Zero-emission diesel combustion using a non-equilibrium-plasma-assisted MnO₂ filter
[ Mar 7, 2019 ]

Abstract:
A Japan-based research team led by Kanazawa University have used ozone from an atmospheric-pressure non-equilibrium plasma together with the desulfurization catalyst MnO2 to almost completely eliminate NOx and SOx from diesel exhaust gas at a low temperature of 473 K. This research shows that ozone can be used to remove not only SOx but also NOx from fossil fuel combustion exhaust streams.

Activated chemical species (O₃, OH radicals etc.) are generated by inducing an atmospheric pressure non-equilibrium plasma. These species promote desulfurization and denitration reactions with MnO₂. In this paper, we evaluated the influence of ozone on the desulfurization and denitrification performance of an MnO₂ filter.

Diesel engines are widely used in agricultural machinery, vehicles, and ships because of their high thermal efficiency. The sulfur contained in the diesel fuel is oxidized to sulfur dioxide by combustion. This sulfur dioxide not only harms human health but also causes deactivation of the catalysts used to treat NOx in the exhaust stream.

This problem can be overcome by using sulfur-free fuels based on biomass or clean coal technology or by installing a desulfurizing filter to remove sulfur oxides upstream of the NOx catalyst. Researchers at Kanazawa university have developed a plasma-assisted MnO2 filter that produces exhaust free of NOx and SOx. This technology augments the desulfurization properties of MnO2 with the activity of ozone from an atmospheric-pressure non-equilibrium plasma (Figure 1). Activated chemical species (O3, OH radicals, etc.) present in the plasma promote desulfurization and denitration reactions.

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