ll/
United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S2-83-037 Sept. 1983
Project Summary
Emission Testing and Evaluation
of the Enclosed Coke Pushing
and Quenching System
G. P. Current
A new coke battery was placed into
operation in May 1973 by National
Steel Corporation's Weirton Steel Divi-
sion. Consisting of 87 ovens, each 6 m
tall, this battery included features to
reduce environmental discharges from
coke pushing and quenching opera-
tions. Pushing emissions were to be
contained by a one-spot coke receiver
car and retractable coke guide hood
evacuated through a fan-scrubber sys-
tem on the traction drive car. The hot
coke would then be discharged from
the receiver car into below-track hop-
pers from which it was withdrawn and
quenched semicontinuously in vibrat-
ing conveyors. From the outset, opera-
bility of the system was severely re-
duced by erosion, corrosion, and oxida-
tion of coke handling components and
the presence of explosive gas mixtures,
especially in the quenching facilities.
Extensive efforts were made to resolve
these problems. The quench system is
currently shut down; alternative facili-
ties are being explored. Emission meas-
urements in the pushing control scrub-
ber exhaust averaged 224 mg/Nm3
(18 g/Mg coke). Operating costs were
documented to be$1.23/short ton for
the pushing system and $4.58 /short
ton for the quenching system. These
costs are estimated to be 26 and 280
percent, respectively, higher than for
conventional uncontrolled coke push-
ing and baffled quench tower installa-
tions.
This Project Summary was developed
by EPA's Industrial Environmental Re-
search Laboratory, Research.Triangle
Park. NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
In May 1973, National Steel Corpora-
tion's Weirton Steel Division completed
the construction of a new coke plant on
Brown's Island, at Mile Point 62 on the
Ohio River near Weirton, W V. The coke
battery consists of 87 ovens, each 6 m tall,
with a design coke production rate of
approximately 2900 metric tons (3200
short tons)/day. This coke plant features
highly advanced production and environ-
mental control facilities. One very signifi-
cant feature of the coke plant involved the
development of new technology for the
control of emissions from the coke pushing
and quenching operations.
In 1972, Weirton Steel entered into the
first of two jointly funded research and
development contracts with the EPA for
developing an enclosed coke pushing and
quenching system. This technology, de-
signed and constructed by Weirton Steel
and Koppers Company with the support
and cooperation of the EPA, provides for
the total enclosure of the coke during the
pushing, transfer, and quenching opera-
tions. Scrubbers and mist eliminators are
used to minimize the paniculate emissions
from these operations.
EPA contract 68-02-0622, executed in
early 1 972, covered the design and con-
struction of this system. This contract
concluded with the issuance of a design
manual.* EPA contract 68-02-1347,
(*) Pengidore, D.A. Enclosed Coke Pushing and Quench-
ing System Design Manual, EPA-650/2-73-028
(NTIS PB 22641 8), September 1973.
-------
"Emission Testing and Evaluation of the
Enclosed Coke Pushing and Quenching
System," was executed in June 1973.
The purpose of this contract was to docu-
ment the system's emission control capa-
bility, reliability, and operating cost over a
12-month period of performance.
Unfortunately, numerous problems have
prevented the continuous operation of this
system. These problems have necessitated
the complete re-design and replacement
of many major components within the
system and have resulted in lengthy delays
during which the system was inoperative.
Programs, costing several million dollars,
have been implemented by National Steel
to improve the operability of the system
between 1973 and 1980. Although sig-
nificant progress has been made in this
regard, continuous operation has still not
been achieved due to potential explosive
hazards associated with the system.
This report was submitted to the EPA in
fulfillment of Contract 68-02-1347. It
documents the design of the system after
the completion of National Steel's multi-
million dollar optimization programs and
describes the problems which were en-
countered. In addition, an analysis of the
environmental, energy, and economic as-
pects of the system is presented. This
work was completed as of December 1980.
Conclusions
The enclosed coke pushing and quench-
ing system demonstration was a full-scale
research and development program. Al-
though the program was not totally suc-
cessful, the technological benefits derived
by others from this demonstration cannot
be over-emphasized. As a forerunner in
the development of enclosed coke pushing
and quenching technology in the U.S., this
program has influenced subsequent de-
signs by others who learned from the early
successes and failures at Weirton Steel.
The enclosed pushing emissions control
system is a viable technology which has the
ability to comply with reasonably available
control technology (RACT) and proposed
lowest available emission rate (LAER)
standards applicable to the Brown's Island
Plant The maintenance requirements
associated with this mobile system are
significant, but acceptable. The operating
cost for this mobile system is estimated to
be $1.35 per metric ton ($1.23 per short
ton), which is approximately 26 percent
higher than a conventional uncontrolled
system. Further modifications are required
to eliminate the potential explosive hazard
associated with the gas cleaning car. This
may be best accomplished via the expan-
sion of gas cleaning car fan capacity and
improvements to the battery refractory
and heating systems to minimize under-
carbonized coke. A major disadvantage of
this mobile system is its present reliance
on a refractory-lined transfer car which
dictates use of an underground continuous
quenching system. Consideration is being
given to replacing the refractory-lined
transfer car with a quench car that is
compatible with aboveground quenching
facilities.
The anticipated advantage of the under-
ground continuous quenching system was
the opportunity for improved control of
coke moisture and steam emissions during
the quenching operation. Improved con-
trol of coke moisture was not achieved by
this installation; in the opinion of National
Steel, the control of steam emissions be-
came an academic point since, given clean
water for quenching, adequate control can
be achieved by the installation of mist
suppressors in conventional quench towers.
The operating cost for the underground
quencher is estimated to be $5.05 per
metric ton ($4.58 per short ton), an in-
crease of 280 percent above the operating
cost of a conventional quench tower. This
cost is excessive, not justified by any
benefits derived from this technology. The
operating experience at Weirton cannot
lead to the recommendation that this tech-
nology be installed elsewhere; Weirton is
considering replacing the underground
quencher with an aboveground quenching
tower.
The enclosed coke pushing and quench-
ing system demonstration exemplifies the
fact that, in many cases, pollution control
technology with the capability of high
operability and reliability at an adequate
paniculate removal efficiency is more en-
vironmentally effective than technology
that operates at low operability and reliabili-
ty, but with an ultrahigh paniculate re-
moval efficiency. Weirton is dedicating
future efforts to developing lower cost
technology which can achieve adequate
emission control and demonstrate the
high degree of reliability required for con-
tinuous operation. One technology under
development at Weirton is the Two-Step
Quenching (TSQ) System for pushing
emissions control.
G. P. Current is with National Steel Corporation, Weirton, WV 26062
Robert C. McCrillis is the EPA Project Officer (see below).
The complete report, entitled "Emission Testing and Evaluation of the Enclosed
Coke Pushing and Quenching System," (Order No. PB 83-206 953; Cost:
$13.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park. NC 27711
AUS GOVERNMENT PRINTING OFFICE 1983-659-017/7181
-------
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Postage and
Fees Paid
Environmental
Protection
Agency
EPA 335
Official Business
Penalty for Private Use $300
Pb 000032V
U S ENVIR PROTECTION AGENCY
REGION 5 LIBRARY1
230 S DEARbORN STREET
CMICAGU IL 60604
------- |