This presentation covers frequent and costly incidents related to catalysts mal-operation with the focus of providing the plant operator with recommendations to avoid plant outages and catalyst losses.
Feedstock's from the gasification of coal or heavy oil contain high levels of sulfur.
Conventional iron-chrome catalysts are not suitable
“Sour” or “Dirty” shift catalysts were developed.
These catalysts achieve maximum activity in the sulfided state.
Require treatment with Sulfur prior to start-up.
Can only be used in streams that contain sufficient sulfur to maintain them in this state
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
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
High level introduction
Mainstream syngas = steam reforming processes
Ammonia; methanol; hydrogen/HyCO
Town gas
Steam reforming; low pressure cyclic
Direct reduction iron (DRI)
HYL type processes; Midrex type processes
Feedstock's from the gasification of coal or heavy oil contain high levels of sulfur.
Conventional iron-chrome catalysts are not suitable
“Sour” or “Dirty” shift catalysts were developed.
These catalysts achieve maximum activity in the sulfided state.
Require treatment with Sulfur prior to start-up.
Can only be used in streams that contain sufficient sulfur to maintain them in this state
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
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
High level introduction
Mainstream syngas = steam reforming processes
Ammonia; methanol; hydrogen/HyCO
Town gas
Steam reforming; low pressure cyclic
Direct reduction iron (DRI)
HYL type processes; Midrex type processes
Pre-reforming
Flow-schemes
Feed-stocks
Catalyst handling, loading & start-up
Benefits of a pre-reformer
Case studies
Effects upon primary reformer
Data analysis
Reactor temperature profiles
Catalyst management
Summary
Catalyst Catastrophes in Syngas Production - II
Contents
Review of incidents by reactor
Primary reforming
Secondary reforming
HTS
LTS
Methanator
Reactor loading
Support media
Some general comments on alternative actions when a plant gets into abnormal operation
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
Pre-reformer in the flowsheet
* positioned upstream of the steam reformer
* uses a specialized high activity catalyst based on Ni
* reaction involves conversion of hydrocarbons to a mix of CH4, CO, CO2 and H2
Pre-reformers - sometimes included at the original design stage
- also can be added to existing units to uprate the plant
The value of selecting the right catalyst
Selecting the key performance criteria
Sources of data:
Plant data
Laboratory reactor data
Catalyst characterization
Recommendations
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
Temperature excursions in hydrogenation reactors may have several causes, the most common ones being:-
i) Loss of recycle quench system. This could be either the liquid or gas stream. The condition is made worse if the make-up gas keeps flowing.
ii) Excessive temperatures. The loss of cooling medium ........
If it can go wrong – it will
If something looks odd – it is
Apparent safe systems can fail
Issues include
Metal dusting
Methanol or hydrogen fires
Intent changes
Methanation
“Safe Systems”
Steam Reforming - The Basics of reforming, shapes and carbon:
Steam Reforming Catalysis :
Chemical reactions
Catalyst shape design
Catalyst chemistry
Carbon formation and removal
Pre-reforming
Flow-schemes
Feed-stocks
Catalyst handling, loading & start-up
Benefits of a pre-reformer
Case studies
Effects upon primary reformer
Data analysis
Reactor temperature profiles
Catalyst management
Summary
Catalyst Catastrophes in Syngas Production - II
Contents
Review of incidents by reactor
Primary reforming
Secondary reforming
HTS
LTS
Methanator
Reactor loading
Support media
Some general comments on alternative actions when a plant gets into abnormal operation
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
Pre-reformer in the flowsheet
* positioned upstream of the steam reformer
* uses a specialized high activity catalyst based on Ni
* reaction involves conversion of hydrocarbons to a mix of CH4, CO, CO2 and H2
Pre-reformers - sometimes included at the original design stage
- also can be added to existing units to uprate the plant
The value of selecting the right catalyst
Selecting the key performance criteria
Sources of data:
Plant data
Laboratory reactor data
Catalyst characterization
Recommendations
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
Temperature excursions in hydrogenation reactors may have several causes, the most common ones being:-
i) Loss of recycle quench system. This could be either the liquid or gas stream. The condition is made worse if the make-up gas keeps flowing.
ii) Excessive temperatures. The loss of cooling medium ........
