Seaweed nanocellulose biorefinery opens in New Zealand

The multi-million-dollar biorefinery, owned by family company AgriSea, will convert seaweed left over from the biostimulant production process into nanocellulose hydrogel. This hydrogel can be used for medical, agricultural, manufacturing and cosmetic purposes. Nanocellulose is a highly versatile material because of its exceptional properties, but most of the world’s supply is currently produced using chemically treated wood pulp. AgriSea and the Bioeconomy Science Institute collaborated to create this material from seaweed, offering a sustainable alternative. 

AgriSea chief executive Clare Bradley said seaweed offers a surprising advantage over traditional wood-pulp sources. 

“Its cellulose chains are up to four times wider and longer, giving the resulting hydrogel twice the thermal conductivity of plant-based equivalents. The extraction process uses non-aggressive chemicals compared to those usually used to produce nanocellulose, making it significantly more workplace and environmentally friendly. The finished material, an opaque gel, is stronger than steel and can absorb greater than 100 times its mass in water,” commented Bradley in a press release.

The biorefinery can produce up to 1600kg of nanocellulose hydrogel a week. Applications for the hydrogel include advanced wound dressings and drug delivery; improving seedling survival in agriculture due to its water-retentive properties; and as a potential biodegradable performance material for adhesives, batteries, and electronics manufacturers. Cosmetics companies also see it as a renewable cream base.

For AgriSea, the biorefinery is the next chapter in a 30-year journey producing seaweed-based bio-stimulants for agriculture. Until now, the fibrous residue from the company’s brewing process had limited value. By transforming it into nanocellulose hydrogel, the company is creating revenue streams while eliminating waste. 

Seaweed biorefinery strengthens New Zealand’s circular bioeconomy

Backed by the Ministry of Business, Innovation and Employment to deliver regional jobs, the new plant is a flagship facility for New Zealand’s aquaculture sector. It can process a wide range of local seaweeds and has already trialled species from around the world – an achievement that opens the door for New Zealand to take a leading role in global markets. The technology also creates multiple pathways for growth, including the ability to contract-manufacture nanocellulose for other industry players, sell its own high-value materials into global markets, or license the process to seaweed farmers in other countries. 

Florian Graichen, general manager of Forests to Biobased Products at the Bioeconomy Science Institute, said the biorefinery is a textbook example of New Zealand’s circular bioeconomy in action: “This partnership has led to a blueprint for ocean-based green technologies that could help global industry transition from fossil-derived materials, while minimising waste and revitalising local economies. 

According to market projections, the potential for this technology is vast. The global seaweed cultivation industry is forecast to reach US$69.5 billion by 2034, while the broader biorefinery market is expected to expand by nearly 8 percent annually, topping US$392 billion in the next 10 years.