RecentTrendsinHeatRecoveryCokemaking_JohnQuanci

7/27/2019 RecentTrendsinHeatRecoveryCokemaking_JohnQuanci

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Recent Trends in Heat Recovery Cokemaking

Processes

Dr. John F. Quanci

SunCoke Energy

Vice-President of TechnologySeptember 2011

September 2011 SunCoke Energy 1


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Outline

Iron Production: Coke Usage

Heat Recovery Cokemaking Technology History

Heat Recovery Cokemaking: Current Practice

Future Requirements and Direction in Heat Recovery



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Iron Production: Coke Usage

3September 2011 SunCoke Energy


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Iron Production: Coke Minimization Coke is the 2nd highest cost consumable in Steel

production

~25% of the total cost

Iron highest at ~40% of total cost

Blast furnace competitiveness depends on lowering

coke use

Steel Industry focused on lowering coke use for the

last 50 years by advances in practices and technology



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Reduction Blast Furnace Reducing Agent Consumption

Impact of Technology over the last 50 years:

Reducing Agents lowered by over 50%

Coke use lowered by over 65%

Source: Sponge Iron Production - Chatterjee

0

100

200

300

400

500

600

700

800

900

1000

1100

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

consumptionofred

uctants

kg/thm

year

coal

oil + others

coke

Ore beneficiation

Input of overseas rich ores

Blast temperature > 1200C

O2 enrichment

Top pressure

Burden distribution

Gas flow control

Improvement of Fe burden

Improvement of coke

Small coke in Fe burden

345

33

104

482

~30%

September 2011 SunCoke Energy5


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Global Demand for Coke and Hot Metal

Even though Steel Companies driving down coke/thm through technology and alternate

reductants, coke demand still increasing

Increasing demand for coking coals expected

Source: US Geological Survey



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Alternate Reductants for Coke Replacement

Increased use of PCI and other reductants to replace coke in

Blast Furnaces

As high as 30-40% of blast furnace coke has been replaced by

alternate reductants like PCI

Alternate reductants could potentially make up as much as

50% of the total reductant

As alternate reductants like PCI increase, higher quality coke

needed:

Supports the burden (about 50% of total reductant)

Distributes gases

Will drive demand for larger and stronger coke!



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Heat Recovery Technology History



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SunCoke Energy Process Flow Diagram

Sun Coke

Process Flow Diagram

Condenser

Coal 1,930 F Flue Gas temperature ID Fans

Heat Recovery

Steam Generators

Coal - BlendedVM 24.50

FC 68.25

Ash 7.25

Moisture 7.00

Furnace coke

Breeze

Co-generation Plant

Steam

Extracted

for Process

Use Electricity to Grid

Heat Recovery Coke Ovens

Flue GasTreating

for SulfurRemoval

Run-of-OvenCoke

Main Stack

Turbine

Feed WaterHeaters, Pumps,DeaeratorsEmergency

Stack



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SunCoke Energy Horizontal Heat Recovery Oven



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Horizontal Non-Heat Recovery Developmental History

1960s

First SunCoke Horizontal Mitchell Ovens in Jewell

1970s

Jewell Thompson ovens built

Precursor to modern HHR design 1980s

Continued R&D

Highest quality coke in US

Jewell Plant Vansant, VA

(Mid-1970s)

Jewell Plant late 1980s



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1990s First Generation Heat Recovery Plant

SunCoke builds first heat

recovery plant in world

Located in East Chicago, Indiana

Started up in March 1998

Coke capacity: 1.3M tpa (268

ovens)

Heat Recovery of 1.0 Mlbs/hr of

superheated steam

Rated for 100 MW of power

generation

Indiana Harbor Coke Plant March 1998



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SunCoke Energy History since 2000 New HR Plants

International Operations

(1) Expected start-up in Q4 2011.

(2) SunCoke holds a preferred interest of $41 million in Vitria and is the operator.

