IMPROVEMENTS IN PROCESSES AND APPARATUS FOR DIVIDING AND DISTILLING CRUDE PETROLEUM AND FOR REFINING THE PRODUCTS OBTAINED and
Year: 1884

page_text: I JOHN CLAYTON MEWBURN of 169 Fleet Street in the City of London, Fellow
of the Institute of Patent Agents do hereby declare the nature of my invention
for "IMPROVEMENTS IN PROCESSES AND APPARATUS FOR DIVIDING AND DISTILLING
CRUDE PETROLEUM AND FOR REFINING THE PRODUCTS OBTAINED and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
33
I will first describe the new process for treating the crude petroleum as it comes
from the wells. The process, so far as it relates to the preliminary division of the
crude oil, consists in the separation of the latter into 2 portions having distinct
characteristics; one of these portions I denominate "Primary Oil" and the other
"Secondary Oil." The proportions these 2 oils bear to each other will vary
somewhat in crude oils from different localities, but with what is known as
Bradford" oil, from the United States, there is obtained about 42 per cent of the
primary oil and 58 per cent of the secondary oil. The average yield of the primary
oil will not, however, exceed 35 per cent.
"
In effecting the division of the crude oil, with the simplest apparatus, I may
proceed as follows:-
I take any quantity of the crude oil and mix it with commercial benzine
previously obtained from petroleum by distillation. It is preferred to employ about
equal parts of benzine and crude oil; the exact proportion is not, however,
essential, but enough benzine should be used to effect a complete separation. This
mixture of benzine and crude oil is placed in an open vessel and the latter vessel
placed in a larger open vessel. The benzine volatilises and leaves the mixture,
carrying with it the primary oil which drops into the larger outer vessel the benzine
itself passing off as a vapor.
After the benzine has all evaporated it will be found that the crude petroleum
has been divided, the inner vessel containing the secondary oil and the outer vessel
the primary oil.

page_text: The primary oil thus obtained cannot be distilled without decomposition, it
thickens at temperatures which do not affect the crude oil nor the secondary oil, is
soluble in sulphuric acid without division, may be filtered to an orange color
through bone black, burns well in all lamps suited to animal oils, stands almost as
high as sperm oil as a lubricant and illuminant, and has a density of about
31° Baumé. The communicants of this invention consider this primary oil as the
nucleus of paraffine, and the source of the non-condensable gases evolved by the
ordinary destructive distillation of crude petroleum.
If the primary oil is to be employed as an illuminant no further treatment of it
will be needed; but if it is to be used as a lubricant I treat it as follows:-
The primary oil is mixed with about one per cent of Amyl Alcohol, with which
it is mixible in all proportions. To this mixture is then added Ethyl Alcohol until
the mixture becomes milky or opalescent. The major portion of the oil now
subsides, leaving dissolved in the Alcohols a small amount of a lighter hydro-carbon.
This super-natant mixture is drawn off and the purified primary oil removed. The
oil thus treated has a density of about 28° Baumné, and the removal of the small
proportion of lighter hydro carbon imparts to it greater wearing qualities as a
lubricant. Only about one per cent of each alcohol is usually needed to effect the
above result, but the proportion may be varied somewhat with different oils.
The secondary oil left in the inner vessel has a density of about 36° Baumé. This
oil is placed in a still and submitted to fractional-not destructive-distillation. It
distils quietly without the evolution of non-condensable gases. The first distillate
is naphtha, which is allowed to run until the temperature rises to about 250° Fahr.
The receiver is then changed and the distillation continued uninterruptedly
until the temperature reaches 550° Fahr. This second distillate is kerosene or
burning oil.
The receiver is changed again and the temperature raised to about 620° Fahr.
This third distillate is a heavy burning oil which I will call "petro-sperm " oil and
has a brownish color.
The residuum left in the still is a heavy oil which makes an excellent lubricant.
The approximate percentages of products obtained from 100 per cent of ordinary
crude petroleum are given below :—
100.
I obtain no tar or waste products in the distillation by this process.
In order to purify the kerosene (second distillate) I treat it as follows:-
I add to 95 per cent of the kerosene about 5 per cent of commercial sulphuric
acid, and when the "sludge" has subsided and been drawn off, and the supernatant
oil has become clear, a small portion of the acid will have remained in combination
with an element or portion of the oil. To remove this I agitate the oil with a
small quantity of alcohol which mixes or combines with the said mixture of acid
and oil and carries it to the bottom. The kerosene will now be clear, limpid,
entirely free from fluorescence, neutral to test and capable of enduring a fire-test
of 130° Fahr.
The loss by the use of the acid is only about 3 per cent. The kerosene obtained
and purified in this manner is free from empyreumatic odours, and is, in fact,
almost odourless. This last is partly due to the employment of alcohol in lieu of
alkalies. The alcohol mixture settles to the bottom of the purifying tank, and
when withdrawn water is added thereto. This liberates the small quantity of
hydro-carbon held by the alcohol, and the former rises to the top and may

