Common poisons include
Sulfur
Chlorides and other halides
Metals including arsenic, vanadium, mercury, alkali metals (including potassium)
Phosphates
Organo-metalics
1. Introduction reasons for purification, types of poisons, and typical systems
2. Hydrogenation
3. Dechlorination
4. Sulfur Removal
5. Purification system start-up and shut-down
Look at two main types
Explain mechanisms
Explain prevention of cracking
Three main types
1 Carbon cracking
2 Boudouard carbon formation
3 CO reduction
VULCAN Series VSG-Z101 Primary Reforming
Initial Catalyst Reduction
Activating (reducing) the catalyst involves changing the nickel oxide to nickel, represented by:
NiO + H2 <==========> Ni + H2O
Natural gas is typically used as the hydrogen source. When it is, the catalyst reduction and putting the reformer on-line are accompanied in the same step.
Common poisons include
Sulfur
Chlorides and other halides
Metals including arsenic, vanadium, mercury, alkali metals (including potassium)
Phosphates
Organo-metalics
1. Introduction reasons for purification, types of poisons, and typical systems
2. Hydrogenation
3. Dechlorination
4. Sulfur Removal
5. Purification system start-up and shut-down
Look at two main types
Explain mechanisms
Explain prevention of cracking
Three main types
1 Carbon cracking
2 Boudouard carbon formation
3 CO reduction
VULCAN Series VSG-Z101 Primary Reforming
Initial Catalyst Reduction
Activating (reducing) the catalyst involves changing the nickel oxide to nickel, represented by:
NiO + H2 <==========> Ni + H2O
Natural gas is typically used as the hydrogen source. When it is, the catalyst reduction and putting the reformer on-line are accompanied in the same step.
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
Introduction and Theoretical Aspects
Catalyst Reduction and Start-up
Normal Operation and Troubleshooting
Shutdown and Catalyst Discharge
Nickel Carbonyl Hazard
Modern Methanation Catalyst Requirements
Purpose
Key to good performance
Problem Areas
Catalysts, heat shields and plant up-rates
Burner Guns
Development of High Intensity Ring Burner
Case Studies
Conclusions
(HTS) High Temperature Shift Catalyst (VSG-F101) - Comprehensiev OverviewGerard B. Hawkins
The high temperature shift duty introduction and theory
HTS catalyst characteristics
developments over time
Typical HTS operational problems
Improved catalysts
VULCAN Series VSG-F101 Series
Summary
- Process effects of pre-reforming
- Process benefits of pre-reforming
- Effect of Pre-reformer Inlet Temp on Primary Reformer Efficiency
- Services for Pre-reforming
Pre-Reforming Problems
- Features: Impact of Sulfur
- High Temperature Operation
- Catalyst Deactivation
- Which is Better - High or Low Inlet Temperatures ?
- Pre Reformer Loading
- Pre-Reformer Installation
- Pre-reformer Startup
- Catalyst Drying
- Catalyst Heating
- Reduction
Equilibrium Effects
- Methane Steam
- Water Gas Shift
Relationship of Kp to Temperature
Relationship of WGS Kp to Temperature
Effect of Temperature on Methane Slip
Approach to Equilibrium
Reaction Path and Equilibrium
Effect of Pressure Increase
Operating Parameters
- Pressure
- Temperature
- Feed Rate
- Steam to Carbon
Effect of Exit Temperature Spread
Useful Tools
Calculating ATM
Hydrogen Plant Flowsheet - Effects of Low Steam RatioGerard B. Hawkins
Effect of Low Steam Ratio on the Steam Reformer
Effect of Low Steam Ratio on H T Shift & PSA
Effect of Low Steam Ratio on Gross Efficiency
Effect of Low Steam Ratio on Net Efficiency
Alternative schemes for improving heat recovery
Reformer Tube design principles
- Larsen Miller Plot
- Larsen Miller & Tube Design
- Design Margins - Stress Data Used
- Max Allowable & Design Temperature
- Tube Life
- Effect of Temperature on Life
- Material Types
HK40: 25 Cr / 20 Ni
HP Modified: 25 Cr / 35 Ni + Nb
Microalloy: 25 Cr / 35 Ni + Nb + Ti
- Alloy Developments
- Comparison of Alloys
Manufacturing Technology
- Welds
Failure mechanisms
- Failure Mechanisms - Creep
- Creep Propagation
- Common Failure Modes
- Uncommon Failure Modes
- Failure by Creep
- Creep Rupture - Cross Section
- Failure at Weld
Actions to Take if Tube Fails
- Pigtail Nipping
Inspection techniques
Classification of Problems
- Visual Examination
- Girth Measurement
- Ultrasonic Attenuation
- Radiography
Eddy Current Measurement
LOTIS Tube Inspection
LOTIS Compared to External Inspection
Introduction High temperature shift Catalysts
Low temperature shift catalysts
Catalyst storage, handling, charging and discharging
Health and safety precautions
Reduction and start-up of high temperature shift catalysts
Operation of high temperature shift catalysts
Reduction and start-up of low temperature shift catalysts
Operation of low temperature shift catalysts
The value of selecting the right catalyst
Selecting the key performance criteria
Sources of data:
Plant data
Laboratory reactor data
Catalyst characterization
Recommendations
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy GasesGerard B. Hawkins
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy Gases
This Process Safety Guide has been written with the aim of assisting process engineers, hazard analysts and environmental advisers in carrying out gas dispersion calculations. The Guide aims to provide assistance by:
• Improving awareness of the range of dispersion models available within GBHE, and providing guidance in choosing the most appropriate model for a particular application.
• Providing guidance to ensure that source terms and other model inputs are correctly specified, and the models are used within their range of applicability.
• Providing guidance to deal with particular topics in gas dispersion such as dense gas dispersion, complex terrain, and modeling the chemistry of oxides of nitrogen.
• Providing general background on air quality and dispersion modeling issues such as meteorology and air quality standards.
• Providing example calculations for real practical problems.
SCOPE
The gas dispersion guide contains the following Parts:
1 Fundamentals of meteorology.
2 Overview of air quality standards.
3 Comparison between different air quality models.
4 Designing a stack.
5 Dense gas dispersion.
6 Calculation of source terms.
7 Building wake effects.
8 Overview of the chemistry of the oxides of nitrogen.
9 Overview of the ADMS complex terrain module.
10 Overview of the ADMS deposition module.
11 ADMS examples.
12 Modeling odorous releases.
13 Bibliography of useful gas dispersion books and reports.
14 Glossary of gas dispersion modeling terms.
Appendix A : Modeling Wind Generation of Particulates.
APPENDIX B TABLE OF PROPERTY VALUES FOR SPECIFIC CHEMICALS
Why have a Secondary Reformer ?
