# Chemical Process Engineering Volume 1

## Design, Analysis, Simulation, Integration, and Problem Solving with Microsoft Excel-UniSim Software for Chemical Engineers Computation, Physical Property, Fluid Flow, Equipment and Instrument Sizing

1. Edition May 2022

544 Pages, Hardcover*Wiley & Sons Ltd*

**978-1-119-51018-5**

Written by two of the most prolific and respected chemical engineers in the world, this groundbreaking two-volume set is the "new standard" in the industry, offering engineers and students alike the most up-do-date, comprehensive, and state-of-the-art coverage of processes and best practices in the field today.

This first new volume in a two-volume set explores and describes integrating new tools for engineering education and practice for better utilization of the existing knowledge on process design. Useful not only for students, professors, scientists and practitioners, especially process, chemical, mechanical and metallurgical engineers, it is also a valuable reference for other engineers, consultants, technicians and scientists concerned about various aspects of industrial design.

The text can be considered as a complementary text to process design for senior and graduate students as well as a hands-on reference work or refresher for engineers at entry level. The contents of the book can also be taught in intensive workshops in the oil, gas, petrochemical, biochemical and process industries.

The book provides a detailed description and hands-on experience on process design in chemical engineering, and it is an integrated text that focuses on practical design with new tools, such as Excel spreadsheets and UniSim simulation software.

Written by two industry and university's most trustworthy and well-known authors, this book is the new standard in chemical, biochemical, pharmaceutical, petrochemical and petroleum refining. Covering design, analysis, simulation, integration, and, perhaps most importantly, the practical application of Microsoft Excel-UniSim software, this is the most comprehensive and up-to-date coverage of all of the latest developments in the industry. It is a must-have for any engineer or student's library.

