American Ceramic Society
Glass and Optical Materials Division
Spring 2006 Meeting
Glass Manufacturing Industry Council
Symposium
Alternatives for Energy Reduction
Thursday, 18 May 2006
Abstract
Title
Pick your Poison:
Natural Gas
Uncertainties and the
American Glass
Industry
PowerPoint
Presenting
Author
M. John Plodinec
SRNL
Time
Slot
8:00 – 8:20
Abstract
The American glass industry is literally facing life-or-death due to the uncertainties
associated with natural gas (NG). The damage caused by Katrina and Rita to the nation’s
NG infrastructure, that compounded the damage from 2004’s hurricanes, has spotlighted
the fragility of America’s NG infrastructure. The NG supply is just not as reliable as it once
was, and wont be for several years. Spot shortages have occurred, with more expected
this winter. Since 2003, the price of NG has been inexorably rising, stressing the glass
industry, but superimposed on this rise have been wild fluctuations in price, so that spot
prices have been as high as $15 a dekatherm. It is unlikely that the underlying price
increase trend or the large fluctuations in price will disappear within the next 2-3 years.
The impact on the industry, although it varies by industry sector, is huge. The energy
portion of the cost of producing glass has risen from about 15% (on average) to over 40%,
in some cases. Further, the fluctuations in the cost of NG has led to a sort of Russian
Roulette for the industry as it chooses between locking in NG at high prices (hopefully
steady supply and price, but historically high costs), or buying the lowest cost gas on the
spot market and risking having to buy whatever is available when needed (probably lowest
cost, but with high supply and cost uncertainty).
Both of these choices constitute potential poison pills for an American glass industry. The
first, accept high but stable costs, leads to the slow death of the industry because
eventually the industry will not have sufficient capital to maintain itself. The second choice,
the high risk path, could lead to a much quicker death, because industry sustainability
Page 1
Recent National
Energy Technology
laboratory Industrial
Gasification Activities
PowerPoint
Don Bonk
NETL
Synthetic Fuel Gas for Peter Walsh
University of
Glass Melting
Alabama
Furnaces: Some
Options and
Requirements
PowerPoint
8:20 – 9:00
9:00 – 9:20
depends on consistently matching or undercutting energy costs of competitors in more
managed economies that can artificially dampen fluctuations. Thus, the American glass
industry must find innovative ways to inoculate itself against these NG uncertainties. The
purpose of this note is to provide context for that search, and to suggest specific actions
for ensuring the continuing viability of the American glass industry.
Paper will review recent activities by the National Energy Technology Laboratory and other
Offices within The U.S. Department of Energy to define and qualify the need for and types
of systems that can reduce the impacts of high natural gas prices by the application of
gasification technology compatible with the needs of the industrial sector of the economy.
Fluctuations in supply and increasing cost of natural gas have renewed interest in
alternative sources of fuel for glass melting. One of the promising candidates is a synthetic
fuel gas produced by gasification of coal. When combined with the high efficiency of
combustion of fuel gas using high purity oxygen and utilization of waste heat in the
combustion products from the melting furnace to produce steam for a turbine/generator, a
system having high overall thermal efficiency can be realized. Even higher efficiencies are
expected using advanced furnace designs, such as one based upon submerged
combustion.
In order to improve the accuracy of estimates of the performance of synthetic-gas-fired
melters and make quantitative comparisons of proposed system configurations, designers
of both melting furnaces and gasification equipment require a set of the specifications to
be met by the gas, such as optimum and minimum heating values and the maximum
permissible levels of sulfur, nitrogen, and particulate matter impurities. There are many
trade-offs to be examined. For example, a fuel gas having a low heating value may be less
costly to produce than one having a higher heating value, but may require increasing the
size of fuel piping and the installation of new burners. We establish the characteristics of
the fuel gas requiring the fewest modifications to existing plant and compare the thermal
efficiencies for plant configurations ranging from air-blown gasification and air-fired
combustion, to oxygen-blown gasification with oxygen-fired combustion, to oxygen-blown
gasification and all-electric melting. The optimum arrangement will be found to depend
upon pull rate, emissions requirements, and the type of glass product.
