Chitin & chitosan

Chitin is the second most abundant biopolymer on Earth after cellulose, forming the shells of crabs, shrimp and lobster, insect exoskeletons, and fungal cell walls; chitosan, its deacetylated derivative, carries a cationic charge in mildly acidic conditions that gives it flocculant, biocidal, biocompatible and film-forming properties unmatched by most other biopolymers. By 2026 the sector has grown from a simple seafood-waste disposal channel into a dedicated biopolymer industry: Tidal Vision’s Tidal Clear platform pairs its ACHPlus hybrid coagulant (alkaline ferric chloride plus precision chitosan formulations) to cut chemical use and sludge in water treatment, while remaining a closed-loop, non-toxic alternative to synthetic polyacrylamide flocculants. On the medical side, Germany’s Heppe Medical Chitosan (HMC) supplies pharmaceutical-grade chitosan and custom oligomers under GMP conditions to European drug developers. Iceland’s Primex, based in Siglufjörður, derives its ChitoClear product line from deep-water shrimp (Pandalus borealis) shells and has extended into cosmetic-grade ChitoCare ingredients for skincare. Belgium’s KitoZyme takes a different sourcing route entirely — fermentation-derived fungal chitosan, certified and marketed as a vegan alternative to synthetic and crustacean-derived polymers for health, beauty and agriculture applications.

The key directions of the chitin/chitosan value chain are:

1. Technical chitin: the semi-finished product from demineralized, deproteinized crustacean shells, used as chitosan feedstock or an animal-feed additive.
2. Industrial (water-treatment-grade) chitosan: moderately deacetylated (75-85%) chitosan used as a biodegradable coagulant/flocculant for industrial and municipal wastewater, removing heavy metals and oils.
3. Agricultural-grade chitosan: used as a seed treatment and foliar spray that acts as an elicitor, activating plants’ natural defense genes against fungal and viral pathogens and reducing chemical-pesticide reliance.
4. High-purity medical/pharma-grade chitosan: ultra-high deacetylation (>95%), minimal ash content (<0.2%) and no detectable protein or endotoxin residue, used in sutures, tissue-engineering scaffolds and controlled-release drug systems.

Sectoral value chain#

[Crustacean Shells] ──> [Demineralization & Deproteinization] ──> [Thermochemical Deacetylation]
                 │                              │                                │
        (Seafood-processing waste)    (Purified chitin recovery)        (Conversion to chitosan)
                                                                                  │
       [End Products (Medical, Packaging)] <─── [Reprecipitation & Dialysis] <────┘

Value chain levels#

Cross-cutting technologies of the sector:

• Enzymatic deacetylation: an alternative to harsh alkaline hydrolysis using recombinant chitin deacetylases (marine or fungal), operating at mild temperature (37°C) and neutral pH to produce chitosan with tightly controlled acetylation patterns without polymer-chain degradation.
• Deep eutectic solvent (DES) extraction: environmentally benign solvent mixtures (e.g., choline chloride/urea) that remove both calcium and protein from raw shells simultaneously, avoiding mineral acids/alkalis entirely and preserving astaxanthin as a valuable antioxidant byproduct.
• Electrospinning of chitosan nanofibers: drawing ultrafine chitosan fibers (50-200 nm diameter) from a trifluoroacetic-acid solution under a strong electric field, creating highly porous matrices that mimic skin extracellular matrix for accelerated deep-burn healing.

Modern chitosan production relies on the following equipment and process stack:

1. Continuous demineralization reactors:
   • Crushed shell feedstock is fed continuously into a cascade of titanium stirred reactors dosed with dilute hydrochloric acid; automated pH sensors hold the reaction at pH 1.5-2.0 to prevent premature protein hydrolysis, while the resulting CO2 is captured and calcium chloride is recovered.
2. High-pressure alkaline deacetylation autoclaves:
   • Dry purified chitin is loaded into 316L stainless-steel reactors with 50% NaOH solution, held under up to 3 bar pressure at 110-120°C; conductivity sensors monitor the degree of acetyl-group removal in real time, automatically stopping the reaction at the target parameters.
3. Wet-spinning nonwoven fiber lines:
   • A pressurized medical-grade chitosan/acetic-acid solution is extruded through spinnerets with thousands of 50-micron microholes into an alkaline coagulation bath, instantly forming continuous filaments that are washed, drawn and wound for weaving into hemostatic gauze.