GLASS GLASS GLASS GLASS GLASS 
DIAGNOSTICS AND MODELING OF 
HIGH-TEMPERATURE CORROSION OF 
SUPERSTRUCTURE REFRACTORIES IN OXYFUEL GLASS FURNACES 
Project Fact Sheet 
B E N E F I T S 
• Reduced production costs, since 
less corrosive refractories will 
lower the frequency of furnace 
rebuilds 
• Reduced emissions through 
increased industry conversion to 
a more cost-effective oxyfuel 
process. Oxyfuel conversion 
can reduce NOx emissions 
from a typical float glass plant 
from over 320 kg/hr to 
approximately 40 kg/hr 
• Improved energy efficiency and 
product quality by reducing 
defects—defects resulting from 
corrosion byproducts dripping 
onto the glass surface currently 
cause a 2 percent reduction in 
yield, and total energy loss for 
the entire U.S. glass industry 
due to defects is approximately 6 
x 1012 Btu/yr 
A P P L I C A T I O N S 
The mathematical models created 
can be used by process designers, 
material engineers, and 
manufacturers in all segments of 
the glass industry not only to 
optimize the oxyfuel process in 
existing furnaces and retrofits but 
also to design new ones. 
EXTENDED SUPERSTRUCTURE REFRACTORY LIFE 
WILL ENHANCE OXYFUEL FIRING PROCESS 
Oxyfuel firing is rapidly becoming an energy-efficient and environmentally sound 
alternative to air combustion in the glass industry. However, because of higher 
temperatures and production of alkali vapors, refractories corrode significantly 
faster in oxyfuel furnaces; furnace crown life can be shortened by a factor of two 
to three. The project partners will determine corrosion factors and develop 
mathematical models that can predict corrosion rates, identify operating 
conditions that minimize corrosion, and define the attributes of improved 
refractories for oxyfuel firing. The researchers will also seek to develop optical 
techniques for monitoring gas-phase alkali concentrations in the melter 
headspace. Improving the oxyfuel process by extending furnace life will increase 
the cost-effectiveness of the process and make conversion more appealing to 
the glass industry. 
CURRENT AVERAGE FURNACE LIFE BASED ON 
CORROSION OF REFRACTORY STRUCTURES 
10
9
8
7
6
5
4
3
2
1
0 
Air 
Technology that improves refractory corrosion resistance will increase furnace longevity, 
making oxyfuel firing more cost-effective. 
YEARS 
Oxyfuel 
FURNACE TYPE 
OFFICE OF INDUSTRIAL TECHNOLOGIES 
ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY
Project Description 
Goal: Characterize silica refractory corrosion processes in oxyfuel furnaces and use 
those characterizations to develop models that predict corrosion rates and define 
attributes of improved refractories. Increasing refractory life will further enhance the 
oxyfuel process. 
During the experimental and diagnostic development phase of the project, the 
researchers will investigate the factors that contribute to the corrosion rates, particularly 
gas-alkali species (e.g., sodium hydroxide, potassium hydroxide), which are the most 
damaging compounds that attack the refractory. High concentrations of water vapor also 
produce increased amounts of damaging alkali. These higher concentrations of both 
alkali compounds and water vapor occur in oxyfuel furnaces as a result of the elimination 
of nitrogen from the input gases. 
Once the corrosion data is gathered, mathematical models and on-line diagnostics will be 
developed that use the data to identify furnace conditions and/or refractory compositions 
that lower corrosion rates. 
Progress and Milestones 
The experimental and diagnostic development phase of the project will be conducted in 
1999 and will include the following activities: 
1. Characterizing new and used silica refractories 
2. Conducting iso-thermal corrosion simulations 
3. Measuring alkali concentrations. 
PROJECT PARTNERS 
Air Liquide 
Countryside, IL 
Air Products and Chemicals, Inc. 
Allentown, PA 
BOC Gases 
Murray Hill, NJ 
PPG Industries 
Pittsburgh, PA 
Praxair, Inc. 
Tarrytown, NY 
Sandia National Laboratories 
Livermore, CA 
Visteon Glass Systems 
Dearborn, MI 
FOR ADDITIONAL INFORMATION, 
PLEASE CONTACT: 
Elliott Levine 
Office of Industrial Technologies 
Phone: (202) 586-1476 
Fax: (202) 586-3180 
elliott.levine@ee.doe.gov 
http://www.oit.doe.gov/glass 
Please send any comments, 
questions, or suggestions to 
webmaster.oit@ee.doe.gov 
Visit our home page at 
http://www.oit.doe.gov 
Office of Industrial Technologies 
Energy Efficiency 
and Renewable Energy 
U.S. Department of Energy 
Washington, D.C. 20585 
December 2000