Delayed Coker Fundamentals, Coker Operations and Reliability

Coker Process, Design, and Troubleshooting

Mechanical Integrity and Reliability of Coke Drums

Sulfur Recovery Fundamentals, Operations and Reliability

This presentation examines persistent challenges of thermal stress and fatigue in delayed coking unit coke drums, with particular focus on shell-to-skirt junction integrity and thermal management during warm-up cycles. Four innovative engineering solutions are introduced — the Mouthguard side inlet nozzle insert, the Floating Drum pedestal support system, the Thermal Stress Control Panel, and a redesigned (SP-3) throttling valve — each offering practical, cost-effective means of mitigating thermal fatigue and extending coke drum service life.

Warren Brown, Principal Engineer & Managing  Director, Integrity Engineering Solutions

Introduction of slotted skirts to reduce the stresses associated with thermal gradients at the drum to skirt junction has been found to only partially improve fatigue performance, with cracking and repair required frequently at that connection. However, there is a strong correlation between slot length and slot location and the effectiveness in reducing stresses at the critical skirt to drum junction. This paper presents an analysis methodology for determination of the optimal slot length and location and the expected improvement in fatigue life associated with different dimensions. The risk of skirt buckling associated with longer slot lengths and associated mitigations for that are also discussed. The method is then applied to extend the life and avoid unnecessary repairs to a existing problematic coke drum skirt applications.

This presentation introduces DrumVision, a non-intrusive nucleonic measurement gauge developed by Tracerco that employs neutron backscatter technology to continuously monitor phase transitions — including air, foam, and liquid — throughout the delayed coking process, offering greater process insight than conventional gamma transmission methods. The system provides real-time foam level detection to enable timely anti-foaming intervention and prevent costly foam-over events, while incorporating innovative shielding solutions that eliminate the need for ionising gases and controlled exclusion zones, with field trial results from the European market to be presented.

Drawing on over 30 years of severe-service valve expertise and a combined field record spanning 49 DCU turnarounds and more than 1,180 valve and actuator repairs, Velan and Sunbelt Supply present a collaborative account of how real-world operational experience has directly informed the next generation of coker valve design. Key engineering advancements — most notably a redesigned steam purge system featuring optimised purge pathways, coke buildup prevention, and a new purge-monitoring capability — are highlighted as practical solutions to extend service life and ensure reliable unit operation between turnarounds.

The E-Crane, a hydraulic balanced equilibrium duty cycle crane, is purpose built for mission critical bulk material handling applications such as coke handling.  The balanced crane designed delivers the highest efficiency and lowest cost per ton handled, while the simplicity of the unique parallelogram boom systems yields high uptime and reliability.  Two case studies will be presented where E-Cranes discharge coke and how the E-Crane solution compares to traditional methods.

This presentation details Wood's Cassette Assembly retube method for double-fired Terrace Wall Delayed Coker heaters, a highly modularised approach that pre-assembles complete radiant coil pass assemblies in the shop and employs specialised transportation frames and installation rigs to minimise field work. Demonstrated across recent project implementations — including a 12-pass DCU retube that achieved a 90%+ reduction in field welds and saved approximately 10,000 manhours of field labour and two weeks of turnaround time — the method offers a compelling case for efficiency-driven heater maintenance strategy.

This presentation by QMax Industries provides a comprehensive overview of practical heating solutions for tanks and vessels within refinery operations, systematically examining the full range of available technologies and their respective applications. Attendees will gain a structured understanding of the options available to support informed selection and optimisation of tank and vessel heating systems across their facilities.

Speaker to be confirmed, Becht

 This presentation examines the expanding role of the process engineer in developing FCC turnaround scope, encompassing operating issue resolution, inspection findings, safety and compliance requirements, chemical cleaning, process hazard analysis, and start-up and shutdown planning — all while navigating organisational pressure to reduce cost and scope. Particular attention is given to the challenge of knowledge continuity in an increasingly mobile workforce, where engineers must effectively advocate for critical turnaround scope with limited unit-specific experience ahead of cycles that typically span five to six years.