If it can go wrong – it will
If something looks odd – it is
Apparent safe systems can fail
Issues include
Metal dusting
Methanol or hydrogen fires
Intent changes
Methanation
“Safe Systems”
Steam Reforming - The Basics of reforming, shapes and carbon:
Steam Reforming Catalysis :
Chemical reactions
Catalyst shape design
Catalyst chemistry
Carbon formation and removal
UlSD Hydrotreater Challenges Overcome to Improve on Stream Factor - MEPEC 2013Alpesh Gurjar
The presentation outlines the experience in overcoming the challenges that faced and the lessons learned, to achieve safe, reliable and profitable Diesel Hydrotreater (2HDU) operation, while meeting all throughput and yield targets and product specifications. The 2HDU success over the 6½ years clearly demonstrated the importance and value of in-house process engineering expertise and experience, while working as a part of cross-functional team.
Super Critical Technology-Fundamental Concepts about Super Critical Technolog...Raghab Gorain
Nicely describe everything about super critical technology in thermal power plant.This slide is very useful for the freshers.Anybody can get the basic fundamental idea about super critical technology from this slide. In India now we have to think some new technology for power sources as sub critical power plants are less efficient and emit more pollutant to the environment and the alternative is the 'Super Critical Power Plant'.
Control Valves for the Power Generation Industry" A Product and Applications ...Belilove Company-Engineers
TrimTeck, a USA manufacturer of industrial control valves, put together this outstanding explanation of where and how control valves are used in a power generation facility.
Catalyst Catastrophes in Syngas Production - I
The Hazards
Review incidents by reactor
Purification….
Through the various unit operations to
Ammonia synthesis
Nickel Carbonyl
Pre-reduced catalysts
Discharging catalysts
Conclusion
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).
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.
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
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
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
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.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
2. Objective
This presentation covers frequent and costly
incidents related to catalysts mal-operation with
the focus of providing the plant operator with
recommendations to avoid plant outages and
catalyst losses.
3. Process Information Disclaimer
Information contained in this publication or as otherwise
supplied to Users is believed to be accurate and correct at time
of going to press, and is given in good faith, but it is for the
User to satisfy itself of the suitability of the Product for its own
particular purpose. GBHE gives no warranty as to the fitness of
the Product for any particular purpose and any implied
warranty or condition (statutory or otherwise) is excluded
except to the extent that exclusion is prevented by law. GBHE
accepts no liability for loss or damage resulting from reliance
on this information. Freedom under Patent, Copyright and
Designs cannot be assumed.
4. Content
Review of incidents by reactor
• Primary reforming
• Secondary reforming
• HTS
• LTS
• Methanator
Reactor loading
Support media
Some general comments on alternative actions when a
plant gets into abnormal operation
5. Reformer Catalyst Loading
UNIDENSETM is now established as key to an even
reformer loading
However UNIDENSE requires some care to
achieve its full potential
A reformer in South America was loaded by an
inexperienced team and had to be unloaded and
reloaded with 20 % catalyst losses.
