Study on a new wet flue gas desulfurization method based on the Bunsen reaction of sulfur-iodine thermochemical cycle

- A new wet FGD method based on the Bunsen reaction was developed.
- I2/HI absorption system exhibited great SO2 removal performance.
- The absorption products are H2SO4 and HI.
- H2SO4 has better market prospect than traditional wet FGD products.
- HI could be used as the raw material for hydrogen production.

A novel wet flue gas desulfurization method based on the Bunsen reaction of sulfur-iodine (SI) thermochemical cycle was investigated in this paper. I2 and HI absorption system was utilized to remove SO2 from simulated coal-fired flue gas. The SO2 removal efficiency was about 98.8% when the I2 concentration was 25.6 mmol/L. The influences of reaction temperature, initial SO2 concentration and the other flue gas components on SO2 removal were investigated, respectively. The absorption products were H2SO4 and HI, which could be easily separated by distillation. Compared with the traditional wet flue gas desulfurization (FGD) byproducts, such as gypsum or magnesium sulfate, H2SO4 has better commercial value and application prospect. Moreover, HI could be used as the raw material for the hydrogen production in the SI thermochemical cycle. In short, it is a promising technology for the SO2 removal and recycling from coal-fired flue gas.

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