Stebbing Engineering-Accelerated Technologies: Steelmaking services page

Accelerated Technologies Steelmaking Services

Leroy Stebbing, P.E.

USING SCRAP TIRES AS A CHEMICAL FUEL SOURCE IN THE ARC FURNACE

Scrap tires make an excellent charge carbon fuel source for melting steel. The tires

are added to the electric arc furnace as a source of chemical energy, replacing coal

or coke. The carbon and hydrogen in the tires provide fuel energy while the steel

belts and beads become part of the heat. Oxygen is injected into the furnaces while

the tires are burning so that combustion is clean and complete. The tires are

completely consumed in the process. Contrary to popular belief, there is no increase

in emissions. The tires will actually reduce emissions, especially carbon monoxide

and the green house gas, carbon dioxide.

The scrap tires are delivered free to the mill. A dumping fee is paid to the mill by

the tire disposal company. The fees vary in different locations.

A twenty-pound passenger tire has a fuel value of approximately 316,000 Btu or the

equivalent of 92 kW of electrical energy. Tires burn much cleaner and hotter than

coal. Tire fuel has about 20% greater fuel value than coal at 15,800 Btu per pound.

Two or more passenger tires can be added per ton of steel. The amount can be

considerably greater depending on equipment and shop practices.  The disposal fees

can result in a significant savings per ton of steel. Reducing or eliminating the

cost for charge carbon and freight realizes additional savings. Further savings

result from reduced electrical power and demand charges by using an even greater

amount of tires then just substituting tires for coal on a pound-for-pound basis.

Some state governments have incentive programs for scrap tire consumers such as

grants for equipment purchases or for disposal fee supplements. The grants are

funded from special fees assessed by the state when new tires are purchased. All

indications are that this is a win-win-win situation for everyone. The environment

is improved by the disposal of the tires. There is a net reduction in energy costs

for either electrical or chemical energy. CO2 emissions are reduced by 19.5% when

comparing scrap tire fuel to coal. It is possible to realize a large operating cost

savings, and have the credit for using the tires as a fuel and scrap source as well.

Truck tires contain 25% high quality steel in the belts and beads; and car tires

contain 10%. There is a large source of tire energy available. More than  250

million tires are taken out of service each year. Other manufacturers such as cement

and electrical power generators have been using scrap tires as a fuel source and

have proven their worth as a clean and acceptable fuel source. Scrap tires contain

1.5% sulfur, which compares favorably with most coal and coke. When scrap tires are

used in the EAF, using this patented process, the scrap tires do not cause any

noticeable change in steel chemistry other than an increase in carbon, if desired.

We have run tests where low sulfur (.025 sulfur) steel was made with no problems.

Scrap tires represent a very large untapped energy source for the EAF. It is an

energy that is better than free and one that will actually improve emissions.

In summary:

  a. The use of scrap tires can easily save several dollars per ton in melting costs.

  b. The tires eliminate the cost for charge carbon.

  c. The mill is paid a disposal fee for accepting the tires from the tire supplier.

  d. The scrap tires contain high-quality scrap steel in the belts and beads.

  e. The tires improve the emissions from the furnace.

  f. The scrap tires act as a catalyst in converting CO to CO2. This reduces the

     amount of objectionable CO emission from the melting process.

  g. The available energy for melting in the furnace is also increased by the

     conversion of CO to CO2.

  h. The tires produce less CO2 than coal, 19.5% less.

  i. The use of tires for additional chemical energy can further reduce electric

     power consumption.

  j. Tires are a proven source as fuel energy in other industries such as

     coal-fired power plants and in cement kilns.

We own the patent and patent pending rights to this invention. We would be happy to

show you how this process works and would like you to know the licensing and royalty

fees are very reasonable, much less than the savings realized by its use. If you

have any questions, comments, or would like to discuss the potential for using this

process, please contact us.

Leroy Stebbing, P.E.

Stebbing Engineering Division

Accelerated Technologies Corporation