Need nitrogen to make ammonia
Wish to make primary as small as possible
Wish to minimise methane slip since methane is an inert in the ammonia synthesis loop
Other methods of achieving this
Braun Purifier process
Can address all these with an air blown secondary
Introduction and Theoretical Aspects
Catalyst Reduction and Start-up
Normal Operation and Troubleshooting
Shutdown and Catalyst Discharge
Nickel Carbonyl Hazard
Modern Methanation Catalyst Requirements
Purpose
Key to good performance
Problem Areas
Catalysts, heat shields and plant up-rates
Burner Guns
Development of High Intensity Ring Burner
Case Studies
Conclusions
(HTS) High Temperature Shift Catalyst (VSG-F101) - Comprehensiev OverviewGerard B. Hawkins
The high temperature shift duty introduction and theory
HTS catalyst characteristics
developments over time
Typical HTS operational problems
Improved catalysts
VULCAN Series VSG-F101 Series
Summary
- Process effects of pre-reforming
- Process benefits of pre-reforming
- Effect of Pre-reformer Inlet Temp on Primary Reformer Efficiency
- Services for Pre-reforming
Pre-Reforming Problems
- Features: Impact of Sulfur
- High Temperature Operation
- Catalyst Deactivation
- Which is Better - High or Low Inlet Temperatures ?
- Pre Reformer Loading
- Pre-Reformer Installation
- Pre-reformer Startup
- Catalyst Drying
- Catalyst Heating
- Reduction
Equilibrium Effects
- Methane Steam
- Water Gas Shift
Relationship of Kp to Temperature
Relationship of WGS Kp to Temperature
Effect of Temperature on Methane Slip
Approach to Equilibrium
Reaction Path and Equilibrium
Effect of Pressure Increase
Operating Parameters
- Pressure
- Temperature
- Feed Rate
- Steam to Carbon
Effect of Exit Temperature Spread
Useful Tools
Calculating ATM
Hydrogen Plant Flowsheet - Effects of Low Steam RatioGerard B. Hawkins
Effect of Low Steam Ratio on the Steam Reformer
Effect of Low Steam Ratio on H T Shift & PSA
Effect of Low Steam Ratio on Gross Efficiency
Effect of Low Steam Ratio on Net Efficiency
Alternative schemes for improving heat recovery
Reformer Tube design principles
- Larsen Miller Plot
- Larsen Miller & Tube Design
- Design Margins - Stress Data Used
- Max Allowable & Design Temperature
- Tube Life
- Effect of Temperature on Life
- Material Types
HK40: 25 Cr / 20 Ni
HP Modified: 25 Cr / 35 Ni + Nb
Microalloy: 25 Cr / 35 Ni + Nb + Ti
- Alloy Developments
- Comparison of Alloys
Manufacturing Technology
- Welds
Failure mechanisms
- Failure Mechanisms - Creep
- Creep Propagation
- Common Failure Modes
- Uncommon Failure Modes
- Failure by Creep
- Creep Rupture - Cross Section
- Failure at Weld
Actions to Take if Tube Fails
- Pigtail Nipping
Inspection techniques
Classification of Problems
- Visual Examination
- Girth Measurement
- Ultrasonic Attenuation
- Radiography
Eddy Current Measurement
LOTIS Tube Inspection
LOTIS Compared to External Inspection
Introduction High temperature shift Catalysts
Low temperature shift catalysts
Catalyst storage, handling, charging and discharging
Health and safety precautions
Reduction and start-up of high temperature shift catalysts
Operation of high temperature shift catalysts
Reduction and start-up of low temperature shift catalysts
Operation of low temperature shift catalysts
The value of selecting the right catalyst
Selecting the key performance criteria
Sources of data:
Plant data
Laboratory reactor data
Catalyst characterization
Recommendations
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy GasesGerard B. Hawkins
GAS DISPERSION - A Definitive Guide to Accidental Releases of Heavy Gases
This Process Safety Guide has been written with the aim of assisting process engineers, hazard analysts and environmental advisers in carrying out gas dispersion calculations. The Guide aims to provide assistance by:
• Improving awareness of the range of dispersion models available within GBHE, and providing guidance in choosing the most appropriate model for a particular application.
• Providing guidance to ensure that source terms and other model inputs are correctly specified, and the models are used within their range of applicability.
• Providing guidance to deal with particular topics in gas dispersion such as dense gas dispersion, complex terrain, and modeling the chemistry of oxides of nitrogen.
• Providing general background on air quality and dispersion modeling issues such as meteorology and air quality standards.
• Providing example calculations for real practical problems.
SCOPE
The gas dispersion guide contains the following Parts:
1 Fundamentals of meteorology.
2 Overview of air quality standards.
3 Comparison between different air quality models.
4 Designing a stack.
5 Dense gas dispersion.
6 Calculation of source terms.
7 Building wake effects.
8 Overview of the chemistry of the oxides of nitrogen.
9 Overview of the ADMS complex terrain module.
10 Overview of the ADMS deposition module.
11 ADMS examples.
12 Modeling odorous releases.
13 Bibliography of useful gas dispersion books and reports.
14 Glossary of gas dispersion modeling terms.
Appendix A : Modeling Wind Generation of Particulates.
APPENDIX B TABLE OF PROPERTY VALUES FOR SPECIFIC CHEMICALS
Pressure Relief Systems
BACKGROUND TO RELIEF SYSTEM DESIGN Vol.1 of 6
The Guide has been written to advise those involved in the design and engineering of pressure relief systems. It takes the user from the initial identification of potential causes of overpressure or under pressure through the process design of relief systems to the detailed mechanical design. "Hazard Studies" and quantitative hazards analysis are not described; these are seen as complementary activities. Typical users of the Guide will use some Parts in detail and others in overview.
Pressure Relief Systems Vol 2
Causes of Relief Situations
This Volume 2 is a guide to the qualitative identification of common causes of overpressure in process equipment. It cannot be exhaustive; the process engineer and relief systems team should look for any credible situation in addition to those given in this Part which could lead to a need for pressure relief (a relief situation).
Need to remove poisons prior to entering downstream catalyst beds, including
Pre reformers
Primary reformers
HTS
LTS
Note : no Secondary - poisons do not stick as temperature is too high
Note that methanator is a purification step
Removes CO and CO2 which poisons synthesis catalyst
The Benefits and Disadvantages of Potash in Steam ReformingGerard B. Hawkins
Why do we include potash ?
What are the benefits ?
What are the disadvantages ?