Speaker to be confirmed, Pertamina

This presentation examines a case study in which elevated salt content in desalted crude — exceeding 8 ptb following a low-cost crude processing strategy — led to progressive ammonium chloride and ammonium bisulfide fouling within an RCC main fractionator, ultimately causing C3/C4 Splitter reboiler degradation, a bottom temperature decline from 106°C to below 90°C, and significant propylene losses to mixed butane product. The study demonstrates how targeted online injection of a specialised salt dispersant directly into the heavy naphtha pumparound loop restored fractionation performance within hours, offering refineries a cost-effective, non-disruptive alternative to water washing when processing challenging crude slates.

Indian Oil Corp. Ltd

This presentation details how Guwahati Refinery resolved longstanding back pressure limitations in the Vapor Blowdown Recovery Unit (VBDRU) section of its Delayed Coker Unit through a cost-neutral, in-house feed distributor redesign — eliminating slop generation entirely and reducing the coking cycle time from 24 hours to 20 hours. The modifications enabled unit throughput to increase from 90% to 125% of design capacity, reduced black oil generation by 150 MTPD, and delivered combined annualised savings of approximately Rs 394 Crore.

This presentation describes how a multidisciplinary team spanning Operations, Maintenance, Engineering, Optimisation, and Process Safety developed and executed an innovative online cleaning solution after a severe coke fines blockage in the main fractionator's fines removal system — following a drum incident in August 2022 — threatened to force an unplanned intermediate turnaround ahead of a campaign scheduled to run until mid-2028. Through the strategic installation of hot tap tie-ins and the deployment of a purpose-built, pressurised rod insertion device incorporating redundant safety systems, the team progressively cleared the blockage over a 16-month period, fully restoring circulation by March 2024 without taking the unit offline.

This presentation documents the operational challenges encountered by HPCL–Mumbai Refinery following the installation of a Tail Gas Treating Unit (TGTU) designed to elevate Sulphur Recovery Unit efficiency from 99% to 99.9% in compliance with tightening environmental emission regulations, detailing a series of unsuccessful commissioning attempts attributable to sulphur carryover, inadequate tail gas preheating, equipment fouling, and unreliable process analysers. Drawing on lessons from the July 2025 restart, the paper outlines targeted corrective measures — spanning reactor performance evaluation, steam supply reconfiguration, sulphur carryover control, and instrumentation upgrades — essential to achieving stable, long-term TGTU operation and minimising adverse impacts on downstream units including the Sour Water Stripping Unit.

This presentation delivers a comparative evaluation of two tail gas treatment technologies employed in sulphur recovery operations — the conventional SCOT inline burner process installed in the AGRP unit and the medium-pressure ejector-based hydrogenation system operating in the NAGRP unit — assessing each against key performance criteria including reactor temperature control, energy consumption, hydrogen utilisation, and CO2 emissions. The analysis provides practical insights into the operational trade-offs between combustion-based and ejector-based hydrogenation configurations, offering a structured basis for technology selection and process optimisation in sulphur recovery applications.

Robert Taylor, Technical Director, 3S Superior Sealing Services

This presentation details an investigation by HPCL Mumbai Refinery into a persistent 30% Waste Heat Boiler duty shortfall following a major Flexicracking FCCU turnaround, which constrained unit feed throughput by approximately 35% — ultimately traced to an unintended consequence of improved regenerator cyclone performance, whereby a reduction in catalyst loss from ~3 TPD to 0.3 TPD eliminated the solids-assisted turbulence that had historically compensated for the absence of dedicated flue gas side turbulence promoters. Systematic troubleshooting, operating trials, and controlled equilibrium catalyst injection upstream of the WHB successfully restored over 20% of heat recovery duty and enabled a 33% throughput recovery, while longer-term solutions including CFD evaluation and mechanical turbulence enhancement are being assessed to ensure performance independent of solids loading.

