Regeneration of Furfural on Activated Carbon with Methanol

The solvent desorption method is one of the best processes for regenerating spent activated carbons. Activated carbon saturated with furfural was regenerated with methanol in a flow mode. Adsorption-desorption cycles were repeated five times. The effects of operating conditions were investigated by varying methanol flow rate and the amount of furfural adsorbed, q. Overall mass transfer coefficient, KFαv, of furfural and methanol at desorption steps is determined by comparison with the theoretical desorption curves. As a result, the KFαv of furfural and methanol is constant through adsorption-desorption was repeated five times. Regarding the effect of q, KFαv of furfural decreased as q increases, and KFαv of methanol was approximately independent of q. For the effect of changing SV of methanol, KFαv of methanol is found to increase as SV increases. The main factor in desorption of furfural from activated carbon is determined by the difference of adsorption equilibrium in aqueous solution from that in methanol solution. Further, the rate determing steps of desorption of furfural are found to be both the back mixing in the column and the surface diffusion in the particle.