An Improved Method of Recovering By-products in the Manufacture of Coke.
Year: 1899

page_text: Date of Application, 12th June, 1899
Complete Specification Left, 23rd Feb., 1900-Accepted, 28th Apr., 1900
PROVISIONAL SPECIFICATION.
An Improved Method of Recovering By-products in the Manufacture
of Coke.
We, CARL STILL, of 310, Halternerstrasse, Recklinghausen, Engineer, and
the GEWERKSCHAFT KÖNIG LUDWI, of Bruch, Westphalia, both in the Empire
of Germany, do hereby declare the nature of this invention to be as follows:-
:-
This invention relates to a method of recovering by-products in the manu-
facture of coke, and has for its object to render said recovery more economical
as to the absorbing agent used in the washers, and to obtain a higher output
of valuable by-products. To this end the principal feature of the present
invention consists in so proceeding after each benzene-absorbing operation that
the absorption capacity is restored to the oil or other absorbing agent as fully
as possible. This is effected by removing from the oil not only benzene as
heretofore, but as much of all the products taken up from the gases in the
washer as may be practicable without damaging the oil itself. By these means
such absorbed products as are liable to reduce the absorbing power of the wash
oil for hydrocarbons are prevented from accumulating in the oil, so that the
latter can be returned to the washer or washers to be used again with but a
slight reduction of its absorbing power, or in other words, the reduction of
said absorbing power is allowed to take place only by slight degrees at each
successive use of the wash oil. Thus the said oil can be used over and over
again without leaving a notable percentage of hydro-carbons unabsorbed, for a
considerably longer time than would be possible when employing the ordinary
method of purification.
The second feature of the invention is that not only is all the benzene
recovered, but its higher homologues are obtained, such as xylene, cumeme &c.,
which have been found to be present in considerable quantities, and which
according to the usual practice are lost by remaining behind in the oil.
The removal of the absorbed products from the oil is effected by a single
distilling operation, preferably with the assistance of a driving-off current of
steam superheated up to a temperature of 230° Centigrade. The bulk of the
products thus removed is finally separated into its constituent hydrocarbons by
fractional distillation, leaving so called solvent naphtha as a useful residue.
By the above process a reduction of the consumption of wash oil is effected
and an increase in the yield of benzene and its homologues is obtained.
Dated this 19th day of June 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: An Improved Method of Recovering By-products in the Manufacture
of Coke.
We, CARL STILL, of 310, Halternerstrasse, Recklinghausen, Engineer, and
the GEWERKSCHAFT KÖNIG LUDWIG, of Bruch, Westphalia, both in the Empire
of Germany, 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:--
This invention relates to a method of recovering by-products in the manufac-
ture of coke, and has for its object to render the said recovery more economical
as to the absorbing agent used in the washers, and to obtain a higher output
of valuable by-products. To this end the principal feature of the present
invention consists in so proceeding after each benzene-absorbing operation that
the absorption capacity is restored to the oil or other absorbing agent as fully
as possible. This is effected by removing from the oil not only benzene as
heretofore, but as much of all the products taken up from the gases in the
washer as may be practicable without damaging the oil itself. By these means
such absorbed products as are liable to reduce the absorbing power of the wash
oil for hydrocarbons are prevented from accumulating in the oil, so that the
latter can be returned to the washer or washers to be used again with but a
slight reduction of its absorbing power, or in other words, the reduction of
said absorbing power is allowed to take place only by slight degrees at each
successive use of the wash oil. Thus the said oil can be used over and over
again without leaving a notable percentage of hydrocarbons unabsorbed, for a
considerably longer time than would be possible when employing the ordinary
method of purification.
The second feature of the invention is that not only is all of the benzene
recovered, but its higher homologues are obtained, such as xylene, cumene etc.;
and also naphtalene, which have been found to be present in considerable quan-
tities, and which according to the usual practice are lost by remaining behind
in the oil.
The removal of the absorbed products from the oil is effected by a single
distilling operation, preferably with the assistance of a driving-off current of
steam superheated up to a temperature of 230° Centigrade. The bulk of the
products thus removed is finally separated into its constituent hydrocarbons by
fractional distillation.
By the above process a reduction of the consumption of wash oil is effected
and an increase in the yield of benzene and its homologues is obtained.
The described process of distilling from the oil or other absorbing agent by
a first operation as much of the more or less volatile hydrocarbon as may be
practicable, and to submit the products of this first distillation to a second
operation as a fractional distillation for the purpose of separating the product
into its constituent hydrocarbons, may be carried out in the usual distilling
apparatus as shown by way of example on the annexed sheet or drawings in
which A represents the still to which the wash oil is supplied by pipe a. After
distillation of the whole of the recoverable by-products and their rectification
they run into the cooler B and from there to a reservoir C which serves as
supply reservoir for the second operation, that is, the separation of the product
into its constituent hydrocarbons.
D is the still for the fractional distillation and E the cooler of the same. The
most volatile constituent being first driven, off collects as benzene of 90 to 93°

page_text: in the first collecting vessel G. On the distillation being continued, and the
test of the product in the cooler E showing that the second grade product, the
Toluol begins to condense the valve g between the cooler and collecting vessel G
is closed and Toluol is collected in H. In the same manner the Xylol is collected
in J and finally the solvent naphtalene, the last constituent, in K by gradually
closing the corresponding valves h and i.
The wash oil from which the valuable by-products are separated and any
residue of the second operation are together collected in the tank F from where
they are conducted through pipe to the washers.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is:-
1. The method of recovering by-products in the manufacture of coke, whereby
a great reduction in the consumption of the wash oil and an increase in the yield
of the hydrocarbons CH and naphtalene are obtained, said method con-
sisting in removing nearly all the by-products from the said wash oil after each
time that it is used, so that the said wash oil may be returned to the washer
with almost full absorbing capacity, while from the removed by-products the
higher evaporating products can be separated, for the purpose specified.
2. In the aforesaid method the separation of the by-products from the wash
oil in a single operation and the fractional distillation of the said separated by-
products, substantially as described.
3. In the aforesaid method the use of superheated steam substantially as and
for the purpose described.
Dated this 23rd day of February 1900
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.