Inorganic nanofiltration membrane and its application in the sugar industry

An inorganic nanofiltration membrane comprising:

• a multichannel monolithic ceramic support consisting essentially of a mixture of Al2O3 and of TiO2 and exhibiting a mean equivalent pore diameter Ds of between 1 and 20 μm,
• a microfiltration membrane separating layer situated at the surface of the channels and consisting essentially of sintered particles of metal oxide(s), whose mean equivalent pore diameter Do before sintering is between 0.1 and 3.0 μm, according to a Ds/Do ratio such that 0.3<Ds/Do<200, the said microfiltration membrane layer exhibiting a mean equivalent pore diameter Dm of between 0.05 and 1.5 μm,
• an ultrafiltration membrane separating layer situated on said microfiltration membrane layer and consisting essentially of sintered particles of metal oxide(s),whose mean equivalent pore diameter Du before sintering is between 2 and 100 nm, according to a Dm/Du ratio such that 0.5<Dm/Du<750, and
• a nanofiltration membrane separating layer situated on said ultrafiltration membrane layer and composed of sintered particles of metal oxide(s), whose mean equivalent pore diameter Dn before sintering is between 0.5 and 1.5 nm,
• said inorganic nanofiltration membrane exhibiting a cutoff threshold of between 100 and 2000 daltons.