US1615991A - Method of petroleum distillation - Google Patents

Description

Feb. 1 1927.

W. D. MASON METHOD OF PETROLEUM DISTILLATION Filed Dec. 1 1922 2 Sheets-Sheet l 1,615,991 Feb. 1, 1927. MASON METHOD OF PETROLEUM DISTILLATION Filed Dec.' 1922 2 Sheets-Sheet 2 Patented Feb. 1, 1927.

UNITED STATES WILLIAM D. MASON, OF RICHMOND, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO STANDARD OIL COMPANY OF OALIFORNIA, OF SAN FRANCISCO, CALI- FORNIA, A CORPORATION OF DELAWARE.

METHOD OF PETROLEUM DISTILLATION.

Application filed December This invention relates to the fractional distillation of petroleum oils and more particularly, to the method of producing and controlling certain desirable conditions of temperature and partial pressure effect for the production of fractions of desirable characteristics.

In the distillation of petroleum oils for the production of distillates, it has been a quite general practice to pass the vapors of distillation to overhead apparatus of some nature, where, due to a drop in temperature of the vapors due'to radiation of heat, to the air or to other cooling media, certain of the heavier and undesirable fractions fall back as reflux to the still.

The general object of this invention is to provide a method or process of distillation whereby distillates of a desired boiling point range may be produced directly from crude oil. An additional result which, if desired, may also be secured by such a process or method, including this invention, is the production of a distillate having a desired range of boiling points Without the necessity of redistillation or blending; alsosucha process or method as can be carried on continuously, as distinguished from a batch method or operation, and by a succession of operations a series of such distillates each of a desired range of boiling points, produced by progressive steps of the process. An additional object is to provide such a method or process as will produce a maximum quantity of the distillate of a particular boiling point range.

One advantage of this invention, in addition to the very important accomplishment of producing desired distillates directly' from crude, is the marked simplicity of the required apparatus, its low first cost and'its low cost of maintenance. Other advantages will appear with the disclosure of the proposed process.

This invention comprehends that for economical production of refined petroleum products it is desirable to produce distillates of desired boiling point range with a single distilling operation. 7

This invention further comprehends that continuous operation of a distilling process augments to marked economies.

This invention further comprehends that, for the production ofthe desired distillates, a direct and positive control of the tempera 11, 1922. Serial No. 606,134.

tures of the vapors passing to the condensing equipment to form the distillates, is necessary. a Y r This invention further comprehends that for a maximum yield of the desired distillates a thorough contacting of the evolved vapors and the liquid oil of feed and reflux is desirable.

This invention further comprehends that the influence of steam in their presence has a marked influence on thecondensing tem perature of petroleum vapors.

It is further recognized that the continuous production of any desired number of distillates of various desired boiling point ranges from the same initial feed is desirable for greatest convenience and economy.

In order to accomplish all the desired results by the operation of this invention, oil is fed into a system including a still with a heating means such as a furnace; a tower in which the vapors evolved in the still are thoroughly contacted with the descending reflux oils (and by preference with the oils fed to the system), a means for controlling the temperatures ofthe vapors within the tower, condensing equipment, residuum and vapor heat exchangers, water and steam supply and other appurtenances necessary for operating such a plant.

The invention may be readily understood in connection with a description of the process as practiced in a given apparatus. lieference is therefore made to the accompanying drawings showing a means by'Which the invention may be practiced.

In the drawings Fig. 1' is a side elevation partially in sec tion of a single unit.

Fig. 2, is a diagrammatic view illustrating two units operating in series.

In Fig. l of the drawings, 1 indicates a still set over furnace 2. Still 1 is divided by partitions 3, having openings 4 in the top and openings 5 in the bottom. From one end of the still 1, vapor line 6 leads to near the bottom of a tower 7 in which trays 01' battles 8 of any desired design such as conventional cap and seal decks or staggered. pans are arranged. Pipe 9 leads the final vapors from the top of tower 7 to vapor heat exchanger 10 whence the vapors pass to condenser 11 and to storage. Line 12 is for the withdrawal of residuum and 13 a residuum ill) heat exchanger. Line 14 supplies steam to the various compartments of the still through pipes 15, by valves 15 and steam spray pipes 16. Pipe 17 supplies the fresh feed, preferably to a point in the tower 7 but on occasion this line may lead directly to the still. Water for cooling the vapors within the tower is supplied through pipe 17 to various spray pipes 18., the quantity of water being controlled by valves 19. Temperature indicating equipment indicated by 20 placed on the tower exit vapor line and still make possible the necessary observation of tem-. peratures, while meters 21' and 22 on the feed and residuum lines respectively aid in the control of the oils to and from the system.

