SO₂-CO₂-H₂O混合ガスと炭素との反応

抄録

Reactivities of several carbons against a SO₂-CO₂-H₂O mixture gas were studied at the temperature range of 600-1000°C to collect the basic data for the design of reduction process of SO₂ to recover elementary sulfur.
The reactivities of carbons against SO₂ were generally much higher than those against H₂O and CO₂ except for Caribbean coke, which contained a significant amount of iron as the catalyst to the gasification by the latter gases. High reactivity of carbon against SO₂ may be ascribed to its exothermic reduction. Product distribution were determined by reactivities of gases against carbons (equations (1), (5), (6)) and consecutive reactions among reduced gases (equations (2)-(4), (7)-(10)).
At the lower temperature range, only SO₂ was reduced to give elementary sulfur. The higher temperature increased the yield until the reactions of sulfur with hydrogen or carbon monoxide, produced from H₂O and CO₂, took place, defining the optimum temperature for the highest sulfur yield. Such a temperature varied from a carbon to carbon, depending on its reactivity against the gases.
The reactivities of blast furnace cokes against SO₂ were discussed from their optical anisotropy, physical structure and catalytic contaminants, to suggest the second factor most influential under the experimental condition examined in the present study.