Vitria(2) (2007)

320 Ovens

Capacity: 1,700kt

Power: 150 MW

Brazil

Indiana Harbor

268 Ovens

Capacity: 1,220kt

Steam: 1,000klbs/hr Haverhill (2005, 2008)

200 Ovens

Capacity: 1,100kt

Steam: 450klb/hr

Power: net 46 MW

Granite City (2009)

120 Ovens

Capacity: 650kt

Steam: 450klbs/hr

Domestic Operations

Coke facility under construction

Existing coke facilities

Jewell Coke

142 Ovens

Capacity: 720kt

Middletown(1)

100 Ovens

Capacity: 550kt

Power: net 46 MW



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SunCoke Heat Recovery Plants

Vitoria, ES Brazil (320 Ovens)

Haverhill, OH Phase II (100 Ovens)



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Most recent project Middletown, OH



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SunCoke Energy Capacity through 2011

HeatRecoveryCapacity

Steady increase in SunCoke Energy heat recovery coking capacity over the last 5 10 years

All new coke plants in United States since 2000 have been Horizontal Heat Recovery



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Last 5-Year Technology Advancements

Improved Oven Design

Improved HRSG design

Pusher charger machine upgrades

Flat push hot car & quench car

Further enhanced charging

emission control system

Advanced FGD Control

EPA Approved Technology

Improved Quench Tower Design



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Heat Recovery Cokemaking:Current Practice



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Typical SunCoke Energy Battery

Coal specifications Typical volatile matter is 21% to 28%, campaign 19% to 32%

Average reflectance range of 1.00 to 1.65

Can generate steam or power

Approximately 9 MW / 100 kmt annual Run of Oven coke production

Annual power production of 788 kW-h / mt coke

No wastewater treatment plant required

Can be constructed on a new site or existing site (brownfield)

48 hour cycle / 43.2 metric tons (48 short tons) coal

1540C max temperature

Plant designed for 30 year run life

Approximately 2 4% Yield Loss

2 5 CSR increase over By-product plant using same coals

Improved Strength attributed to slower heating rate, higher temperatures and longer soak

time resulting in consistent crystal growth



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HHR Coal Flexibility Not limited by coal expansion

Can use high wall-pressure coals

Can use low and high rank coals

SunCoke demonstrated use of PCI coal (25%), Petroleum Coke (10%), non-

coking coal (10%), soft or semi-coking coal (25%) and breeze with minimalimpact to CSR

No oven damage risk associated with blend changes

Minimal need to run pilot/moveable wall oven studies

Less risk of exposure to coal supply shortages / issues

SunCoke Energy facilities can change coal blends weekly Up to 80+ different coal blends used per year



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Heat Recovery Oven Flexibility

HHR Not constrained

to this maximumHR only

HR &

By-Product

Heat recovery plants can blend in more high pressure coals

Elimination of wall pressure constraints increases blend flexibility

Hypothetical

blend of 3 coals



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Environmental Impact Benefits

Low VOC emissions

Ovens operate under negative pressure conditions during coking cycle

Complete combustion of VM

SunCoke Energy sets the technology standard in United States

SDA / baghouse is typical

Successfully integrated advanced FGD with coking process

No net waste-water discharge

All process water consumed by quenching



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Factors Favoring Heat Recovery Plants

Minimal need for COG in the steel plant

High cost of electricity or no electricity supply available

Steam required for process needs HHR is a Cogen plant and can replace existing boilers

Coal blend flexibility (no wall pressure limits) Can utilize wide range of coals (lower cost blends)

Plant location at risk for coal supply disruptions

Strict environmental regulations

No or limited waste water treatment plant

Higher quality coke is required Large blast furnaces and/or high PCI rates



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Future Trends in Heat Recovery

Cokemaking


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SCE Horizontal HR Coke Plant Improvement Summary

Critical Areas for Customers Next Plant Future Plants

Footprint Potential 30% Smaller >30% Smaller

Capital Cost Value Engineered -

Lower Capital

Further Capital Decrease Driven by

Footprint

Coke Yield Lower Yield Loss Increased Yield Gain

Lower Coal Cost Flexibility for Stamp Charging

Predictive coal blend modeling

improvements

New Designs

Turndown Greater than 25% >50% and Turn Off

Environmental Regs Meet or exceed New EPA Regs Exceed EPA Regs

Continue to set the standard

Oven Operation/Life New Monitoring Tools Structure

Improvements

New Materials of Construction and

CFD/FEA

Increased Power New HRSG Design Further Improvements based on

CFD



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Value Engineering Coke Plant: Conceptual Designs

