THE YEAR-BOOK OF THE COKE OVEN - Coke-oven-managers.org

Introduction
Application of New Coke Oven Battery Technologies
on the World Market
by
Dr. Martin Reinke
UHDE GmbH, Germany
E-mail: Martin.Reinke@thyssenkrupp.com
In the early years of our century steel industry starts growing with
remarkable production increases year after year. This was mainly
influenced by the development in China, but also other countries, especially
in the rest of Asia followed this trend. Productions of steel and hot metal as
produced in blast furnaces are strongly influencing the demand for
metallurgical coke. As a consequence the coke price on the world market
was extremely high. Coke imported from China rose up to more than 500
US$ per ton, it’s quality was not always fully satisfactory and also the
reliability in terms of delivery schedule generated operational problems for
some blast furnace managers. High performing blast furnaces need
homogeneous coke with high and even quality parameters. All these factors
have been and still are the reasons for many new investments, either reinstallations
or expansion projects for coke oven plants, resulting in the
desired supply of “mono-coke”, which guarantees an undisturbed operation
of hot metal production. High quality coke has to be produced on the basis
of reasonably low capital and operational expenses, covering most stringent
environmental rules and matching the demand for high stability of the
ovens for a long life expectancy with an outlook to affordable long-term
maintenance cost. Steady development work in the design, engineering and
supply of coke oven batteries as performed for more than 130 years in
Germany lead to current technical concepts that are not comparable to old
existing units.
Dr Reinke presented this paper at the AIST Conference in Pittsburg
2010 and we are thankful to be able to include this version in the
COMA Year Book.
1

Discussion
Driving Forces for New Investments
The most important influences are the situation on the coke market, the age
of existing plants in connection with considerations referring to medium-
and long-term cost development of maintenance cost. In case of new
batteries to be built capital and operation expenses are taken as a basis for
decisions on technical concepts. Last but not least more and more stringent
environmental requirements have to be taken into account, which
consequently leads to the installation of coke oven batteries providing most
modern technologies in this regard, too.
Coke Market
A strong increasing demand for coke is indirectly demonstrated in figure 1.
An amount of more than 67% of oxygen steel, which is based on hot metal
production in blast furnaces, is a clear indication that this classical
production route keeps its dominant role. In relation to the growth of steel
production as shown here, the annual amount of coke produced rose from
350 million mt in 2003 worldwide to more than 540 million mt in 2008.
Demand and availability of coke during this period was not completely
outbalanced which led to the well known development of the coke price on
the spot market as illustrated in figure 2. It shows tremendous values still
in 2008 with a strong decrease after the beginning of the crisis. The price
FOB China is kept thereafter on a constant value, which obviously
represents an artificial figure, keeping in mind that the amount of exported
coke from China has dropped down to some 10-thousand tons of coke per
month in comparison to average values of about 1.2 million tons per month
in the foregoing period. A recovery of the market is visualized by the
increasing coke price CFR Europe, which represents a realistic relation
between demand and availability and also the Chinese coke price is
increasing at the beginning of 2010, despite the fact that only small portions
have been exported.
2

600
500
400
300
200
100
0
1600
1400
1200
1000
800
600
Oxygen steel
Electric steel
Open hearth steel
Thomas steel
400
200
30.7 %
0
2.1 %
1970 75 1980 85 1990 95 2000 2005
Source : Stahlzentrum / VDEh - Düsseldorf
3
67.2 %
Figure 1 World Crude Steel Production by Process (mill. mt /
year) 1
US $ / t
800
Coke export China Mill t/month
Mill t/month
1,8
700
1,6
FOB China
CFR Europe
2005 2006 2007 2008 2009 2010
Figure 2 Coke Prices (US$ / mt) and Coke Export ex
China (mill. mt / month) 2
1,4
1,2
1
0,8
0,6
0,4
0,2
0

