Fraunhofer Institute for Interfacial Engineering and Biotechnology IGBFraunhofer IGB is your partner for all questions and applications relating to chitin and chitosan: from the refinement of agro-industrial waste streams to the replacement of petroleum-based polymers with chitosan. We support you in adding value to your chitin-containing waste or residue stream, producing high-purity chitin and chitosan, analyzing them, and investigating possible applications. Thanks to our expertise and that of our partner network, we have used chitosan to make textiles water-repellent and determined the most suitable chitosans for treating wastewater.
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Chitin Biorefinery: Refining Chitin-Containing Residues to Produce Chitin and Chitosan
From the refinement of agro-industrial waste streams to the replacement of petroleum-based polymers with chitosan
Residual material streams containing chitin
Chitin is formed as a structural component by many organisms—crustaceans, insects, and fungi—and is the second most common natural polymer on earth after cellulose, which is formed by plants. However, it is not only its high availability that gives chitin great potential as a resource.
Raw materials with potential: Chitin-containing agro-industrial waste streams
The biopolymer chitin is a nitrogen-containing polysaccharide and serves, among other things, as a raw material for the production of chitosan and glucosamine or is used as a fertilizer and soil improver in agriculture.
Commercial use is currently limited to chitin obtained from crab shells. However, other chitin-containing residues from food production and processing also offer potential for further value creation, such as waste streams from insect protein production, or residues from industrial fermentation with fungi. At Fraunhofer IGB, we have succeeded in using our expertise to make these resources usable as sources of chitin.
Chitosan (left: derived from A. niger; middle: from adult flies) and high-purified chitosan from larval exuviae (right)
Our approach
Isolation and purification of chitin from different sources
At Fraunhofer IGB, chitin is extracted using a process involving mainly chemical methods. To achieve optimal results, however, we adapt this process to each individual raw material: there are general purification steps that need to be refined or changed in sequence due to the different composition of the biomass.
In addition to mild chemical processes, we also use enzymatic or microbial processes for chitin purification. Here, we use individual enzymes or enzyme cocktails to remove contaminants from the chitin matrix. Wet-chemical methods are used with a view to separating impurities as effectively as possible while preserving the chemical-physical properties of chitin. In this context, it is also worth mentioning the preferred use of aqueous media over organic solvents, which require increased safety precautions in a large-scale process.
Economic efficiency through optimization and scaling
To ensure that subsequent implementation is economically feasible, we analyze and optimize individual process steps on a laboratory scale, e.g., by reducing the use of washing water. At Fraunhofer IGB, we also use biotechnological tools (e.g., enzymes) for purification. Regardless of this, the developed process should generally be scalable.
With our expertise in scaling up chitin purification (e.g., for waste streams from insect protein production), we identify and overcome bottlenecks in transferring to the next larger scale.
Composition and chitin content of Aspergillus niger
Determining the film thickness with a digital caliper
High-purified chitosan purified from insect skins
Methods for analyzing chitin raw materials and controlling chitin processing
Knowledge of the composition of the raw biomass is essential. On the one hand, the success of the purification process can be assessed and controlled by means of appropriate analyses; on the other hand, the natural substances to be removed from the chitin must be known to design and economically implement the downstream process. At Fraunhofer IGB, we have developed various analytical methods for analyzing raw materials and controlling the processing steps, depending on the requirements of the starting material. These methods allow, for example, the chitin content of the intermediate products to be determined after each purification step.
Identification of other valuable substances
Our specially developed analytical methods also enable us to identify other valuable substances in the biomass so that they can also be recovered as pure fractions using a coupling and cascading approach. For example, we have detected a high glucan content in fungal biomass. This enables further value creation from the biomass but requires an adjustment of the chitin extraction process. Similarly, minerals obtained from the processing of chitin can potentially be used as setting accelerators for cement.
