Energy concept for future oil refineries with an emphasis on separation processes - PowerPoint PPT Presentation

Loading...

PPT – Energy concept for future oil refineries with an emphasis on separation processes PowerPoint presentation | free to download - id: 3ce518-ZmJhM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Energy concept for future oil refineries with an emphasis on separation processes

Description:

Energy concept for future oil refineries with an emphasis on separation processes Antonio Brand o Department of Chemical Engineering Federal University of Campina Grande – PowerPoint PPT presentation

Number of Views:100
Avg rating:3.0/5.0
Slides: 64
Provided by: ntNtnuNo
Learn more at: http://www.nt.ntnu.no
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Energy concept for future oil refineries with an emphasis on separation processes


1
Energy concept for future oil refineries with an
emphasis on separation processes
  • Antonio Brandão
  • Department of Chemical Engineering
  • Federal University of Campina Grande
  • Campina Grande, Paraiba
  • December 2011

2
About this presentation
  • Motivation
  • Focus on environmental aspects in oil refining is
    not enough (Szklo 2007, DOE 2000).
  • Energy-efficient processes in oil refining are
    paramount.
  • Need for research in this field is a must.
  • Important literature
  • U.S. DOE, Energy Bandwidth for Petroleum Refining
    Processes, Office of Energy Efficiency and
    Renewable Energy, Office of Industrial
    Technologies, 2006.
  • Szklo, A., Schaeffer, R., Fuel specification,
    energy consumption and CO2 emission in oil
    refineries, Energy 32, 10751092, 2007.
  • Focus
  • Whats up on the future of energy consumption in
    oil refineries.
  • Opportunities Attempt to give directions, not
    specific solutions for particular problems (e.g.,
    impact of sulfur reduction in diesel and/or
    gasoline).
  • Looking at the big picture Not restricted to
    separation processes.
  • Goal
  • Attempting to show what one can expect in terms
    of more energy-efficient refineries in the long
    run.

3
About this presentation
  • Lets tear things down

Energy concept Energy efficiency. Keep it
simple!
Energy concept for future refineries.
Directions will be given but problems wont be
solved here!
Splitter
Future Next 20 years??? Nothing futuristic! No
revolution!
  • Directions will be given Well, it cannot be
    different since there are lots of alternatives to
    consider. But details wont be discussed here!
  • You may try, e.g., Oil Refining Industry -
    Process Flow - Data Sheets.pdf, for specifics.

4
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

5
A vision for the future
  • According to the APIs Technology Vision 2020 A
    Technology Vision for the U.S. Petroleum Refining
    Industry API 2000 report,
  • The petroleum industry of the future will be
    environmentally sound, energy-efficient, safe and
    simpler to operate. It will be completely
    automated, operate with minimal inventory, and
    use processes that are fundamentally
    well-understood. Over the long term, it will be
    sustainable, viable, and profitable, with
    complete synergy between refineries and product
    consumers.
  • To improve energy and process efficiency, the
    industry will strive to use cost-effective
    technology with lower energy-intensity.
    Refineries will integrate state-of-the-art
    technology (e.g., separations, catalysts, sensors
    and controls, biotechnology) to leapfrog current
    refinery practice and bring efficiency to new
    levels.

6
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

7
A simple guide to oil refining
  • According to the North American Industry
    Classification System (NAICS) DOE 2006,
    petroleum refineries are defined as
  • Establishments primarily engaged in refining
    crude petroleum into refined petroleum.

Picture of the oil refinery of the future, if the
oil consumption maintains its forever growing
pace Actually, this is a 1876 oil refinery in
California.
8
A simple guide to oil refining Exxon 2005
9
A simple guide to oil refining
  • In short
  • Everything is upgraded to valuable products More
    fuel!
  • Over 43 of production is gasoline.
  • C.a. 80 is converted to fuel.
  • It is a huge, extremely complex process
    facility!!!
  • Lots of reactions and separations to add value to
    the products.
  • Many opportunities for energy savings.

10
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

11
Energetic issues in an oil refinery (DOE 2000,
Pellegrino 2005)
  • Refinery gas petroleum coke other oil-based
    by-products accounts for 65 of the energy
    sources in an oil refinery.
  • 38 of the energy sources in an oil refinery are
    used to produce non-fuel products like lubricant
    oils, wax, asphalt, and petrochemical feedstocks.
  • Oil refineries generate large amounts of
    electricity on-site. In the U.S., over 40 (1994)
    of electricity in refineries are on-site
    generated.
  • The cost of energy for heat and power accounts
    for c.a. 40 of the operating costs in a
    refinery!!!

