At Matís in Iceland, the SeaFoodture team has spent the past few years focusing on the extraction of nanocellulose from the solid residue remaining after protein extraction from various locally sourced brown seaweed species.
Once protein has been extracted from brown seaweed, a solid residue remains, composed of a mixture of saccharides, including cellulose. The aim of the project was to extract cellulose and nanocellulose from the residue, with the goal of incorporating it as a raw material in sustainable packaging applications such as films or aerogels.
Early protocols relied on reagents that were effective at lab scale but unsuitable for a scale-up process intended to produce an environmentally friendly product. Although the chemicals used for the cellulose extraction were efficient, they were also hazardous, most notably sodium chlorite, and so the decision was made to explore greener extraction alternatives. It made little sense to replace conventional, polluting packaging materials with a green alternative if the process used to produce it was itself harmful. The team therefore shifted its focus toward greener extraction methods.
Over the past three months, that work gained momentum with the arrival of Callistine Harlet, an intern from the École de Chimie de Rennes in France. Working alongside Cécile Dargentolle and Sophie Jensen, Callistine has contributed to the optimisation of both the green extraction method and the scale-up process itself.
Figure illustrating the stepwise transformation of the algae throughout the green extraction process.
Scaling up is not simply a matter of multiplying quantities. Each step, from chemical concentrations and ratios to timing and handling, behaves differently at larger volumes and requires careful re-optimisation. The team has now reached a working scale of 300 grams of dry seaweed per batch, compared to the 10 grams used in the earliest experiments. The next steps will be to test at kilogram scale and evaluate if the optimised process still achieve good purity and yields.