Catalyst Deactivation
Carbon Deposition : Thermodynamics & Kinetics
Carbon formation margin
Reaction chemistry (Tube inlet)
Hydrocarbons undergo cracking reactions on hot surfaces at the tube inlet
Products of catalytic cracking reactions can form polymeric carbon
Introduction and Theoretical Aspects
Catalyst Reduction and Start-up
Normal Operation and Troubleshooting
Shutdown and Catalyst Discharge
Nickel Carbonyl Hazard
Process Synthesis
INTRODUCTION
1 A SUGGESTED GENERAL APPROACH
2 EXAMPLES OF PROCESS SELECTION
2.1 Harvesting and Thickening of Single Cell Protein
2.2 Dewatering of a Specialty Latex
3 REFERENCES
TABLES
1 THE ADVANTAGES AND DISADVANTAGES OF DIFFERENT RANGE OF PH FOR “PROTEIN” ORGANISM FLOCCULATION
2 THE ADVANTAGES AND DISADVANTAGES OF VARYING EXTENTS OF CELL BREAKAGES
3 PREDICTED AND OBSERVED FILTER CAKE SOLIDS CONTENTS FOR THE VARIOUS LATICES AFTER COAGULATION
FIGURES
1 THE “PROTEIN” BACTERIAL HARVESTING SYSTEM
2 PROCESS FOR MANUFACTURE OF CALCIUM CARBONATE FILTERS
3 H-ACID ISOLATION
4 A SUGGESTED APPROACH TO DETERMINING FEASIBLE PROCESS OPTIONS, AND OPERATING CONDITIONS FOR SEPARATION OF FINE SOLIDS FROM SUSPENSION
5 MODULI VERSUS SOLIDS CONTENT FORTYPICAL FORWARD FLOCCULATED “PROTEIN” SUSPENSIONS
6 DECISION TREE FOR SELECTION OF AS1 HARVESTING CONDITIONS WHEN PRINCIPAL CONSTRAINT CONCERNS THE DEGREE OF THICKENING REQUIRED IN THE CONCENTRATE
7 DECISION TREE FOR SELECTION OF AS1 HARVESTING CONDITIONS WHEN PRINCIPAL CONSTRAINT CONCERNS THE USE OF FLOTATION AS A UNIT OPERATION FOR THICKENING
8 DECISION TREE FOR SELECTION OF AS1 HARVESTING CONDITIONS WHEN PRINCIPAL CONSTRAINT CONCERNS THE QUALITY OF THE RECYCLED LIQUOR
9 MODULUS SOLIDS CONTENT CURVES FOR THEVARIOUS COAGULATED LATICES
Other Separations Techniques for Suspensions
PRESSURE-DRIVEN MEMBRANE SEPARATION
PROCESSES
1.1 INTRODUCTION
1.2 MEMBRANES
1.3 OPERATION
1.4 FACTORS AFFECTING PERFORMANCE
1.4.1 Polarization / Fouling
1.4.2 Pressure
1.4.3 Crossflow
1.4.4 Temperature
1.4.5 Concentration
1.4.6 Membrane Pore Size
1.4.7 Particle Size
1.4.8 Particle Charge
1.4.9 Other Factors
1.5 ADVANTAGES / LIMITATIONS
1.6 SUMMARY OF SYMBOLS USED
2 ELECTRO-DIALYSIS
2.1 INTRODUCTION
2.2 EQUIPMENT
2.3 IMPORTANT PARAMETERS IN ED
2.4 EXAMPLES
3 ELECTRODEWATERING AND ELECTRODECANTATION
3.1 INTRODUCTION
3.2 PRINCIPLES AND OPERATION
3.3 EQUIPMENT AND OPERATING PARAMETERS
3.4 EXAMPLES
4 MAGNETIC SEPARATION METHODS
5 REFERENCES
FIGURES
1 APPLICATION RANGES FOR MEMBRANE SEPARATION TECHNIQUES
2 SIMPLE UF / CMF RIG
4 FLUX VERSUS PRESSURE
5 ELECTRODIALYSIS PROCESS
6 ELECTRODIALYSIS PLANT FOR BATCH PROCESS
7 DEPENDENCE OF MEMBRANE AREA AND ENERGY ON
CURRENT DENSITY
8 DIFFUSION ACROSS THE BOUNDARY LAYER
Determination of Argon in Ammonia Plant Process Gas Streams by Gas Chromatogr...Gerard B. Hawkins
Determination of Argon in Ammonia Plant Process Gas Streams by Gas Chromatography
SCOPE AND FIELD OF APPLICATION
This document is a method for the determination of argon in process gas streams in the range 0-10% v/v.
BENFIELD LIQUOR:Determination of Diethanolamine Using an Auto TitratorGerard B. Hawkins
BENFIELD LIQUOR:Determination of Diethanolamine Using an Auto Titrator
1 SCOPE AND FIELD OF APPLICATION
This method is suitable for the determination of diethanolamine in Benfield Liquor.
2 PRINCIPLE
Diethanolamine is converted quantitatively into ammonia by boiling in the presence of sulfuric acid and copper sulfate. The ammonia is distilled from an alkaline medium and absorbed into boric acid. The solution is titrated with standard acid.
Determination of Hydrocarbons in Anhydrous Ammonia By Gas ChromatographyGerard B. Hawkins
Determination of Hydrocarbons in Anhydrous Ammonia By Gas Chromatography
SCOPE AND FIELD OF APPLICATION
The method is suitable for the determination of hydrocarbons from C1 to C4 (see 6.4.2) in gaseous ammonia, or in mixtures of ammonia and air. It is valid for concentrations in the range 10-10000 ppm.
The method may be used for the analysis of the atmosphere from a ships hold After purging with ammonia and for the analysis of gasified liquid anhydrous ammonia during or after loading. In these cases, hydrocarbon contamination may arise from the previous cargo of the vessel, the nature of which should be ascertained prior to carrying out the analysis
Carbon Formation in Mixed Feed Preheat Coils:
Maximum Mixed Feed Pre-heat Temperature
What follows is a crude but effective routine, which evaluates the maximum possible temperature allowable to prevent excessive carbon laydown in the mixed feed pre-heat coils.
Reactor Modeling Tools – Multiple Regressions
CONTENTS
0 INTRODUCTION
1 SCOPE
2 THEORY
3 EXCEL 2007: MULTIPLE REGRESSIONS
3.1 Overview
3.2 Multiple Regression Using the Data Analysis ADD-IN
3.3 Interpret Regression Statistics Table
3.4 Interpret ANOVA Table
3.5 Interpret Regression Coefficients Table
3.6 Confidence Intervals for Slope Coefficients
3.7 Test Hypothesis of Zero Slope Coefficients ("Test of Statistical Significance")
3.8 Test Hypothesis on a Regression Parameter
3.8.1 Using the p-value approach
3.8.2 Using the critical value approach
3.9 Overall Test of Significance of the Regression Parameters
3.10 Predicted Value of Y Given Regressors
3.11 Excel Limitations
4 SPECIAL FEATURES REQUIRING MORE SOPHISTICATED TECHNIQUES
5 USER INFORMATION SUPPLIED
A SUBROUTINE
B DATA
C RESULTS
6 EXAMPLE
Steam Reformer Surveys - Techniques for Optimization of Primary Reformer Oper...Gerard B. Hawkins
Introduction
Background Radiation and Temperature Measurement
Reformer Survey Inputs
Other Troubleshooting Tools
Safety
Preparation
Onsite Data Collection
TWT Survey
Observation/Troubleshooting
Modelling and Analysis
Results/Outputs
Case Studies
Conclusions
Case Study 1
Case Study 2
Case Study 3
Conclusions
Most modern ammonia processes are based on steam-reforming of natural gas or naphtha.