Lesson – check experience of UNIDENSE loading
supervisors
UNIDENSE is a trademark of Yara International ASA
6. Reforming – Burners Lighting
Lighting burners during start-up is a critical activity
The clear requirement is to increase the number of lit
burners as the plant rate is increased
• and ensure the pattern of burners always gives an
even heat input
Obvious – but was one component leading to this:
7. Reforming – Burners Lighting
Lesson – light only the number of burners you need at
each stage of start-up and keep the pattern/heat
generation even
8. Reformer - Carbon
Carbon deposition will occur when excess hydrocarbons
are introduced
There are several ways to do this:
• Inadequate purging during a plant trip can lead to feed
being stored in the desulfurization vessel / pipe work
Then introducing nitrogen purge pushes this
hydrocarbon into the reformer
• Naphtha fed plants have a high risk of feed condensing
and sitting in dead legs until some motive force pushes
this into the furnace
• Erroneous feed flow measurement – more critical in
low steam ratio plants
9. Reformer – Carbon from Naphtha
Introduction of nitrogen during a start-up increased the
reformer pressure drop from 1.4 to 7 bar in 2 minutes
The nitrogen feed line was 100mm diameter and around
1km long, capable of holding up to 10te of naphtha
A spectacle plate was not swung during earlier operation
On previous occasions a drain valve was opened on the
nitrogen compressor – this time the valve was not
operable
10. Reformer – Naphtha in Dead Legs
Situation After Plant Trip
Steam to
Reformer
Flow
Feed CV
Feed ESDV
Steam to
Preheat
Coil
FM
Final ZnO
Bed
Feed
To Collector
or Flare
PCV
S Pt
Trapped Feed After Plant Trip
11. Reforming - Carbon from Liquid
HCs
A couple of ammonia plants in South America had
problems before the natural gas condensate removal
plant was installed
These plants took their feed off the bottom of the supply
line and hence took any liquids that were present
The liquid did not register in the flow meters which were
orifice plate type – thereby reducing the actual steam to
feed ratio
Non-alkalized catalysts lasted as little as 6 weeks – and
when replaced by alkalized products lasted a 2 year run
12. Reforming - Carbon from Liquid
HCs
Lessons
• Gas flow meters largely ignore the presence
of condensed higher hydrocarbons
• Note also that during startup flowmeters may
read in error if not compensated for
temperature and pressure
• Alkalized reforming catalysts give very
significant additional margin against carbon
formation in primary reformers
13. Reforming – Tube Failure from
Higher Hydrocarbons
A plant in North America was the sole user of gas that
came down a branch that went under a river
During a start-up after an extended shutdown - when
lighting burners – liquid was seen flowing from a few
burners onto tubes
While the operator exited and radioed the control room
to shut off the fuel - a tube burst leading to significant
damage to the furnace/tubes
14. Reforming – Tube Failure from
Higher Hydrocarbons
It was thought that hydrocarbons had
condensed in the cooler section of pipe under
the river
Lessons:
• Consider potential for condensation of higher
hydrocarbons, especially
If lines are cooled below normal
If levels of higher hydrocarbons increase
15. Reforming – Failure from
Condensation
We have another example of catalyst breakage
from condensation on start-up
A naphtha fed plant was not able to provide
nitrogen purge for the initial phase of start-up and
so heated the reformer using steam
Around 20 start-ups from cold eventually led to
breakage of catalyst, poor flow distribution, hot
spots and required catalyst change
16. Reforming – Failure from
Condensation
Lesson:
• Reforming catalyst should be warmed up to
50°C above the dew point before introduction
of steam
17. Secondary Reforming
All incidents on secondary reformers are related
to the burners
The problem of increasing plant rate to the point
that there is inadequate mixing zone is well
understood but requires detailed CFD modelling
to predict
18. Secondary Burner Problems
Cost of Problems:
7-10 day
turnaround
Short Catalyst life
$52K/yr less than 10yr
Mechanical repairs
Estimated $65K/year
Poor mixing Burner failure
Bed damage Refractory damage
19. Secondary Burner Solution
Small flame cores
from all nozzles
No flame attachment
to rings
Good mixing of the
process gas and air
20. HTS
The main problem with HTS reactors is
upstream boiler leaks
We have another case where dehydration of the
catalyst has lead to an exotherm on startup
21. HTS - Boiler Leaks
This is a potential problem on ammonia plants with high pressure
boilers upstream of the HTS
Boiler leaks put stress onto the HTS catalyst by:
• rapid wetting/drying and
• pressure-drop build-up from accumulated boiler solids
These leaks are inevitable with steam pressures of 100bar
• A serious leak will occur approximately every 12 years
Selecting a catalyst with high in-service strength significantly
improves probability of survival
22. HTS VSG-F101 Resists Boiler
Leaks
A plant in China suffered a complete
tube failure that tripped the plant
• F101 was unaffected by this incident:
23. HTS - Dehydration
A plant in China had kept a charge of HTS catalyst in a spare reactor
for 1 year – but had left this reactor open to the air – so the catalyst
had adsorbed water
The start-up required nitrogen heating for 2 days to dry the whole bed
– and in doing so dehydrated the catalyst in the top/bulk of the bed
100% steam was switched into the reactor against our advice of 5%
An exotherm started and then (unrelated) the plant tripped (site power
trip) which held the reactor with 100% steam
The exotherm reached 530°C, and look several hours to cool down
with N2
The final activity when on-line looked good, with expected low
pressure-drop.