Value engineering can reduce capital investment

Maintain coke rate with less supporting capital equipment

Reviewed existing design and reduced number of machines

Also looking to use low-cost country sourcing

Design Enhancements

Plot space saving

Simplified power production design

Meets or exceeds new Environmental requirements Modular expansion provides more flexibility for brownfield

sites



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Coke Yield Improvements

Currently studying parameters that effect the Run of Oven

coke yield

Goal is to minimize burn loss through fundamental design

changes of the coke oven

Ties in very well with future modeling work (CFD and

combustion kinetics)



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Low Cost Coal Utilization

Horizontal Heat Recovery ovens have blend advantage since nowall pressure limit Larger selection of low quality and low cost coals

Coal Compaction/Stamp charging has high potential to loweroverall coke cost Significantly reduce coal costs and maintain high coke quality

Required in India/China where large quantities of low quality coal

International coke producers claim 40 to 60% low quality coal usage in coalblends

Coal/Coke Blend Modeling is crucial to take advantage of Coal

Flexibility and Stamp Charging



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Coal/Coke Chemistry and Blend Modeling

Advance fundamental knowledge of the coking process

Coal blend/coke prediction model for world-wide applications

Optimization of coal/coke blends through first principlemodeling

Go beyond current empirical correlations Function of Operating Conditions, Coal Properties and Reaction Kinetics

CSR, Stability, Yield, Power, etc

Coal/Coke Non-Linear Program Optimization Tool

Pilot plant and large-scale testing for coal blend testing, model

development and next generation coke oven design



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Model Development: Coal Blends

Develop coal blends/models with non-linear multidimensional optimization and design of

experiment

Pilot Plant studies allow for non-production viable blends to be tested for the purpose of

statistical leverage on model building and testing

Planned test Space

Coal 3

Coal 2Coal 1

reflectance

log(fl

uidity)

optimalcoking range



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Computational Fluid Dynamics (CFD) OvenModel

Advance coke making science, technology and principles through the use and application of Advanced

Computational Tools (CFD/FEA/Rxn Kinetics)

Link CFD, coke/coal blend/kinetic models and oven structural FEA models to allow fully integrated design and

optimization

Using CFD to optimize oven design and operation; lower yield loss, faster rates, new designs etc

Temperature

(F)



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Coke Oven Turndown Optimization

Allow flexibility for industry turndowns and coal shortages

Safe , efficient, and quick turndown of SCE oven without

damage to the oven structure or life while maintaining coke

yield and quality

Improve Max turndown on existing plant

Ovens have been turned down greater than 25%

Further tests may show greater turndown possible

Improvements to allow more turndown and potentially turn

off existing ovens



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Next Generation Environmental Control

Next North American Plant to meet or exceed EPA regulations

Lower SOx

No planned venting

Still lowest in HAPs/VOCs since negative pressure

Improved Quench Tower Design Lower Emissions

Better Reliability

Faster and more efficient quenching

Environmental Controls can be optimized to meet localrequirements and needs



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Next Generation Coking Process Future Goals

Lower Capital Cost and Lower Cost of Conversion

High Turndown (turn off)

Improved HRSG/FGD reliability and integration

Low yield loss (9 MW/100k mtpa Coke)

Smaller Footprint Coke Plant

Improved Coke Quality

Maximize low quality coal Increased throughput over current designs

Meet or exceed Environmental requirements



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Summary SunCoke Energy has advanced horizontal heat recovery

technology over the last 50 years

Oven design perfected from 1960s to 2010s

Currently looking to optimize heat recovery and push the limits of

technology

Will continue to improve the Heat Recovery process Better coal blend predictions

Lowest possible turndown capabilities

Advanced process modeling for optimal operation

Smaller footprint with lower CapEx and OpEx costs Improved Environmental Controls

Aspiring to bring science to the art of cokemaking


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RecentTrendsinHeatRecoveryCokemaking_JohnQuanci