12
Energetic issues in an oil refinery DOE 2007
13
Energetic issues in an oil refinery DOE 1998
  • According to the NAICS (The North American
    Industry Classification System), petroleum
    refineries consumed 3.1 quadrillion Btu (fuel use
    alone) in 2002, almost 20 of the fuel energy
    consumed by the U.S..
  • From the Table, c.a. 31 is consumed in two
    distillation processes.
  • As expected, hydrotreating is also very high, 15
    alone.
  • Hydrogen generation is yet another high energy
    consumption process.
  • Large amounts of energy are consumed as fuel,
    while the rest is basically steam.
  • The bullets represent units prone to be
    optimized energetically as they represent
    approx. 86 of the energy consumed by the
    refining process.
  • We will focus on these units.

14
Energetic issues in an oil refinery Worrell 2005
15
Energetic issues in an oil refinery
16
Energetic issues in an oil refinery DOE 2000
  • Future characteristics of oil refineries in terms
    of energy use
  • Energy use is optimized throughout the refinery
    complex (plantwide energy optimization).
  • Energy efficiency and process control are
    integrated (plantwide process control).
  • Fouling of heat exchangers is essentially
    eliminated.
  • Innovative heat exchangers are in place (all
    helical, vertical, no baffles)
  • Use of cogeneration in refineries is optimized,
    and refineries are power producers.
  • Use of very energy-intensive processes (e.g.,
    distillation, furnaces) is mitigated.
  • Source of heat loss (e.g., in pipes) are easily
    identified through monitoring.
  • How?
  • Identify entirely new technologies.
  • Upgrade existing inefficient technologies.

17
Energetic issues in an oil refinery DOE 2000
  • Replacing the conventional energy-intensive
    separation processes has a tremendous impact on
    energy consumption.
  • Waste recovery in the short term.
  • Fouling mitigation and new refining processes in
    the mid and long terms.
  • Membrane is the first step.
  • Catalytic distillation is in the mid run.
  • Long run distillation beyond membrane.
  • Pelegrino 1999 say the target is 15-20 energy
    reduction for U.S. refineries.

Distillation roadmap
18
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

19
Thermodynamic analysis DOE 2006
  • Remember the 6 processes with the largest energy
    consumption?
  • A thermodynamic analysis of these 6 processes is
    performed here.
  • Three measures are defined
  • TW Theoretical Work The least amount of energy
    that a process would require under ideal
    conditions. E.g., for separation processes it is
    basically the sensible and latent heat of each
    component in the mixture considered as an ideal
    solution, and for reaction systems the heat of
    reaction under 100 selectivity at equilibrium
    conditions.
  • CW Current Work Energy consumed under actual
    plant conditions where energy losses from
    inefficient or outdated equipment and process
    design, poor heat integration, and poor
    conversion and selectivities, among other factors
    are considered. Source USA DOE.
  • PW Practical Work Minimum energy required to
    run the process in real-world, non-standard
    conditions by applying cutting edge technologies
    still on the drawing board. The savings are then
    deducted from the CW requirement.
  • Therefore, the maximum potential for energy
    savings can be quantified by

PI (Potential Improvement) CW (Current Work)
PW (Practical Work)
20
Crude oil distillation (atmospheric and vacuum)
  • Atmospheric distillation
  • It is the heart of the refinery.
  • It produces a range of products, from LPG to
    heavy crude residue.
  • High temperature (bottom 600oC), low pressure
    (near atmospheric) process.
  • Vacuum distillation
  • It has heavy crude (high boiling point) as
    feedstock.
  • It must then be conducted at vacuum conditions.
  • It produces light and heavy gas oil and asphalt
    (or resid).
  • These products are upgraded.

21
Crude oil distillation (atmospheric and vacuum)
22
Crude oil distillation (atmospheric and vacuum)
  • Atmospheric distillation energetic assessment
    DOE 2006
  • Theoretical work 22 x 103 Btu/bbl feed
  • Current work 114 x 103 Btu/bbl feed
  • Practical work 50 x 103 Btu/bbl feed
  • Potential improvement 64 x 103 Btu/bbl feed

Note Electricity losses incurs during the
generation, transmission, and distribution of
electricity.
23
Crude oil distillation (atmospheric and vacuum)
  • Atmospheric distillation energetic assessment
    DOE 2006
  • Theoretical work 22 x 103 Btu/bbl feed
  • Current work 114 x 103 Btu/bbl feed
  • Practical work 50 x 103 Btu/bbl feed
  • Potential improvement 64 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (Gadalla 2003a, Gadalla 2003b, ANL 1999,
    TDGI 2001, Liporace 2005, Seo 2000, Rivero
    2004, Yeap 2005, Hovd 1997, Sharma 1999)
  • Control of fouling in the crude preheat train and
    fired heater.
  • Improved heat integration between the atmospheric
    and vacuum towers.
  • Improved tray design and heat integration between
    trays, and optimization of the number of trays
    and operating conditions for improved
    vapor-liquid contact and higher throughput.
  • Enhanced cooling to lower overhead condenser
    cooling water from 75 to 50F.
  • Implementation of advanced control or revamp of
    the control structure with simple plantwide
    control.