page_text: be removed. The alcohol may be wholly recovered by distillation over an alkali
or other base capable of taking up the acid it contains.
The "petro-sperm" oil may be purified in substantially the same manner as the
kerosene, and will stand a fire test of 300° Fahr. It contains no paraffine and
does not form a crust on the wick when burned. It also is almost inodourous.
The first step in the process, namely, the division of the crude oil into primary
and secondary oils is the most important as it controls the remaining steps. I have
said that I employ benzine to effect this separation in preference to other light
products of petroleum. The reasons for this are that the other light products, such
as righoline, gasoline, &c. will carry over a part of the primary oil, but they appear
to volatilize too readily to be very effective.
On the other hand, kerosene does not appear to volatilize readily enough.
Therefore, I prefer, as producing the best results, that product of petroleum having
a density of about 71° Baumé, and which I call commercial benzine.
By first separating from the crude petroleum the portion I call "primary" oil I
remove the principal difficulties incident to petroleum distillation by the known
methods, and make of this element or portion a most valuable illuminant and
lubricant. On the other hand, owing in part to the improvement in the products
obtained therefrom, their quantity, the ease with which it can be fractionally
distilled, and the absence of waste products, the "secondary" oil becomes nearly as
valuable as the entire quantity of crude petroleum from which it is obtained would
ordinarily be.
I have described a simple apparatus whereby the division of the crude petroleum
may be effected, but I usually employ, when carrying out the process on a large
scale, the improved apparatus which I will now describe with reference to the
drawings annexed :-
Figure 1 is a front end elevation. Fig 2 is a vertical, transverse section on
line 2---
2 in Fig: 3. Fig 3 is a vertical, longitudinal mid-section on line 3---3
Fig 2. Figs 4, 5 and 6 are diagrams illustrating modified forms of the separating
and collecting surfaces.
A is a tight casing or shell proferably arched at the top and terminating in a
wedge at the bottom. This shell may be of sheet-metal. B is a drum or cylinder,
also by preference of sheet metal, and provided with removable heads a a to give
access to the interior. The ends of B have a bearing in the ends of A. The
cylinder B may be provided with a heating coil C, but this is not necessary
ordinarily, as the dividing process may be carried on at normal temperatures, or by
simply warming the room in which the apparatus is placed. Where a steam coil is
employed as shewn, b is the inlet and c the outlet pipe.
D is a perforated pipe or trough arranged over the crown of the drum B and
extending the entire length of the latter. This pipe D is supplied with a mixture
of crude petroleum and benzine by a pipe d, and the perforated pipe or trough D
delivers it in fine jets, streams or spray on to the crown of B.
A cock e is or may
be provided to regulate the admission to D. Thermometers f. f may be used if
needed. E is a safety liquid seal to control the accumulation of gaseous pressure
in A. The lower, wedge-like, portion of A may be refrigerated when desired or
necessary.
The
It will be seen that the upper half of B forms a double inclined surface for the
film or sheet of oil to flow over in opposite directions, and this upper half I will
call the " separating" surface; the lower or under surface of B provides double
adhering or capillary surfaces which I will call the " collecting" surface.
line ---
which corresponds in this case with the horizontal diameter of
cylinder B is the dividing line between the "separating" and "collecting" surfaces.
The mixture of crude oil and benzine delivered by D on the crown of B, flows
down in opposite directions; in flowing over the separating surface the division of
the oil is determined, and when the mixture reaches the points x, the mixture of
primary oil and benzine, which has least density, drips off into troughs i i, and
Hows out through a common outlet ; which may be trapped. The secondary oil,