Page 2
Gasification
PDF File
David Denton
Eastman Chemicals
BREAK
Keeping Glass as a
Thriving Part of U.S.
Economy. Coal
Gasification as
Alternative to Natural
Gas
PowerPoint
Glass Melting in
Energy Saving
Fashion
PDF File
9:20 – 10:00
Since 1999, domestic prices of natural gas and oil have more than tripled their historical
levels. The results have been devastating to a number of U.S. industries, including
chemicals, fertilizers, glass and steel. Gasification offers the potential to break the death
spiral of rising energy costs by enabling the economic and environmentally friendly
utilization of coal and other domestic resources as feedstocks and fuels for these
industries. Eastman Chemical Company was a pioneer in coal gasification and has used it
very successfully for over two decades to produce chemicals found in products you use
everyday, including photographic film, toothbrush and screwdriver handles, mending tape,
pain relievers, artificial sweeteners, automotive coatings, and pharmaceuticals. This
tutorial presentation will provide an overview of gasification technology, of Eastman's
operational experience and performance with gasification, and of the potential for
application of gasification technology to the glass industry.
10:00 – 10:20
Peter Garforth
10:20 – 10:40
Garforth International
Rising energy costs have hit the glass industry very hard, resulting in the exporting of jobs
and reduced profit margins. Syngas from clean coal gasification technologies may provide
a viable solution. This white paper outlines an alternative path that the glass industry may
wish to pursue as it investigates the possible solution to this problem. We propose a
public/private partnership that may well have implications far beyond the glass industry
alone.
Oleg Prokhorenko
LGP Intnl
Growing fuel prices make keeping manufacturing cost at low level more difficult. Solution
#1 is to move all production to the sites with cheaper fuel and labor. However, fast
industrialization of these places will return the problem back soon. Solution #2 is to
develop a new glass melting system. In both cases one should be prepared to invest and
to wait. Are where alternative plans, offering simple and effective measures to increase
energy consumption of existing glass plants? Can it be done in parallel with development
of efficient technological solutions? The following qualitative criteria of energy efficient
glass melting can be offered.
11:20 – 12:00
Page 3
The short-term task is to lower energy consumption at melting by 1.0 M BTU per short ton
of glass by lowering furnace peak temperature by 100K. Long-term target is to develop
and introduce new glass melting technology with coefficient of efficiency equal to 70%.
To bring T2-100 glass compositions to life systematic re-formulation of major commercial
glass compositions should be performed. Physical and chemical properties of updated
glass compositions must meet current industry standards. New glasses should behave at
forming and annealing too. One should modify glass composition with of without adding
new components to glass formula. Increase of batch cost should be paid off by fuel
economy.
Synthesis of commercial glasses can be improved dramatically by replacing lose batch
with batch granules pre-treated by special regime. It decreases temperature of synthesis of
glass mass by 100K, liquidates batch segregation problem, and minimizes volatilization.
As a result high yield of quality glass mass can be obtained even for hard-to-melt glass
compositions.
In gas-fired furnace significant part of heat energy is brought into the melt by forced
convection. Increase of heat exchange by convection leads to decrease of retention of
volatile components. More efficient radiation heating molten glass can solve this problem.
Crown should absorb more energy of hot gas and re-radiate it toward the melt surface.
The crown with developed inner surface, low hydraulic resistance, and high emissivity in
near infrared range can help decreasing pick temperature in combustion space by 100K at
the same glass temperature.
Page 4
LUNCH
12:00 – 1:20
Is there any Fruit Left
on the EnergySavings Tree?
PowerPoint
MS-Word
Doug Davis
TECO
1:20 – 1:40
Energy Savings in the
Glass Industry: A
Different Approach
and New Solutions
Power Point
Heiko Hessenkemper
1:40 – 2:00
Technical University
of Freiberg, Germany
The energy required for glassmaking has decreased over the years. Compared to 1930,
we are very close to the Theoretical Limit. For SLS glass, this 2.2 million Btu per ton is
determined only by the energy for reactions and changes of state and by the final
temperature. But the actual energy used by an end-port regenerative furnace could well be
4-5 MM Btu. To see if any of those large gaps between theoretical and actual energy is
retrievable, the energy gap was broken into distinct energy levels. Level A is the
theoretical minimum required to make the glass, but the minimum can be reduced by using
artificial minerals that may shortcut reactions, or by using a lower viscosity glass that can
be used at lower temperatures.