24
Crude oil distillation (atmospheric and vacuum)
  • Vacuum distillation energetic assessment DOE
    2006
  • Theoretical work 46 x 103 Btu/bbl feed
  • Current work 92 x 103 Btu/bbl feed
  • Practical work 54 x 103 Btu/bbl feed
  • Potential improvement 38 x 103 Btu/bbl feed

25
Crude oil distillation (atmospheric and vacuum)
  • Vacuum distillation energetic assessment DOE
    2006
  • Theoretical work 46 x 103 Btu/bbl feed
  • Current work 92 x 103 Btu/bbl feed
  • Practical work 54 x 103 Btu/bbl feed
  • Potential improvement 38 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (Gadalla 2003a, Gadalla 2003b, ANL 1999,
    TDGI 2001, Sharma 1999, Liporace 2005, Seo
    2000, Rivero 2004, Yeap 2005)
  • Control of fouling in the fired heater.
  • Improved heat integration between the atmospheric
    and vacuum towers.
  • Improved tray design and heat integration between
    trays, and optimization of the number of trays
    and operating conditions for improved
    vapor-liquid contact and higher throughput.
  • Enhanced cooling to lower overhead condenser
    cooling water from 75F to 50F.
  • Implementation of advanced control or revamp of
    the control structure with simple plantwide
    control.

26
Fluid catalytic cracking
  • Objective Convert heavy oils into more valuable
    gasoline and lighter products.
  • Feedstocks are light and heavy gas oil from
    atmospheric or vacuum distillation, coking, and
    deasphalting operations.

High temperature, catalytic cracking reactions
27
Fluid catalytic cracking
28
Fluid catalytic cracking
  • Energetic assessment DOE 2006
  • Theoretical work 40 x 103 Btu/bbl feed
  • Current work 209 x 103 Btu/bbl feed
  • Practical work 132 x 103 Btu/bbl feed
  • Potential improvement 77 x 103 Btu/bbl feed

29
Fluid catalytic cracking
  • Energetic assessment DOE 2006
  • Theoretical work 40 x 103 Btu/bbl feed
  • Current work 209 x 103 Btu/bbl feed
  • Practical work 132 x 103 Btu/bbl feed
  • Potential improvement 77 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (Linhoff 2002, ANL 1999)
  • Addition of a power recovery turbine.
  • Conversion of condensing turbine drive to
    electric motor drive (wet gas compressor).
  • Improved heat integration, pinch analysis.
  • Minimization of other miscellaneous losses.
  • Extra Implementation of advanced control or
    revamp of the control structure with simple
    plantwide control.

30
Catalytic hydrotreating
  • Objective Remove sulfur, nitrogen, and metals
    and upgrade heavy olefinic feed by saturation
    with hydrogen to produce paraffins.
  • It commonly appears in multiple locations in a
    refinery (5 or more of these units).
  • They are usually placed upstream of units where
    catalyst deactivation may occur from feed
    impurities.
  • Typically we can distinguish Naphtha
    hydrotreater, kerosene hydrotreater, and gas oil
    hydrotreater.
  • Main reactions

31
Catalytic hydrotreating
32
Catalytic hydrotreating
  • Energetic assessment DOE 2006
  • Theoretical work 30 x 103 Btu/bbl feed
  • Current work 88 x 103 Btu/bbl feed
  • Practical work 55 x 103 Btu/bbl feed
  • Potential improvement 33 x 103 Btu/bbl feed

33
Catalytic hydrotreating
  • Energetic assessment DOE 2006
  • Theoretical work 30 x 103 Btu/bbl feed
  • Current work 88 x 103 Btu/bbl feed
  • Practical work 55 x 103 Btu/bbl feed
  • Potential improvement 33 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (ANL 1999, Gary 2001, Linhoff 2002,
    Liebmann 1998)
  • Improved pre-heater performance.
  • Improved catalyst.
  • Improved heat integration, pinch analysis.
  • Minimization of other miscellaneous losses.
  • Extra Implementation of advanced control or
    revamp of the control structure with simple
    plantwide control.

