INVESTIGATION INTO GAS FLARING REDUCTION IN THE OIL …

1 INVESTIGATION into GAS FLARING REDUCTION IN THE OIL AND gas industry MUSA BASHIR ABUHESA Thesis 2010 INVESTIGATION into GAS FLARING REDUCTION IN THE OIL AND gas industry Musa Bashir ABUHESA BSc, MRes. School of Computing, Sciences and Engineering University of Salford, Manchester, UK Submitted in Partial Fulfilment of the Requirements of the Degree of Doctor of Philosophy, December 2010 DEDICTED TO MY MOTHER FOR HER SUPPORT, MY WIFE, MY SONS; AMMAR, MOHAMED, BASHIR AND NASER AND MY DAUGHTERS; SUHAILA, SUZAN AND SUNDESS i CONTENTS CONTENTS .. i LIST OF TABLES .. ix LIST OF FIGURES .. x ACKNOWLEDGMENTS .. xix DECLARATION .. xx NOMENCLATURE .. xxi ABSTRACT .. xxiii CHAPTER-1: 2 Overview of the Topic.

2 2 Aims .. 4 Objectives .. 4 Thesis Structure .. 5 CHAPTER-2: GENERAL BACKGROUND .. 7 Introduction .. 7 Problem Definition .. 9 Gas FLARING Emission .. 11 Sources of Gas FLARING .. 13 Typical Composition of Natural Gas .. 14 Flare Stack .. 15 Barriers to Gas Utilisation .. 15 Natural Gas Utilisation Options .. 16 ii Re-injection of Natural Gas .. 17 Gas Transportation .. 18 Gas to Pipelines .. 18 Power Generation .. 19 Liquefied Natural Gas .. 20 Hydrogen Production .. 21 Gas to Liquid Technology .. 21 Methane Steam Reforming .. 24 Autothermal Reforming .. 27 Partial Oxidation of Methane .. 28 Comparison Between Steam Reforming and Partial Oxidation of Methane .. 28 Synthesis Gas Production .. 29 Carbon Nanotubes .. 30 Carbon Nanotubes Synthesis .. 32 Laser Vaporisation Method .. 32 Chemical Vapour Deposition .. 33 Arc Discharge .. 33 CNTs Generation Using Sprays and Atomisation Techniques .. 34 CHAPTER-3: MEMBRANES OVERVIEW.

3 36 Introduction .. 36 What are Membranes? .. 36 Organic Membranes .. 38 iii Inorganic Membranes .. 39 Porous Membranes .. 39 Non-porous Membranes .. 42 Synthesis of Ceramic Membrane Powders .. 44 Sol-gel Method .. 44 Solid-state Method .. 45 Combustion Spray Pyrolysis Method .. 45 Membrane Reactors .. 45 Ceramic Membrane Reactors .. 49 Natural Gas Conversion into Syngas by Partial Oxidation .. 49 Oxygen Permeation in Perovskite Membranes .. 50 CHAPTER-4: SYNGAS PRODUCTION INVESTIGATION .. 54 Introduction .. 54 Feasibility Study for POM using Perovskite Membranes .. 54 Introduction .. 54 Considration of LSCF Membrane .. 57 Thin Layer Membranes on a Porous Substrate .. 58 Assumptions and Calculation Procedures .. 61 Number of Tubes Required Calculation .. 63 Amount of LSCF (6428) and Cost .. 65 Analysis .. 66 CHAPTER-5: THE BACKGROUND TO SPRAYS AND ATOMISATION .. 72 Introduction .. 72 Definition of an Atomisation.

4 72 iv Basic Mechanisms of Atomisation .. 73 Break-up of Liquid Jets .. 74 Break-up of Liquid Sheets .. 75 Break-up of Droplets .. 76 Characterisation of Sprays .. 77 Factors Affecting a Spray .. 80 Fluid Properties .. 80 Pressure .. 81 Temperature .. 81 Flow Rate .. 81 Drop Size Distribution .. 82 Settling Velocity .. 88 Drop Size Measurements .. 91 The Malvern Mastersizer-X .. 92 Operating Procedure of Malvern Mastersizer-X .. 94 Limitations of Mastersizer-X and Measurement Errors .. 95 Atomiser Types .. 95 Twin Fluid Atomisers .. 96 Single Fluid Atomisers .. 98 Rotary Atomiser .. 98 Ultrasonic Atomiser .. 99 Electrostatic Atomiser .. 100 Pressure Atomisers .. 101 v CHAPTER - 6: DESIGN OF A FINE SPRAY ATOMISER DEVICE, EXPERIMENTAL SET-UP AND PROCEDURE .. 108 Introduction .. 108 Design Philosophy and Procedure .. 109 Atomiser Device Design Specification: B1 .. 110 Design of Fine Spray Atomiser Device.

5 111 The INVESTIGATION and Gathering of Information (IGI): B2 .. 111 Generation of Ideas and Evaluation (GIE): B3 - B5 .. 116 Atomiser Device Development and Testing (D and T): B6 .. 116 Estimation of Settling Velocity (D and T): B6 .. 122 Experimental Apparatus Set-up .. 124 Overview .. 124 Apparatus Set-up .. 124 Reservoir Tank and Water Pump .. 126 Air Supply and Flow Metering .. 127 Atomiser Holding and Positioning Assembly .. 129 Malvern Mastersizer-X Set-up .. 129 Still Camera .. 131 Experimental Procedure .. 132 Phase I: Spraying and Atomisation Experimental Procedure .. 132 vi Phase II: Proposed Prototype and Testing (PP and T): B8 .. 133 CHAPTER-7: RESULTS, ANALYSIS AND DISCUSSION .. 136 Introduction .. 136 Results and Discussion: Feasibility Studyof the Partial Oxidation of Methane to Syngas .. 136 Oxygen Permeation through Membrane Tubes .. 137 Effect of Oxygen Partial Pressure on Oxygen Permeation . 139 Modelling of Partial Oxidation of Natural Gas.