Age of the Production Units
Since 2003 European suppliers of coke plants have realized order intakes
for approx. 30 mill. mt/year in total, reflecting 21 million mt for reinvestments
and 9 million mt for extensions. Only re-investments have
taken place in Japan within 8 projects for approx. 5 million mt. This is
caused by the comparably high age of Japanese plants with more than 36
years on average in comparison to the worldwide average of approx. 26
years. Due to intensive preventive maintenance coke oven batteries in
Japan are of an extremely high age. This is illustrated in figure 3 showing
the age distribution with almost 80% of ovens older than 30 years.
2000
1600
1200
800
400
0
Number of ovens
2.6 %
4.2 %
14.0 %
< 20 20 - 25 25 - 30 30 - 35 35 - 40 > 40
Years Takahashi Miwa / NSC, 4th ICSTI, Osaka, November 2006
4
39.5 %
33.7 %
Figure 3 Age distribution of Japanese coke oven batteries 3
Decisions for High-Capacity Ovens
(Capital and Operation Cost/Lifetime)
6.0 %
The development of high-capacity ovens is illustrated in figure 4. Starting
with less than 10 mt per charge and comparably small chamber volumes in
1900 the modern high capacity ovens with more than 90 m³ volumes are
producing more than 50 mt per oven.

The advantages of such big chamber volumes are the reduction of capital
and operation cost, optimization of environmental issues and the extension
of lifetime. A comparison of these items is shown in table 1. All figures
refer to a coke production of 2 million mt / year with typical oven heights
of 4.3m respectively 6m and common volumes in comparison to 7.6m high
ovens with a volume of 76m³. By applying the 7.6m-concept a reduction of
capital cost is influenced by less oven units, less space on site and less sets
of oven machines required. Less operation teams are required, which leads
to an optimization of operation cost. Even more than 2 million mt of coke
can be produced with on set of machines and one operation team,
demonstrated at coking plant Schwelgern producing more than 2.6 million
per year since 2003 for the blast furnaces of ThyssenKrupp Steel in
Duisburg, Germany 4 . The specific manpower at Schwelgern counts to 106
people per million mt. The former batteries produced the same amount of
coke with a specific manpower of 336 people per million mt. In a longterm
consideration it is also the expected lifetime of a battery that takes an
influence on the cost situation.
60
50
40
30
20
10
0
1900
tons of coke per oven
13 m³
32 m³
1920
1940
39 m³
1960
5
53 m³
1980
76 m³
2000
94 m³
useable chamber volumes
Figure 4 Development of Chamber Volumes - History

Oven height
Number of batteries
Number of ovens
Oven width
Useable volume p. oven
Numb. of pushes/charges p. day
Total length of sealings
(doors, standpipes, charging holes)
Required space for the batteries
Sets of oven machines
2
3
5
Operation teams 1
2
3
Typical number of pushes per oven during its lifetime :
World average / Maximum
12,000 15,000
Oven width : 450 mm
Coking time : 20 hr
Pushes per oven :
per day : 1.2
per year : 438
7.6 m 6.0 m 4.3 m
2 4 5
140 220 325
590 mm 450 mm 450 mm
76 m³ 34 m³ 20 m³
135 300 520
4.8 km 6.0 km 6.5 km
40,000 m 2
Oven width : 590 mm
Coking time : 27 hr
Pushes per oven :
per day : 0.9
per year : 324
Lifetime per oven ( average / maximum )
27 / 34 years 37 / 46 years
6
50,000 m 2
Table 1 Comparison for 2 million mt of Coke Per Year
55,000 m 2
The extended lifetime of a battery with high-capacity ovens in comparison
to a common design is illustrated in figure 5. A typical number of
operation cycles per oven within the lifetime of a battery is 12,000 on
average with maximum figures of approx. 15,000. Common ovens having
a typical chamber width of 450mm and a coking time of 20h are pushed 1.2
times a day with 438 pushes per year. High capacity ovens with a chamber
width of 590mm have 0.9 pushes per day and 324 pushes per year. This
leads to a total lifetime of 27/34 years of the common batteries in
comparison to 37/46 years for the high capacity units.
Figure 5 Different lifetimes of batteries

Environmental issues
The comparison in table 1 indicates a general better environmental situation
with the application of high-capacity ovens, generated by less pushing and
charging per day as well as by a reduced total length of sealing elements at
the oven closures, followed by less visible emissions.
A further and high efficient improvement of this emission behavior can be
achieved by applying the PROven ® - system, which represents a pressure
control system for each individual oven of a coke oven battery. Its general
function is illustrated in figure 6. The variable gas pressure
Coking Chamber
variable pressure
during coking to be
controlled by
PROven
PC
variable flow
resistance
constant and low pressure
in the coking chamber
with PROven
7
Collecting
Main
approx.
-25 mm w.c.
Figure 6 General Function of the PROven ® - System, a
Pressure Control for Each Individual Oven
inside the oven chamber is compensated by a variable and controlled flow
resistance, installed in the standpipe of each oven 5 . The collecting main
pressure is kept under a constant suction (typical -25 mm W.C.). By
applying additional fine tunings of the set points for the pressure control the
gas pressure inside the oven is kept on a low and constant positive level.
This results in low fugitive emissions at the doors and all other oven
closures and prevents air ingress at the doors into the ovens, avoiding
damage of the refractory material by overheating charging emissions, too,
are reduced drastically, since the full suction in the collecting mains can be
used for transferring the charging gases to the raw gas system.

