DON’T WASTE SEAFOOD WASTEUpdate: 5/4/2017
DON’T WASTE SEAFOOD WASTE
Every year, some 6 million to 8 million tonnes of waste crab, shrimp and lobster shells are produced globally — about 1.5 million tonnes in Southeast Asia. In developing countries, waste shells are often just dumped in landfill or the sea. In developed countries, disposal can be costly up to US$150 per tonne in Australia.
However, today we should be aware that shells contain useful chemicals such as protein, calcium carbonate and chitin which contains nitrogen. Turning cast-off shells into nitrogen-rich chemicals would benefit economies and the environment.
Dried shrimp shells are valued at a mere $100–120 per tonne. They can be ground down and the powder used as an animal-feed supplement, bait or fertilizer, as well as in chitin production.
Crustacean shells are 20–40% protein, 20–50% calcium carbonate and 15–40% chitin. What could these parts be used for?
Protein is good for animal feeds.
Calcium carbonate has extensive applications in the pharmaceutical, agricultural, construction and paper industries.
Chitin is a linear polymer and the second most abundant natural biopolymer on Earth. Unlike most other forms of biomass such as cellulose, chitin contains nitrogen. Nitrogen containing compounds widely used in the pharmaceutical industry, carbon dioxide fixation and textiles, are crucial for modern life. For example, the nitrogen containing organic compound pyrazine, is integral to several best-selling drugs such as eszopiclone (for sleeping difficulties) and varenicline (to treat nicotine addiction).