Level B is the minimum practical energy required to produce saleable glass, including
additional energy for refining, for dissolving the sand, and structural losses. An emphasis
on improved heat recovery, better insulation, and greater flame luminosity and coverage,
has reduced this level over time. But still fruitful can be obtaining better flame coverage,
increased flame luminosity, hotter flames, additional tonnage through the same furnace,
pre-heating of cullet and batch, and application of electric boost. Level C includes the
addition of extra fuel to fight low swings in quality. Possibilities for lowering the level
include improved quality control to minimize process variation, minimizing tramp air
incursion, continuous firing, and addition of supervisory computer controls.
Level D includes the extra energy required to overcome the effect of adding excess air/O2
to ensure complete combustion. Savings in this area could come from compartmentalized
regenerators, and more frequent oxygen monitoring.
Energy savings in glass industry becomes more and more a strategic aspect. New
techniques like oxy-fuel, batch preheating and an increased use of culets get more
importance. But there is still a big potential for additional activities. The partly substitution
of carbonates by hydrates and the industrial experience with this is an example. An
increase of more than 10% of the pull rate has been achieved with the same crown
temperature. With the same pull rate a substantial decrease of the needed energy and
emissions could be observed and the decrease of temperature increases the lifetime of the
furnace. The control of foam in the furnace by destroying it is another subject. In a half
industrial furnace different possibilities have been tested based on the physics of the
process:
Page 5
High-Intensity Plasma
Glass-Melting
“GLASSON_DEMAND”
PowerPoint
MPEG
J. Ronald Gonterman
Plasmelt Glass
Technologies
2:20 – 2:40
To influence the viscosity of the foam lamella by chemical or thermal means and/or
changing the surface tension. The acceleration of the SiO2 dissolution and the refining
process is possible by using the results of the ultrasonic laboratory experiments of the
past. To transfer them into industry the bubbling with H2 and O2 to create mechanical
waves in the melt is a successful way. If both bubbles meet in the melt there is a chemical
reaction creating an explosion with mechanical waves of different amplitudes and
frequencies. This technique has been tested also in a half industrial scale where the result
of the improved SiO2 dissolution and improved refining has been seen. Linde now
transfers this technique into industry. Last not least the old question of weight reduction as
a substantial saving of energy and emissions has got new perspectives by using low cost
online surface treatments in the glass industry. By simple means the hot glass surface just
after the forming process is contacted with AlCl3 vapor. Together with an improved
temperature control the mechanical properties could be increased more than 50 %, which
enables the industry to reduce weight further on.
Plasmelt Glass Technologies is developing and testing a revolutionary melting method that
utilizes high-intensity dc electrical-arc plasmas. The purpose of this study is to develop
energy efficient, lower cost, highly flexible alternatives to traditional methods of melting
glasses of interest to the industry. A laboratory scale melter was designed, constructed,
and operated to conduct multiple experimental melting trials on various glass
compositions. Glass quality was assessed. Although the melter design is generic and
equally applicable to all sectors within the glass industry, the development of this melter
has focused primarily on fiberglass with additional exploratory melting trials of frits,
specialty, and minerals-melting applications. Throughput, energy efficiency, and glass
quality have been shown to be heavily dependent on the selected glass composition.
Plasmelt has now completed the proof-of-concept work in our Boulder, CO Lab to show
the technical feasibility of this transferred-arc plasma method. Current work is focused on
developing the processes and evaluating the economic viability of plasma melting aimed at
the specific glasses of interest to specific client companies. Some work is also on going
with client companies to address broader non-glass materials such as refractories and
industrial minerals. Experimental results will be presented to show that the good quality of
plasma-melted fiberglass compositions, such as E-glass, can result in good fiberizing
performance. Fiberizing performance and tensile strength data will be presented to support
this conclusion. High seed counts are a feature of the current lab scale melter. Seed count
Page 6
Oxy-Gas Glass Melter David Rue
Efficiency Increase by GTI
Exhaust Gas
Thermochemical
Recuperation
PowerPoint
2:40 – 3:00
BREAK
3:00 – 3:20
Fuel Reduction by
Combining Oxy-Fuel
Firing with
Batch/Cullet
Preheating
PowerPoint
Leonard Switzer
Praxair, Inc.