24. HTS Lessons
Do not leave catalysts exposed to damp
atmospheres
VSG-F101 give the best survival of boiler leak
and over-reduction incidents
Incorporate the GBHE VULCAN Series
procedures when over-reduction is suspected
25. LTS
A plant in North America had to top skim its LTS
bed due to high pressure drop
The main cause was poor atomization of quench
water
This was not helped by the competitive catalyst
installed which developed very poor strength
when wetted
26. LTS
Lessons:
• Ensure quench water nozzles are on the
shutdown inspection list
• Check for adequate pipe length for
vaporization
• Use catalyst with good strength after
wetting
27. Methanator
The main hazards when methanation reactors
are shutdown are nickel carbonyl (see plant
safety presentation on nickel Carbonyl) and self
heating when exposed to air
An example of self heating comes from a
methanator on an olefin cracker
28. Methanator self heating
The plant was shut down and purged with
nitrogen
The inlet and exit valves and thermocouples
were removed for repair
Open ends were covered in plastic sheet
Catalyst was in reduced state, with N2 purge
29. Methanator Self-heating
A reading of 454°C/850°F was seen on re-
connection of the thermocouples
• The plastic sheeting was not adequate isolation
• Air entered the vessel and
A downward purge of nitrogen then gave a
reading of 649°C/1200°F on the bottom
thermocouple
Decided to change catalyst as needed 5 yr run
GBHE had product on site within 4 days
(including a weekend)
30. Methanator Learning
Reduced methanation catalyst becomes very hot
when exposed to air
Secure isolation/inert purge is essential for
maintenance on vessels containing reduced
catalyst
With little or no gas flow, thermocouples do not
show the peak temperature
31. Support Media
Don’t spoil a ship for a few cents worth of tar!
Below Bed:
• Support media does a key job preventing catalyst pass
through the exit collector – and doing this with low
pressure-drop
Above Bed:
• Support media placed on top of the bed protects
catalysts from high inlet gas velocities - which have the
potential to break catalysts through disturbance and
milling
• High voidage media can also be used to reduce the
effects of boiler solid build-up
32. Support Media - problems
A plant decided to use some old support
balls that had been stored outside for some
years
This was a LTS duty so either alumina or
silica-alumina would be suitable
Shortly after start-up the reactor pressure-
drop started to increase
This eventually required a shutdown to
address
33. Support Media - problems
Investigation showed failure of the
support media
The catalyst had to be replaced
Cause is believed to have been rapid
drying of support that had got wet during
storage
34. Support Media – use of Si/Al
Silica-alumina support is cheaper
A plant decided to use silica-alumina balls in a high
temperature shift bed
It was thought that this would be a low enough
temperature for silica migration not to be an issue
Not true – silica migrated downstream and
collected on the tubes of the exchanger before the
LTS – which required regular shutdowns to clean
A recent enquiry associated with HDS and HTS
catalysts simply specified ‘ceramic balls’
35. Support Media – Catalyst
Protection
For the most severe duties, including
secondary reformers GBHE recommends
fused alumina lumps
• High density
• High strength
• Inert (high purity alumina)
• Difficult to blow around!
