The Principle of Supercritical Treatment

Previous scientific studies explored the hydrolysis of cellulose and oligosaccharides in supercritical water. These investigations showed that cellulose is initially converted into water-soluble oligosaccharides like cellobiose, cellotriose, and cellopentaose. Further hydrolysis processes lead to the transformation of raw cellulose into glucose, fructose, and various by-products through reactions involving dehydration and cleavage.

Fig.1 illustrates the reaction mechanism involved in cellulose hydrolysis under supercritical water conditions. The pretreatment of lignocellulose in supercritical water capitalizes on the remarkable dissolving and catalytic properties of this medium, enabling the separation of lignin from cellulose. Cellulose undergoes rapid hydrolysis facilitated by the catalytic effects of H⁺ ionization. However, further research has demonstrated that cellulose hydrolysis in supercritical water generates not only high yields of oligosaccharides but also significant quantities of glucose fragmentation products. This observation is likely attributed to the rapid breakdown of glucose derived from cellulose into non-fermentable products such as erythrose and furfural.

Fig.1 Reaction mechanism of cellulose hydrolysis in supercritical water. (Zhao, et al., 2009)

Supercritical Treatment Services at CD BioGlyco

CD BioGlyco focuses on the field of carbohydrate production, We provide clients with a high-quality One-Stop Solution for Carbohydrate Manufacture. Supercritical treatment is a technology in the Physical-/Chemical Process for Oligosaccharide Manufacture, which is one of our advantageous services.

Due to the inherent recalcitrant nature of cellulose, cellooligosaccharides are limited in availability and expensive. Cellulose is a linear polysaccharide composed of β(1→4) linked D-anhydroglucopyranose units (AGUs), where every other AGU is rotated 180° in the plane and adjacent units form cellobiose. Cellulose exists as a polymer with a degree of polymerization (DP) of up to 10,000 AGU. In the naturally occurring cellulose I allomorph, cellulose chains are arranged in parallel, forming sheets stacked on top of each other, resulting in ordered crystalline domains. In the crystalline domains, a rigid network of intra- and inter-chain hydrogen bonds forms in the cellulose sheets, and these sheets are held together by van der Waals forces.

In order to produce water-soluble cellooligosaccharides, cellulose must be depolymerized in a controlled manner, which will render it water-soluble. The challenge is to hydrolyze cellulose to oligomers, not to obtain monomers. CD BioGlyco provides supercritical treatment technology to produce cellooligosaccharides with a DP of 2-9. Supercritical treatment forms water-soluble cellooligosaccharides by dissolving and depolymerizing microcrystalline cellulose. The services provided by CD BioGlyco will strictly control key steps such as cellulose depolymerization, filtration operation and further fractionating to improve the yield and purity of oligomeric cellulose.

Fig.2 Process for the production of oligosaccharides using supercritical treatment technology. (CD BioGlyco)

Applications

• Bioactive oligosaccharide production: Supercritical treatment stands as a promising method for manufacturing bioactive oligosaccharides with tailored properties.
• Biopolymer modification: Supercritical treatment offers a unique avenue for modifying biopolymers by introducing oligosaccharide moieties.
• Glycosylation of biopharmaceuticals: The method of supercritical treatment plays a pivotal role in glycosylation processes for biopharmaceuticals. By leveraging this technique, researchers attach specific oligosaccharide chains to therapeutic proteins with precision.

Advantages

• Supercritical treatment allows the hydrolyzed oligosaccharides to dissolve not in the form of monomers but in the form of oligomers or short polymers.
• The recovery of oligosaccharides produced by supercritical treatment is high.
• Supercritical treatment technology is a controlled depolymerization method, and the final oligosaccharides produced are soluble.

CD BioGlyco has first-class technology and well-trained technicians to provide clients with comprehensive and reliable Oligosaccharide Manufacture Services. We encourage you to contact us for additional details.

• Chemical Hydrolysis
• Chemical Synthesis