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Oxy reduction of CO2 and H2S for syngas production

This activity concerns the application of the novel Acid Gas To Syngas (AG2S™) technology to the gasification of solid fuels. The AG2S™ technology is an effective and environmentally friendly technology for handling emissions from solid fuel gasification and combustion. The process, which is the result of breakthrough research at the “Politecnico di Milano”, makes it possible to reduce the environmental impact of coal use and, at the same time, improves the yield of the coal gasification processes thanks to the innovative idea of coupling the reduction potential of H2S with the CO2 molecule. Implicitly, the reaction

2H2S+CO2=CO+H2+S2+H2O

leads to other possible advantages that influence different scientific and engineering areas, including:

  • H2S is massively produced by hydro-desulphurization or hydrotreating processes, where H2 is consumed. The technology allows restoring the hydrogen balance, by recovering it from H2S and recycling to hydro-desulphurization and treating. Therefore, the capacity load of the upstream reforming unit for producing hydrogen can be downscaled, with a consequent saving of energy and CO2
  • Some natural gases contain both H2S and CO2. In such cases, the costly reinjection of CO2 into remote deposits is more critical due to the presence of H2S, because of a possible chemical attack on underground structures. By adopting the AG2S™ technology, the need for reinjection declines.
  • Some coal and oil fields are currently unexploited due to the high content of sulphur and large CO2 impact, like some Canadian tar sands and North American/North European shale gases. AG2S™ can provide clearance for them.

Preliminary theoretical studies show the paramount possibility of synthesizing methanol from coal, rich in sulphur, without any emissions of CO2 by implementing AG2S™. The same would apply to other syngas-based chemicals, such as ammonia.

A bench-scale plant has been designed for experimental tests and is currently under construction.