Investigation on carbon deposition deactivation of Fe-Ni-Ca/Al2O3 catalyst under volatiles reforming of biomass pyrolysis

The changes in the carbon deposition behavior of biomass pyrolysis volatile fraction reforming process with different catalysts (Fe, Fe-Ni, Fe-Ni-Ca) were investigated in a laboratory-scale fixed-bed reactor. The pyrolysis experiments were carried out on wheat straw (WS) at different temperature, observing changes in the experimental conditions after the addition of catalysts which were characterized by XRD, SEM-EDS and TEM analyses. The experimental results indicated that the temperature and catalyst had an effect on the product distribution, syngas composition, and the generation of carbon deposition. Both the increase of temperature and the addition of additives can reduce the formation of heavy oil and increase the yield of the synthesis gas. The addition of Ni to the A@ 5Fe catalyst as an additive increasing the transfer of Coke1 to Coke2, the addition of Ca to this catalyst resulted in an increase in the amount of Coke2 due to the formation of CaCO3, which also led to an increase in catalyst activity. The carbon deposition was divided into two parts to investigate the formation mechanism, providing some theoretical basis for extending the reactor life and catalyst activity.