3:20 – 3:40
data will be provided and potential seed reduction approaches discussed.
This paper will also discuss specific glass compositions that have been shown to be
suitable for plasma melting, as well as their glass quality and melting efficiencies.
Exploratory melts of non-glassy materials, such as zirconium silicate and alumino-silicate
melts will be included in the presentation.
Partial reforming of natural gas using steam or hot exhaust gas can improve process
efficiency by returning a portion of the wasted heat to the process as chemical energy. In
this process, known as thermochemical recuperation (TCR), a portion of the fuel gas and
superheated steam are reacted to produce hydrogen and carbon monoxide containing
more energy content than the initial fuel gas. TCR requires high temperatures and
therefore is an excellent technique to recover energy from the hot exhaust gases from oxygas glass melters. With 20 percent recovery of the more than 20 percent of heat lost to
the exhaust, TCR can increase oxy-gas melter efficiencies by up to 5 percent.Lower
temperature exhaust gases from regenerative and recuperative glass melters can also be
used to recover chemical energy by TCR, but the efficiency gains are significantly lower.
With rising natural gas costs and increasing competition, TCR is becoming attractive for
oxy-gas melters and may eventually become attractive for all melters.
Rising energy prices are causing operators of glass furnaces to re-evaluate various fuel
savings options in order to reduce operating costs. Conversion to oxy-fuel firing can save
approximately 10 to 20% on fuel consumption compared to a regenerative air-fired furnace
(e.g., container or float), and even higher savings compared to recuperative air-fired
systems. Use of oxygen, however, requires an additional operating cost that must be offset
by the fuel savings and other operational savings (e.g., emissions reduction, production
increase, etc.). In order to further increase the fuel savings associated with oxy-fuel
combustion, recovery of heat from the flue gas is necessary. Comparing the energy in the
flue gas of glass furnaces, reveals that the flue gas of oxy-fuel fired melters have
substantially more recoverable waste heat than air-fired regenerative systems. This heat
can be recovered by installation of a waste heat boiler, preheating the batch and cullet,
preheating the fuel, or preheating the oxygen. In this presentation, three oxy-fuel fired
container glass furnaces that employ heat recovery options will be investigated, including
batch or cullet preheating and installation of a waste heat boiler.
Page 7
A Novel Glass
Furnace Combining
the Best of Oxy- and
Air-Fuel Melting
PDF
Open Discussion
Michael Habel
Air Products &
Chemicals
3:40 – 4:00
The results show that substantial energy savings can be realized using an oxy-fuel fired
furnace with batch/cullet preheating or a waste heat boiler compared to an air-fired
regenerative system.
A novel furnace concept has been developed which combines oxy-fuel combustion over
the unmelted batch and air-fuel combustion downstream. This hybrid furnace offers a
number of advantages over both air-fuel and oxy-fuel furnaces. As compared to air-fuel,
the hybrid furnace technology provides increased production, improved glass quality, fuel
savings, better furnace temperature control, and a more stable batch pattern. As compared
to 100% oxy-fuel, the hybrid furnace delivers similar production levels, improved glass
quality, reduced levels of foam on the glass surface, and lower overall oxygen costs. One
can think of the hybrid furnace as the optimum between air-fuel and oxy-fuel melting. The
end result is that the hybrid furnace provides the means to achieve the lowest overall glass
melting cost.
From the emissions point of view, combining oxy-fuel and air-fuel combustion in a furnace
presents a challenge with regard to NOx emissions. An in-depth modeling study was
undertaken to overcome this issue with excellent results. Burner design considerations for
implementing the hybrid furnace will be presented. A discussion of a detailed economic
model comparing the costs of hybrid furnace technology relative to air-fuel and full oxy-fuel
technology is included. The results are discussed in terms of the sensitivity to parameters
such as production increase, yield, and fuel usage.
4:00 – 4:30
Page 8