Seaweed & Industry

 In the 18th and 19th centuries seaweed was the primary source of soda and potash used for making glass and glazes.   Kelp was harvested and dried before being burnt in big pits.  The ash was then collected for use in these industries.    However by the 1830's natural deposits of these minerals had been discovered and the kelp industry began to decline.  In the  Isle of Orkney at its peak they expoted 3,000 tons of kelp ash every year.  The collapse of the kelp industry caused great hardship and servere poverty, with people being forced to leave their homes and land and search for work and a living elsewhere.   

In 1812 an Army chemist called Courtois discovered iodine and by 1829 the first factory specialising in iodine production was founded.   By the 1860 there were a dozen factories producing in the region of  60 to 70 tons of iodine every year.    

Alginates and Carrageens appeared on the market in the late 1800's and are now used widely in industry.
 



Crissy Haydon Kenick Sands 2009
Alginates

Alginates have three main properties of use to industry:
  • the ability to thicken a solution when dissolved in water
  • form a gel when sodium alginate is added to calcium salts in water
  • form films of sodium or calcium alginate and fibres of calcium alginate

 

Some industrial uses include:

  • paper coatings
  • welding rod coatings
  • moulding polymers
  • mastics
  • pharmaceutical products
  • bio-plastics
  • food industry
  • canning industry
  • paints
  • dyes
  • medical wound dressings
  • dental moulds

About 50% of the global production of alginate is used in the textile industry to provide an inert thick paste carrier for the dye pigment.  The use of alginates in the food industry is very wide spread and they are used as stabilizers in ice-cream to jelly film to protect frozen fish.

A comprehensive report on Industrial uses for alginates can be found here

 A guide to the seaweed industry Dennis J McHugh Series title: FAO Fisheries Technical Paper T441, 2003 118 pg, ISBN: 9251049580   Y4765/E

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Seaweed Processing Plants

Seaweed: slimy, sexy and saleable: UKs only Kelp factory work round the clock to meet health conscious Britains demands.

To many people, seaweed is little more than a slimy, pungent pest that spoils an otherwise beautiful sandy beach. But the 'grass of the sea' is fast becoming one of the country's most versatile and lucrative natural resources.

Whether it's for age-defying beauty products, a food delicacy, a weapon in the battle against obesity or a potential source of fuel, demand is outstripping supply.

Britain's only seaweed-processing factory, which opened eight months ago near Stornoway, on the Hebridean island of Lewis, is to operate 24 hours a day, six days a week. It is only shut on Sundays because the Sabbath is still regarded as a day of rest and prayer on Lewis and nearby Harris.   Full Article Here

Lorna Martin, Scotland editor
The Observer, Sunday 28 January 2007
http://www.guardian.co.uk/uk/2007/jan/28/scotland.travelnews
AGA EXTRACTION TECHNIQUES
A short and simplified description of the extraction of agar from seaweeds is that the seaweed is washed to remove foreign matter and then heated with water for several hours. The agar dissolves in the water and the mixture is filtered to remove the residual seaweed. The hot filtrate is cooled and forms a gel (jelly) which contains about 1 percent agar. The gel is broken into pieces, and sometimes washed to remove soluble salts, and, if necessary, it can be treated with bleach to reduce the colour. Then the water is removed from the gel, either by a freeze-thaw process or by squeezing it out using pressure. After this treatment, the remaining water is removed by drying in a hot-air oven. The product is then milled to a suitable and uniform particle size.

However, for a better understanding of the process, some of the details and difficulties need to be described.

 

 Qingdao Gather Great Ocean
Seaweed
Industry Co., Ltd

 

Profile of a Seaweed Plant in China:
Qingdao Gather Great Ocean Seaweed Industry Co., Ltd.

 Qingdao Gather Great Ocean Seaweed Industry Co., Ltd is a comprehensive seaweed processing private enterprise, which is growing up quickly near Kiaochow bay in Qingdao. Covering a floor area of 36 thousand sq meters with the building area of 21 thousand sq meters, the corporation owns total assets of RMB50 million. Additionally, the corporation has food-grade and industry-grade seaweed products production bases and marketing and financing center. 

Our corporation mainly processes and produces series of seaweed products by using seaweed as raw material. Thereinto, we annually manufacture 1200 tons sodium alginate, 20 tons iodine, 500 tons mannitol, 200 tons alginic acid, 1000 tons seaweed powder, 600 tons carrageenin and 2000 tons compound seaweed albumen feeds. Our corporation passed the ISO 9001: 2000 International Quality System Certification and gained the import & export right in 2002. Moreover, our corporation was approved to be hi-tech Enterprise by People's Government of Qingdao. 

 Full Profile with Informative Photos of the factory layout, click here
INTERESTING READING
A MANUAL FOR THE PROCESSING OF AGAR FROM GRACILARIA -
FAO PROJECT REPORT,  SANTOS, G A Project Report, 190, 37 pg, AG156
 

Pigments
The natural pigments produced by algae can be used as an alternative to chemical dyes and coloring agents.[
Arad, Shoshana; Spharim, Ishai (1998). "Production of Valuable Products from Microalgae: An Emerging Agroindustry". in Altman, Arie. Agricultural Biotechnology. Books in Soils, Plants, and the Environment. 61. CRC Press. p. 638. ISBN 0824794397, 9780824794392.

Irish Seaweed Industy : An Overview, Stefan Kraan, Irish Seaweed Centre, National University of Ireland, Galway
   
 
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