US1652886A - Process and apparatus for fractionating hydrocarbon oils - Google Patents

Description

D"e.13,1927." I 1,652,886

J. C. BLACK PROCESS AND APPARATUS FOR FRACTIONATING HYDROCARBON OILS Filed April s, 1923 COND/SAUER.

53 JTORAGE TANK Q 47 JTORAGE 7:4/v/( abkomwq Patented Dec. '13, 1927.

JOHN C. BLACK, F DESTREBAN, LOUISIANA.

Application filed April 5,

This invention relates to a process and apparatus for fractionating hydrocarbon oils. One important object of the present inven tion is to fractionate or separate hydrocarbons of various boiling points from a vapor in which they are comingled, to segregate various fractions, and to provide a method and means for the regulation and control of the fractionating apparatus.

In my prior Patent, Number 1,447,118, issued February 27, 1923, I described a method whereby I am enabled to make vari ous separated fractions by the use of a tower apparatus. In a single tower, with one compartment, two fractions may be separated; in a two compartment tower, three fractions,

. or as many fractions as may be desired by increasing the number of compartments.

In my present invention I employ the same principle in the preliminary steps of my fractionating apparatus, but by the addition of other apparatus hereinafter to be described. I am enabled to greatly improve the quality of the final condensation product and to eliminate from the fractions separated by the washing and condensing action described in my patent above referred to, those hydrocarbons that are more desirable in the final condensation product thereby in? to creasing its yield to a very marked extent. Coincidentally, the purity of the fractions are improved by the elimination of intermediates, this being accomplished by the more thorough sifting and separating of these hydrocarbons having boiling points within certain predetermined ranges, consistent with the composition of thevapors and the capacity of the apparatus.

In the apparatus shown in the accompanying drawing, I am enabled to produce products of exceptional quality not previously obtainable by ordinary methods of distillation, and furthermore, to conserve the more volatile hydrocarbons which are lost by the old method of crude still distillation with subsequent steam still distillation, as for instance, in the production of gasoline.

I am also enabled to conserve the heat of vaporization and to obtain, in a single dis- 5 tillation operation, the quality heretofore obtained by a double distillation with its double ap lication and consumption of heat.

lh this apparatus I employ, in conjunc- 1923. Serial No. 630,147.

tion with other fractionating means as described in my above mentioned patent, the 5 old and well known fractionatingcolumn which has been employed for many years in the coal tar industry for the separation of ben'zol, toluol, and similar hydrocarbons, and

which consists of a column or tower fitted with boiling decks and boiling caps, and a means for condensing a portion of the vapor leaving the tower, such condensate acting as a reflux and returning down through the tower .or column to act as a condensing I apparatus is very efiicient if it is not overloaded, and in the coal tar industry, is usually of small size and fitted. to batch stills where close regulation can be had. 1 By my present invention I adapt this type of tower, in conjunction with other apparatus, to ordinary crude or rerun stills, preferably of the continuous type, whereby I am enabled.

to obtain-products of exceptional quality,

and an increased yield in a single operation. so For instance, ifthe oil being run is for the production of gasoline, a product can be produced of very close range boiling points and also an increased yield maybe realized when running for the production of a definitely specified grade. I am enabled to obtain these results in a single distillation; whereas, iii the ordinary production of gasoline, a crude naphtha is usually produced at first from whic t1on.'

In the drawing accompanyingthis specification, there is represented a dlagrammatw view of the improved apparatus. I will now f describe in detail the construction of thisapparatus and the functions of the various parts.

. 1 In the said drawing, -1 represents a still/ of the ordinary or conventional type, and" in turn, gasoline is subse- 90 quently made by a separate steam distillatower 3 is a steam header l iforming the supply pipe and Leading from the bottom part of this compartment 4 is a pipe 5 which extends back to the still to return any heavy condensate or entrained crude oil, this pipe 5 being controlled by a valve 5'. At the top of the-compartment 4 there is provided a hooded opening 6, which leads into the bottom part of a compartment 7 provided above the hood with a grating 7 supporting tiling or the like, so that the ascending vapors are compelled to percolate through the interstices of the tiling. Leading out of the top ,of this i 8 which'extends downward along side of iilfe tower, and opens into the tower 9 at a point intermediate in the height of said tower. This tower 9 is provided with an up er set of boiling decks 10 above the point 0 entry of the pipe 8, and a lower set of boiling decks 10 below the point of entry of said pipe. Below the decks 10' is a receiving compartment 11, which is here shown as forming .the bottom part of the tower 9, although it may be, if desired a separate piece of apparatus connected to said tower by means of plp-ing.