34
Catalytic reforming
  • Objective Convert naphthas and heavy
    straight-run gasoline into high-octane gasoline
    blending components, as well as hydrogen
    generation.
  • It essentially restructures hydrocarbon molecules
    to increase the octane of motor gasoline.
  • Main reactions
  • Dehydrogenation of naphthenes to aromatics
  • Methylcyclohexane ? Toluene 3H2
  • Methylcyclopentane ? Cyclohexane ? Benzene 3H2
  • Dehydrocyclization of paraffins to aromatics
  • n-Heptane ? Toluene 4H2
  • Isomerization
  • n-Hexane ? Isohexane
  • Methylcyclopentane ? Cyclohexane
  • Hydrocracking
  • n-Decane ? Isohexane nButane

35
Catalytic reforming
36
Catalytic reforming
  • Energetic assessment DOE 2006
  • Theoretical work 79 x 103 Btu/bbl feed
  • Current work 269 x 103 Btu/bbl feed
  • Practical work 203 x 103 Btu/bbl feed
  • Potential improvement 66 x 103 Btu/bbl feed

37
Catalytic reforming
  • Energetic assessment DOE 2006
  • Theoretical work 79 x 103 Btu/bbl feed
  • Current work 269 x 103 Btu/bbl feed
  • Practical work 203 x 103 Btu/bbl feed
  • Potential improvement 66 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (ANL 1999, Gary 2001, Packinox 2003)
  • Improved feed and interstage process heater
    performance (e.g., improved convection section
    heat recovery).
  • Replace horizontal feed/effluent heat exchangers
    with vertical plate and frame exchanger.
  • Improved equipment efficiency (e.g., recycle and
    net gas compressor, reactor product air cooler).
  • Additional process cooling to improve light ends
    recovery (vapor compression vs. ammonia
    absorption).
  • Minimization of other miscellaneous losses.
  • Extra Implementation of advanced control or
    revamp of the control structure with simple
    plantwide control.

38
Alkylation
  • Objective Produce branched paraffins that are
    used as blending components in fuels to boost
    octane levels without increasing the fuel
    volatility.
  • There are two alkylation processes sulfuric
    acid-based and hydrofluoric acid-based.
  • Both are low-temperature, low-pressure,
    liquid-phase catalyst reactions.
  • Main reaction

39
Alkylation (H2SO4 process)
40
Alkylation (H2SO4 process)
  • Energetic assessment DOE 2006
  • Theoretical work -58 x 103 Btu/bbl feed
  • Current work 335 x 103 Btu/bbl feed
  • Practical work 156 x 103 Btu/bbl feed
  • Potential improvement 179 x 103 Btu/bbl feed

41
Alkylation (H2SO4 process)
  • Energetic assessment DOE 2006
  • Theoretical work -58 x 103 Btu/bbl feed
  • Current work 335 x 103 Btu/bbl feed
  • Practical work 156 x 103 Btu/bbl feed
  • Potential improvement 179 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (Gadalla 2003a, TDGI 2001, DOE 2006,
    Schultz 2002)
  • Improved compressor efficiency, from 25 to 50.
  • Improved heat integration, pinch analysis.
  • Use of a dividing wall column design or other
    advanced separation technology.
  • Upgraded control system revamp of the control
    structure with simple plantwide control.

42
Hydrogen production
  • Objective Generate (complement) H2 for
    hydrocracking, hydrotreating, hydroconversion,
    and hydrofinishing process throughout the
    refinery.
  • Sources for hydrogen in a refinery are basically
    by-products from catalytic reforming, recovery
    from H2 rich off-gases, and the hydrogen plant
    production.
  • The principal process for converting hydrocarbons
    into hydrogen is catalytic steam reforming.
  • The main reactions are
  • CH4 H2O ? CO 3H2 (-?Ho298 -206 kJ/mol)
  • CO H2O ? CO2 H2 (-?Ho298 41 kJ/mol)
  • CnHm H2O ? nCO (m2n)/2H2 (-?Ho298 -1109
    kJ/mol for nC7H16)
  • The main reaction, methane conversion, must be
    carried out at high temperature, high steam to
    carbon ratio, and low pressure to achieve maximum
    conversion.

43
Hydrogen production
44
Hydrogen production
  • Energetic assessment Rostrup-Nielsen 2005
  • Theoretical work 67 x 103 Btu/bbl feed
  • Current work 111 x 103 Btu/bbl feed
  • Practical work 71 x 103 Btu/bbl feed
  • Potential improvement 30 x 103 Btu/bbl feed
  • The potential improvement can be achieved by
    (Rostrup-Nielsen 2005)
  • Higher (optimized) reforming temperature (gt 900
    oC) and lower (optimized) steam to carbon ratio
    (lt 2.0).
  • Reformer design that does not export steam.
  • Catalysts to reduce carbon formation.
  • Membrane reforming technology with CO2
    sequestration.
  • Extra Implementation of advanced control or
    revamp of the control structure with simple
    plantwide control.

45
Summary
  • The overall savings, including capacities, can
    reach up to 42.
  • Atmospheric vacuum distillations have the
    largest potential for savings.
  • Followed by alkylation and catalytic treatments.
  • Note that separation sections are also included
    in the conversion processes.
  • As a general potential improvement in the short
    term, I particularly would also include
    assessment of the control structure design of the
    entire refinery.