The 3 main technology suppliers are Uhde (Uhde/JM Partnership), Topsoe & KBR.
The process steps are very similar in all cases.
Other suppliers are Linde (LAC) & Ammonia Casale.
The presentation discusses the various factors which affect the performance of Power Boilers including the quality of coal, airheater performance, air ingress etc.
Incineration and control of waste to energy boilerRajuSubedi1
I had prepared this slides of incineration and control of WtE boiler when I was the part of Keppel Seghers Engineering Qatar. Control of waste combustion is the fundamental aspect of operating WtE boiler.
Post-combustion CO2 capture and its effects on power plantsHamid Abroshan
This slide is a presentation of a conference paper discussing the post-combustion Carbon Dioxide capture from steam power plants. The main question in this paper was to choose the best location in flue gas path, where flue gas will be extracted and sent to absorption tower.
Some fact about Ammonia Production by Prem Baboo.pdfPremBaboo4
Operation of the plant is mainly supervised by the operators in the control room, who monitor the various instruments and adjust operating conditions in order to obtain satisfactory operation. They should also react when an alarm is activated. In some cases they can re-establish normal conditions by adjusting the controls in the control room; in other cases they give instructions to a field operator to make the necessary adjustments at various locations in the plant. Field operators work in regular shifts in the plant, especially in the reforming section, in order to supervise the firing of the reformer and the temperature of the tubes in the reformer, to record local instrument readings, and to notice any irregularities such as leaks. Every change of temperature of the reformer a little change can bring big change resulting energy losses, e.g. temperature of the primary reformer and CO slip losses in methanation etc.
Emission Measurements of Various Biofuels using a Commercial Swirl-Type Air-A...JOACHIM AGOU
A joint university-industry research program funded by Rolls-Royce Canada, NSERC and CRIAQ is actually pursued at Université Laval to characterize the combustion performance of liquid (biodiesel blends) and gaseous (syngas blends) biofuels in terms of emissions & smoke and lean blow out. The final objective of the proposed research is to characterize the most promising liquid and gaseous novel biofuels for use in industrial gas turbines in order to reduce greenhouse gases and potentially operation costs. These combustion tests allowed the characterization of standard diesel fuel as a baseline plus two biodiesel blends as well as standard methane as a baseline plus ten syngas blends (CH4, H2, CO and CO2) in order to evaluate the emissions of the main pollutants (CO, CO2, NOx, UHCs and smoke). Combustor exit and wall temperature measurements were also taken to characterize adequately the boundary conditions for future CFD simulations. The flame was contained in a quartz tube combustor operating at ambient outlet conditions and the fuel was delivered through a commercial swirl-type, airblast dual fuel atomizer. The air mass flow rate was kept constant for all fuels to maintain the same pressure drop (ΔP) across the fuel injector while the fuel flow was varied to cover equivalence ratios from 0.5 to 1. A probe connected to a FTIR/FID/O2 gas analyzer system and a smoke filter was fixed to a 3D-axis traverse in order to sample combustion products in a cross pattern at the combustor exit. This way, concentrations of various emissions were obtained at five radial positions. Burned gases and wall temperatures were measured with thermocouples along the test rig. This paper reports the findings of these experimental tests and presents the comparisons of the biofuels with baseline fuels to identify some benefits of these novel biofuels while maintaining an acceptable overall combustion performance.
Changing Best Practices in Flue Gas AnalysisYokogawa1
Zirconium Oxide and Catalytic Bead sensor based analyzers have been the primary means of flue gas analysis for control and safety. The recently published API-556 has highlighted several considerations when using these technologies that were not commonly known throughout the industry. This webinar will explain the theory of operation of tunable diode laser spectrometers and the application thereof to gas fired reformers, boilers, & heaters as a layer of protection during startup and efficiency diagnostic during operation.
During this webinar recording, you will learn:
-What is the purpose of flue gas?
-The evolution of flue gas Analyzers
-Industry standards and recommended practices on the application of different types of instruments
