US1843742A - Apparatus for treating hydrocarbons - Google Patents

Description

` Feb. 2, R932,

GOO GG Patented Feb. 2, 1932 UNITED STATES PATENT oFF-ICE e l I JEAN D. YSiIliG'UY, 0F CHICAGO, ILLINOIS, SSIGNOR TO UNIVERSAL OIL PRODUCTS COM- PANY, OF CHICAGO',- ILLINOIS, A CORPORATION OF SOUTH DAKOTA APPARATUS FOR TREATING HYDROCARBONS Application led March 15, 1929.` Serial iNo.` 347,832.

The invention relates to the production of lower boiling point hydrocarbons from heavier hydrocarbons by treatment of the latter at temperatures within the cracking range.

It is my belief that a cracking reaction is divided into two steps, a primary reaction where the largest portion of the gasolinelike or light distillates is produced with accompanying formation of heavier liquid products; and a secondary reaction, where said heavier liquid products are converted mostly into sludge-.like and coke-like products with little attendant increase in the formation of light distillates.

As a feature of the invention, I therefore propose to subject hydrocarbon oil to conditions of conversion, and to remove the heavier liquid products from the reaction or separating zone before secondary reaction has 2o proceeded to the extent of forming objectionable quantities of coke and sludge-like constituents. i

Regulation, of the rate of withdrawal of the liquid products may be obtained by observing the proportion of sludge and cokelike products contained in -the liquid products withdrawn from the reaction or separating zone, and so controlling the rate of withdrawal that a deinite limit of proportion of coke and sludge-like constituents is not exceeded, as shown by any analytical method, such as benzolcentrifu e. The limit should be below 5% and pre erably below 2%. Experience has indicated that, when the limit is not exceeded, comparatively little coke formation occurs in the process.

' The degree of secondary reaction taking place in the heavier liquid products is con trolled mainly by the rate of withdrawal 4o thereof, and, therefore, by the size or volume of the pool of unvaporized oil mainy tained in the reaction or separating zone at high temperature. The sizes of reaction orseparating zones now in use commercially,

and which'have diameters of 5to 10 feet,

tice sometimes renders the control of the operation difficult for the operator, as a small increase in height of the pool means a comparatively large increase in the time during which the heavier liquid products of primary reaction remain in the reaction or separating zone subjected to high temperature.

VAs a feature of the invention, I propose to design the lower part of vertical reaction or separating chambers now in use in a manner proper to facilitate control of the withdrawal of the heavy liquid products of primary reaction.

To this end the part of the reaction or separating drum wherein the liquid products of reaction collect before their withdrawal takes preferably the shape of an elongated conduit of small diameter relative to the main portion of thedrum, for instance 2 feet or less, or it'may take a conical shape of restricted area, orsuch other shape as will permit the residue contained therein to have a relatively large height in relation to its horizontal cross section. In this manner, relatively small variations of volume correspond to relatively great variations in height.

parent from thev following description and from the attached drawing, where the single figure is a diagrammatic` view'partly in section, partly in elevation, of an apparatus suitable to carry out the invention.'

While I have illustrated an application of the principle of the invention to a particular type of oil conversion process, and to a particular design of reaction chamber, it is to be understood that the invention may be used in any type of process wherein oil is raised to a conversion temperature and in other types of apparatus used therefor.

Referringv to the drawing, oil may be charged from line 1, through pump 2 to and through heating coil 3 located in suitable furnace setting 4. The oil is heated while passing through coil 3 to a cracking temperature and isv discharged through transfer line 5 and valve' into chamber 7, in which separation of vapors from heavier liquid products of reaction takes place. The vapors may be removed from chamber -7 through -`l ine 8 and valve 9, passing into dephlegmator 10, wherein fractionation may be eected, assisted if necessary by an additional cooling medium, such4 as raw oil or distillate injected through lines 11 and valves 12 in the usual manner.

Vapors -remaining uncondensed after passing through dephlegmator pass-out the top thereof through line 1 3 and valve 14:, then through condenser 15; liquid condensate and uncondensable, gases pass into receiver 16, provided with usual gas and distillate valve-controlled draw-offs 17 and 18.

Reflux condensate formed in dephlegmator 10 may be withdrawn ,from the bottomv thereof through line 19, having valve 20, and returned to thecharging line'l in the usual manner through lines and hot oil pump (not shown) or removed totally or partly. from the system. l

Temperatures, rate of feed and pressures in heating coil 3 and chamber 7 are so regulated that the heavier lliquid products separated in and withdrawn from chamber 7 do not contain sludge-like or coke-like material in excess of the predeterminedlimit, as heretofore described. u

As a feature of the invention, the vertical chamber 7, which is usually provided with bottom manhole throat 21, may be further provided with a vertical conical extension reservoir 22 connected with throat 21, and having its apex at the bottom. The pool of unvaporized oil is preferably maintained with its surface or level Within the conical reservoir, such as indicated at A, and usual liquid level indicating devices are provided,

such as temperature recorders or level try` cocks, asshown at 23 and 24.

The liquid products of reaction are prefery ably removed through the apex of the reservoir, through lowermost line 25 having valve 26-additional side draw-0H lines 27 having recata@ without accompanying reaction, and where digestion or soaking zones may be interposed between the heating coil and the separating chamber;

As an illustration of the operation according to the invention, the conversion of an oil having a gravity of about 20 B. at a temperature of about 900-920 F. and a pressure of about 170 pounds on the heating coil and chamber, produced a yield of' about 30% of 437 end point gasoline, with a yield of about 55% of cracked residuum having a gravity of about 10 B., containing 1% of B. S. This was accompanied with formation of coke in the process to the extent of less than five one-thousandths (0.005) of one pound per barrel of oil treated.

l claim as my invention:

In a combination with anenlarged vapor separating chamber of an oil cracking system having a cylindrical bottom manhole throat extending downwardly therefrom and of materially smaller diameter than said chamber, of an inverted conically-shaped elongated residual draw-olil neans conforming in its largest diameter to t-he diameter of said throat and in registration with the bottom of said throat, and an outlet pipe connected to the apex of said inverted conicallyshaped .draw-off means.

In testimony whereof ll affix my signature.

JEAN D. SEGUY.

valves 28 may be., provided in case of emergency. p

While ll have shown a con1cal reservoir 22,

a cylindrical reservoir having'small diameter relative to chamber 7 may be used, but I have found that a conical reservoir possesses additional advantages over other forms. For instance, the tendency of the unvaporized oil to become converted beyond the limit pre-' scribed, and the tendency of solid or semisolid material t'o deposit at the bottom of the.

reservoir are odset by the progressively increasing turbulence of the stream of unvaporized material as it reaches zones of progressively decreasing diameter during its passage through conical reservoir 22, until it is removed through lower draw-0H 25.

The invention may be applied to processes Where separation of vapors from unvaporized products takes place in a chamberor chambers under approximately the same .temperatures and pressures as are obtained at the discharge of the heating coil, or under reduced gtemperatureand/or pressure, with or

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