46
Summary
  • Remember this picture?
  • Now have a look at the figures on the right.
  • Gasoline requires the largest amount of energy to
    be produced. While gasoline makes up 43 by
    volume of refinery product output, its production
    consumes 62 of the refinery energy requirement.
  • Distillate fuel oil is the next most
    energy-intensive product stream, consuming 17 of
    refinery energy requirement.
  • The remaining 21 is distributed fairly evenly
    between the other product streams.

TBtu/year
47
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

48
Separation processes
  • The majority of the available literature is
    related to the issue concerning distillation, and
    they are heavily concentrated in the atmospheric
    and vacuum columns. I bet you know the reason!
  • Future solutions for improving energy efficiency
    in separation processes in oil refineries are
    basically related to
  • Membrane technology.
  • Fouling mitigation.
  • Optimization and advanced process control.
  • Heat integration.
  • Design of efficient separation systems.
  • What follows are mostly on the drawing board,
    i.e., no real-world implementation.

49
Separation processes
  • Membrane technology (still an on going
    development)
  • Wauquier 2000 discusses that membrane
    technology is still an infant in the world of
    grown-up inefficient processes in the oil
    industry. Its main application is in
    hydrodesulfurization processes in catalytic
    hydrotreating units, replacing existing
    separation processes with energy savings up to
    20.
  • Nevertheless, Goulda 2001 and White 2000
    claimed a fuel reduction of 36,000 bbl/year (or
    20 w.r.t. the conventional process) by adding a
    membrane unit in the dewaxing unit to recover
    part of the solvent stream. The membrane is
    selective to the solvent from the solvent/oil/wax
    mix.
  • According to Szklo 2007, further research is
    needed to develop appropriate membrane materials
    that can withstand the harsh conditions in
    petroleum refining processes.

50
Separation processes
  • Fouling mitigation (basically monitoring)
  • Panchal 2000 presented a performance monitoring
    via an Excel spreadsheet of the preheat train
    for a crude distillation unit. The authors claim
    that by using their technique the energy loss in
    a period of 2 years can be reduced by almost 60.
  • Nasr 2006 proposed a model of crude oil fouling
    in preheat exchangers with the aim of better
    controlling fouling formation. In contrast with
    other models, the one proposed by the authors
    consider the mechanisms of formation and natural
    removal.
  • Yeap 2005 presented the application of existing
    fouling models to maximize heat recovery in the
    preheat train of the crude oil distillation. The
    authors conclusion was that designing for
    maximum heat recovery results in a less efficient
    system over time due to fouling effects.
  • However, Szklo 2007 states that the very
    complex mechanisms which lead to fouling are
    still not properly understood to the extent they
    can be safely used for fouling mitigation
    techniques (anti-fouling agents and coatings).

51
Separation processes
  • Advanced process control and optimization
    (essentially modeling)
  • Domijan 2005 optimized a crude distillation
    unit by using a model that, according to the
    authors, has some advantages over commercial ones
    since it is adapted to real plant conditions, it
    is open source as well as flexible and fast.
    Moreover, it can also identify fouling level and
    be applied for planning shutdowns and maintenance
    stops. They claimed they found an optimal
    solution that saves up to 3.2 of energy
    consumption vis-à-vis actual operating
    conditions.
  • Seo 2000 considered the optimal design of the
    crude distillation unit (atmospheric, vacuum, and
    naphtha stabilizer) by optimizing feed locations,
    heat duties of pumparounds and operating
    conditions of the preheat train. They use a MINLP
    framework. They claim the energy recovery in
    pumparounds and preheat train could save up to 20
    million kcal/h.
  • Hovd 1997 proposed the implementation of MPC in
    a crude oil distillation. They used the MPC
    package (D-MPC) of Fantoft Prosess and a linear
    model of the process obtained using
    first-principle model equations and laboratory
    data. They implemented the MPC strategy in a
    refinery in Sweden and reported a reduction in
    energy consumption equivalent to USD20,000/year
    for a project investment of USD250,000.
  • Gadalla 2003b performed a very simple
    optimization of existing heat-integrated
    distillation systems for crude oil units where
    the column (with fixed configuration) and the
    associated heat exchanger network are considered
    simultaneously. Only one design (retrofit)
    variable is assumed area of the HEN. They
    claimed savings up to 25 over the base case.