The first development of PROven ® - was carried out by the company DMT
in Essen, Germany 6 . In cooperation with Uhde the system was developed
for technical application. In total it took about 10 years until the first coke
oven batteries without any additional provisions, such as high pressure
water aspiration have been installed at the Schwelgern coking plant in
Germany. The history of the development is shown in table 2, indicating
its technical maturity.
1991 - 1994 1995 - 1997 1997 - 1999 1999 - 2003
R & D
at DMT
semi-technical
research
+
assignation of
patent
Testing at
5 ovens of
coking plant
August
Thyssen (ATH)
4m-high
chambers
30 ovens
4m-chambers
same battery
(ATH)
+
DMT grants
Uhde an
exclusive
license
8
6m-Battery
ATH at
52 ovens
(DMT+Uhde)
+
2003 :
2x70 ovens
Schwelgern
Table 2 10 years development of the PROven ® - system
After the commissioning of PROven ® at Schwelgern many other
applications have been realized world wide, which is also shown in table 3.
In total 33 batteries comprising more then 2000 ovens are under contract
with a different status of realization. Likewise, existing batteries under
operation have been and, respectively, will be equipped with this system.
The contract for the battery in the USA is on hold, resulting from influences
of the crisis. In this connection it should be mentioned, that the EPA has
acknowledged this technology as an alternative to the heat-recovery type of
ovens due to its convincing environmental features.

Contracts for the PROven ® - System
Country Oven height
No. of
batteries
9
No. of
ovens
Mio t of coke
per year
New batteries
Germany 8.4 m 2 140 2,6
China 7.6 m 12 840 12,0
S.-Korea 7.6 m 8 440 6,0
6.7 m 1 75 0,8
Existing batteries
Brazil 6.0 m 3 105 1,1
6.6 m 3 147 1.8
Options for new batteries
S.-Korea 7.6 m 2 120 1,6
Germany 7.8 m 1 70 1,1
USA 6.1 m 1 85 0,9
Total
33 2022 26,1
Table 3 Acceptance of PROven ® Worldwide
Installation of New Production Capacities
One of the results has already been shown in connection with the
installation of PROven ® at new and existing batteries. The general trend
with regard to the type of batteries moves strongly into the direction of
batteries comprising high-capacity ovens, clearly influenced by the
advantages as indicated above. The first step was the dismantling of the
former coking plant “Kaiserstuhl”, located in Dortmund, Germany, with a
rebuild of all facilities in Yangkuang, China. This happened in the period
from 2003 to 2005, followed by many new batteries of this type in China.
In total approximately 14 million mt of coke production capacity has and,
respectively, will be installed in this strong growing country. Location and
production figures are illustrated in figure 7.

WUGANG
TISCO
Two
coke oven batteries
7.6 m height
2 million tpy
Two
coke oven batteries
7.6 m height
2 million tpy
Beijing
SHOUGANG / Caofeidian
Shanghai
MAGANG
SHAGANG
Two
coke oven batteries
7.6 m height
2 million tpy
10
Four
coke oven batteries
7.6 m height
4 million tpy
YANKUANG
Relocation Kaiserstuhl
Two
coke oven batteries
7.6 m height
2 million tpy
Figure 7 Installation of Batteries With High Capacity
Ovens in China – 14 million mt/a in Total
This development also had an influence on other markets, as shown in
figure 8. Actually 4 batteries each of this type are under construction
and/or have entered into the commissioning phase in South Korea, that
means for POSCO in Gwang Yang and for Hyundai Steel in Dangjin,
respectively. A second option for another two batteries for Hyundai Steel is
under consideration. In all cases complete gas treatment plants for the
whole production belong to the scope of supply.
Several conventional coke oven batteries with normal oven volumes have
been installed in Asia and other countries, comprising all remaining new
technology items, such as equipment for environmental protection.
Situation After the Crisis
From about 1.4 billion mt of crude steel in 2006 the annual production
dropped down to 1.2 billion mt in 2009. Accordingly the coke production
was influenced due to the reduced demand. Coke oven batteries have been
set in idle-hot or in some extreme cases they have been shut down totally.

