Characterization and performance analysis of an innovative Ni/Mayenite catalyst for the steam reforming of raw syngas

- A Ni/Mayenite catalyst was prepared with citrate sol-gel method and characterized.
- Catalyst was tested for tar steam reforming downstream a biomass gasifier for 50 h.
- Conversion rates: heavy tars 100%, toluene 90%, benzene 70%, methane 25%.
- Characterization after tests show very low C deposits, traces of Nickel Sulphide.

Biomass gasification is an effective way to produce syngas that must be conditioned to remove the main pollutants (tars) for its use in energy production systems. Catalytic steam reforming of tar and CH4 is thus necessary; Nickel catalysts are excellent candidates but still have deactivation problems related to carbon deposition and sulphur poisoning. Various studies demonstrated that Mayenite as binder for Nickel has free oxygen ions that protect the catalyst from coke formation and H2S poisoning. Similar studies are carried out only with tar representative compounds (e.g. toluene); here the catalyst was tested with real syngas from biomass gasification containing CH4, benzene and tars. Ni/Mayenite was synthesized with citrate sol-gel method, characterized (XRD, BET, SEM, XRF), tested for 50 h and again characterized in order to study its degradation. Heavier tars were 100% converted; lower tars were converted with high rate; CH4 showed a decrease in conversion after 2 h.