Electric Melting

Electric glass melting tanks are typically used for the production of specialty products or for smaller capacities – generally smaller than 75 t/day (Worrell et al., 2008. p.69). Electric melting offers higher direct thermal efficiencies as compared to fossil-fuel fired furnaces. The complete replacement of fossil fuels in the furnace eliminates the formation of combustion products on the site. Overall energy and emission performance, however, depends on nature of production and distribution of used electricity (IPTS/EC, 2013. p. 171-172)

Main advantages and disadvantages of electric melting include the following: 

Advantages:

  • Very low direct emissions;
  • Potentially increased melting rate per m2 of furnace area;
  • Improved direct energy efficiency;
  • In some cases lower raw material costs;
  • In some cases electric melting gives a better quality and more homogenous glass;
  • Reduced capital cost and furnace space requirements;
  • Potentially simpler operation.

Disadvantages

  • High operating cost;
  • Reduced campaign length;
  • Not currently technically and economically viable for very large-scale glass production;
  • Less flexible and not adapted to large pull variations for high quality glasses;
  • Associated environmental implications of electricity generation (IPTS/EC, 2013. p. 173)
Development Status Products
Commercial
Glass

Electric MeltingCosts & Benefits

Parent Process: Melting and Refining
Energy Savings Potential

State of the art electric melters consume 2.81 to 2.88 GJ/t of soda-lime or sodium-borate glass (Worrell et al., 2008. p.69)

Thermal efficiency of electric furnaces are 2 to 4 times better than air-fuel-fired furnaces (IPTS/EC, 2013. p. 175)

CO2 Emission Reduction Potential

Emission reductions will depend on the nature and efficiency by which electricity is produced and supplied to the site. 

Costs

Electric furnaces have lower capital costs, but have shorter campaign life (2 to 7 years compared to 10 to 20 years for conventional furnaces) and higher energy costs (In the EU, average electricity costs per unit of energy are 4 to 5 times the cost of fuel oil) (EPTS/EC, 2013. p. 175)

Electric Melting Publications

Page Number: 

69

Electric Melting Reference Documents

Best Available Techniques (BAT) Reference Document for the Manufacture of Glass

As a reference of the EU Industrial Emissions Directive (2010/75 EU) this new version provides extensive information on Best Available Techniques (BATs) applicable to European Glass Manufacturing Industry for reducing environmental impact. The document is prepared by the  Institute for the Prospective Technological Studies of European Commission's Joint Research Center. 

Page Number: 

171-177