IMPROVEMENTS IN REFINING LAMP OIL MADE FROM OLEAGINOUS SEED
Year: 1859

page_text: LETTERS PATENT to Pierre Marchand, Emile Marchand, and Josse
Marchand, of Dunkirk, France, trading under the Firm of Pierre
Marchand, Brothers, for the Invention of "IMPROVEMENTS IN REFINING
LAMP OIL MADE FROM OLEAGINOUS SEED."
PROVISIONAL SPECIFICATION left by the said Pierre Marchand, Emile
Marchand, and Josse Marchand, at the Office of the Commissioners of
Patents, with their Petition, on the 22nd November 1859.
We, PIERRE MARCHAND, EMILE MARCHAND, and JOSSE MARCHAND, of
Dunkirk, France, trading under the Firm of Pierre Marcband, Brothers, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN RE-
FINING LAMP OIL MADE FROM OLEAGINOUS SEED," to be as follows:-
We take, say, a thousand kilogrammes of unrefined oil, either native or
exotic, rapeseed, or other seed, and submit it to the usual system of refining,
that is, put the oil into a reservoir, adding one and a half per cent. of
sulphuric acid, beat the liquid for an hour, then add ten per cent. water, and
beat the whole together; let it settle eight or ten days, and when the water
and acid are sufficiently separated from the oil, say, nearly pure, pass it

page_text: through a filter of sawdust, tow, charcoal, or other matter, and the process is
finished.
By our system, instead of letting the oil settle eight or ten days, we at the
end of two or three days put it into a reservoir, quite clean and prepared
purposely; we throw in a quantity of pulverised limestone, say one to three
parts, per thousand kilogrammes, as the oil is more or less acid after the first
refining, which we ascertain by turnsol paper soaked in the oil on each
addition, and the process continues constantly beating the oil and the lime
untill the acid is destroyed, the proof of which is that the paper soaked in the
oil preserves it original colour; constant beating of the oil is indispensable
that each part saturated with lime, of which it seems a greater quantity might
be used at first, but it would cause saponification of the oil, which is avoided
by following strictly the indications above given. If the process is properly
conducted, after settling two days the oil will be clarified, and will not contain
an atom of acid or water; the lime will have destroyed and absorbed all. We
still filter through something usual, provided it is new or has not been used
for other oils refined by the ordinary process. There is still an advantage for
the refiner whose expence for filters is great, having been in contact with the
acid, they are soon burnt and useless, having a quantity of oil attached to
them; here the filters last an indifinite time, owing to the total absence of
acid; it suffices from time to time to submit them to a suitable pressure to
extract the scum adhering, and then to wash them in warm water; the oil
obtained will have a limpidity and a paleness without equal, will possess all
the qualities suitable for burning and for greasing machinery, and will never
become cloudy.
Calcarious stone or white chalk, in powder and quite dry, also has the
property not quite like the lime of absorbing and destroying the acid, but in
precipitating it and on putting in a much greater quantity, say four per cent.,
it produces on the oil an effect almost analogous to that by lime. After
having well beaten the oil, leave it to settle, and at the end of ten or twelve
hours it may be seen if the oil is clarifying; if it is not, add two or three per
cent. of chalk, and let it settle. Filtering is in all cases necessary. Alkali,
either in powder or liquid, may also be used to destroy the effect of the acid on
the oil; if used in powder, care must be taken to add thereto a fourth or fifth
part of bay salt; this addition is to prevent saponification, and to accelerate
the separation of the oil and alkali; the latter ought to precipitate itself with
the acid and water which it will have absorbed. The whole must be beaten
for a quarter of an hour, and again six hours afterwards, assuring oneself of

page_text: the effect by means of turnsol paper. In some cases we have been obliged to
put a fifth part per thousand, in others one-half part per thousand, sometimes
one, and up to two parts per thousand; as we have above stated, it is always
by the turnsol paper that we are guided in the operation; these differences
arise from the greater or smaller quantity of acid that the oil has retained after
the settling which followed the ordinary operation of refining. Having assured
ourselves that our oil contains no acid, without however being soapy, we heat
it during ten hours at a temperature of thirty degrees in a boiler heated by
means of tubes, taking care to take away the scum which arises to the surface;
we then let the matter rest untill the temperature has fallen to ten or fifteen
degrees, we pass it through a new ordinary filter, which we cover with some
pretty fine cotton cloths, in order to stop the scum, which without this pre-
caution would immediately invade the filter. If instead of alkali in powder,
whether soda or potash, it should be used liquid; it should be very strong
from twenty-eight to thirty degrees, with an addition of a third part salt,
assuring oneself by turnsol paper of the quantity to mix with the oil; it
must be heated sufficiently to cause evaporation of the liquid before filtering,
which is indispensable. These last processes, for which we also request to
be patented, present a result less certain, and have much more difficulties than
the former one by lime. We have discovered them in the course of the
numerous experiments which we have been making during several years.