'In the system, as presented in the above preferred form for the production of a single product the operation of the process is as follows' After the still is charged and brought to a desired distilling temperature the feed is passed at a regulated rate through the vapor and tar heat exchangers to the tower. The temperature on the exit vapors going to make the distillates is observed and by the injection of water to thetower by means of the spray pipe is maintained at a constant temperature for the production of the desired distillate. The quantity of Water introduced will depend upon the distillation operation. As an example under certain distillation conditions I have introduced one gallon of water into the reflux tower for every nine gallons of distillate produced. In other operations I have used one gallon of water introduced into the reflux tower for twenty-nine gallons of distillate produced. In other operations I have used as small'an amount as one gallon of water for every forty gallons of distillate produced. These examples illustrate that the amount of water required for the desired control and partial pressure effect, will vary in accordance with the distillation operation as carried on and with the oil undergoing treatment. The practical refiner can readily determine the most desirable proportion of water so to be introduced to the tower orevolve-d vapors. Residuu'm is drawn at the rate to maintain a constant level in the stills. Steam is supplied to the still as appears desirable. It will be understood that because the temperatures within the tower are above that of boiling water, the water sprayed into the tower is immediately converted to steam. The effect of the presence of steam upon the condensing temperature of the vapors together with the control of the amount of cooling make practical an almost unlimited control of the boiling point range of the distillate from the exit vapors, while. the introduction of the steam (resulting from I the water) at various points in the tower makes it possible to control, within limits,

thepercentage of the product that will distill off at a given temperature. That is, the shape of the fractionation curve can be changed, a most desirable feature when it is necessary to run a product to fixed fractionation specifications.

It has been found that not only can distillates of desired boiling point characteristics be produced from crude or other charge without re-distilling, but the yield of the desired distillate can be made a maximum.

When it is desired to produce two or more distillates continuously and simultaneously fromthe same feed it is only necessary to feed to the first unit as disclosed, draw the residuum from the first still and feed to the second unit, the residuum from the second feeding the third and'so on, as indicated in Fig. 2. The distillates may be for example; gasoline, engine distillate, water white, etc., from the various units.

Since it is possible for one understanding the process as disclosed to practice the invention with the use of a modified form of apparatus, I do not limit the use of the invention to the specific form of apparatus described, it having been presented only for purposes of clarity in the disclosure of the invention. 1

I claim- 1. The process of continuously producing 'from crude petroleum a distillateflhaving substantially uniform characteristics and requiring no re-di'stillation which includes continuously feedin into .a system crude oil, continuously evo ving therein mixed petroleum vapors, passing the mixed vapors therein evolved into a tower'wherein thorough contact is had between the evolved mixed vapors and the reflux oils and the feed oil introduced in said tower, introducing water in controlled quantities into the tower, and condensing the residual vapors leaving the tower.

2. A process of continuously distilling petroleum oil, which comprises continuously feeding into a system petroleum oil, continuously evolving therein mixed petroleum vapors, continuously assing the mixed vapors therein evolved "into ,a tower wherein thorough contact is had between the evolved mixed vapors and reflux oil and the feed oil introduced into said tower, continuously introducing such feed oil into such tower, introducing water ,into the tower, and condensing the residual vapors leaving the tower. 1

' 3. A process of continuously distilling petroleum oil, which comprises continuously vaporizing such oil, continuously passing Ill such vapors-to a vapor tower, continuously introducing the feed oil of the system into such tower, continuously passing the condensate of such tower to the source evolving such vapors, continuously removing the residual oil from the vaporizing zone, and continuously introducing water into such tower in such quantities that all of the water is vaporized and passes ofi with the residual vapors.

4. A process of continuously distilling petroleum oil, which comprises continuously vaporizing oil in a still, continuously passing the vapors to a tower from which all the recondensed oils are returned to said still,.

therein subjecting the vapors to the condensing action of the feed oil in the system, then introducing into the vapors water in such proportions that all of the water is converted into steam and passes ofi with the vapors escaping from such tower, and condensing such resulting, va ors.

Signed at Richmond, alifi, this 29 day of November 1922;

D. MASON.

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