A Process of Refining and Treating Crude Petroleum, and of Producing Asphalt from Petroleum and its Products.
Year: 1898

page_text: Date of Application, 4th Oct., 1898-Accepted, 23rd Dec., 1898
COMPLETE SPECIFICATION.
A Process of Refining and Treating Crude Petroleum, and of
Producing Asphalt from Petroleum and its Products.
We, CHAUNCEY B. FORWARD, Physician, residing at The Avon, Fairmount Street,
in the City of Cleveland, Cuyahoga County, Ohio, and JOHN MILNE DAVIDSON,
Chemist, residing at Cedar Heights, in the City of Cleveland, County of Cuyahoga,
and State of Ohio, 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 :-
Our invention relates to a method of obtaining asphalt from crude petroleum,
petroleum tar, or any heavy hydro carbon oil and also to a method of refining or
reducing crude petroleum so as to obtain asphalt as one of the results of the
process.
By our improved process we take either the crude petroleum as it comes from the
well or after the lighter oils have been distilled therefrom but before the process of
distillation has been carried far enough to become destructive. What is left after
the lighter oils have been distilled off is known by the name of petroleum tar or
residue oil. We mix the crude petroleum, petroleum tar, or heavy hydrocarbon oil
in agitators or other receptacles with sulphuric acid (the oil of vitriol of commerce)
which precipitates the heavy black or carbonaceous matter contained therein. The
quantity of acid used for a given quantity of the crude petroleum, petroleum tar, or
heavy hydro-carbon oil depends somewhat upon the nature of the material to be
treated. The more of the carbonaceous matter contained in the material treated,
the greater is the amount of acid required, and the petroleum tar, containing as it
does a greater percentage of the carbonaceous matter than the crude petroleum itself
before the lighter oils have been taken off, requires a larger percentage of acid than
the crude petroleum from which it is derived, and the more oil that has been taken
off, the greater the percentage of carbonaceous matter in the tar or residuum will be,
and the greater the amount of acid required. It is best to regulate the quantity
used by experiment with the particular material or residuum under treatment, being
sure to use enough. Generally speaking, the amount of acid will vary from 5% to 20%
of the amount of the crude petroleum, petroleum tar, or heavy hydro-carbon oil
under treatment. It will rarely, if ever, be found necessary to use more than 20%.
It is easy, by a little experience in the particular material under treatment, to regu-
late the percentage of acid which it is best to use.
The material is then heated in the agitators and thoroughly agitated. If the
crude petroleum as it comes from the well is under treatment, the heat should not
exceed about 80 degrees, Fahrenheit, else a considerable part of the lighter oils will
pass off in vapor. If the petroleum tar or the heavy hydro-carbon oil is being
treated, the heat may be as high as 100 or 110 degrees without injury. In treating
the crude oil, we prefer to take off by distillation some, at least, of the lighter oils
first, because it enables us to use a greater degree of heat in the agitating process
and the results are more satisfactory. After this material in the agitators has been
It will be found that the acid has
so heated and agitated, it is allowed to settle.
united with the carbonaceous matter and as the material in the agitators settles, this
037

page_text: combination of the carbonaceous matter and the acid is precipitated to the bottom
and it or the clear material above may be drawn off and thus the oils separated from
the carbonaceous matter. The oils so freed from the carbonaceous matter which was
before contained in them should be thoroughly washed so as to remove any remaining
acid therefrom. The process of washing is well known. The material to be washed
is thoroughly mixed with alkaline water, and then, upon settling, the oil rises to the
top and the water carrying the acid sinks to the bottom. The oil may be drawn off
from the top of the tank or an agitator and the water containing the acid drawn off
from the bottom and thus they are separated.
