IMPROVEMENT OF THE FLUIDISABILITY OF NI/SIO2 AEROGELS BY REDUCING INTERPARTICLE FORCES

Ni/SiO2 aerogels belong to group C of the Geldart particle classification, which is usually very difficult to fluidise. This behaviour is due to interparticle forces too large to be overcome by the drag force exerted by the fluidising gas. Based on the theoretical expression of the van der Waals force, practical ways of decreasing the interparticle forces, and thereby improving the quality of aerogel fluidisation, are proposed: increase of initial bed porosity, presence of Ni under oxidized rather than metallic form, high humidity of the fluidising gas and addition of alumina particles.