52
Separation processes
  • Heat integration
  • Gadalla 2006 optimized an existing crude
    distillation column where a gas turbine/generator
    is integrated with the preheat furnace. They
    claim energy reductions of up to 21. The idea
    was then to maximize the energy generated in the
    gas turbine by adjusting the temperature of the
    feed, reflux ratio, steam flow rates, temperature
    difference of each pumparound, and the flow rate
    of the liquid through each pumparound.
  • Gadalla 2005 studied the design of an
    internally heat-integrated distillation column
    for separating an equimolar propylene-propane
    mixture where the 57 stages of the stripping
    column are heated by the first 57 stages of the
    rectification column. They claim that by
    increasing the heat transfer rate per stage,
    energy savings can reach up to 100 of reboiler
    duties. For this, the compressor power would
    increase only 15 w.r.t. the base HIDiC case.
  • By applying pinch analysis, Plesu 2003 propose
    to thermally couple crude distillation units and
    delayed coking units through the utility system.
    They basically proposed to send the vacuum
    bottoms to the delayed coking unit at a higher
    thermal load and use this artifice to generate
    part of the steam needed in the crude
    distillation unit. They do not report energy
    saving figures.

53
Separation processes
  • Heat integration
  • Liebmann 1998 proposed a systematic algorithm
    based on pinch analysis that lends to automation
    of the design procedure of crude oil distillation
    units where the column, the heat exchanger
    network, and their simultaneous interactions are
    considered together. Modifications that further
    increase the efficiency of the process are
    installation of reboilers rather than stripping
    stream and the thermal coupling of column
    sections. They claimed that units conceived by
    this method can save up to 20 energy w.r.t. the
    base case.
  • Szklo 2007 states that heat integration and
    waste heat recovery appears as one of the main
    options for saving fuel in the short to mid terms.

54
Separation processes
  • Design of efficient separation systems
  • Szklo 2007 discussed the use of catalytic
    distillation (CD) as an indeed very promise
    alternative to hydrotreating units, namely to FCC
    gasoline. The idea is to fractionate the gasoline
    by distillation, which yields several gasoline
    fractions, and then treat each fraction for
    sulfur according to their prevailing sulfur
    compound reactivities, all in the same unit.
    Lighter fraction are treated more severely while
    the heavier ones undergo desulfurization at
    higher temperatures at the bottom of the CD
    column. The authors claimed that up to 62 of
    energy can be saved w.r.t. conventional HDS
    processes.
  • Szklo 2007 also discussed the application of
    biodesulfurization in replacement of conventional
    HDS with energy savings of up to 80. However,
    the technology is still at its dawn, and the main
    barriers are the understanding of biological
    mechanisms of biocatalysts and the development of
    efficient two-phase biodesulfurization systems.
  • Schultz 2002 defended the thesis that
    dividing-wall columns (DWC) can save up to 30 in
    energy costs. In this technology, remixing of
    components towards the bottom or top of a direct
    sequenced train which causes thermal inefficiency
    is mitigated by cutting the product at their
    maximum compositions. However, Szklo 2007
    emphasized the need for further development of
    DWC for major distillation processes in the oil
    refining industry.

55
Separation processes
  • Design of efficient separation systems
  • According to Pellegrino 1999 a potentially
    attractive refining process modification is to
    input the crude directly into controlled thermal
    cracking units, thereby bypassing CDU. The idea
    is to crack large hydrocarbon molecules (e.g.,
    large asphaltene-type molecules) into smaller
    ones. They reported a reduction in energy
    consumption of 23 in addition to the fact that
    up to 80 of the energy generated in the unit can
    be recovered as reusable energy.
  • EIPCCB 2001 discussed the use of a radical
    revamp that encompasses atmospheric and vacuum
    distillation, gasoline fractionation, naphtha
    stabilizer and gas plant in one unit progressive
    distillation. It consists of a fairly complex set
    of separation steps and extensively uses pinch
    technology to minimize heat supplied by external
    means. The savings can reach up to 30 on total
    energy consumption for these units.

56
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

57
Recap and future directions
  • It seems there is no radical revolution going on
    in the oil refining industry so to handle energy
    efficiency. Instead, the 2020 Vision report API
    2000 lists
  • Reduction of fouling in heat exchangers is a
    definite priority.
  • Improved convection in furnaces is necessary.
  • Cogeneration needs to be optimized.
  • Use of conventional distillation should be
    minimized. Try membrane and catalytic
    distillation.
  • Lets not forget research in catalysis.
  • Comprehensive mathematical process models in oil
    refinery are a must for short term results DOE
    2000.
  • Process optimization is definitely in the oil
    refinery agenda Domijan 2005.
  • Investments in RD represent one way to help
    drive the industry toward a higher level of
    energy efficiency. However, implementation is
    still at its very infancy as there are still
    technological/psicological barriers.
  • Accordingly, separation processes need to be
    updated. However, one should look at the big
    picture.
  • Needless to say, energy reduction ? CO2 emission
    reduction!

