IMPROVEMENTS IN OBTAINING AND TREATING CERTAIN BASES FROM COAL-TAR NAPHTHAS AND OILS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Edward Sonstadt at the Office of
the Commissioners of Patents on the 3rd February 1883.
EDWARD SONSTADT of Cheshunt in the County of Hertford
"IMPROVEMENTS
IN OBTAINING AND TREATING CERTAIN BASES FROM COAL-TAR NAPHTHAS AND
OILS"
According to the method hitherto adopted for obtaining quinoline and other
bases from creosote or other coal-tar oils, such oils are treated with an Acid and the
solution of bases which separates is collected for further treatment.
This process
however leaves a large proportion of the bases behind in solution in the oils, and
the first part of my present invention consists in a method for obtaining such
retained bases or certain of them, which method is also applicable to naphthas and
oils that have undergone no acid treatment
First I agitate the oils with any re-agent, whether. in a solid or liquid state or in
solution, capable of inducing the formation of a solid precipitate containing the bases
or certain of the bases (including quinoline and its homologues and acridine) to be
separated; the precipitate is then collected and subjected to such further treatinent
based on known chemical reactions as may be adapted to its constitution and the
particular products required-The process I prefer consists in the employment in
the manner aforesaid of hydrogen ferro cyanide, or of sodium, potassium, or other
suitable soluble ferrocyanide, in solution, to which, preferably in the case of using
hydrogen ferro cyanide, and necessarily in the other cases, acid is to be added, the
acid preferred being hydrochloric or sulphuric acid. - The ferro cyanide solution
should be of such dilution as not to be precipitated on adding the proportion of acid
found desirable-The proportion of acid to be added will vary with circumstances,
but it is preferred to add, when commercial hydrochloric acid of full strength is
used and proportionably when sulphuric or other acid is used, not less than an
equal weight to the ferro cyanide employed-and in many cases more than this
proportion may be needed-Instead of adding the acid to the ferro cyanide solution,
it may be added to the oils for treatment before or after addition separately of the
latter to the oils; but in any case the agitation of the solution or solutions and of
the oils together should be effectively carried out-The proportion of ferro cyanide
Price 2d 1

page_text: and acid required in any case may be determined on a trial sample-Acid solutions
of ferrocyanides do not form precipitates with all the bases contained in coal-tar
oils, and this invention relates only to the recovery of such bases, including
quinoline, its homologues, and acridine, as are precipitated in the manner described―
After drawing or filtering off the liquids from the precipitate as far as useful it is
preferred to subject the latter to pressure in a filter press-The pressed mass may
be ground and washed with benzol, petroleum spirit or other solvent liquid to
remove adhering oils as far as practicable, but some hydro-carbons remain obstinately
with the precipitate, and can only conveniently be separated at a later stage of the
process
Second The precipitate may be treated in any convenient way, as by heating
with alkalies or with alkali carbonates, or with lime, with or without the aid of a
current of steam, in a suitable apparatus adinitting of collection of the bases so
expelled; or it may be converted into prussian blue and an acid solution of bases
by treatment with a suitable ferric salt in solution, or by ferrous sulphate
solution with access of air, as is well understood; but it is preferably digested with
solution of sodium or potassium hydrate or carbonate, whereby an alkali metal
ferro cyanide is formed while the bases separate and may be removed by
decantation. The recovered sodium or potassium ferro cyanide may at once, after
addition of acid in suitable proportion, be used to precipitate the bases from fresh
portions of oils, in which case any adhering bases are reprecipitated and recovered
with the next precipitate- It is recommended to dissolve the bases thus obtained
in an acid, filter off from any undissolved bydro-carbons, and then precipitate the
bases from the solution, preferably by sodium hydrate or carbonate
Third The quinoline and other bases are capable of being in some degree
separated from one another, on the principle of fractional precipitation-The oils
may be treated with successive portions of the acid ferro cyanide solution described,
and the precipitates collected apart for separate working-or the solution of bases
obtained as stated in the preceding paragraph may be fractionally precipitated by
the same re-agent, such precipitates being collected and treated apart to obtain
portions of bases rich respectively in one or other desired product.
The bases obtained as above may be further fractionally distilled or otherwise
treated by any of the known processes to obtain quinoline, lepidine, or other
desired base contained in the matter treated.
Fourth-The acid liquors resulting from the treatment with acid of creosote and
other coal-tar oils according to the previously described method, may be treated
with the ferro cyanide solution for the precipitation and subsequent recovery of
certain bases in a purified state, as quinoline and its homologues, substantially in
the manner already indicated.
Fifth Crude quinoline liquors from whatsoever source, other than coal-tar
products, may be treated substantially according to the process above described,
modified in details as may be needed to suit special cases
Although oils are mentioned throughout, this Invention is equally applicable to
the treatment of Naphthas.