xvEPA
United States
Environmental Protection
Agency
Industrial Environmental Research"
Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S7-81-038 May 1981
Project Summary
Batch Pretreatment Process
Technology for Abatement of
Emissions and Conservation of
Energy in Glass Melting
Furnaces: Phase I. Process
Design Manual
R. E. Miller, K. R. Jones, N. J. Camancho, G. B. Boettner, J. H. Bruns, and
B. Bansal
The Environmental Protection Agen-
cy contracted with Corning Glass
Works for the development of a glass
batch pretreatment process which
would abate emissions and reduce
energy usage in the melting furnace.
The project is funded by the Environ-
mental Protection Agency, the De-
partment of Energy, and the Corning
Glass Works.
This project was initiated to demon-
strate the feasibility of the glass batch
preheating concept and to provide
preliminary economic data on full-
scale implementation of the concept.
The contract consists of two phases
of work. Phase I, now completed and
reported in this document, was a
laboratory phase to supply the infor-
mation needed to design a pilot plant
system, and based on this design, to
estimate the energy, pollution, and
economic advantages of the program.
Phase II will consist of constructing
and operating a batch preheating pilot
plant test facility to confirm the bench
scale test results and to provide the
necessary design and operating infor-
mation for a full-scale production
facility. The Phase II results will also
be used to update the energy, pollu-
tion, and economic advantages of the
process.
This report is submitted in fulfill-
ment of the Phase I portion of Contract
#68-02-2640 by Corning Glass Works
under the sponsorship of the U.S.
Environmental Protection Agency.
The report covers the period from
August 15, 1977 to November 1,
1978.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory. Cincinnati. OH,
to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
Phase I consisted of eight tasks and
was primarily concerned with soda-lime
glass batch since over 75 percent of the
glass produced in the United States isof
this composition. A limited amount of
work was. performed with borosilicate
glass batch. These tasks are described
below:
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Task 1 — Information Analysis
An information and patent search was
completed to document available litera-
ture concerning glass batch agglomera-
tion and preheating.
Task 2 — Material Selection
Batch materials were investigated and
selected to conform with present glass
making practices, taking into account
geographic locations and tonnages.
Task 3 — Consolidation
The process of pelletizing was charac-
terized in terms of optimum materials,
water content, type of equipment and
equipment operations. Pellets and bri-
quettes'were made from soda-lime and
borosilicate glass batches.
Task 4 — Drying and Preheating
A laboratory static bed preheater was
constructed and operated to test the
drying and heating of soda-lime glass
batch pellets. Requirements for a pro-
duction system were developed, and
dried and preheated soda-lime glass
batch pellets were supplied for subse-
quent tasks.
Task 5 — Pollutant Capture
The preheater was operated to determine
the capture of sulfur dioxide (S02) and
sodium sulfate (Na2S04) particulates by
a static bed of soda-lime glass batch
pellets at 800°C. Typical flow rates and
pollutant concentrations from a produc-
tion glass melting furnace waste heat
system were simulated. Preheated and
partially prereacted pellets were supplied
for analysis and melting studies.
Task 6 — Hot Transfer
The handling, flew, and sticking behavior
of pellets were studied. Full-scale testing
was conducted feeding loose batch and
cold pellets through a batch charger and
a simulated furnace backwall.
Task 7 — Melting Studies
Comparative quality evaluations were
made of crucible melts of preheated
pellets, dried pellets, and various loose
batch formations.
Task 8 — Process Design Manual
A technology potential was completed,
based on expected benefits for energy,
pollution, and economics and informa-
tion was developed to establish specifi-
cations and costs for a pilot plant system
in Phase II.
Conclusions
The conclusions derived from the
Phase I studies are based on detailed
experimental results on each aspect of
the glass batch preheating technology.
They include studies made on raw
material acquisition and handling,
chemical and physical properties of
glass batch and batch materials, batch
melting properties and glass melts
quality. The following conclusions are
based on the results of these experi-
ments and studies.
Raw Materials
Soda-lime glass batch materials can
be palletized and preheated prior to the
introduction into a melting furnace.
Although minor changes in batch com-
position will be necessary, studies have
shown that the raw materials required
to produce pelletized batch are com-
mercially available. The additional cost
of the materials will be offset by the
savings derived from improved furnace
output. Studies of preheated pellets
made from these batch materials have
also shown that there should be an
increase in glass productivity without a
sacrifice in glass quality.
Consolidation
Both briquetting and pelletizing are
viable methods of consolidating (ag-
glomerating) soda-lime glass batch.
