Chitosan recovery from insect biomass

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• funding program: ZIM KF (BMWI)
• term: 01.07.2018 – 30.06.2020
• project partner:
  • Reptile Food Handels- & Zucht GmbH
  • Calbe Chemie GmbH

Initial position:

Chitin is the second most abundant biopolymer after cellulose and is mainly found in insects and marine crustaceans. Although strong polar interactions make chitin highly resistant to highly concentrated chemicals, it also makes extraction very intricate. (Türck, 2014)

In 2011, 1600 tonnes of purified chitin (derived from marine biomass) were extracted worldwide, with Japan as main producer. Due to the wide range of products (purity, qualities), the price range varies between 10-1000 $ per kg. (Türck, 2014)

The existing method for chitin extraction from marine biomass (crustaceans, zooplankton) is not very efficient (low yields: chitin about 6%, chitosan 2.5%) and not environmentally friendly. Due to the increased use of marine resources and their potential ecological and social implications, the sustainability of the bioplastic chitosan, from marine biomass, must be considered critically. (Lindenthal, Schlaak, & Siefert, 2010)

The extraction of chitin from crab shells and its conversion to chitosan occurs within three main steps: demineralization, deproteination, deacetylation (Rigby, 1936). Between every single main step, at least one washing step is necessary, which makes the preparation even more expensive. The relatively low product yields and the process intricacy show the need for development work in this area.

The chitin content of marine crustaceans of about 20-31% is comparable to that of insects (10-36% in dry matter). However, the conditions for the acid treatment (demineralization) in the extraction from insects are significantly more moderate than those in the extraction from marine crustaceans. The reason for this is the lower content of inorganic substances in the insects (<10%) compared to the marine crustaceans (20-40%), (Kaya, Erdogan, Mol, & Baran, 2014b), so the acid treatment could possibly be omitted.

Aim:

The intention is to develop a process for the chemical and enzymatic production of chitin or chitosan from insect biomass. Examplary, chitosan-based flocculants for precipitation processes in wastewater technology will be developed in order to recover biodegradable sludges. It is also intended to produce the chitosane substances in a very pure form for teh use in medical and other applications.

Results:

The project is ongoing.

Literature:

Kaya, M., Erdogan, S., Mol, A., & Baran, T. (2014b). Comparison of chitin structures isolated from seven Orthoptera species. International Journal of Biological Macromolecules 72 (2015), S. 797-805.

Lindenthal, W., Schlaak, M., & Siefert, E. (April 2010). Nachwachsender Rohstoff aus dem Meer – Vom Abfall zum Wertstoff. GIT Laborfachzeitschrift.

Rigby, G. (1936). Patentnr. 2,040,879. United States of America.

Türck, O. (2014). Stoffliche Nutzung nachwachsener Rohstoffe – Grundlagen, Werkstoffe, Anwendungen. Wiesbaden: Springer Fachmedien.

picture: Prof. Dr. Hans-Jörg Ferenz