We have now remaining the carbonaceous matter, previously contained in the
crude petroleum, petroleum tar or heavy hydrocarbon oil, mixed with the greater
portion of the acid which has been used in the treatment. It is from this substance
that the asphalt or bituminous pro.luct is made. We first wash it to separate the
acid therefrom. The process of washing this is similar to that employed in washing
the oil and the result is that the water containing the acid sinks to the bottom and
the carbonaceous matter, substantially clear of the acid, rises to the top and the
carbonaceous matter may be drawn off from the top, or the water from the bottom,
and so separated. This acid can be removed from this water by a process of distilla-
tion which is well understood.
It is usually best to repeat this washing process two or three times in order to
more thoroughly remove the acid from the carbonaceous matter. Most of the acid
will be recovered in the first washing but some of it will always remain to be taken
out by a second and third washing and its presence in the carbonaceous matter in
any considerable amount is injurious.
We now have the carbonaceous matter, which was originally in the crude petroleum
or petroleum tar, with the oil and acid removed. Some portion of the oil will adhere
to the carbonaceous matter and its presence is beneficial rather than otherwise, and
some traces of the acid may remain, but if the washing has been thorough there will
not be enough to do any harm.
This material by itself will not make the best grade of asphalt. It contains too
large a portion of volatile matter. For the best results it is necessary to mix it
with some heavy oil. The heavy hydro-carbon oil, one of the well known products
of any system of petroleum refining, answers this purpose. Under our process, such
oil will be produced from the mixture of oils which remains after the carbonaceous
matter has been separated therefrom by the acid treatment, being the product
remaining in the still after all lighter oils have been separated from said mixture by
distillation; and under the treatment heretofore employed in petroleum refining it
will be produced as one of the last products of distillation. The heavier the oil, the
better; and it makes no difference whether or not it has been treated so as to purify
it. All that is necessary is that it should be very heavy oil.
The proportion of heavy oil to the carbonaceous matter may vary according to the
character of the material to be mixed with it and of the product required, as will be
hereinafter more particularly explained. This heavy oil and the carbonaceous matter
are then thoroughly mixed. The mixture may be effected by any mechanical means
adapted to the purpose. The mixture is then subjected to a high degree of heat,
preferably as high as 800 degrees, Fahrenheit. This heat should be kept up from
four to eight hours. During the heating, such mechanical changes or chemical re-
actions take place as to convert the combined material into a superior grade of
asphalt and the process may in some cases be terminated at this stage.
But, for many purposes, the asphalt is improved and the product made cheaper by
the addition to it of a proportion of marl. The marl is introduced after the heating
process and before the substance cools and becomes hard.
In the mixture of the heavy oil and the carbonaceous matter, we prefer about 25%
of the oil to 75% of the carbonaceous matter but these proportions may vary. The
carbonaceous matter is not always of exactly the same constituency. That obtained
from one oil field will differ from that obtained from another, and the carbonaceous
matter obtained from the petroleum tar after the lighter oils have been distilled away

page_text: is a little different from that obtained from the crude petroleum for the reason that
in the distillations of the lighter oils, sone of the more volatile parts of the
carbonaceous matter have been distilled away with them, and its character varies
somewhat according to the amount of acid employed and the care with which it has
been removed, as well as the thoroughness with which the separation between the oil
and the carbonaceous matter has been effected. The percentage of heavy oil to the
carbonaceous matter also depends in some degree upon the character of the oil
employed. The heavier the oil, the less of it necessary, because it is the heaviest
part of the oil that produces the beneficial result. Exactitude in the percentage
between the oil and the carbonaceous matter is not necessary. Generally speaking,
the heavier the carbonaceous matter-that is, the more its volatile portions have
been removed the more oil should be used; and the more elastic and pliable the
manufacturer desires the asphalt to be, the more heavy oil should be used. The
proportion of 25% of oil to 75% of carbonaceous matter will always produce an
asphalt of high grade and it will not be found necessary to vary in any considerable
degree from these percentages.
