Hokkaido University Research Profiles


Detoxification and Removal of Nitrogen from Carbon Resources Using Nanoparticles

Use of nanoparticles for fuel nitrogen pre-removal and high-temperature gas purification

To establish principles for advanced utilization of carbon resources in harmony with the global environment is one of the most important research themes for the next generation. With this study, we aim to develop a catalytic process that can efficiently convert carbon resources into clean energy using nanoscale metal and metal oxide particles.

Content of research

Nitrogen in carbon resources (Fuel-N) is emitted as NOx and N2O during combustion. During high-temperature gasification, it is mainly converted to NH3, which becomes a source of NOx in later-stage gas combustion. With this study, we have worked on the development of a method to convert Fuel-N into harmless N2 through a pyrolysis process prior to combustion or gasification, and found that Ca ions supported by the ion-exchange method change into CaO nanoparticles during pyrolysis and catalyze the formation of N2 formation.
We have also found that Fe ions, which are originally contained in lignite coal, and FeOOH, which is abundantly found in brown iron ore, readily become metallic iron nanoparticles during the heating process, and that N2 is selectively produced during the decomposition reaction of NH3, pyridine and pyrrole by this catalyst. Since these N-containing species are contained in the crude gas produced during coal gasification, we are working to develop a new high-temperature gas purification method for the removal of these compounds.

  • Fig. Catalytic performance of lignite for pyridine decomposition at 500°C.

Potential for social implementation

  • ・Prior detoxification of Fuel-N
  • ・Hot gas cleanup
  • ・Carbon resource conversion
  • ・Environmental purification reaction
  • ・Co-processing
  • ・Contribution to Goal 7, Goal 9, Goal 13, etc. of the SDGs

Appealing points to industry and local governments

It is well known that metal and metal oxide nanoparticles have different properties from bulk particles, and that they exhibit high reactivity and unique catalytic ability. At our laboratory, we are working to establish technology to efficiently promote carbon resource conversion (low- temperature gasification of coal and biomass, etc.) and environmental purification reactions (removal of malodorous substances, etc.) using nanoparticles highly dispersed on carbon surfaces.