Acknowledgments xix

About the Authors xxi

1 Computations with Excel Spreadsheet-UniSim Design Simulation 1

SECTION I - NUMERICAL ANALYSIS 1

INTRODUCTION 1

Excel Spreadsheet 1

Functions 2

Trendline Coefficients 2

Goal Seek 5

SOLVER 6

LINEAR REGRESSION 7

Measuring Regression Quality 9

MULTIPLE REGRESSION 9

POLYNOMIAL REGRESSION 11

SIMULTANEOUS LINEAR EQUATIONS 11

NONLINEAR EQUATIONS 12

INTERPOLATIONS 13

INTEGRATIONS 14

The Trapezoidal Rule 14

Simpson's 1/3 Rule 15

Simpson's 3/8 Rule 15

DIFFERENTIAL EQUATIONS 15

Nth Order Ordinary Differential Equations 15

Solution of First-Order Ordinary Differential Equations 15

Runge-Kutta Methods 16

EXAMPLES AND SOLUTIONS 17

SECTION II - PROCESS SIMULATION 28

INTRODUCTION 28

Thermodynamics for Process Simulators 29

UNISIM Design Software 30

EXAMPLES AND SOLUTIONS 31

References 78

2 Physical Property of Pure Components and Mixtures 81

PURE COMPONENTS 81

Density of Liquid 82

Viscosity of Liquid 83

Heat Capacity of Liquid 85

Thermal Conductivity of Liquid 87

Volumetric Expansion Rate 90

Vapor Pressure 91

Viscosity of Gas 93

Thermal Conductivity of Gas 94

Heat Capacity of Gases 95

MIXTURES 97

Surface Tensions 98

Viscosity of Gas Mixture 99

Enthalpy of Formation 101

Enthalpy of Vaporization 103

Gibbs Energy of Reaction 105

Henry's Law Constant for Gases in Water 107

Coefficient of Thermal Expansion of Liquid 108

DIFFUSION COEFFICIENTS 109

Gas-Phase Diffusion Coefficients 109

Liquid-Phase Diffusion Coefficients 110

COMPRESSIBILITY Z-FACTOR 111

SOLUBILITY AND ADSORPTION 116

Solubility of Hydrocarbons in Water 116

Solubility of Gases in Water 117

Solubility of Sulfur and Nitrogen Compounds in Water 118

Adsorption on Activated Carbon 119

References 119

3 Fluid Flow 121

INTRODUCTION 121

Flow of Fluids in Pipes 121

EQUIVALENT LENGTH OF VARIOUS FITTINGS AND VALVES 123

Excess Head Loss 123

Pipe Reduction and Enlargement 124

PRESSURE DROP CALCULATIONS FOR SINGLE-PHASE INCOMPRESSIBLE FLUIDS 124

Friction Factor 127

Overall Pressure Drop 128

Nomenclature 130

COMPRESSIBLE FLUID FLOW IN PIPES 130

Maximum Flow and Pressure Drop 131

Critical or Sonic Flow and the Mach Number 131

Mach Number 132

Mathematical Model of Compressible Isothermal Flow 134

Flow Rate Through Pipeline 136

Pipeline Pressure Drop 138

Nomenclature 139

Subscripts 139

TWO-PHASE FLOW IN PROCESS PIPING 139

Flow Patterns 140

Flow Regimes 142

Pressure Drop 142

Erosion-Corrosion 145

Nomenclature 145

VAPOR-LIQUID TWO-PHASE VERTICAL DOWNFLOW 146

The Equations 147

The Algorithm 147

Nomenclature 147

LINE SIZES FOR FLASHING STEAM CONDENSATE 148

The Equations 148

Nomenclature 149

FLOW THROUGH PACKED BEDS 150

The Equations 151

Nomenclature 152

EXAMPLES AND SOLUTIONS 152

References 162

4 Equipment Sizing 165

INTRODUCTION 165

SIZING OF VERTICAL AND HORIZONTAL SEPARATORS 166

Vertical Separators 166

Calculation Method for a Vertical Drum 168

Calculation Method for a Horizontal Drum 170

Liquid Holdup and Vapor Space Disengagement 171

Wire Mesh Pad 171

Standards for Horizontal Separators 172

Piping Requirements 172

Nomenclature 172

SIZING OF PARTLY FILLED VESSELS AND TANKS 173

The Equations 173

Nomenclature 175

PRELIMINARY VESSEL DESIGN 176

Nomenclature 177

CYCLONE DESIGN 178

Introduction 178

Cyclone Design Procedure 178

The Equations 179

Saltation Velocity 180

Pressure Drop 181

Troubleshooting Cyclone Maloperations 182

Cyclone Collection Efficiency 182

Cyclone Design Factor 182

Cyclone Design Procedure 183

Nomenclature 183

GAS DRYER DESIGN 184

The Equations 186

Pressure Drop 187

Desiccant Reactivation 188

Nomenclature 188

EXAMPLES AND SOLUTIONS 189

References 194

5 Instrument Sizing 195

INTRODUCTION 195