Chlorides in the FCC Main Column overhead system can lead to several issues, such as salting and catalyst deactivation. While there are several mitigation strategies available, some refiners may not be aware of them until after they encounter an issue. This presentation will highlight the role of overhead temperature control, column water washing, and catalyst selection as mitigation measures to avoid shutdowns. 

Speaker to be confirmed, Pertamina

This presentation shares operational lessons from a Sumatera, Indonesia refinery where progressive coke accumulation in the 24-inch vapour line of a 35.3 MBSD Delayed Coker Unit caused rising chamber pressure, reduced middle distillate yield, and downstream operational disruptions — with conventional cleaning methods proving insufficient to clear the approximately 45-metre blocked section during scheduled turnarounds. The paper details the diagnostic approach, interim mitigation strategies including antifoam injection and HCGO quench optimisation, and the successful adoption of hydroblasting with rotary nozzle technology as a new turnaround best practice, restoring normal chamber pressure and product yields upon restart.

This presentation details a CFD-supported thermal reactor retrofit for a Sulphur Recovery Unit, addressing persistent reliability risks at the thermal reactor and Waste Heat Boiler inlet — including combustion maldistribution, corrosion, and undesired COS and CS2 formation — through targeted geometry modifications, acid gas burner revisions, bypass optimisation, and replacement of the traditional brick checker-wall with a refractory vortex-mixing checker-wall, underpinned by a project-specific reaction library validated for ammonia-bearing acid gas feeds. The redesigned configuration demonstrates earlier and more stable combustion, improved temperature and velocity uniformity at the WHB inlet, and measurable reductions in hot and cold spot formation — delivering enhanced run length and reliability with modest pressure impact and without major infrastructure changes.

This presentation provides a structured comparison of thermal and catalytic incineration techniques employed as the final tail gas treatment step in Sulphur Recovery Units across petroleum refineries and natural gas processing plants, evaluating each against key criteria including combustion efficiency, environmental impact, operational costs, and practical applicability. As regulatory pressure on sulphur compound emissions intensifies, the analysis offers timely guidance for operators and policymakers weighing the trade-offs between the operational flexibility of thermal incineration and the potential efficiency and emissions advantages of catalytic alternatives.

Sierra Butler, Systems Engineer GSE Solutions, GSE Solutions

This presentation introduces an innovative inspection methodology for internal corrosion assessment in oil and gas piping that leverages the statistical variability and density of ultrasonic spot thickness measurements — combining extreme value analysis, corrosion rate assessment, fitness-for-service evaluation, and risk-based inspection planning — to achieve scanning-equivalent confidence without the cost and logistical constraints of full ultrasonic scanning. Validated in field applications, the approach delivers comparable integrity assurance at approximately one third of the cost, offering a practical and scalable alternative for optimising turnaround scope and managing localised corrosion damage in risk-based inspection programmes.

Speaker to be confirmed, YASREF

This presentation details a dual-faceted integrity investigation at the Yasref Delayed Coker Unit, addressing two concurrent failure mechanisms — severe bottom flange distortion and ovalization attributed to dual feed inlet thermal loading, and recurrent through-wall cracking across the blowdown header system, where 14 failures occurred within ten years of operation — resolved through extensive field data collection, finite element analysis, piping stress modelling, and parametric fatigue assessment. The resulting corrective actions, including flange replacement, blowdown header modifications with enhanced fabrication tolerances, and the adoption of Sweepolet connections, provide a validated, data-driven framework for root cause analysis and long-term integrity management of coke drum systems.

Unplanned and unexpected SRU shutdowns have very high costs for repair work and even higher costs due to lost production. Faced with threats like elevated emissions, high differential pressure in equipment, deactivated catalyst, excessive temperatures with higher corrosion rates, it may look like an unplanned SRU and TGTU outage is an immediate inevitable outcome. However, with a correct understanding of the risks in play, and the limits of the equipment, catalysts and chemistry, sometimes the inevitable can be delayed. This paper will share some of the creative and practical solutions that allowed refineries to delay unplanned outages or extended the SRU run into a planned turnaround window. How each change was implemented, how it helped mitigate and manage the problem, the limits of the “abnormal operating mode” and what additional measures were required to achieve success will be discussed in this presentation. While not every solution can work in every plant, knowing what may be is possible and how to evaluate and implement these solutions can limit losses and help avoid those unwanted and unplanned outages.