The degree of heat to which the mixture of the carbonaceous matter and the
heavy oil is subjected, and the length of time to which it is subjected to that heat,
also depends somewhat upon the character of the material used and of the result
required. The heat should be continued long enough to effect the desired change in
the substances. A good test of whether or not sufficient heat has been employed is
If the
to take out a sample of the substance and subject it to the action of water.
heat has been employed long enough, the water will not disintegrate it. If not, it
will. After the heating process has been continued for the proper length of time
one can handle it and chew it like chewing gum, without any disagreeable results.
It will be easy in this way to determine when the heating process is complete.
The quantity of marl used will depend upon the character of the asphalt required
and the purpose for which it is to be used. The marl gives it weight, body, consis-
tency, and tensile strength. For asphalt designed for ordinary street paving, it will
be found advisable to add about 20% of marl. For some purposes as inuch as 30%,
or even a very much higher percentage, may be added. A mixture of marl and the
asphalt as it is produced at the end of the heating process, in the ratio of about three
parts marl to one part of the asphalt, makes a most excellent and durable paving
brick.
For the cheaper grade of asphalt, the heavy oil may he entirely omitted. In this
case, the carbonaceous matter should be subjected to the same treatment by heat as
we have described for the mixture of the carbonaceous matter and the heavy oil,
except that it cannot be subjected to as high a degree of heat because that degree.
of heat would be destructive of the substance if the oil was omitted.
600 degrees,
Fahrenheit would be as high a degree of heat as it would be safe to employ
without the oil. If marl is added, it should be at the close of the heating process
in the same way as we have described when the heavy oil is used. Marl is mostly
carbonate of lime, and lime in any other form may be used instead of marl, but the
cheapness of marl makes its use preferable and it gives the best result.
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 process of making asphalt from crude petroleum, or any heavy hydro-carbon
oil by treating the erude petroleum or heavy hydrocarbon oil with acid to separate the
carbonaceous matter from the oils, washing the carbonaceous matter to free it from
the acid, then mixing it with heavy hydrocarbon oil and subjecting it to a high
degree of heat for a considerable period, substantially as described.
2. The process of making asphalt from petroleum tar or from crude petroleum
after the lighter oils have been distilled off by treating it with acid to separate the
carbonaceous matter from the remaining oils, washing the carbonaceous matter to
remove the acid, then mixing it with heavy hydrocarbon oil and subjecting the

page_text: mixture to a high degree of heat for a considerable period, substantially as
described.
3. The process of refining or reducing crude petroleum by treating it with
acid to separate the mixture of oils obtained by this process into oils of various
kinds by successive distillations, by mixing the carbonaceous matter separated as
above from the oil with heavy hydrocarbon oil and subjecting the mixture to a
high degree of heat for a considerable period, substantially as described.
4. The process of making asphalt from crude petroleum or any hydrocarbon oil by
first treating the crude petroleum with acid to separate the carbonaceous matter
from the oils, then adding to said carbonaceous matter a heavy hydrocarbon oil and
subjecting the same to a high degree of heat, and then adding marl or lime,
substantially as described.
5. The process of treating petroleum tar or petroleum after the lighter oils have
been removed by distillation, by using acid to separate the carbonaceous matter from
the remaining oils, by mixing the same with a heavy hydrocarbon oil and subjecting
the mixture to a bigh degree of heat and then adding inarl or lime, substantially as
described.
6. The process of producing asphalt from crude petroleumn, petroleum tar or
any heavy hydrocarbon oil by treating the same with acid to separate the
carbonaceous matter from the oils, then subjecting this carbonaceous matter to a
considerable degree of heat for a considerable period, substantially as described.
7. The process of producing asphalt from crude petroleum, petroleum tar or
any beavy hydrocarbon oil by treating the same with acid to separate the
'carbonaceous matter from the oils, then subjecting this carbonaceous matter to a
considerable degree of heat for a considerable period and then adding marl or lime,
substantially as described.
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicants.