Refining Technology
As a follow-up to last year's symposium, the Chicago Section of
AIChE will provide a half day of additional information on refinery
technology. We will be including some of the papers presented at this
year's AIChE Spring Conference, including some from a special topical
conference: AIChE 10th Topical Conference on Refinery Processing. The
sessions will include a look at the impact of tie-ins, technology to
control unit heater fouling, and alternative refinery feedstocks.
Abstracts:
Improvements in Coke Drum Life Through Operational Optimization and Design
Author: Bobby W. Wright, P.E., Director Downstream Development,
Stress Engineering Services, Inc.
Download presentation
Coke drums are vessels critical to the operation and profitability of today's oil
refineries, crude upgrader units and tar sands facilities. These vessels operate in
batch cycles at relatively high temperatures, and about once a day they are
filled with hydrocarbon vapors & hot oil and finally quenched with water. They have
historically been designed according to ASME Section VIII, Division 1 with little or
no account for the cyclic operations. As operators work to increase throughput, coker
cycles have become shorter, and cycle times steadily decreased from 24-hours to less
than 12-hours (oil-in to oil-out), and more recently, some refineries have decreased
to 9-hour cycles. As a result of shorter cycles, some new coke drums with traditional
designs have been failing after only a few years of service.
Stress Engineering Services (SES) began investigating coke drum cracking
fifteen years ago in conjunction with several oil companies. As part of their evaluations
SES installed strain gages and thermocouples to measure the "actual" thermal gradients and
local stresses in over 50 coke drums - monitoring over 3000 coke drum cycles. Before these
studies, operating stresses were assumed to be caused only by process pressure and
temperature variations. Strain gage monitoring and stress assessments showed that
"actual" coke drum stresses were significantly higher than previously thought. SES
worked with unit operators to better understand what aspects of the process were causing
coke drums to crack and ways to optimize the process to avoid cracking and extend drum life.
As a result of these studies the oil industry learned the following:
- Drums were experiencing lower than expected drum switch temperatures, and this contributed
to failures as the vessel skirt welds.
- Drums were being locally heated and cooled much faster than what was indicated by
traditional process monitoring and typically process monitoring parameters did not
correlate with coke drum life.
- Contraction of the drum walls during cooling compacts the coke inside the drum
and this turned out to be a major influencing factor in drum life since coke hardness
has been increasing due to crude composition changes
- Reducing coker cycle times by as little as two hours caused the drum damage
rate to increase by about 30%
- Optimized operational control improvements coupled with strain gage based
health monitoring could significantly reduce drum damage and extend life
This presentation will discuss how monitoring coke drums can be use
to "optimize" the operational parameter to improve drum reliability and extend drum
life while still maintaining the required goals for throughput.
Speaker Bio: Bobby Wright has over twenty-one years of varied
refinery and chemical plant engineering experience both domestically and
internationally. His expertise includes knowledge of most plant mechanical and materials
engineering applications including knowledge of pressure vessels, reactors,
coke drums, heaters, piping, boilers and rotating equipment. At Stress Engineering
he is responsible for direction and management of engineering consulting and process
problem solving projects and services for refineries, chemical plants and power stations.
He has specific experience relating engineering aspects of coke drums, refinery pressure
vessels, reactors, and piping. Before joining Stress Engineering he was Vice President
US Operations, ERA Technology, Inc. (Houston) and prior to that he was Manager, Applications
Engineering, Det Norkse Veritas, Inc. (Houston). Bobby also worked for five years at
Tosco's El Dorado Refinery. He has a BS degree from the University of Arkansas and he
is a Professional Engineer in Texas.
New Technology Controls Thermal Conversion Unit Heater
Fouling
Authors: Bruce Wright
and Tom Falkler, Baker Petrolite
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Baker Petrolite has developed thermal conversion unit heater fouling
control technology that significantly reduces heater tube fouling
rates. Benefits can include extended runlength, maintaining higher
transfer line temperatures for increased conversion, running feedstocks
with higher fouling potential, and reduced frequency and cost of
coil decoking procedures. Using proprietary unit feedstock characterization
testing and analytical database comparisons, multi-component fouling
control solutions are selected that effectively interrupt the key
fouling mechanisms identified for specific unit operations and
feedstock qualities.
In this presentation we provide an overview of thermal conversion
unit heater fouling mechanisms, and discuss feedstock characteristics
that can cause accelerated fouling. We also discuss the results
of recent applications of Baker Petrolite’s fouling control
technology in refinery coker heaters.
Legal Aspects of the Clean Water Act
Enforcement
Author: Cheryl T. Rose, Esq., United States Environmental Protection Agency,
Office of Enforcement and Compliance Assurance, Water Enforcement Division
Oil and hazardous substance spills can pose a serious threat to human
health and often have a long-lasting impact on the environment. The discharge
of these substances into waters in quantities that may be harmful is prohibited
under the Clean Water Act. EPA investigations have revealed large scale compliance
problems, such as pipeline breaks, leaking tanks, faulty valves, overturned trucks,
leaking ships and illegal dumping. Facilities that process, manufacture or use
chemicals must have measures to prevent spills in violation of the Act. This
session will provide information on legal requirements and expectations regarding
oil and hazardous substance spills and ensuring that spills do not occur.
Speaker Bio:Cheryl Rose is a Senior Attorney with the Water
Enforcement Division of the Office of Enforcement and Compliance Assurance (OECA) at
the U.S. Environmental Protection Agency (EPA). She has worked at EPA for more than
12 years. Cheryl currently specializes in oil spills, vessel pollution and sewage
treatment violations and is her office's Pipeline Enforcement Coordinator.
Cheryl has worked on some of EPA's largest Clean Water Act civil enforcement
actions, including several against pipeline companies for large oil spills caused
by corrosion and other problems. She works closely with technical experts, including
chemical engineers, to identify causes of Clean Water Act violations and appropriate
solutions. Cheryl also works on legislation, regulations, policy and inter-agency
coordination. She works closely with colleagues at PHMSA, the Coast Guard,
Department of Justice and others. Prior to joining OECA in 1998, Cheryl spent
three years in EPA's Office of Administrative Law Judges where she reviewed many
administrative penalty actions in several environmental areas. Cheryl received her
law degree in 1994 from Washington University in St. Louis and her B.A. in International
Affairs in 1987 from The George Washington University.
Improved Alkylation Processes for Refineries
Author: Lyle F. Albright, School of Chemical Engineering Purdue University, West Lafayette, IN
Alkylation of isobutane with C3-C5 olefins produces in refineries the
cleanest burning, best quality gasolines. Current processes use either sulfuric acid or HF
as catalysts and both have potential safety hazards. Alternative catalysts have been suggested,
and this presentation will cover the follow aspects of alkylation catalysts.
- Advantages and disadvantages of alkylation processes with different
catalysts will be reviewed including ones with solid catalysts and triflic acid.
- Safety concerns of various processes will be discussed plus suggestions
to minimize hazards.
- Factors causing degradation of catalysts plus methods for
regenerating catalysts will be discussed. Decreased rates of degradation have been
developed recently.
- Methods to improve both design and operation of alkylation reactors are
possible. Such modifications will likely result in better quality alkylates, reduced
consumption of feedstocks, and reduced operating cost.
Speaker Bio: Dr. Lyle F. Albright, Professor of Chemical Engineering at
Purdue University, has been actively involved in numerous areas of alkylation of isobutane
with light olefins for over 40 years. In addition, he has consulted with several refineries
and engineering firms on alkylation problems involving both sulfuric acid and HF as
catalysts. At Purdue, his emphasis has been in the following areas: laboratory scale
reactors, chemistry of both desired plus undesired side reactions, and physical steps for
reactants and products in two phase reaction mixtures. These alkylation efforts have
resulted in 46 technical papers plus one edited book. Two of his alkylation patents are
employed industrially. Dr. Lyle began his education at the University of Michigan, and he
received is BS in 1943. He received his masters in 1944, but then he delayed progress
on his PhD to work for two years on the Manhattan Project. After the Manhattan Project
he went back to Michigan and received his PhD in 1950. Dr. Albright is currently
writing a handbook that will be titled, Albright's Chemical Engineering Handbook
that will be published by Taylor and Francis (it will be a competitor to
Perry's Chemical Engineer's Handbook).
Sulfuric Acid Regeneration
Author: Jesse Wright, Rhodia, ECO Services, Hammond Facility
Production Engineer
Download presentation
Sulfuric acid is one of the largest chemicals produced by weight in
the world. The acid is used in nearly every industry including agro-products,
mining, paper & pulp, steel production, water treatment, surfactants (soaps),
plastics and petrochemicals. Sulfuric acid regeneration processes service the
petrochemical industry through recycling the sulfuric acid used as a catalyst in
alkylation units. This is an important service within the refining process that
supplies the alkylation unit with fresh active catalyst. Spent acid regeneration
is a service based process that must provide the product as promised so that
production on the refinery is not affected. In attempts to deliver acid as promised
a preventive maintenance and performance prediction culture has evolved. This paper
will discuss the regeneration process and how it is used to support sulfuric acid alkylation in refineries.
Speaker Bio: Mr. Wright received a B.S. in Chemical Engineering from Michigan State University, and is
currently working on a M.S. in Chemical Engineering at University of Toledo studying high
temperature corrosion of ceramics. He has been in the sulfuric acid industry for about
2 years. He has been stationed at two different regeneration units to date and has
worked on multiple regeneration units from the Gulf Coast to Northern Canada. His
role is mainly process reliability, including monitoring process metrics, individual
equipment assessments, assessing new materials and implementing new technology.
Jerry Wilks |
Ade Ogunrinde |
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