page_text: which is denser, adheres to the collecting surface and flows down to the lower-most
point of the cylinder B, when the 2 currents meet and the oil drips off into the
trough G, flowing off, eventually, at an outlet pipe h which may also be trapped.
The vapors of benzine given off in the separation will condense on the inner wall
of casing A collecting at the bottom of same, where it may be drawn off through
a trapped pipe g and collected in a refrigerated vessel F.
In some cases I may dispense entirely with the troughs i i, and allow the
primary oil to collect in the bottom of A. and afterwards distil off the benzine.
Or, I may omit the lower wedge shaped portion of the casing and the troughs i.
In this case the casing A may have any desired form.
The casing may have peep-holes k, glazed to admit light or to serve for
inspection, and a drainage-cock may also be provided.
The separating and collecting surfaces are conveniently furnished by a
cylinder, B, but this form is not necessary; I may employ only a semi-cylinder,
as in Fig 4; or the separating surface may be convex and the collecting surface
a plane, as in Fig: 5, the 2 being connected by a sharp curve or an angle, at x or
both surfaces may be planes, as in Fig: 6.
If it be desired that the separation be determined by the time the flowing liquid
reaches the point the separating surface must be sufficiently extended; otherwise
the primary oil may not drip off at the point x, but at some point between x and
the trough G. As the facility of separation is not always uniform, varying with
different oils, with different temperatures and with the amount of benzine used,
to some extent, the dripping may not all be effected at a, consequently the
troughs i. may be made wide so as to be sure of catching all.
I may vary the quantity of benzine employed for effecting the separation of the
crude oil, and the amount necessary to produce the best and most economic.il
results will depend somewhat on the temperature and character of the oil treated.
With this apparatus it is found that a proportion of 20 per cent of benzine will
produce good results with temperatures varying from 60° to 80° Fahr.
In lieu of dividing the crude oil as it comes from the wells, I may subject it to
fractional distillation up to about 500° Fahr. to remove some of the lighter
products, and then divide it as described.
With my apparatus the division of the oil proceeds, or may proceed, continuously.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The herein described process for dividing crude petroleum into 2 parts,
designated "primary" and "secondary" oils, which consists in mixing together
crude petroleum and benzine and volatilizing the benzine, whereby it is caused to
carry over with it, or separate, the primary oil, leaving the secondary oil behind,
substantially as described.
2. The herein described method of dividing and distilling crude petroleum which
consists in first separating the primary oil by the method substantially as described
and then subjecting the secondary oil to fractional distillation substantially as
set forth.
3. The herein described method of purifying the distillates derived from the
secondary oil, which consists in first mixing the distillate with a small quantity of
sulphuric acid and then removing the acid remaining in the distillate by means of
alcohol, substantially as set forth.
4. The herein described method of treating the primary oil obtained by the
division of crude petroleum, in order to prepare it the better to serve as a lubricant,
which consists in first mixing it with Amyl Alcohol, then adding Ethyl alcohol
until it becomes milky, and then removing the super-natant mixture of alcohol and
lighter hydro-carbon, substantially as set forth.
5. An apparatus for dividing crude petroleum, comprising a plate or part having
an upper inclined "separating" surface and a lower inclined "collecting" surface,
which surfaces are continuous as described, means substantially as described for

page_text: delivering the oil to be separated to the upper part of the separating surface, and
means substantially as described for collecting the primary and secondary oils,
separately, as they drip off, substantially as set forth.
6. In an apparatus for dividing crude petroleum, the combination of a plate
or part having an upper inclined" separating" surface, and a lower inclined
"collecting" surface, which surfaces are continuous, a perforated pipe or trough
to deliver the oil to the separating surface, a pipe to supply the said perforated
trough or pipe, a trough to collect the secondary oil at the bottom, and means
substantially as described for collecting the primary oil, all arranged to operate
substantially as described.
7. The combination of the casing A, the cylinder B, or its substantial equivalent,
the delivery pipe or trough D, the trough G, and the supply pipe d, all constructed
and arranged substantially as set forth.
8. The combination of the wedge-shaped casing A, the cylinder B, or its
substantial equivalent, the perforated pipe or trough D, and its supply pipe d, the
troughs G and i, the outlet pipe g, and the heating apparatus C, all constructed
and arranged substantially as set forth.