Glass manufacture is an energy-intensive process, involving the melting of raw materials at high temperatures. Principal process emissions are to air due to the combustion of fuel and decomposition of carbonate raw materials.
Glass-melting furnaces produce various pollutants. The most significant of these are;
- sulphur oxides from refining agents and oil fuel contaminants
- nitrogen oxides formed from the combustion air in the hot combustion process
- particulate matter derived from the melting process, and
- carbon dioxide from both the raw material decomposition and the combusted fuels.
We are tackling these emissions with a range of primary and secondary control techniques.
Primary methods are designed to reduce pollutant formation at source and include techniques such as avoiding certain raw materials and heavy fuel oil types that contribute to emissions. Other primary techniques include using special burners and operating the furnace in an energy-efficient manner. There is a special focus on this latter area as it will also reduce production costs.
Secondary control involves employing abatement equipment to remove the emissions from the furnace waste gases before they are emitted through the chimney. Techniques such as acid scrubbers, electrostatic precipitators and selective catalytic reduction units are not widespread and being installed at more sites around the world.