US1162729A - Process of treating crude petroleum. - Google Patents

Description

F. SEIDENSCHNU'R & J. DEHNST.

PROCESS OF TREATING CRUDE PETROLEUM. APPLICATION FILEDYJUNE 13. 1908.

' Patented Nov. 30, 1915.

2 SHEETSQSHEET x.

F. SELDENSCHNUR & J. DEHNST.

PROCESS OF TREATING CRUDE PETROLEUM.

APPLICATION man mums. 1908.

1 ,162,729. Patnted Nov. 30, 1915.

- 2 SHEETS-SHEET 2. 4/5

FRIEDRICH SEIDENSCHNUR,

OF CHARLOTTENBURG, AND JULIUS DEHNST, OF

HALENSEE, NEAR BERLIN, GERMANY, ASSIGNORS TO THE FIRM 0F RIITGERS- WERKE ACTIENGESELLSCHAFT, OF BERLIN, GERMANY.

PROCESS OF TREATING CRUDE PETROLEUM.

Patented Nov. 30, 1915..

Application filed June 13, 1908. Serial No. 438x101.

. of Treating Crude Petroleum, of which the following is aspecification.

Heretofore it has been proposed to treat crude petroleum by converting small quantities of the crude material to be treated into vapor as suddenly as possible in highly heated apparatus under a high vacuum an by the agency of superheated steam. How-.

ever, several difficulties are encountered during the execution of this process and it is the object of the present invention to overcome these difliculties.

The difficulties are the following: First.

' The formation of coke which (a) necessiburn owing to tom which inter aha results in greatidanger tates the cleansing of the decomposing vessel after each single operation and therefore prevents a continuous distillation, and (b) readily causes the decomposing vessel to the superhcating of its hotand wear of the decomposing vessels. Second. Relatively high loss in distillation; this loss may amount to 6% or more of the raw oil to be distilled. The reason for this is that owing to the formation of coke a considerable quantity of-gases develops. The evolved gas cannot be condensedby simply cooling it to the ordinary temperature, and therefore, it must be removed from the apparatus for immediate use as fuel or for lighting purposes. These defects are overcome if the resultant product in the decomposing vessel is asphalt instead of coke, that is to say, if instead of vaporizing all of the material adapted to be converted into vapor, only the greater part of it is vaporized, for instance, all but from 5 to 10%, which then remains in the vessel in the form of asphalt. In order to do this it is necessary to closely follow a distinct procedure. This procedure or process is characterized by the following features:

1. Maintaining in the decomposing-vessel a definite temperature variable only within very narrow limits, a temperature of 380 to l00 C. appears to be the most advantageous one.

2. The injection of large quantities of highly superheated steam (450 to 500 C.) durmgthe distillation, the amount of the injected, highly superheated steam not being less than 30 to 40% of the weight of the material under treatment. If the injection of the highly superheated steam should cease, the petroleum would be decomposed. '3. The termination of the supply of oil will be governed according to the quality of asphalt desired; when it is terminated the temperature in the decomposing vessel is raised to 420 up to 430 C., and then the steam which has hitherto entered the decomposing vessel under a slight vacuum is now supplied under a slight pressure. The slight vacuum under which the steam en ters may be a pressure of about 200 millimeters mercury barometric pressure inside the retort. It is so chosen that no decomposition of the. easily decomposable constituents takes place. After those constituents of the petroleum which may easily be decomposed have been driven out, the operator leads the steam under pressure, for instance, 800 to 850 millimeters mercury barometric pressure into the retort. The selection of the pressure depends on the boiling points of the constituents of the petroleum. If the proportions of the constituents having high boiling points is high, a higher pressure of the steam must beused than if a relatively small proportion of highly boil- I ing constituent were present. v

4. The employment of a decomposing ves-.

sel of a given form, that is to say, one which has a very large bottom but. is comparatively low. With this purpose in view, a retort measuring between 1.4 and 2 meters in diameter and practically not more than between 80 and 120 c. m. in height has been found to be the most suitable, as in a vessel of this kind the heavy vapors of the constituents of, thecrude material which have high boiling points are very easily and quickly driven into the condenser.

5. Introduction of the steam and of the crude material to be treated into the decomposing vessel at. a large number of places. With a bottom area of 1%; square meters, four steam inlets are sufficient, with a larger bottom area the number of the steam inlets must be correspondingly increased. The

steam inlets must be directed obliquely downward and the oil inlets should be arranged as close to them as possible so that the previously heated crude material: on

- entering, may at once reach the hot bottom is. possible to distil continuously, as the asphalt when it has attained a certain height in the decomposing vessel can readily be removed by suitably employing superheated steam which operation will only cause a .very slight interruption in the distilling process which will not amount to more than a few minutes. Third. The losses hitherto occurring in the treatment of crude petroleum are avoided and the distillation loss does not amount to more than from 1 to 2% by weight of the petroleum. Fourth. An improved product is obtained. The socalled cylinder oils obtained as the prodacts of the distillation will be practically free of asphaltic substances. With reference to this fact, the cylinder oils (and other distillates) obtained according to the present process may be used without subjecting them first to refining processes which always cause losses.