Conversion of chitin to chitosan
Chitosan is by far the most important derivative of chitin. Unlike chitin, this derivative is soluble in water and therefore has a much wider range of applications. The chitosan production process itself is drastic – at least in terms of the temperature and composition of the reaction solution.
Compared to chitin production, which can be carried out with basic chemical knowledge, chitosan production requires proven chemical expertise; in addition, safety-related aspects must be considered. Depending on the molecular weight and degree of deacetylation of chitosan, the viscosity and solubility change significantly. Chitosan also changes its electronic properties with the pH value, and incompatibilities with other substances are not uncommon. Experience in handling and knowledge of the properties of chitosan are particularly important here. One way to identify incompatibilities and evaluate the properties and applications of chitosan is to form a film by solvent casting.
During our investigations, we successfully applied various methods to produce chitosan, mitigated and optimized the reaction conditions, explored the potential for recycling, and ultimately obtained high-purity chitosan.
Deacetylation of chitin to chitosan
Unique selling points: How you benefit from our expertise
We create added value from chitin-containing residual materials or waste streams. Chitin-containing agro-industrial residues are currently used, for example, as animal feed. However, animal husbandry in Germany is in decline, so alternatives are needed.
We are specialists in the analysis and processing of chitin-rich waste streams and the production of an applicable form of the purified products. In addition, we try to design the processes in such a way that, in addition to chitin/chitosan, other products can also be obtained in a coupling and cascading use. In short: we can offer solutions along the entire value chain.
Through more than ten years of research, we have built up extensive expertise in the handling of chitin/chitosan. In addition, at Fraunhofer IGB, we have created the capabilities to comprehensively analyze chitosan and its properties to identify the most suitable areas of application. Together with our partner network, we have already investigated applications for chitosan in the fields of textile finishing and water treatment.
Applications of chitosan
Chitosan is already used in the textile industry, for example to protect yarn during weaving. Due to its chemical structure with binding sites for additional functionalities, we have also modified the renewable biopolymer for sustainable finishing and fluorine-free water-repellent treatment of cotton, polyester, and blended fabrics.
Chitosan can also be used as a bio-based flocculant for treating complex and turbid wastewater. At Fraunhofer IGB, we have developed LaChiPur, a bio-based and functionalized flocculant that can be used to efficiently purify wastewater containing complex substances: The enzyme laccase in a chitosan matrix ensures that toxic phenols are removed from the water without compromising the flocculant activity.
At the institute, we also use chitosan as a bio-based material for the production of micro- and nanoparticles for encapsulation and as release systems.
Overview of possible applications
- Textile industry: sizing agents, templates for water-repellent and flame-retardant finishes, odor-inhibiting finishes
- Wastewater treatment: Flocculants for removing heavy metals and suspended solids
- Packaging: bio-based coating and edible material
- Pharmaceuticals and medicine: wound dressings, drug delivery systems, antimicrobial coatings
- Cosmetics: moisturizers and skin care additives in creams and lotions
- Food processing: clarification of liquids, suppression of off-flavors
- Agriculture: Plant protection products, seed coatings, and soil improvers
Chitosan films are well suited for packaging applications because of their balanced elasticity and transparency.
Chitosan weist vielversprechende Eigenschaften für die Verwendung in Folienverpackungen auf.
Chitosan could be used in cosmetics as a skin-care and moisturizing ingredient.
Video: Application of chitosan in the textile industry
bioökonomie.de – an initiative of the German Federal Ministry of Education and Research (BMBF) – shows in a video how digitalization and innovative materials are changing the textile industry (in German).
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Collaboration
Collaboration
Your challenges and queries
Do you have a waste stream rich in chitin that has not yet been recycled or is only being utilized thermally?
Don't just see this stream as waste, but as a material to be valorized. There are a number of challenges: the exact composition is unknown, the current process is easy and well-established, but the application of potential new products is still unknown. We can support you in providing answers to these questions. Literature, patent, and market research are a good place to start when identifying alternative applications for your residual materials.
