INCAPE   05401
INSTITUTO DE INVESTIGACIONES EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Deglycerolization of biodiesel streams by Adsorption over silica beds
Autor/es:
J.C. YORI; S.A. D’IPPOLITO; V.M. BENITEZ; C.L. PIECK; C. R. VERA
Lugar:
Buenos Aires, Argentina
Reunión:
Congreso; XXII CIIQ 2006 – V CAIQ – Congreso Argentino de Ingeniería Química – Congreso Interamericano de Ingeniería Química; 2006
Resumen:
Adsorption over silica beds is posed as a method for removing glycerol from mixtures of fatty acid methyl esters and for adjusting its content to the quality standard for biodiesel. Fresh silica has a great processing capacity and the breakthrough of the bed depends mainly on the feed rate, the concentration of glycerol and the mass of adsorbent. If the particle diameter is 1-1.5 mm the breakthrough and saturation points almost coincide and the full capacity of the bed is used. However industrial adsorption units with 1/8” silica beads suffer from pore diffusion limitations and the breakthrough point (C/C0=0.01) can be lower than one half the saturation point. For a glycerol concentration of 0.11-0.25% and for an entrance velocity of 11 cm min-1, a 2 m high silica bed with 1/8” beads has a breakthrough point of 8 h and a net processing capacity of 0.01-0.02 m3 biodiesel kgsilica-1. The UNIFAC method yields a value of the Henry’s constant of 1.1 m3 kg-1. The measured saturation capacity (0.13 gglycerol gsilica-1) is close to the monolayer capacity (13-15% w/w). The breakthrough curves are fairly well predicted using an irreversible isotherm, a shrinkingcore adsorption model and known mass transfer correlations. The silica bed is completely regenerated eluting 2-4 bed volumes of methanol and drying with a nitrogen stream for 1 h. The eluted volume can be recycled to the transesterification reactors with no waste of products or reactants.