58
Recap and future directions
  • Wanna a hint to decide your PhD project? Energy
    efficiency program for future oil refineries.
    Ease, 5 (huge) PhD projects
  • Fouling modeling and elucidation of its
    mechanism in the crude distillation unit
    (atmospheric and vacuum columns and respective
    HEN) as well as development of anti-fouling
    chemicals that little affects refining products
    quality.
  • Membrane theres still a technological barrier
    with the current membranes. More research is
    needed to extend the application to other
    separation units throughout the refinery.
  • Advanced process control and optimization
    investigation of plantwide control and
    optimization (I only found information about
    these issues applied to individual units).
  • Check also Hydrocarbon Processing Advanced
    Process Control and Information Systems 2005.pdf.
  • Heat integration investigation of more plantwide
    heat integration opportunities by pinch or exergy
    analysis.
  • Distillation design more on reactive (catalytic)
    distillation and dividing-wall technology applied
    to energy-intensive units (FCC, alkylation,
    hydrotreating, reforming, and crude distillation
    units). Especially, biodesulfurization.

59
Outline
  • A vision for the future
  • A simple guide to oil refining
  • Energetic issues in an oil refinery
  • Thermodynamic analysis and measures to improve
    energy consumption.
  • Crude oil distillation (atmospheric and vacuum)
  • Fluid catalytic cracking
  • Catalytic hydrotreating
  • Catalytic reforming
  • Alkylation
  • Hydrogen generation
  • Separation processes
  • Recap and future directions
  • References

60
References
  • Gadalla 2003a Gadalla, M., Jobson, M., and
    Smith, R., Increase Capacity and Decrease Energy
    for Existing Refinery Distillation Columns,
    Chemical Engineering Progress, April 2003, p. 44.
  • ANL 1999 - Petrick, M. and Pellegrino, J., The
    Potential for Reducing Energy Utilization in the
    Refining Industry, Argonne National Laboratory,
    ANL/ESD/TM-158, August 1999.
  • Linhoff 2002 - Linhoff March, a division of KBC
    Process Technology Ltd., The Methodology and
    Benefits of Total Site Pinch Analysis, 2002,
    http//www.linnhoffmarch.com/resources/technical.h
    tml.
  • Gary 2001 - Gary, J.H., and Handwerk, G.E.,
    Petroleum Refining Technology and Economics, 4th
    Edition, Marcel Dekker, Inc., New York, NY.,
    2001.
  • Packinox 2003 - Reverdy, F., Packinox, Inc.,
    High-Efficiency Plate and Frame Heat Exchangers,
    presented at the 2003 Texas Technology Showcase,
    Houston, Texas, March 2003.
  • Schultz 2002 - Schultz, M.A., Stewart, D.G.,
    Harris, J.M., Rosenblum, S.P., Shakur, M.S., and
    OBrien, D.E., Reduce Costs with Dividing-Wall
    Columns, Chemical Engineering Progress, p. 64,
    May 2002.
  • TDGI 2001 - The Distillation Group, Inc.,
    Distillation Energy Savings Improvements with
    Capital Investments (Section 4), 2001,
    http//www.distillationgroup.com/distillation/H003
    /H003_04.htm.
  • Liporace 2005 Liporace, F. S. and Oliveira,
    S. G., Real-time fouling diagnosis and heat
    exchanger performance, Petrobrás, Internal
    communication, 2005.
  • Exxon 2005 ExxonMobil, A simple guide to oil
    refining, 2005, http//www.exxonmobil.com/Europe-E
    nglish/Files/Simple_Guide_to_oil_refining.pdf

61
References
  • DOE 1998 - U.S. Department of Energy, Energy
    and Environmental Profile of the U.S. Petroleum
    Refining Industry, Office of Energy Efficiency
    and Renewable Energy, Office of Industrial
    Technologies, 1998.
  • API 2000 - American Petroleum Institute,
    Technology Vision 2020 A Technology Vision for
    the U.S. Petroleum Refining Industry, October
    1999.
  • Pellegrino 2005 - Pellegrino, J. and Carole, T.
    M., Impacts of Condition Assessment on Energy
    Use Selected Applications in Chemicals
    Processing and Petroleum Refining, U.S.
    Department of Energy, Industrial Technologies
    Program, 2005.
  • Seo 2000 Seo, J. W., Oh, M., and Lee, T. H.,
    Design Optimization of Crude Oil Distillation,
    Chem. Eng. Technol. 23 , p. 2, 2000.
  • Sharma 1999 Sharma, R., Jindal, A.,
    Mandawala, D., and Jana, S. K., Design/Retrofit
    Targets of Pump-Around Refluxes for Better Energy
    Integration of a Crude Distillation Column, Ind.
    Eng. Chem. Res. 38, 2411-2417, 1999.
  • Al-Qahtani 2006 - Al-Qahtani, A. H., Al-Juhani,
    A. Y., and Kumana, J. D., Detailed Energy
    Assessment at Oil Refinery Tools and Results,
    AIChE Annual Meeting, San Francisco, Nov 12-17,
    2006.
  • Kosobokova 2001 Kosobokova, E. M. and
    Berezinets, P. A., Developing an energy-saving at
    oil refineries, Chemistry and Technology of Fuels
    and Oils, Vol. 37, No. 1, 2001.
  • DOE 2000 U.S. Department of Energy,
    Technology Roadmap for the Petroleum Industry,
    Office of Energy Efficiency and Renewable Energy,
    Office of Industrial Technologies, 2000.
  • Liebmann 1998 Liebmann, K., Dhole, V. R., and
    Jobson, M., Integrated design of a conventional
    crude oil distillation tower using pinch
    analysis, Trans IChemE, 76, Part A, 1998.