Speaker to be confirmed, Kurita America

Fluid Catalytic Cracking Units (FCCUs) are critical to modern refining, converting heavy fractions into high-value products while offering operational flexibility. However, evolving market trends and feedstock variations have intensified corrosion risks, particularly from acidic salts such as ammonium chloride and bromide. This article examines the combined operational influences—such as diesel maximization strategies and halogen-contaminated feedstocks—that promote severe salt deposition and corrosion in FCCUs. Mechanistic insights into salt formation, its impact on equipment reliability, and associated operational challenges are discussed. Preventive and remedial countermeasures, including feedstock management, temperature control, water washing, and chemical additives, are evaluated. A case study demonstrates the successful application of Kurita’s Ammonium Chloride Free Technology, a water-soluble salt resolver, in mitigating fouling and corrosion under challenging conditions. The findings underscore the need for integrated strategies to safeguard FCCU assets and maintain profitability amid dynamic market and environmental pressures.

Optimised Gas Treating

Heather Bass, VP & GM of Carolina Process Equipment Cleaning, Carolina Process Equipment

TBC

Trimeric

This presentation makes the case for treating expansion joints in FCC Units as engineered assets requiring structured Mechanical Integrity programmes — rather than simple consumable items — addressing common failure mechanisms, installation best practices, and on-stream monitoring techniques for early detection of performance degradation. By integrating these elements into a formal MI framework, refineries can meaningfully extend expansion joint service life, improve unit reliability, and reduce the frequency and cost of unplanned outages associated with thermal expansion joint failures.

This presentation provides a comprehensive examination of steam utilisation across the Delayed Coker Unit, covering its critical roles in valve purging, furnace coking rate control, coke bed stripping, fractionator heat balance, equipment shutdown preparation, and emergency feed loss protection — as well as its influence on coke drum foam height, coke morphology, and product quality. Drawing on operational and safety considerations across multiple pressure levels, the session offers practical insight into how steam management decisions affect reliability, process efficiency, and day-to-day DCU operations.

Phillips66

Industrial Ceramics

Speaker to be confirmed, SILICON

Operational reliability in Fluid Catalytic Cracking (FCC) units is frequently compromised by the failure of abrasion-resistant refractory linings. These failures often lead to unplanned shutdowns, significant catalyst loss, and emergency repairs, incurring substantial costs for refinery operators. While industry discussions typically focus on secondary symptoms like erosion or spalling, this paper identifies a fundamental root cause: Refractory Lining Bypass.Refractory lining bypass occurs when process gases and liquids penetrate behind the lining through gaps or cracks caused by the differential thermal expansion between the steel shell and the refractory material. This phenomenon triggers different destructive mechanisms depending on the environment:In Coking Environments (Reactor): Bypass leads to "coke jacking," where carbon buildup behind the lining exerts massive pressure, resulting in shell deformation and mechanical failure of the anchoring system.In Non-Coking Environments (Regenerator): Bypass causes "biscuiting" (lamination) and accelerated anchor corrosion, leading to catastrophic refractory loss and massive catalyst bypass.This paper provides a detailed technical analysis of these failure mechanisms, supported by case studies from FCC reactor and regenerator cyclones. It evaluates the limitations of conventional closed-cell (hexmetal) and non-closed-cell anchoring systems in managing thermal stress and bypass.Finally, the paper introduces an innovative semi-closed anchoring system designed to mitigate bypass while maintaining the structural integrity of the lining. By addressing the root cause rather than the symptoms, this technology offers a proven path to extending run lengths, enhancing safety, and optimizing the life cycle of critical petrochemical processing equipment.