Neither method is clearly superior to the
other.
Drying
Drying temperatures and rates for
batch pellets were investigated to deter-
mine the importance of pellet strength
and integrity. Since pellets when first
formed are wet and weak, partial drying
will be required for pellets to survive
further handling.
Preheating
Soda-lime glass batch pellets pre-
heated to 800°C were judged to have
strengths satisfactory for feeding glass
melting furnaces. No pellet sticking
problem is anticipated at that tempera-
ture. From the static bed preheater
experiments, relationships were devel-
oped for designing the pilot plant pre-
heater. This work confirmed Columbia
Gas pilot plant design equations for
preheated batch.
Pre-reaction
Pre-reaction of preheated pellets was
investigated using a thermogravimetric
analyzer. Pre-reaction is considered
important because it means that the
actual melting process will begin with
some gaseous reaction products escap-
ing before the materials are introduced
in the melting furnace. Less gas intro-
duced with the pre-reacted pellets
requires less gas to be fined or removed
from the molten glass bath, and hence
melting rates may be increased or
melting temperatures may be decreased.
Studies showed that pre-reaction oc-
curring below 600°C was insignificant,
but that half of the possible pre-reaction
occurred at 800°C.
Pollutant Capture
Using a static bed preheater, studies
indicated that 800°C soda-lime glass
batch pellets can capture from 75-85
percent of the SOz in a gas stream
flowing at 0.43 m/sec. (17 in./sec.)
through the bed.
Hot Transfer
The static bed studies indicated that
at least 32 percent of the Na2SC<4 par-
ticulate matter in the gas stream can be
captured, based on particulate in the 10
micron range.
Melting Studies
The combined effect of a 50°C reduc-
tion in melting temperature and the
associated 15 percent reduction in fuel
results in an overall 65 percent reduc-
tion in expected NO* emissions.
Pilot Plant Design Study
The average regenerative, soda-lime
furnace stack, gas temperature is not
high enough to preheat pellets to 800°C,
although the energy lost through inef-
ficiences is sufficient to do so. However,
there are means to modify existing
furnaces to achieve the desired temper-
ature, while new furnaces can be speci-
fically constructed to achieve the de-
sired 800°C temperature. The pilot
plant design will utilize a direct-fired
furnace capable of achieving 800°C
without modifications. Use of this type
of furnace will not negate the results of
the pilot study to verify the viability of A
the technology. ™
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Energy and Cost Savings
Energy savings are projected to be 8.5
x 1016 joules/year (1.4 x 106 barrels of
oil equivalent) if 35 percent of the soda-
lime container furnaces utilized this
technology.
Recommendations
The completion of the Phase I portion
of the program has resulted in the
identification of additional background
requirements to the basic program.
However, the results do indicate that
the concept is both feasible and viable
and that the final demonstration should
be undertaken. Therefore, based on the
Phase I results the following program
actions are recommended:
1. The pilot plant. Phase II, should be
pursued to confirm the pollution,
energy, and cost savings benefits
indicated and projected in Phase I
and define and identify the operating
characteristics of a production sys-
tem. Furthermore, this demonstra-
tion will decrease costs and risks in
developing a full-scale production
application. Development of this
concept will involve a major invest-
ment of capital. This magnitude of
R&D investment is typically not
possible in the glass industry which
usually operates on a relatively low
profit margin. Thus, this program
would remove a significant part of
the capital risks associated with R&D
effort and would permit proceeding
to the full-scale system with a mini-
mum of risk.
2. Palletized batch is the recommended
method for batch agglomeration,
however, additional studies could be
conducted to verify the advantages
of this procedure.
3. Prior to initiation of the demonstra-
tion, packed bed studies utilizing
pelletized glass batch should be run
to predict the paniculate capture
efficiency of a packed bed preheater.
These studies should be conducted
using actual operating regenerative
furnace exhaust emissions.
R. E. Miller, K. R. Jones, N. J. Camancho. G. B. Boettner. J. H. Bruns, and B.
Bansal are with Corning Glass Works, Corning, NY 14830.
Charles Darvin is the EPA Project Officer (see below).
The complete report, entitled "Batch Pretreatment Process Technology for
Abatement of Emissions and Conservation of Energy in Glass Melting
Furnaces: Phase I. Process Design Manual," fOrder No. PB 81-175 929;
Cost: $23.00, 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
Cincinnati, OH 45268
> US GOVERNMENT PRINTING OFFICE 1881-757-01Z/7131
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