Theory of Carbon Formation in Steam Reforming
Contents
1 Introduction
2 Underpinning Theory
2.1 Conceptualization
2.2 Reforming Reactions
2.3 Carbon Formation Chemistry
2.3.1 Natural Gas
2.3.2 Carbon Formation for Naphtha Feeds
2.3.3 Carbon Gasification
2.4 Heat Transfer
3 Causes
3.1 Effects of Carbon Formation
3.2 Types of Carbon
4 What are the Effects of Carbon Formation?
4.1 Why does Carbon Formation Get Worse?
4.1.1 So what is the Next Step?
4.2 Consequences of Carbon Formation
4.3 Why does Carbon Form where it does?
4.3.1 Effect on Process Gas Temperature
4.4 Why does Carbon Formation Propagate Down the Tube?
4.4.1 Effect on Radiation on the Fluegas Side
4.5 Why does Carbon Formation propagate Up the Tube?
5 How do we Prevent Carbon Formation
5.1 The Role of Potash
5.2 Inclusion of Pre-reformer
5.3 Primary Reformer Catalyst Parameters
5.3.1 Activity
5.3.2 Heat Transfer
5.3.3 Increased Steam to Carbon Ratio
6 Steam Out
6.1 Why does increasing the Steam to Carbon Ratio Not Work?
6.2 Why does reducing the Feed Rate not help?
6.3 Fundamental Principles of Steam Outs
TABLES
1 Heat Transfer Coefficients in a Typical Reformer
2 Typical Catalyst Loading Options
FIGURES
1 Hot Bands
2 Conceptual Pellet
3 Naphtha Carbon Formation
4 Heat Transfer within an Reformer
5 Types of Carbon Formation
6 Effect of Carbon on Nickel Crystallites
7 Absorption of Heat
8 Comparison of "Base Case" v Carbon Forming Tube
9 Carbon Formation Vicious Circle
10 Temperature Profiles
11 Carbon Pinch Point
12 Carbon Formation
13 Effect on Process Gas Temperature
14 How does Carbon Propagate into an Unaffected Zone?
15 Movement of the Carbon Forming Region
16 Effect of Hot Bands on Radiative Heat Transfer
17 Effect of Potash on Carbon Formation
18 Application of a Pre-reformer
19 Effect of Activity on Carbon Formation
Calculation of an Ammonia Plant Energy Consumption: Gerard B. Hawkins
Calculation of an Ammonia Plant Energy Consumption:
Case Study: #06023300
Plant Note Book Series: PNBS-0602
CONTENTS
0 SCOPE
1 CALCULATION OF NATURAL GAS PROCESS FEED CONSUMPTION
2 CALCULATION OF NATURAL GAS PROCESS FUEL CONSUMPTION
3 CALCULATION OF NATURAL GAS CONSUMPTION FOR PILOT BURNERS OF FLARES
4 CALCULATION OF DEMIN. WATER FROM DEMIN. UNIT
5 CALCULATION OF DEMIN. WATER TO PACKAGE BOILERS
6 CALCULATION OF MP STEAM EXPORT
7 CALCULATION OF LP STEAM IMPORT
8 DETERMINATION OF ELECTRIC POWER CONSUMPTION
9 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT ISBL
10 ADJUSTMENT OF ELECTRIC POWER CONSUMPTION FOR TEST RUN CONDITIONS
11 CALCULATION OF AMMONIA SHARE IN MP STEAM CONSUMPTION IN UTILITIES
12 CALCULATION OF AMMONIA SHARE IN ELECTRIC POWER CONSUMPTION IN UTILITIES
13 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT OSBL
14 DETERMINATION OF THE TOTAL ENERGY CONSUMPTION OF THE AMMONIA PLANT
Ammonia Plant Technology
Pre-Commissioning Best Practices
GBHE-APT-0102
PICKLING & PASSIVATION
CONTENTS
1 PURPOSE OF THE WORK
2 CHEMICAL CONCEPT
3 TECHNICAL CONCEPT
4 WASTES & SAFETY CONCEPT
5 TARGET RESULTS
6 THE GENERAL CLEANING SEQUENCE MANAGEMENT
6.6.1 Pre-cleaning or “Physical Cleaning
6.6.2 Pre-rinsing
6.6.3 Chemical Cleaning
6.6.4 Critical Factors in Cleaning Success
6.6.5 Rinsing
6.6.6 Inspection and Re-Cleaning, if Necessary
7 Systems to be treated by Pickling/Passivation
Ammonia Plant Technology
Pre-Commissioning Best Practices
Piping and Vessels Flushing and Cleaning Procedure
CONTENTS
1 Scope
2 Aim/purpose
3 Responsibilities
4 Procedure
4.1 Main cleaning methods
4.1.1 Mechanical cleaning
4.1.2 Cleaning with air
4.1.3 Cleaning with steam (for steam networks only)
4.1.4 Cleaning with water
4.2 Choice of the cleaning method
4.3 Cleaning preparation
4.4 Protection of the devices included in the network
4.5 Protection of devices in the vicinity of the network
4.6 Water flushing procedure
4.6.1 Specific problems of water flushing
4.6.2 Preparation for water flushing
4.6.3 Performing a water flush
4.6.4 Cleanliness criteria
4.7 Air blowing procedure
4.7.1 Specific problems of air blowing
4.7.2 Preparation for air blowing
4.7.3 Performing air blowing
4.7.4 Cleanliness checks
4.8 Steam blowing procedure
4.8.1 Specific problems of steam blowing
4.8.2 Preparation for steam blowing
4.8.3 Performing steam blowing
4.8.4 Cleanliness checks
4.9 Chemical cleaning procedure
4.9.1 Specific problems of cleaning with a chemical solution
4.9.2 Preparation for chemical cleaning
4.9.3 Performing a chemical cleaning
4.9.4 Cleanliness criteria
4.10 Re-assembly - general guideline
4.11 Preservation of flushed piping
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS Gerard B. Hawkins
DESIGN OF VENT GAS COLLECTION AND DESTRUCTION SYSTEMS
CONTENTS
1 INTRODUCTION
1.1 Purpose
1.2 Scope of this Guide
1.3 Use of the Guide
2 ENVIRONMENTAL ISSUES
2.1 Principal Concerns
2.2 Mechanisms for Ozone Formation
2.3 Photochemical Ozone Creation Potential
2.4 Health and Environmental Effects
2.5 Air Quality Standards for Ground Level Concentrations of Ozone, Targets for Reduction of VOC Discharges and Statutory Discharge Limits
3 VENTS REDUCTION PHILOSOPHY
3.1 Reduction at Source
3.2 End-of-pipe Treatment
4 METHODOLOGY FOR COLLECTION & ASSESSMENT OF PROCESS FLOW DATA
4.1 General
4.2 Identification of Vent Sources
4.3 Characterization of Vents
4.4 Quantification of Process Vent Flows
4.5 Component Flammability Data Collection
4.6 Identification of Operating Scenarios
4.7 Quantification of Flammability Characteristics for Combined Vents
4.8 Identification, Quantification and Assessment of Possibility of Air Ingress Routes
4.9 Tabulation of Data
4.10 Hazard Study and Risk Assessment
4.11 Note on Aqueous / Organic Wastes
4.12 Complexity of Systems
4.13 Summary
5 SAFE DESIGN OF VENT COLLECTION HEADER SYSTEMS
5.1 General
5.2 Process Design of Vent Headers
5.3 Liquid in Vent Headers
5.4 Materials of Construction
5.5 Static Electricity Hazard
5.6 Diversion Systems
5.7 Snuffing Systems
6 SAFE DESIGN OF THERMAL OXIDISERS
6.1 Introduction
6.2 Design Basis
6.3 Types of High Temperature Thermal Oxidizer
6.4 Refractories
6.5 Flue Gas Treatment
6.6 Control and Safety Systems
6.7 Project Program
6.8 Commissioning
6.9 Operational and Maintenance Management
APPENDICES
A GLOSSARY
B FLAMMABILITY
C EXAMPLE PROFORMA
D REFERENCES
DOCUMENTS REFERRED TO IN THIS PROCESS GUIDE
TABLE
1 PHOTOCHEMICAL OZONE CREATION POTENTIAL REFERENCED
TO ETHYLENE AS UNITY
FIGURES
1 SCHEMATIC OF TYPICAL VENT COLLECTION AND THERMAL OXIDIZER SYSTEM
2 TYPICAL KNOCK-OUT POT WITH LUTED DRAIN
