An Improved Method of Treating Sea Weed to Obtain Valuable Products therefrom.
Year: 1896

page_text: Date of Application, 27th May, 1896-Accepted, 29th Aug., 1896
COMPLETE SPECIFICATION.
An Improved Method of Treating Sea Weed to Obtain Valuable
Products therefrom.
I, AXEL KREFTING of Karl Johansgade 10, Christiania, Norway, Engineer,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
The English chemist E. C. C. Stanford was the first to point out, that different
species of sea-weed besides the inorganic salts of technical importance (for instance
the iodids) also contain a valuable organic substance, which he called algin-acid.
This substance he produced by boiling the sea-weed for a long time in solutions of
carbonate of potash or soda until the sea-weed was decomposed and formed a soup.
This he filtered and then precipitated out of the clear solution the voluminous
substance the algin-acid.
The valuable properties of this matter have been exactly examined by
Mr. E. C. C. Stanford, whose statements have been controlled in all respects by.
the inventor of the present method, who can entirely substantiate the correctness
of Mr. Stanford's statements. The inventor has also found other important
properties in the matter, which up to the present time have not been thought of
any importance.
The reason, why Mr. Stanford-who has patented his invention in many
countries-did not manage to produce the substance at such a cheap price, that he
could manufacture it, was doubtless the long and expensive boiling of the sea-weed
with the carbonates of potash or soda, which with thicker leaves and stems are
unable to effect the decomposition of the plant.
The inventor of the present method, who has for a long time examined the
different species of sea-weed or tangs has discovered, that the substance, which
cements the vegetable fibres of the sea-weed consists of the salt of lime of a
peculiar organic acid, which he has called the tang-acid; this tang-acid he has
examined by means of the organic elementary analysis and he has found, that the
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page_text: concluded that the algin-acid is a nitrogenous compound, which is not the case with
the pure tang-acid.
The method, which is the subject of the present invention consists in the
treatment of the sea-weed with diluted sulphuric acid or other suitable acid-
before any other chemical treatment takes place-except a washing out or an
elutriation with water, in case this is desirable-so that the lime may be extracted.
The sea-weed does not change its appearance by this treatment, and its fibres
seem to have the same cohesive power as before; but now it appears, that the
addition of a cold and very thin solution of alkalis or of carbonates of potash or
soda effects a momentary solution of the substance "tang-acid," which cements the
vegetable fibres, because it forms a salt of soda or potash and tang-acid, which is
soluble in water. This circumstance effects the complete loosening of the vegetable
fibres, which separate. If we now filter the liquid thus formed, from the filtrate
we can precipitate the non-nitrogenous and pure tang-acid, with all its valuable
properties. The great advantage, which this method has over Stanford's process
consists in the rapidity, with which the reactions take place and in the fact, that
no warming up is necessary.
In carrying out the herein described method I make use of sulphuric acid of a
strength of 1% to 6% to draw out the lime of the tang. When all the lime is
drawn out and the tang washed out with water I add as much carbonate of soda
(in the form of a powder or as a solution of an arbitrary strength) as will fully
decompose the sea-weed and form a soup. (Also until all the present tang-acid ís
neutralized.)
For precipitating the tang acid out of the filtrate from the soup I use common
diluted sulphuric acid. As such is also used the wash-water from the washing out
of the sea-weed after being treated with sulphuric-acid. I cannot here give fixed
rules for the strengths as it is preferable to use as little as possible of acid and
carbonate of soda.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The method of producing substances of technical importance from different
species of sea-weed or tang characterized by the extraction of the lime from the
sea-weed, by means of suitable acid, before any other chemical treatment of the
sea-weed takes place, except an elutriation with water, in case this is desirable.
Dated this 27th day of May 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.