Variable-Head Meters 195

Macroscopic Mechanical Energy Balance 196

Variable-Head Meters 196

Orifice Sizing for Liquid and Gas Flows 200

Orifice Sizing for Liquid Flows 201

Orifice Sizing for Gas Flows 202

Orifice Sizing for Liquid Flow 204

Orifice Sizing for Gas Flow 204

Types of Restriction Orifice Plates 205

Case Study 1 205

Nomenclature 212

CONTROL VALVE SIZING 221

Introduction 221

Control Valve Characteristics 223

Pressure Drop for Sizing 224

Choked Flow 224

Flashing and Cavitation 224

Control Valve Sizing for Liquid, Gas, Steam and Two-Phase Flows 225

Liquid Sizing 226

Gas Sizing 227

Critical Condition 227

Steam Sizing 227

Two-Phase Flow 228

Installation 229

Noise 229

Control Valve Sizing Criteria 230

Valve Sizing Criteria 230

Self-Acting Regulators 231

Types of Self-Acting Regulators 231

Case Study 2 233

Rules of Thumb 246

Nomenclature 246

References 247

6 Pumps and Compressors Sizing 249

PUMPS 249

Introduction 249

Pumping of Liquids 249

Pump Design Standardization 252

Basic Parts of a Centrifugal Pump 253

Impellers 253

Casing 253

Shaft 254

CENTRIFUGAL PUMP SELECTION 255

Single-Stage (Single Impeller) Pumps 256

Hydraulic Characteristics for Centrifugal Pumps 260

Friction Losses Due to Flow 269

Velocity Head 269

Friction 271

NET POSITIVE SUCTION HEAD (NPSH) AND PUMP SUCTION 271

General Suction System 277

Reductions in NPSHR 279

Corrections to NPSHR for Hot Liquid Hydrocarbons and Water 279

Charting NPSHR Values of Pumps 280

Net Positive Suction Head (NPSH) 280

Specific Speed 282

"Type Specific Speed" 285

Rotative Speed 286

Pumping Systems and Performance 286

System Head Using Two Different Pipe Sizes in Same Line 288

POWER REQUIREMENTS FOR PUMPING THROUGH PROCESS LINES 291

Hydraulic Power 292

Relations Between Head, Horsepower, Capacity, Speed 293

Brake Horsepower (BHP) Input at Pump 293

AFFINITY LAWS 296

Pump Parameters 298

Specific Speed, Flowrate and Power Required by a Pump 299

Pump Sizing of Gas-Oil 301

Debutanizer Unit 303

CENTRIFUGAL PUMP EFFICIENCY 306

Centrifugal Pump Specifications 311

Pump Specifications 311

Steps in Pump Sizing 312

Reciprocating Pumps 313

Significant Features in Reciprocating Pump Arrangements 314

Application 316

Performance 316

Discharge Flow Patterns 317

HORSEPOWER 318

Pump Selection 318

Selection Rules-of-Thumb 318

A CASE STUDY 321

Pump Simulation on a PFD 321

Variables Descriptions 322

SIMULATION ALGORITHM 322

Problem 323

Discussion 324

Pump Cavitation 332

Factors in Pump Selection 333

COMPRESSORS 334

INTRODUCTION 334

General Application Guide 334

Specification Guides 337

GENERAL CONSIDERATIONS FOR ANY TYPE OF COMPRESSOR FLOW CONDITIONS 337

Fluid Properties 338

Compressibility 338

Corrosive Nature 338

Moisture 339

Special Conditions 339

Specification Sheet 339

PERFORMANCE CONSIDERATIONS 339

Cooling Water to Cylinder Jackets 339

Heat Rejected to Water 339

Drivers 340

Ideal Pressure - Volume Relationship 341

Actual Compressor Diagram 343

DEVIATIONS FROM IDEAL GAS LAWS: COMPRESSIBILITY 343

Adiabatic Calculations 346

Charles' Law at Constant Pressure 346

Amonton's Law at Constant Volume 346

Combined Boyle's and Charles' Laws 346

Entropy Balance Method 347

Isentropic Exponent Method 347

COMPRESSION RATIO 354

Horsepower 356

Single Stage 356

Theoretical Hp 356

Actual Brake Horsepower, Bhp 356

Actual Brake Horsepower, Bhp (Alternate Correction for Compressibility) 361

Temperature Rise - Adiabatic 363

Temperature Rise - Polytropic 365

A CASE STUDY USING UNISIM DESIGN R460.1 SOFTWARE FOR A

TWO-STAGE COMPRESSION 365

CASE STUDY 2 365

Solution 365

1. Starting UniSim Design Software 366

2. Creating a New Simulation 366

Saving the Simulation 367

