Novasep Technologies: Adsorption

Purification processes

Novasep Process has been supplying the food and bio industries with Applexion® adsorption units for many years.

Adsorption is a key process for the extraction of impurities on valuable chemicals. The adsorbents can be from various origins (synthetic polymers or carbonaceous material). They are commonly used to decolorize sugar solution or to recover antibiotics, plant extracts, proteins, ...

Adsorption Principle

Adsorption consists in the binding of molecules to the surface of an adsorbent, whereas absorption consists in the filling of the pores in the solid. Usually both mechanisms take place. The adsorbents are mainly characterized by their surface and porosity; the most commonly used are activated carbon either in granular form (GAC), powdered form (PAC) or polymeric adsorbents based on a polystyrene divinyl matrix. The adsorption media can be operated in liquid or gas phases, in aqueous or solvent phases.

Comparison in between AC. and ADS (Typical values)

	Activated carbon	Polymeric adsorbents
Structure	Carbonaceous	Aromatic or aliphatic matrix
Surface area	500 - 2000 m 2 /g	150 - 1000 m 2 /g
Pore radius	10 - 28 Angstroms	30 - 50 Angstroms
Pore volume	0,3 - 0,7 cm 3 /g	0,9 - 1,6 cm 3 /g

 

Polymeric adsorbent resin structure

Definition of adsorption in the glossary.

Adsorption Mechanism

There are several mechanisms which cause the adsorption: we can list Van der Waals forces, steric interaction, hydrogen bonds, hydrophobicity and polarity. Since the solution to be treated contains a mixture of organics with different properties, the adsorption process is a combination of these mechanisms. Color removal with ion exchange resins is also a combination of ion exchange and adsorption. In fact the main mechanism is adsorption rather ion exchange.

Regeneration of Adsorbents

We have to distinguish the case of GAC which can be reactivated through volatilization of adsorbed contaminants with steam or hot inert gas and polymeric adsorbents which are usually regenerated with a combination of chemicals (NaOH, HCl or solvents). Spent activated carbon rejuvenation is incomplete and losses are faced. Sometimes the activated carbon spent is disposed of.

Example of an UPFLOW decolorization process (Production & regeneration)

Adsorption Applications

Novasep Process has been using adsorbent media in numerous applications sometimes combining both activated carbon and polymeric adsorbents in order to meet the most stringent customer specifications.

The main driver of this technology is the production of a final product with very stable organoleptic properties in terms of color, taste and odor.

Novasep Process has supplied the industry with complete Applexion® units, designing the whole process for the agro-food, pharmaceutical and nutraceutical industries.

Typical applications are:

• decolorization of cane refinery syrups,
• polishing of sweeteners and polyols juices,
• production of liquid sugar,
• recovery of flavonoids, plant extracts, colorants, aroma, .
• recovery of antibiotics,
• recovery of proteins,
• fruit juice debittering,
• and more...

Novasep Ion adsorption equipment

Novasep Process has a strong experience in adsorption processes and has been supplying the food and bio industries with adsorption units for many years for applications such as decolorization of cane sugar juices, polishing units of liquid sugar, sweeteners and polyols, recovery of plant extracts and colorants, recovery of antibiotics and many others.

Please feel free to consult us for any additional information: industrialbiotech@novasep.com