6 141 Results and Discussion: Single-Walled Carbon Nanotubes (SWCNT) Production .. 149 Overview .. 149 Phase I: Spray Characterisation .. 150 Inverted Atomiser Device Position .. 151 Horizontal Atomiser Device Position .. 151 Vertical Atomiser Device Position .. 154 Summary .. 182 Phase II: Single-Walled Carbon Nanotubes Generation: Highlight of the Results and Disscusion .. 183 CHAPTER-8: CONSIDRATION OF ECONOMIC ANALYSIS .. 189 Introduction .. 189 Concept of a Visual Basic Programme .. 190 Programming Fundamentals and Overview of the Economic Analysis .. 191 vii Feasibility Study .. 192 Software Identification .. 193 Analysis Stage .. 193 Functional and Non-functional Requirements .. 195 Entities and Attributes .. 196 Entities Relationship Diagram .. 198 Context Diagram and Level 1 Data flow Diagram 199 Design Stage .. 200 Interface Structure .. 200 Database Structure .. 202 Links Between VB Interface and the Database.

7 203 Implementation Stage .. 203 VB scripts .. 203 Testing .. 204 User Guide .. 204 Economic Analysis and Comparison .. 205 Assumption .. 205 Scenario 1: Gas is Flared .. 205 Scenario 2: Gas is Recycled .. 206 CHAPTER-9: CONCLUSIONS AND RECOMMENDATIONS .. 211 Conclusions .. 211 Recommendations for Future Work .. 213 APPENDICES .. 215 viii Appendix A: Tabulated Results of Chapter 4 and Chapter 7 ( ) Analysis .. 216 Appendix B: Experimental Design and Experimental Results .. 222 Appendix C: Normalisation Table .. 257 Appendix D: Visual Basic Scripts .. 258 Appendix E: VB programme Testing Results .. 265 Appendix F: User Guide for CCS System .. 268 Appendix G: Comparison and Economic Analysis Results .. 279 REFERENCES .. 283 ix LIST OF TABLES Table : Worldwide top twenty gas flarer countries in 2008 .. 12 Table : General typical composition of natural gas .. 14 Table : Pipeline gas quality specifications .. 19 Table : Classification of porous membranes.

8 40 Table 4 1: Oxygen flux summary for some work on LSCF membrane .. 60 Table : Mean diameters and their applications .. 87 Table : Performance specification, 121 hollow-cone spray atomisers .. 115 Table : Operating parameters .. 150 Table : Summary of horizontal position results of the atomiser device .. 153 Table : Initial experimental results of atomiser device vertical position at baffle plate position of 110 mm and aerosol tube position of 100 mm from the base cover .. 161 Table : Typical experimental data obtained for the optimum baffle plate and aersol tube positions .. 166 Table : Results of various tests showing the effect of water supply pressure and water flow rate on droplet sizes .. 169 Table : Typical results of air flow rates and water s upply pressures on droplet sizes .. 172 Table : Typical results showing the effect of downstream distance of atomiser exit on droplet sizes .. 177 Table : List of entities and relevant attributes.

9 197 Table : Economic analysis results .. 208 x LIST OF FIGURES Figure : Typical processes flow diagram of oil and gas production .. 10 Figure : Carbon nanotubes molecular 30 Figure : A membrane separation principle .. 37 Figure : The main membrane functions in the membrane reactor .. 47 Figure : Dense membrane reactor mechanisms .. 62 Figure : Effect of oxygen permeation on a number of tubes (O2 flow rate = 10,000 m3/day, tube outer diameter, m, tube thickness= m and tube length = m) .. 67 Figure : Effect of tube relative length on a number of tubes (O2 flow rate = 10,000 m3/day, tube outer diameter, m and tube = m thickness) .. 68 Figure : Effect of oxygen flow rate on a number of tubes (tube outer diameter = m, tube thickness = m, tube length = m, O2 flux = 10 ml/( )) .. 68 Figure : Effect of tube thickness on the price of tubes (tube outer diameter = m, tube length = m, O2 flux = 10 ml/( )) .. 69 Figure : General atomisation mechanisms.

10 73 Figure : Liquid column break-up at different velocities .. 75 Figure : Break-up mechanism of a liquid sheet into ligaments and 76 Figure : Drop break-up mechanism in low and high Weber numbers .. 77 Figure : Spray cone angle defination .. 78 Figure : Various spray patternations .. 80 xi Figure : Typical drop size distribution .. 82 Figure : Drop size histograms based on number and volume .. 83 Figure : Typical drop size frequency distribution curves .. 84 Figure : Typical shape of cumulative drop size .. 84 Figure : Creeping flow past a spherical particle .. 88 Figure : Optical arrangement employed in Malvern Mastersizer-X .. 93 Figure : Two-fluid atomiser design .. 97 Figure : Schematic diagram of rotary atomiser .. 98 Figure : Schematic diagram of ultrasonic atomiser .. 99 Figure : Schematic diagram of electrostatic 100 Figure : Typical plain orifice pressure atomiser .. 102 Figure : Fan (Vee) Jet atomiser .. 102 Figure : Various designs of pressure swirl atomiser.