Or do you have a petrochemical product/polymer that has been working reliably in a wide variety of applications for years?
A switch to a bio-based and sustainable alternative seems inevitable in the coming years: Consumer awareness and, with it, industry awareness is changing, as is legislation. In addition, manufacturers are currently dependent on a few non-European sources for their supplies. The versatile chitosan may be able to replace at least some of the ingredients used to date. But is it compatible with other compounds contained and, if so, which chitosan is most suitable? We will investigate this for you.
Are you already using chitin and chitosan, but see further potential for improvement in terms of handling and performance?
In fact, the properties of polymers are highly dependent on the pattern and degree of deacetylation as well as molecular weight and purity. We can show you ways to “upgrade” your chitosan. Cross-linking and enzymatic or chemical modification of chitosan are also part of our portfolio.
What we can do for you
We are happy to advise you on all matters relating to the processing of chitin from a variety of sources, as well as on its analysis. We also carry out initial feasibility studies on the use of chitin or chitosan in our laboratories.
In order to assess the effect of the isolated chitosan, it is necessary to know various significant parameters such as the degree of deacetylation, purity and molecular weight. Chitosan is not usually used on its own, but in combination with other substances in so-called formulations. Compatibility with various substances is therefore necessary. In both cases, we can support you with feasibility studies.
For large-scale projects, we are also happy to assist you in finding public funding (federal, state, EU) and will work with you to submit a project application to the funding agency.
Contact us!
If you have any further questions or concerns that are not listed here, please feel free to contact us. If so, please feel free to contact us to arrange a meeting to discuss this. We look forward to receiving your call or email and will be happy to arrange an initial, informal meeting.
Range of services
Range of services
Fraunhofer IGB is your central point of contact for everything related to chitin and chitosan – from resources and analysis to applications.
We offer the following services on behalf of our customers and within the framework of joint projects:
Research, consulting
Literature and patent searches on chitin and chitosan resources, processes, and applications
Analysis
- Determination of the chitin content and chemical composition of chitin-containing materials/residues
- Chitin analysis: Measurement of ash, melanin and protein contamination, purity, and degree of acetylation
- Chitosan analysis including molecular weight, degree of deacetylation, film formation, swelling, and purity. The pattern could be analyzed in one of our partner laboratories.
Extraction of chitin
Process development from raw material to chitin, including:
- Evaluation of the use of biotechnological tools, e.g., purification using enzymes
- Investigation of optimization potential (washing water reduction, etc.)
- Evaluation of the most important process parameters
- Scale-up of the purification steps
- Evaluation of the holistic utilization of raw biomass
- Production of sample quantities of chitin on a higher gram scale
Production of chitosan
- Chemical chitin deacetylation for the production of chitosan
- Production of sample quantities of chitosan on a gram scale
Modification and application of chitosan
- Enzymatic chitosan modifications and cross-linking
- Testing of various chitosan cross-linkers in our proprietary plate-based assay
- Investigation of the suitability of chitosans for various applications, including compatibility tests
Equipment
Equipment
- Titrator with sample changer for determining the degree of deacetylation of chitin and chitosan
- Infrared spectrometer for determining the degree of deacetylation and confirming the functional groups of chitin and chitosan
- NMR spectroscopy for determining the degree of deacetylation and purity of chitosan
- Viscosimeter for determining the viscosity of chitosan solutions (pumpability, handling) and molecular weight (MV)
- Size-exclusion chromatography to determine molecular-weight (Mw, Mn) of the chitosan
- Soxhlet apparatus in various sizes for quantitative determination of fat content and preparative degreasing
- 25- and 50-liter reactors for chitin purification on a larger scale
- Different filter types and sizes (dead-end, continuous) for designing filtration on a pilot scale
Presentations (Videos)
Presentation “Chitin extraction and chitosan production from non-marine sources”
Presentation at the Euchis Webinar #3 - Thomas Hahn & Stefan Cord-Landwehr on June 29, 2021
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Given at the 3rd Bioeconomy Congress on September 21, 2020, in the session: “Innovative fibers and technical textiles derived from biomass”
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- Hahn, T., J. Egger, S. Krake, M. Dyballa, L. Stegbauer, N. von Seggern, I. Bruheim and S. Zibek (2024). Comprehensive characterization and evaluation of the process chain and products from Euphausia superba exocuticles to chitosan. Journal of Applied Polymer Science. 141: e54789.