3 SCHEMATIC OF DIVERSION SYSTEM
4 CONVENTIONAL VERTICAL THERMAL OXIDIZER
5 CONVENTIONAL OXIDIZER WITH INTEGRAL WATER SPARGER
6 THERMAL OXIDIZER WITH STAGED AIR INJECTION
7 DOWN-FIRED UNIT WITH WATER BATH QUENCH
8 FLAMELESS THERMAL OXIDATION UNIT
9 THERMAL OXIDIZER WITH REGENERATIVE HEAT RECOVERY
10 TYPICAL PROJECT PROGRAM
11 TYPICAL FLAMMABILITY DIAGRAM
12 EFFECT OF DILUTION WITH AIR
13 EFFECT OF DILUTION WITH AIR ON 100 Rm³ OF FLAMMABLE GAS
PRACTICAL GUIDE ON THE SELECTION OF PROCESS TECHNOLOGY FOR THE TREATMENT OF A...Gerard B. Hawkins
PRACTICAL GUIDE ON THE SELECTION OF PROCESS TECHNOLOGY FOR THE TREATMENT OF AQUEOUS ORGANIC EFFLUENT STREAMS
CONTENTS
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
3.1 IPU
3.2 AOS
3.3 BODs
3.4 COD
3.5 TOC
3.6 Toxicity
3.7 Refractory Organics/Hard COD
3.8 Heavy Metals
3.9 EA
3.10 Biological Treatment Terms
3.11 BATNEEC
3.12 BPEO
3.13 EQS/LV
3.14 IPC
3.15 VOC
3.16 F/M Ratio
3.17 MLSS
3.18 MLVSS
4 DESIGN/ECONOMIC GUIDELINES
5 EUROPEAN LEGISLATION
5.1 General
5.2 Integrated Pollution Control (IPC)
5.3 Best Available Techniques Not Entailing Excessive Costs (BATNEEC)
5.4 Best Practicable Environmental Option (BPEO)
5.5 Environmental Quality Standards(EQS)
6 IPU EXIT CONCENTRATION
7 SITE/LOCAL REQUIREMENTS
8 PROCESS SELECTION PROCEDURE
8.1 Waste Minimization Techniques (WMT)
8.2 AOS Stream Definition
8.3 Technical Check List
8.4 Preliminary Selection of Suitable Technologies
8.5 Process Sequences
8.6 Economic Evaluation
8.7 Process Selection
APPENDICES
A DIRECTIVE 76/464/EEC - LIST 1
B DIRECTIVE 76/464/EEC - LIST 2
C THE EUROPEAN COMMISSION PRIORITY CANDIDATE LIST
D THE UK RED LIST
E CURRENT VALUES FOR EUROPEAN COMMUNITY ENVIRONMENTAL QUALITY STANDARDS AND CORRESPONDING LIMIT VALUES
F ESTABLISHED TECHNOLOGIES
G EMERGING TECHNOLOGY
H PROPRIETARY/LESS COMMON TECHNOLOGIES
J COMPARATIVE COST DATA
PRACTICAL GUIDE ON THE REDUCTION OF DISCHARGES TO ATMOSPHERE OF VOLATILE ORGA...Gerard B. Hawkins
PRACTICAL GUIDE ON THE REDUCTION OF DISCHARGES TO ATMOSPHERE OF VOLATILE ORGANIC COMPOUNDS (VOCs)
FOREWORD
CONTENTS
1 INTRODUCTION
2 THE NEED FOR VOC CONTROL
3 CONTROL AT SOURCE
3.1 Choice or Solvent
3.2 Venting Arrangements
3.3 Nitrogen Blanketing
3.4 Pump Versus Pneumatic Transfer
3.5 Batch Charging
3.6 Reduction of Volumetric Flow
3.7 Stock Tank Design
4 DISCHARGE MEASUREMENT
4.1 By Inference or Calculation
4.2 Flow Monitoring Equipment
4.3 Analytical Instruments
4.4 Vent Emissions Database
5 ABATEMENT TECHNOLOGY
5.1 Available Options
5.2 Selection of Preferred Option
5.3 Condensation
5.4 Adsorption
5.5 Absorption
5.6 Thermal Incineration
5.7 Catalytic Oxidation
5.8 Biological Filtration
5.9 Combinations of Process technologies
5.10 Processes Under Development
6 GLOSSARY OF TERMS
7 REFERENCES
Appendix 1. Photochemical Ozone Creation Potentials
Appendix 2. Examples of Adsorption Preliminary Calculations
Appendix 3. Example of Thermal Incineration Heat and Mass Balance
Appendix 4. Cost Correlations
Getting the Most Out of Your Refinery Hydrogen PlantGerard B. Hawkins
Getting the Most Out of Your Refinery Hydrogen Plant
Contents
Summary
1 Introduction
2 "On-purpose" Hydrogen Production
3 Operational Aspects
4 Uprating Options on the Steam Reformer
4.1 Steam Reforming Catalysts and Tube Metallurgy
4.2 Oxygen-blown Secondary Reformer
4.3 Pre-reforming
4.4 Post-reforming
5 Downstream Units
6 Summary of Uprating Options
7 Conclusions
EMERGENCY ISOLATION OF CHEMICAL PLANTS
CONTENTS
1 Introduction
2 When should Emergency Isolation Valves be Installed
3 Emergency Isolation Valves and Associated Equipment
3.1 Installations on existing plant
3.2 Actuators
3.3 Power to close or power to open
3.4 The need for testing
3.5 Hand operated Emergency Valves
3.6 The need to stop pumps in an emergency
3.7 Location of Operating Buttons
3.8 Use of control valves for Isolation
4 Detection of Leaks and Fires
5 Precautions during Maintenance
6 Training Operators to use Emergency Isolation Valves
7 Emergency Isolation when no remotely operated valve is available
References
Glossary
Appendix I Some Fires or Serious Escapes of Flammable Gases or Liquids that could have been controlled by Emergency Isolation Valves
Appendix II Some typical Installations
Amine Gas Treating Unit - Best Practices - Troubleshooting Guide Gerard B. Hawkins
Amine Gas Treating Unit Best Practices - Troubleshooting Guide for H2S/CO2 Amine Systems
Contents
Process Capabilities for gas treating process
Typical Amine Treating
Typical Amine System Improvements
Primary Equipment Overview
Inlet Gas Knockout
Absorber
Three Phase Flash Tank
Lean/Rich Heat Exchanger
Regenerator
Filtration
Amine Reclaimer
Operating Difficulties Overview
Foaming
Failure to Meet Gas Specification
Solvent Losses
Corrosion
Typical Amine System Improvements
Degradation of Amines and Alkanolamines during Sour Gas Treating
APPENDIX
Best Practices - Troubleshooting Guide
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GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
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https://arxiv.org/abs/2306.08302
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Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
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Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
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Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
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- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
DevOps and Testing slides at DASA ConnectKari Kakkonen
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Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
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Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
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Speakers:
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👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
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Topics covered:
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Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
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The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
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https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
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FIDO Alliance Osaka Seminar: Passkeys and the Road Ahead.pdf
Hydrogen Plant - Normal Operations