Four
coke oven batteries
240 ovens
7.6 m height
3.2 million tpy
incl. gas treatment
+ option :
Two
coke oven batteries
120 ovens
7.6 m height
1.6 million tpy
incl. gas treatment
HYUNDAI STEEL CORP:
POSCO - GWANGYANG:
Figure 8 New high capacity ovens in South Korea
11
Four
coke oven batteries
200 ovens
7.6 m height
2.8 million tpy
incl. gas treatment
With regard to the situation for new projects, delays, terminations and onhold
settings were the result.
Some examples:
The contract for the second battery of Hüttenwerke Krupp Mannesmann
(HKM), located in Duisburg, Germany was placed on hold. The
engineering for 70 high-capacity slot-type ovens for a production of 1.1
mill t/year has been finalised and the preparation site works have been
stopped. So far there is no further progress visible.
In the USA two contracts have been influenced. One was for US-Steel
Clairton Works and has been terminated. Uhde Dortmund as technologysupplier
for Uhde Corporation of America (UCA) has prepared a certain
amount of the engineering work for the rebuild of Battery C, comprising 85
slot-type ovens with a height of 6.1m and providing a production capacity
of 0.9 mill t/year. After a long period this was the first contract for a
conventional coke oven battery in the US due to the fact that the EPA has
acknowledged the installation of PROVen ® the single oven pressure control
system at this battery as an alternative to the environmentally friendly heatrecovery
coking technology.
The second project in the US to be mentioned is kept on hold. A leading
steel company has placed an order to UCA for a heat-recovery coking plant,

comprising 140 ovens and prepared for a production of 0.9 mill t/year,
based on a coal compacting technology developed by Uhde. In this case,
too, UCA has placed an order to the German technology supplier Uhde
Dortmund. Certain engineering packages have been finished and the
delivered equipment has been taken on stock. Further progress is still open.
However the increasing production figures for steel worldwide are a strong
indication that in the field of new investment for coking plants, too, a
positive market can be expected. Likewise, the coke price has shown an
increasing trend by the beginning of 2010.
Summary and Outlook
Before the economic crisis, accompanied by critical developments in the
iron and steel industry, conditions for new investments world wide, and in
the field of coke making, too, were excellent. Many new plants have been
installed either as substitutions of existing old facilities or as extension
projects covering the increasing demand for steel, hot metal and
consequently coke. Long lasting work of development for the coke making
technologies could be materialised at many places in the world, especially
in China and in the rest of Asia. Efforts for optimizing specific cost for
investment and operation can be covered by installing batteries with highcapacity
ovens. Batteries of this type have been installed for a total
production of approximately 20 million t/year since 2003. Likewise, the
environmental situation will be improved by the operation of high capacity
ovens, since for a certain coke production per year less charging- and
pushing cycles have to be carried out. In addition this takes a positive
effect on the lifetime to be expected for these production units. A big jump
forward in terms of environmental optimisation was realised by the
development of a single chamber pressure control system, called PROven ® ,
which brings the fugitive and visible emissions of a coke oven battery down
to almost zero, including charging emissions. The development of this
system within a period of 10 years stands for a technical mature technology.
Its application on more than 2000 ovens proves its acceptance wide.
12

References
1. Private communication, Stahlzentrum, VDEh-Düsseldorf, Germany
2. A. Jones, Coke Market Report, Analysis of the Global Coke &
Metallurgical Coal Market, www.resource-net.com
3. T. Miwa, Development if recent iron-making technologies in Japan, The
4 th International Congress on the Science and Technology of Ironmaking,
November 26-30, 2006 Osaka, Japan, Proceedings pp. 26-32
4.K. Hofherr; Improved Environmental Protection through Modern Coke
Plant Technology at the New Plant in Schwelgern; Coke Making
International, Vol.13, 1/2001, pp 39-45
5. H. J. Giertz, New process to avoid emissions: constant pressure in coke
ovens, Ironmaking Conf. Proc. 54, 1995, 439-445 (Nashville)
6.Operation Experience Gained with PROven ® (Pressure Regulated Oven
System) in the New Schwelgern Coke Oven Plant, Proc. 5th European
Coke and Ironmaking Congress, June 12-15, 2005, Stockholm,
13