An apparatusfo'r carryin the invention intop'ractice is illustrated iv way of example in the accompanying. drawings, in which Figure I isa vertical section through the preferred form ofapparatus for carrying our process into practice. Fig. 2 1s a plan view of part of the apparatus Fig. 3 is a vertical section through a modified form ofthe apparatus. F ig. 4: is a section on the line wm of Fig. 3.

The process may be carried into practice in the following manner: The decomposing vessel A is inwacuo and is traversed by heated steam and is also heated from an external source of heat; when it has been heated to about 100degrees centigrade, ap-

proximately 200 kilograms of crude oil,

heated by steam are allowed to flow in quickly. vThe vacuum is maintained, and the steam is caused to pass constantly, and after the temperature has reached about 380 centigrade, fresh oil in the same amount as before indicated is charged into the vessel A in a. continuous stream, the

temperature being kept uniformly between 380 and 400 centigrade. After abbut 2,000

5 k. g. of oil in all per square meter of bottom area have beenadmitted, thesupply is cut off and the temperature is raised to between 400 and 430 centigrade at which it is kept for about one hour. released and the distillates are cooled fractionally in the usual manner. If the distillation of a certain portion of the petroleum has been finished so that distillates are had in the vessels E, G, J, the distillate is allowed to flow out through the outlets t, -t, t, into'appropriate tanks Z, Z, Z In order to accelerate the discharge of the vessels E, G, J the operator can force out the oil through the pipes t, t, 25 into the vessels The vacuum is then- Z, Z, Z by introducing superheated steam by introducing superheated steam into the vessel A through the pipe 6. Fresh oil is now allowed to enter the vessel A and the process is then repeated in the above describedmanner. 7

It has been discovered that the apparatus for carrying out our process into practice should preferably be constructed as follows: The preferred form of apparatus consists of the heating vessel A provided with an admission pipe I) for superheated steam. The crude oil is introduced through a pipe 0 and the vapors are carried ofi through d. The pipe 0 extends to nearly the bottom and branches out into four inlets Z, m, n and 0 (Fig.2) which are inclined toward the bottom. Also the steam admission pipe presents four openings located in close prox imi-ty to each individual admission orifice of the oil pipe. The discharge pipe cl enters the condenser E for the cylinder oil. The

. vessel E is connected with the vessel G by,

means of the pipe 7, and .the vessel G is connected with the vessel J by means of a pipe 72.. A portion of the vapors coming vessel G into the vesselJ and is there condensed. This portion of the vapors may be used as so-called spindle oil. which have not been condensed in the vessel J pass through the pipe 70 into the cooler H .where they are condensed and whence the condensate flows into the vessel Z which is connected with the exhaust pump R.

According to the quality of the product to be obtained, the condenser E is heated to a temperature between 270 and 300 the condenser G is heated to a temperature between 180 and 200 and the condenser J to a temperature between 140 and 160. The

The vapors proximately the dimensions of a cylindrical vessel of about 80 to 120 c. m. in height and 11} to 2% meters in diameter. The practice has shown that if a certain high temperature is maintained, asphaltum of a certain degree of hardness is formed, and that in such a case, the construction heretofore described does not produce the desired result. The asphalt in the decomposing vessel gradually begins a circular movement so that a certain portion of the asphalt in the middle of the decomposing vessel will remain at rest. The stationary part of the asphalt therefore, may readily become coked during the subsequent rise of temperature and burnt into the bottom of thevessel thus being the cause for an undesirable interruption of the entire operation of distilling. It has been discovered that this difficulty can be avoided when the inlets for the superheated steam and the oil under treatment are not arranged all discharging tangentially in the same direction as in Fig. 2, but are directed almost one against the other in part so that the streams of steam and oil from the several inlets pass close by each other and in addition, the steam inlets and the oil inlets are combined so as to form a nozzle-like structure of injector form or in form of a spraying nozzler Such an arrangement is shown for instance in Figs. 3 and 4.

As shown in Fig. 3, A is a vessel of suitable form, the cover 8 and the bottom g of which are preferably somewhat curved. Through the cover 8 passes the oil inlet a, the steam inlet 6, a thermometer a and a pipe e which ends near the bottom 9. By introducing steam through the pipe I) the asphaltum formed in the vessel A is removed therefrom into a storage vessel not shown in Fig. 3. The apparatus according to Figs. 3 and 4 is distinguished from the arrangement shown in Figs. 1 and 2 by a somewhat different construction of the oil and steam outlets. One steam inlet and one oil inlet are combined to a nozzlep. Four of the so-constructed nozzles are used. Two of the nozzles are direct-' ed oppositely t0 the other two so that the vapors and the oil coming from each of the nozzles is met by vapors and oil coming from an oppositely directed nozzle.-

We claim The process for separating the volatilizable constituents of crude petroleum which consists in atomizing crude petroleum at a temperature between 380 and 400 centigrade, under a barometric pressure inside the vessel of less than 760 millimeters mercury and introducing superheated steam of temperatures of from 450 to 500 centigrade into the heated atomized crude petroleum in a proportion corresponding to between 30 and 40 per cent. of the crude petroleum to be treated, raising the temperature of the

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