US EPA

1708120 

Journal Article 

SOx emissions from glass manufacturing: Decomposition of sodium sulfate as influenced by carbon 

Samadhi, TW; Jones, LE; Clare, AG 

2000 

73 

361-369 

WOS:000167470300041 

degreesa(2)SO(4), which is added as a fining agent in silicate glass batches, has been identified as a source of SOx and particulate emission. Interaction between Na2SO4 and carbon in silicate glass batches influences the decomposition behavior of Na2SO4. Na2SO4 and Na2SO4 + C decomposition experiments are undertaken in inert and On-rich atmospheres. Decomposition of Na2SO4 alone is observed to initiate at similar to 1100 degreesC. Carbon promotes decomposition at lower temperatures, indicated by the presence of lower-temperature decomposition regions at similar to 500 degreesC in O-2 and similar to 850 degreesC in N-2. SOx is released at temperatures as low as 500 degreesC in O-2 SO(g) and SO2(g) are the decomposition products in O-2 In N-2, SO2(g) is the sole decomposition product. For Na2SO4 + C in O-(2) over left arrow, the concentration of SO(g) at 500 degreesC is 230 ppmV, with a SO/SO2 peak ratio of 1.23. Decomposition mechanism of Na2SO4 can be described by a surface reaction, in which SOx is formed via rearrangements of active S-O complexes on Na2SO4 melt surface. Isothermal decomposition of Na2SO4 + C in N-2 at 1200 degreesC exhibits a rapid mass-loss during the heating-up period, and a region of higher decomposition rate at shorter times. At longer times, the decomposition rate is similar to that of Na2SO4 alone.