J. F. (2002). Chemical engineering (Vol.2).Oxford: Pergamon Press. 17. G, GUT and R jaeger kinetics of cyclohexanol dehydrogenation to cyclohexanone Accepted in 6 july,1981 18. Albright, L. F. (n.d.). Albright's Chemical Engineering Handbook. 19. Stankiewicz, A. (1989). Advances in modeling and design of multitubular fixed bed reactor. Chemical engineering and technology-CET, 12(1), 1132130.