1. Normal Operation of Steam
Reformers on Hydrogen
Plants
By:
Gerard B. Hawkins
Managing Director, CEO
2. Contents
Typical controlled variables
Plant data analysis
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
3. Typical Controlled Variables
Process gas exit temperature
Process gas and steam inlet temperature
Steam/carbon ratio
Process pressure
Furnace parameters
• Air preheat temperature
• Excess air
4. ExitMethaneSlip(mol%Dry)
Catalyst
Activity
40%
200%
Plant Rate
130%
80%
Exit
Pressure
-1 bar
+1 bar
Exit
Temp(oC)
-10
-20
+20
+10
Steam
Ratio
-10%
-8%
+8%
+10%
5
4
3
2
1
0
Reformer Optimization : Hydrogen Reformer
(Top-Fired) Exit Temperature 856oC (1573oF)
Note relatively small changes in exit
temperature or steam to carbon ratio
can have significant effect on exit
Methane slip
Catalyst activity has relatively less
impact
8. Hot Band Hot Tube SettlingGiraffe
Necking
Tiger
Tailing
Reformer Tube Appearance
9. Contents
Typical controlled variables
Plant data analysis
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
10. Plant Data Analysis
Important to cross-check measured data
• gas compositions
inlet steam reformer
exit steam reformer
exit shift reactors(s)
• pressures/temperatures at these points
• flowrates
recycle hydrogen
hydrocarbon feedstocks
steam (need also steam/BFW HTS feed
quench)
fuel & air
11. Plant Data Analysis
Match measured plant data with heat/mass balance
• if good match, then data accurate
• if poor match, then errors in plant data
Total plant data computer fitting program
• can use product rates and compositions etc for
cross-checking of data
• can suggest likely sources of measurement error
12. Plant Data Analysis
Total plant data fitting
• CO conversion across shift converter(s)
temperature increase very accurate due to
multiple thermocouples
cross-checks CO analysis AND steam rate
• Product rate/composition (methanator exit or
PSA product and offgas)
cross-checks feed rate, steam rate and
methane in reformer exit analysis
• Methanator temperature rise
cross-checks CO slip from LTS and CO2 slip
from CO2 removal system
13. Steam Reformer
Feed flow (Nm3/hr)
Steam flow (tonne/hr)
Exit gas temperature (oC)
Exit gas composition (mol % dry)
H2
N2
CH4
CO
CO2
Exit gas flow (Nm3/hr)
Steam : dry gas ratio
Equilibrium temperature (oC)
Approach to M/S equilb.(oC)
Steam : carbon ratio
Measured
Value
1975
11.2
750.0
65.27
-
4.65
9.02
21.05
7.009
Best Fit
Value
2459
11.1
765.0
71.37
0
3.23
8.63
16.77
8634
1.1745
755.5
9.5
5.575
Percentage
Error
24.5
-1.1
1.4
-9.3
-
30.5
4.3
20.3
Plant data Verification - Poor Fit
14. Plant Data Verification - Poor Fit
Poor fit
Areas to check
• feed flowrate
• exit methane
• exit CO/CO2
Feed flowrate originally quoted as 1.156 tonne/hr naphtha
- Revised to be 1.59 te/hr naphtha
15. Plant Data Verification - Revised Fit
Steam Reformer
Feed flow (Nm3/hr)
Steam flow (tonne/hr)
Exit gas temperature (oC)
Exit gas composition (mol % dry)
H2
N2
CH4
CO
CO2
Exit gas flow (Nm3/hr)
Steam : dry gas ratio
Equilibrium temperature (oC)
Approach to M/S equilb.(oC)
Steam : carbon ratio
Measured
Value
2644
11.2
750.0
65.27
-
4.65
9.02
21.05
5.244
Best Fit
Value
2554
11.2
758.0
71.33
0
3.23
8.68
16.76
8954
1.1384
758.1
0
5.442
Percentage
Error
-3.4
0.3
0.8
-9.3
-
30.4
3.8
20.4
16. Plant Data Verification - Revised Fit
Better fit for flowrate
Significant error still on reformer exit gas
analysis
CH4
CO/CO2
Methane slip originally quoted as 4.65 mol %(dry)
- Revised to 3.56 mol % (dry)
17. Plant Data Verification - Final Fit
Steam Reformer
Feed flow (Nm3/hr)
Steam flow (tonne/hr)
Exit gas temperature (oC)
Exit gas composition (mol % dry)
H2
N2
CH4
CO
CO2
Exit gas flow (Nm3/hr)
Steam : dry gas ratio
Equilibrium temperature (oC)
Approach to M/S equilb.(oC)
Steam : carbon ratio
Measured
Value
2644
11.2
750.0
69.86
-
3.56
8.24
18.34
5.244
Best Fit
Value
2554
11.2
758.0
71.33
0
3.23
8.68
16.76
8954
1.1384
758.1
0
5.442
Percentage
Error
-3.4
0.3
0.8
-2.1
-
9.4
5.3
8.6
18. Plant Data Measurement - Problem
Areas
Sampling/analysing exit gas compositions
Exit temperature from reformer
Flow measurement
19. Exit Gas Composition
CO shift reaction can occur if not quench
cooled quickly
CO2 may dissolve in water
• dry gas analysis!
Analysis of sample must be taken in the
same time frame as the process data
recording
20. Exit Reforming
Catalyst
(mol % dry)
"Shifted" Sample
Analysis
(mol % dry)
CH4 4.4 4.2
CO 13.8 10.3
CO2 8.6 11.4
H2 71.9 72.8
N2 1.3 1.3
CO>CO2 CO<CO2
“Shifting” in Gas Sample
Note also reduction in CH4
21. Exit Temperature
Heat/mass balance requires temperature exit
catalyst
Plant temperature measurement often at inlet to
waste heat boiler
• large heat losses possible
outlet pigtails, headers, transfer mains
Top-fired : 10-20oC (18-36oF) heat loss
Side-fired : 25-35oC (45-63oF) heat loss
(Air ingress at base of steam reformer can lead to further cooling)
22. Note that hydrocarbon composition variations
may effect the metered accuracy and also the
steam/carbon ratio calculation
Flow Measurement
Hydrocarbon feedstock generally high accuracy
• “costing” meter
• multiple feed streams may be less accurate
Steam flow often less accurate
• error in steam/carbon ratio can have a
significant effect on heat/mass balance
23. Plant Data Analysis
Best to record trends
• relative changes partially remove
measurement errors
Monitor monthly/quarterly
• measures of catalyst activity
methane slip
assuming constant operating conditions
• approach to equilibrium
• tube wall temperature
26. Contents
Typical controlled variables
Plant data analysis
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
27. Approach Tms = Actual T gas - Equilibrium T gas
(A.T.E.)
Measured Calculated
• Measure of catalyst activity
• If ATE = O, system at equilibrium
• As catalyst activity decreases, ATE increases
Approach to Equilibrium
CH4 + H2O CO + 3H2⇔
28. Calculation of Approach to
Equilibrium
1. Take gas samples and record steam
reformer exit temperature
2. Calculate wet reformer exit composition
- Hydrogen atom molar balance (inlet/exit)
- Calculate steam in exit gas
- Convert exit dry gas to wet gas composition
3. Calculate equilibrium temperature
corresponding to this exit composition
- Use tables or equations
4. Calculate approach to equilibrium
29. Contents
Typical controlled variables
Plant data analysis
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
30. Case Study
Terraced wall reformer
How much longer will catalyst last (from
Jan’08)
Change-out when?