62
References
  • Panchal 2000 Panchal, C. B. and Huangfu,
    E-P., Effects of Mitigating Fouling on the Energy
    Efficiency of Crude-Oil Distillation, Heat
    Transfer Engineering, 21 3-9, 2000.
  • Gadalla 2003b Gadalla, M., Jobson, M., and
    Smith, R., Optimization of existing
    heat-integrated refinery distillation systems,
    Trans IChemE, Vol 81, Part A, January 2003.
  • Rivero 2004 Rivero, R., Rendón, C., Gallegos,
    S., Exergy and exergoeconomic analysis of a crude
    oil combined distillation unit, Energy 29,
    19091927, 2004.
  • Szklo 2007 Szklo, A., Schaeffer, R., Fuel
    specification, energy consumption and CO2
    emission in oil refineries, Energy 32, 10751092,
    2007.
  • Goulda 2001 Goulda, R. M., White, L. S.,
    Wildemuth, C. R., Membrane Separation in Solvent
    Lube Dewaxing, Environmental Progress, 20 (1),
    2001.
  • Domijan 2005 Domijan, P. and Kalpic, D.,
    Off-Line Energy Optimization Model for Crude
    Distillation Unit, IEEE ISIE, June 20-23,
    Dubrovnik, Croatia, 2005.
  • Yeap 2005 Yeap, B. L., Wilson, D. I., Polley,
    G. T., Pugh, S. J., Retrofitting Crude Oil
    Refinery Heat Exchanger Networks to Minimize
    Fouling While Maximizing Heat Recovery, Heat
    Transfer Engineering, 26(1) 2334, 2005.
  • DOE 2006 - U.S. Department of Energy, Energy
    Bandwidth for Petroleum Refining Processes,
    Office of Energy Efficiency and Renewable Energy,
    Office of Industrial Technologies, 2006.
  • Al-Muslim 2005 - Al-Muslim, H. and Dincer, I.,
    Thermodynamic analysis of crude oil distillation
    systems, Int. J. Energy Res. 29, 637655, 2005.
  • Hovd 1997 Hovd, M., Michaelsent, R., Montin,
    T., Model Predictive Control of a Crude Oil
    Distillation Column, Computers Chem. Engng, Vol.
    21, Suppl., pp. S893-S897, 1997.

63
References
  • Wauquier 2000 Wauquier, J. P., Petroleum
    refining, Vol.2 Separation Processes, Editions
    Technip, Paris, 2000.
  • White 2000 White, L. S. and Nitsch, A. R.,
    Solvent recovery from lube oil filtrates with a
    polyimide membrane, Journal of Membrane Science,
    179, 267-274, 2000.
  • Nasr 2006 Nasr, M. R. J. and Give, M. M.,
    Modeling of crude oil fouling in preheat
    exchangers of refinery distillation units,
    Applied Thermal Engineering 26, 1572-1577, 2006.
  • Worrell 2005 - Worrell, E. and Galitsky, C.,
    Energy efficiency improvement and cost saving
    opportunities for petroleum refineries,
    Environmental Energy Technologies Division,
    Berkely, February 2005.
  • Gadalla 2006 - Gadalla, M., Olujic, Z., Jobson,
    M., and Smith R., Estimation and reduction od CO2
    emissions from crude oil distillation units,
    Energy 31, 2398-2408, 2006.
  • Gadalla 2005 - Gadalla, M., Olujic, Z.,
    Jansens, P. J., Jobson, M., and Smith R.,
    Reducing CO2 emissions and energy consumption of
    heat-integrated distillation systems, Environ.
    Sci. Technol. 39, 6860-6870, 2005.
  • EIPCCB 2001 - EIPCCB. Reference document for
    BAT for mineral refineries. Integrated pollution
    and control. Belgium European Comission, 2001.
  • DOE 2007 - U.S. Department of Energy, Energy
    and Environmental Profile of the U.S. Petroleum
    Refining Industry, Energetics Incorporated
    Columbia, 2007.
  • Rostrup-Nielsen 2005 - Rostrup-Nielsen, T.,
    Manufacture of hydrogen, Catalysis Today 106,
    293-296, 2005.
About PowerShow.com