- Hahn, T., E. Tafi, N. von Seggern, P. Falabella, R. Salvia, J. Thomä, E. Febel, M. Fijalkowska, E. Schmitt, L. Stegbauer and S. Zibek (2022). "Purification of Chitin from Pupal Exuviae of the Black Soldier Fly." Waste and Biomass Valorization 13(4): 1993-2008. https://doi.org/10.1007/s12649-021-01645-1
- Hahn, T., E. Tafi, A. Paul, R. Salvia, P. Falabella and S. Zibek (2020). Current state of chitin purification and chitosan production from insects. Journal of Chemical Technology & Biotechnology. 95: 2775-2795.
- Hahn, T., A. Roth, R. Ji, E. Schmitt and S. Zibek (2020). "Chitosan production with larval exoskeletons derived from the insect protein production." Journal of Biotechnology 310: 62-67. https://doi.org/10.1016/j.jbiotec.2019.12.015
- Guarnieri, A., M. Triunfo, C. Scieuzo, D. Ianniciello, E. Tafi, T. Hahn, S. Zibek, R. Salvia, A. De Bonis and P. Falabella (2022). Antimicrobial properties of chitosan from different developmental stages of the bioconverter insect Hermetia illucens. Scientific Reports. 12: 8084.
- Triunfo, M., E. Tafi, A. Guarnieri, C. Scieuzo, T. Hahn, S. Zibek, R. Salvia and P. Falabella (2021). "Insect Chitin-Based Nanomaterials for Innovative Cosmetics and Cosmeceuticals." Cosmetics 8(2): 40.
- Krake, S., C. Conzelmann, S. Heuer, M. Dyballa, S. Zibek and T. Hahn (2024). "Production of chitosan from Aspergillus niger and quantitative evaluation of the process using adapted analytical tools." Biotechnology and Bioprocess Engineering 29(5): 942-954. https://doi.org/10.1007/s12257-024-00124-3
- Hahn, T., L. Bossog, T. Hager, W. Wunderlich, R. Breier, T. Stegmaier and S. Zibek (2019). Chitosan Application in Textile Processing and Fabric Coating. Chitin and Chitosan: Properties and Applications. B. van den Broek and C. Boeriu, Wiley VCH. https://doi.org/10.1002/9781119450467.ch16
- Hahn, T. and S. Zibek (2018). Sewage Polluted Water Treatment via Chitosan: A Review. Chitin - Chitosan Myriad Functionalities in Science and Technology. R. Dongre. Rijeka, IntechOpen. 10.5772/intechopen.75395
- Hahn, T. and D. Eufracio Lucio (2024). Komplexe Abwässer einfach aufgereinigt. DVI Energie + Umwelt. 1: 48-49.
- Hahn, T., S. Zibek, A. Weber and J. Schmucker (2022). "Chitosan als Multitalent in Textilprozessen." TEXTILplus 05/06: 24-26.
- Weber, A. and T. Hahn (2021). Textilien mit Chitosan nachhaltig beschichten. melliand Textilberichte: 28-29.
- Hahn, T., Roth, A., Febel, E., Fijalkowska, M., Schmitt, E., Arsiwalla, T., Zibek, S. 2018. New methods for high-accuracy insect chitin measurement. in: Journal of the Science of Food and Agriculture, Vol. 98, pp. 5069-5073. Doi:10.1002/jsfa.9044