(526g) Reducing Carbon Emissions through Novel Hydrogen Sulfide Processing Strategies to Produce Hydrogen Gas

We present a novel hydrogen sulfide processing scheme that leverages the oxidation of H₂S to produce HI from H₂S, H₂O and I₂. We further propose that the HI generated by this reaction could be decomposed into H₂ and I₂, net producing H₂ from H₂S and H₂O. The reactions comprising this cycle are listed below.

H₂S + 2H₂O + 3 I₂ → 6 HI + SO₂

6 HI → 3H₂ + 3 I₂

With separation steps removing the SO₂ after the first reaction and H₂ after the second reaction, we believe that this chemistry could present an alternative to the Claus Process, with the added benefit of H₂ production.

The development of this invention is motivated principally by the possibly of reducing CO₂emissions by avoiding H₂ production from natural gas. As nations adopt increasingly strict and widespread sulfur emission standards, the demand for hydrogen gas as a reactant in hydrodesulfurization processes rises. This demand is almost entirely met with hydrocarbon reforming, producing hundreds of millions of metric tons of CO₂. The proposed cycle eliminates the need to generate additional CO₂ for hydrodesulfurization by producing H₂ from H₂S and H₂O. While limited by the amount of H₂S available, even at current levels, the potential for CO₂ emission reductions is significant. Given global trends in desulfurization practices and upcoming governmental actions we anticipate the impact of such a process to continue to rise.

This work includes experiments detailing the first reaction step and process modeling describing the proposed process. In addition, the potential impact on world CO₂ emissions is discussed. Future directions and ongoing experiments illustrate where we intend to take this technology.