3. Adding Components to the Simulation 367

4. Selecting a Fluids Package 368

5. Select the Units for the Simulation 369

6. Enter Simulation Environment 369

Accidentally Closing the PFD 371

Object Palette 371

7. Adding Material Streams 371

8. Specifying Material Streams 372

9. Adding A Compressor 374

Specifications 381

COMPRESSION PROCESS 385

Adiabatic 385

Isothermal 385

Polytropic 385

Efficiency 388

Head 390

ADIABATIC HEAD DEVELOPED PER SINGLE-STAGE WHEEL 390

Polytropic Head 391

Polytropic 391

Brake Horsepower 393

Speed of Rotation 396

TEMPERATURE RISE DURING COMPRESSION 397

Sonic or Acoustic Velocity 399

MACH NUMBER 402

Specific Speed 402

COMPRESSOR EQUATIONS IN SI UNITS 403

Polytropic Compressor 405

Adiabatic Compressor 408

Efficiency 409

Mass Flow Rate, w 409

Mechanical Losses 410

Estimating Compressor Horsepower 411

Multistage Compressors 412

Multicomponent Gas Streams 414

AFFINITY LAWS 422

Speed 423

Impeller Diameters (Similar) 423

Impeller Diameter (Changed) 424

Effect of Temperature 424

AFFINITY LAW PERFORMANCE 425

TROUBLESHOOTING OF CENTRIFUGAL AND RECIPROCATING COMPRESSORS 425

NOMENCLATURE 429

Greek Symbols 431

Subscripts 432

Nomenclature 432

Subscripts 434

Greek Symbols 434

References 434

Pumps 434

Bibliography 435

References 435

Compressors 435

Bibliography 436

7 Mass Transfer 437

INTRODUCTION 437

VAPOR LIQUID EQUILIBRIUM 437

BUBBLE POINT CALCULATION 441

DEW POINT CALCULATION 442

EQUILIBRIUM FLASH COMPOSITION 442

Fundamental 443

The Equations 444

The Algorithm 445

Nomenclature 446

TOWER SIZING FOR VALVE TRAYS 446

Introduction 446

The Equations 448

Nomenclature 452

Greek Letters 465

PACKED TOWER DESIGN 466

Introduction 466

Pressure Drop 466

Flooding 466

Operating and Design Conditions 468

Design Equations 471

Packed Towers versus Trayed Towers 473

Economic Trade-Offs 473

Nomenclature 474

Greek Letters 474

DETERMINATION OF PLATES IN FRACTIONATING COLUMNS

BY THE SMOKER EQUATIONS 474

Introduction 474

The Equations 474

Application to a Distillation Column 475

Rectifying Section: 475

Stripping Section: 476

Nomenclature 476

MULTICOMPONENT DISTRIBUTION AND MINIMUM TRAYS

IN DISTILLATION COLUMNS 477

Introduction 477

Key Components 477

Equations Surveyed 477

Fractionating Tray Stability Diagrams 479

Areas of Unacceptable Operation 479

Foaming 480

Flooding 480

Entrainment 480

Weeping/Dumping 480

Fractionation Problem Solving Considerations 481

Mathematical Modeling 481

The Fenske's Method for Total Reflux 483

The Gilliland Method for Number of Equilibrium Stages 484

The Underwood Method 485

Equations for Describing Gilliland's Graph 486

Kirkbride's Feed Plate Location 487

Nomenclature 487

Greek Letters 488

EXAMPLES AND SOLUTIONS 488

References 499

Index 501

Rahmat Sotudeh-Gharebaagh, PhD, is a full professor of chemical engineering at the University of Tehran. He teaches process modeling and simulation, transport phenomena, plant design and economics and soft skills. His research interests include computer-aided process design and simulation, fluidization, and engineering education. He holds a BEng degree in chemical engineering from Iran's Sharif University of Technology, plus a MSc and a PhD in fluidization engineering from Canada's Polytechnique. He has been an invited Professor at Qatar University and Polytechnique de Montréal. Professor Sotudeh has more than 300 publications in major international journals and conferences, plus four books and four book chapters. He is the co-founder and editor-in-chief of the journal, Chemical Product and Process Modeling, a member of the Iranian Elite Foundation, and an official expert (OE) on the oil industry with the Iranian Official Expert Organization.