• September ‘08
• April ‘09
• September ‘09
34. 0 0.2 0.4 0.6 0.8
1260
1360
1460
1560
Fraction down Tube (%)
Tube Wall Temperature Process Gas
Delta T
1
Tube Wall Temperatures
GBH Enterprises Ltd.
35. Bottom minus Top
01/Apr/06 26/May/07 20/Jul/08 12/Sep/08 06/Nov/09
0
20
40
60
80
100
120
140
-9oF/year
Tube wall Temperatures
Date
GBH Enterprises Ltd.
36. June 06 June 07 June 08 Sep 08 Sep 09
Exit CH4 (mol% dry) 7 7 7 7 7
Exit Temp oC
(oF)
787
(1432)
789
(1452)
795
(1463)
795
(1463)
795
(1463)
Max Tube Temp oC
(oF)
829
(1524)
831
(1528)
838
(1540)
838
(1540)
838
(1540)
M/S Equilib. Approach oC
(oF)
10
(18)
12
(22)
13
(23)
14
(25)
15
(27)
Steam Reformer Data
Looks OK to September ‘09 BUT……..….
37. 0 0.2 0.4 0.6 0.8 1
500
600
700
800
900
Fraction from inlet of tube
Carbon
Formation Catalyst ageing
New catalyst
Carbon Formation
GBH Enterprises Ltd.
38. Activity Decay Factor
Need to consider carbon formation
• Accurate model of catalyst activities needed to
correctly simulate catalyst ageing
Take data at different times and calculate
relative activity
• for terraced wall reformer
(i) top 30% slowly poisoned
(ii) middle 30% very slowly poisoned
(iii) bottom 40% sinters very slowly
(i) and (ii) account for delta T
(iii) accounts for increased approach
GBH Enterprises Ltd.
39. Jan
02
May Sep Jan
03
May Sep Jan
04
May Sep Jan
05
May Sep
0
50
100
150
200
250
Today September
‘04
September
‘05
Carbon
margin
Date
CarbonMargin(oF)
Carbon Margin with Time
GBH Enterprises Ltd.
41. Conclusions #1
In terms of M/S Approach and Tube Wall
Temperatures, can run till September ‘05
Concern about carbon margin from April ‘05
onwards
• options
change April ‘05 - CHOSEN OPTION
OR run with spare on site and change
September ‘05
GBH Enterprises Ltd.
42. Conclusions #2
• Sometimes difficult for operator to predict
change-out requirement
– Couldn’t rely on M/S Equilibrium Approach
and Tube Wall Temperature trending
– Needed complex reformer simulation
• HOWEVER, recording of historic data from
start-of-run conditions allowed accurate
assessment by the catalyst vendor
– Take data from SOR!
GBH Enterprises Ltd.
43. Contents
Typical controlled variables
Plant data analysis
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
GBH Enterprises Ltd.
44. Importance of Tube Wall
Temperature Measurement
Need accurate information
• Tube life !
• Artificial limitation on plant rate
GBH Enterprises Ltd.
47. Surface Thermocouples
Continuous measurement, by condution
“Slotting” can weaken tube wall
Spray-welding leads to high readings
Short, unpredictable lives (6-12 months)
Not commonly used for steam reformer tubes
GBH Enterprises Ltd.
48. Disappearing Filament
Hand held instrument
Tungsten filament superimposed on
image of target
Current through filament altered until it
“disappears”
Current calibrated to temperature
Range 800-3000oC (1470 - 5430oF)
Very operator sensitive
Largely displaced by IR
GBH Enterprises Ltd.
49. Infra-red Pyrometer
Easy to use
Need to correct for
emissivity and reflected
radiation
Inexpensive
GBH Enterprises Ltd.
50. Radiation Methods
Measure emitted energy at given wavelength
Use Planck’s Law to give temperature
Correction factors needed
• target emissivity
real versus black body
• reflected radiation
GBH Enterprises Ltd.
51. Tw
"e" is the emissivity
of the tube
Target Tube
Tt
Refractory Wall
Measured
Temperature
Tm
Flame Tf
e
The Effect of Reflected Radiation from
Target Surroundings
52. Measured True Averaged
target target background
temperature temperature temperature
e = emissivity
r = reflectance
= (1-e)
Temperature Correction
E (Tm) = e E (Tt) + r E (T’w)
GBH Enterprises Ltd.
53. 0.7 0.75 0.8 0.85 0.9 0.95 1
Difference in wall and target
temperature oC (oF)
300
200
100
Deg C Deg F
(540 F)
(360 F)
(180 F)
200
150
100
50
0
392
302
212
122
0
Target Emissivity
Error in measured tube temperature
Theoretical Effect of Wall Temperature
(0.9 micron pyrometer)
GBH Enterprises Ltd.
54. Laser Pyrometers
Laser pulse fired at target and return signal
detected
Can determine target emissivity
Must correct for background radiation
High speed selectivity
Very accurate for flat surfaces
GBH Enterprises Ltd.
56. Gold Cup Pyrometer
Excludes all reflected radiation
Approximates to black body conditions
High accuracy/reproducibility
But…..
• limited access
• awkward to use
GBH Enterprises Ltd.
58. Accurate Temperature Measurement
Combination of IR pyrometer and Gold
Cup
• Gold Cup allows us to calculate “e”
• Full accurate survey of reformer
possible with IR
GBH Enterprises Ltd.
59. • Measure Tt using Gold Cup
• Measure Tm and Tw using Infra Red Pyrometer
• Calculate e
Calculate "e"Use IR to give Tt with measured
T’w and Tm and calculated e
Accurate Temperature Measurement
E (Tm) = e E (Tt) + (1-e) E (T’w)
GBH Enterprises Ltd.
60. A
a (Nearby tubes)2
Background Temperature
Measurement
Background Measurement for Tube A
a1
Refractory
Wall
GBH Enterprises Ltd.
62. Tube Wall Temperature
Measurement - Conclusions
IR typically reads high
• top-fired reformer 32oC (58oF)
• side-fired reformer 50oC (90oF)
IR with Gold Cup “calibration”
• top-fired reformer 2oC (4oF)
• side-fired reformer 16oC (29oF)
GBH Enterprises Ltd.
63. Summary
Effect of operating variables on performance
Plant data analysis
• fitting plant data
• problem areas
reformer exit temperature
flow errors
sample analysis shifting
Approach to equilibrium
Prediction of remaining catalyst life
Tube wall temperature measurement
GBH Enterprises Ltd.