Performance research of lanthanum-loaded dolomite catalyst for pine catalytic gasification

To enhance the catalytic effect of dolomite, La/Dol catalyst was prepared by impregnation modification of dolomite with La (NO₃)₃ as additive. The catalyst was characterized by BET, SEM and XRD. With pine rods as raw materials and La/Dol as reforming catalysts, the effects of gasification temperature and La amount of catalysts on the catalytic gasification of pine were compared and analyzed in a self-made two-stage biomass gasification reforming experimental furnace. The results show that a small amount of La (2%) can obviously promote the forward progress of water gas reaction and perfect the catalytic reforming effect. Under the working condition of steam flow rate of 10 g/min, 2-La/Dol catalyst and reforming temperature of 750℃, with the increase of gasification temperature, the amount of H₂ increases significantly, and the highest volume fraction of H₂ increases from 28.51% (0-La/Dol) to 41.72% (2-La/Dol). La₂O₃ in the catalyst promotes the secondary cracking of tar. As a result, the tar content of liquid phase product is obviously reduced, and the number of functional groups is also reduced. La₂O₃ on dolomite surface occupies active sites, so carbon filaments are not suitable for accumulation and carbon deposition is inhibited. Carbonate (La₂O₂CO₃) in the catalyst can react with carbon to slow down the carbon deposition on the surface and improve the activity and service life of the catalyst.