FCCU waste heat boiler is a critical component to maximize energy efficiency and yields valuable steam that is returned to the overall process. Boiler reliability is key not only for steam production but also to ensure maximum FCCU throughput is obtained. This presentation will examine a unique case study where a replacement in kind waste heat boiler began vibrating during start up and boiler components began to fail shortly after. A multidisciplinary team analyzed the operational data, took vibration measurements, and utilized advanced analysis to replicate the observed vibration. In the end it was a simple and practical solution that is atypical for most vibration problems that allowed the boiler to return to normal reliable operation.

Speaker to be cofirmed, Cenovus & Houston Engineering Services

Bulges that form along or adjacent to the circumferential seams of coke drums are mostly driven by the mechanical resistance of hard coke during quenching and the mismatch in yield strength between the base metal and weld metal. The modern design of coke drums typically includes a provision to increase the yield strength of the base metal which is intended to reduce susceptibility to bulging. While the impact of yield strength on bulging is generally understood, the magnitude of this impact has not been quantified. In this presentation, finite element analysis is used to simulate seam bulges and evaluate the impact of base metal yield strength on bulging magnitude. 

HEC Technologies

Antonio P. Antunes Jr., Sr. Business Development Manager, Freudenberg Flow Technologies

Speaker to be confirmed, Carolina PEC

As FCC and rFCC units increasingly process resid-rich and metals-bearing feedstocks, porous metal filtration systems are subjected to accelerated fouling and complex contaminant loading that can degrade performance beyond the limits of conventional operational monitoring. While filters may remain mechanically intact and meet nominal integrity criteria, embedded fouling can alter pore architecture, create preferential flow paths, and reduce effective barrier performance. This filtration performance decay represents a latent reliability risk, enabling intermittent or sustained passage of ultrafine catalyst fines and metal-bearing particulates into the circulating catalyst inventory.The resulting increase in catalyst losses and accumulation of nickel, vanadium, iron, and other dehydrogenation-active metals can adversely impact hydrogen yield, coke selectivity, and catalyst life, even in the absence of overt filter failure. This paper demonstrates that pressure drop trends and blowback frequency alone are insufficient to assess filtration condition under severe feedstock conditions. Instead, a combination of integrity testing (bubble point and wetted airflow) and cleanliness validation (dry air pressure drop and percent recovery analysis) is required to distinguish recoverable fouling from permanent permeability loss.By integrating quantitative filtration validation into FCC reliability and catalyst management programs, refiners can mitigate catalyst contamination risk, stabilize unit operation, and safely expand crude slate flexibility while maintaining long-term filtration and catalyst performance.

Cristhian Oses, Projects Engineer, Specialist, Enap Refinerias & Ralf Matthaes, Head of Department Business Development, Endress+Hauser Level+Pressure

Nucleonic measurement technologies are widely applied in processes where conventional measuring principles are not feasible. They excel in environments with extreme conditions such as high temperature, high pressure, abrasive media, or where any internal installations are not possible. These challenges are common in refineries. This presentation will share insights from a recent revamp project executed in collaboration with ENAP and Endress+Hauser. The project involved replacing legacy backscatter devices with advanced gamma scintillator technology in the Delayed Coking Unit and Fractionating Towers. Key aspects of the project execution will be discussed, including implementation steps and the resulting improvements in level measurement performance compared to the previous technology.

Chuck Munro, Refinery Applications Specialist, Spraying Systems Co.

Gas conditioning applications play a critical role in refinery operations by enabling units to meet process objectives and protect downstream equipment. In Fluid Catalytic Cracking (FCC) units, effective gas cooling of regenerator off-gas is essential—whether for emergency quench scenarios or to maintain temperature limits compatible with downstream processing hardware. While standard enthalpy-based methods provide a preliminary basis for system design, more advanced approaches, including Computational Fluid Dynamics (CFD) and rigorous spray nozzle selection, are often required to ensure reliable performance. This presentation will review key considerations that influence gas conditioning effectiveness, discuss design and operational challenges, and present case studies demonstrating how appropriate modeling tools and equipment specification drive successful implementation.

Delta Controls