36. Support Media - advice
Lessons:
• Store support media to the same standard as
catalysts – the cost will be the same if they
fail!
• Only use high purity alumina support above
300°C in steam environments
• Use GBHE ‘A2ST’ for protection against
accumulation of boiler solids from boiler leaks
• Use fused alumina lumps for the ultimate
protection against bed disturbance
‘A2ST’ Advanced Alumina Support Technology
37. Reactor loading
Don’t be tempted to put that last bit in!
A methanol plant with a water cooled reactor experienced an
increasing pressure-drop on a new charge of catalyst
Eventually the plant had to be shut down
Inspection showed that catalyst had been loaded on top of
the tube-sheet as well as in the tubes
Removal of the catalyst on top of the reactor and 150mm
down the tubes restored the pressure-drop to normal
38. Reactor overloading
A hydrogen plant in Europe implemented a plant up-rate
and as part of this increased the HTS volume (we advised
it could be lowered)
In order to maximize the catalyst volume the hold-down
system was removed!
Milling then increased the pressure-drop
A reactor ‘inlet distributor’ is better described as ‘inlet gas
momentum destruction device’
Lesson – gas distribution/bed protection requires careful
design along with the rest of a plant up-rate
39. Reactor loading
A plant with a HTS reactor with two beds (one
vessel) went with a short load and split the short
load equally between each of the two beds.
The net effect was a bed L/D of 0.2 – a long way
below the minimum recommendation of 1.0
The charge had to be replaced after 2 years
One can debate the merits of two beds with L/D
of 0.2 with gas mixing in-between or one bed with
an L/D of 0.4
The key is neither – but to load the bed(s)
carefully:
40. Reactor Loading
The ideal catalyst loading method is by sock with
the minimum or raking
Any raking will introduce density differences that
will lead to early discharge of the catalyst due to
the uneven flow distribution produced
Lesson: allowing your loading company to rake
catalyst is equivalent to throwing catalyst away
41. Priorities When Things go Wrong
There is no universal advice – but some
up-front thinking can lead to faster more
confident decisions
A number of incidents have involved
exotherms on catalysts which threatened
the integrity of their reactors
42. Example exotherm and action
Hydrogen was being removed from a process
stream using a copper oxide catalyst
During commissioning a hydrogen stream was
mistakenly introduced and the catalyst
temperature rose to 1000°C
GBHE staff on site advised immediate
depressurization
Vessel damage was avoided
There were problems later on downstream mol
sieve driers from water produced which
accumulated in a dead leg
43. Depressurization vs Purging
With the previous example in mind it is
worth reflecting on the merits of
depressurization and purging
44. Depressurization
Several advantages:
• It decreases the partial pressure of
reactants which may help slow the
temperature rise
• It reduces the stress on equipment
enabling the handling of higher
temperatures
• No motive force is required – so it is
reliable
• Lowering the pressure makes purging
more effective
45. Depressurization
Risks
• Depressurization can generate high gas
velocities – enough to fluidize catalyst beds
• Fluidized catalyst beds can lose their top
protective layer (into the bed) and suffer:
flow distribution problems or
pressure drop increase if loss of the top layer
allows milling
46. Purging
Advantages
• Can maintain plant pressure (but is
better if pressure reduced)
• Fluidization risks to catalyst beds much
lower
47. Purging
Disadvantages
• Difficult to achieve high flow-rates – steam is
often the purge gas with highest availability
• Steam can deactivate catalysts through
oxidation and in some cases sintering
• Nitrogen is a good inert material – but often
the available flow is limited
• Need to consider trace oxygen in nitrogen
Ideal is nitrogen with enough hydrogen to ensure
reducing conditions
48. Conclusions
The incidents here suggest:
• Selecting the right catalyst has a significant
impact on the ability of a plant to continue
operation through an unplanned event
• Operator training/procedures are key to
avoiding incidents