The compartment 11 is fitted with an open steam coil 12 so that steam may be introduced into this compartment. This compartment 1s further fitted with a'closed steam heating coil 13. These two coils are connected to a the admission of steam to the coils from this header is controlled by the valves 12and 13 respectively. This compartment is also Q provided with an overflow pipe 15, the flow through which is controlled through valve 15'. This pipe is for the purpose of draining oif accumulated oil and which may be passed through a cooler 16 and allowed to flow into a tank B. The tower 9 is also connected through a cross line 17 to the bottom of the compartment 7 in the tower 3, and

with boiling dec s 10",. a branch line 20.

the flow through this cross-over line is controlled by valve 17, the line being likewise provided .with a trap 18. Thevalve 17 is located between the tower 9, and a bypass connection 19 which may be used to permit the oil from the lower portion of the compartment 7 'to be /run back to a re-vaporlzing chamber 11' in the bottom of the tower 3, this re-vaporizin chamber being-provided controlled by a valve 20 aifording the proper communication between the pipe 19 and said lower chamber 11'.

Furthermore, the pipe 19 may, if desired, be connected to a cooler 22 by means of a pipe 21 controlled by the valve 21' said pipe communicating with the pipe 19. From the cooler 22, the cooled oil may pass to the q tank 0.

The upper portion of the tower 9 ;is fitted with what I denominate as an analizer 23 having tubes 24 therein which are supplied with a cooling medium circulated by a pump 25 through a line 26 joined at 26 to a pipe 27 communicating with the analyzer and cont-rolled by valve 27. The pipe 26 also has a connection with a pipe 33 which leads to the spraying-apparatus 31 and which may be controlled by the valves 33. and 28. Branching off from the pipe 33 adjacent to the top of the tower 3 is a pipe 29 which is fitted with a valve 28", and leads to the analyzer. There is a bypass connection 29, having a valve 20*, leading from 29 con nected to the cooler 54 so that the pump may force the cooling medium through this cooler and back into the tank B or tank C through line 54 and valves 54 and 54'. A suction pipe 30 leads from these tanks to said pump, and being controlled by a valve 30, leading to tank C and through line 32 and valve 32 to tank B.

Connected to the pipe 26 is a pipe 34, which branches at 34, one of its branches being indicated by 35, and leads to the still 1, a valve 35 controlling this branch. The other branch is shown by 36, and leads to a storage tank 47, being controlled by a valve' 36: From the top of the analyzer 23 runs a vapor pipe 37, which leads to a condenser 38 having an outlet 38 connected to a gas A. It will also be noted that the pipe 5 is connected to the bottom of the compartment 7 by a branch pipe 42 controlled by a valve 42. There is furthermore a vapor pipe 43 which connects the upper part of the compartment 11 in tower 3 with the middle portion of tower 9 between the sets "of boiling decks. I

It will also be noted that compartment 11 is fitted with steam coils 49 and 50 with control valves 49' and 50 and may'receive a supply of steam from the steam line 51, these coils are similar in construction and operation to those in compartment 11. There is also an overflow connection 52 controlled by valve 52' connecting with cooler- 52" and through the line 52 to the storage tank 53 .and is designed to'carry away the accumuis vaporized, and these vapors pass through i the vapor pipe 2, into the compartment 4 wherein any heavy oil or entrained crude oil is separated from the vapor and asses back to the still below the oil level t rough the pipe 5, the valve 5 being open at this time:

The yapor in compartment 4 now ascends through the opening 6 into the compartment 7, and passes up through the interstices of the tiling, here meeting a down flowing supply of wash oil. This wash oil may be supplied from the analyzer cooling tubes in pipe 31. Also by closing the valve 27 and opening the valve 33 and the valve 28' and closing 28" a direct feed may be obtained from the pump or any. combination of the two may be used. The quantity of wash oil employed is so regulated that the vapor leaving the upper part of compartment 7' through" the vapor pipe 8 will be largely denuded of the higher boiling point hydrocarbons, which will be carried dpwn by the wash oil and discharged, with the wash oil,

into the tower 9 through the line 17, the valve 17 being open for this-purpose. If desired, the valve 17 may be left closed, and these higher boiling point hydrocarbons and wash oil may be conducted to the boiling decks in the compartment 11 through the pipes 19 and 20, and valve 20. Or if desired, they may be run through the line 21 and valve 21 with "valve 17 and valve 20 being closed to the cooler 22 thence into tank C. The compartment 11 with its boiling decks is utilized to drive ofi vapor from the oil entering this compartment, which is conducted through the pipe 43 to the tower 9 there to comingle. with the vapors entering through the pipe 8 and to be fractionated along with these vapors.

The residue from the compartment 11. may be passed through an overflow pipe 52 to a cooler 52", this pipe being controlled by a valve 52' as previously stated. The

circulated through the tubes 24, and the.

characteristics of the vapor entering the column and the vapor ultimately passing to the analyzer'are modified by the quantity close regulation and control of the columnof wash oil circulated through the wash tower 3 so that in this way an extremely or tower is obtained. If for instance, thg analyzer is not capable of eliminating to the extent desired, the undesirable hydrocarbons from the vapor, additional wash oil could be supplied to the tower 3,. thereby removing a greaterquantity of the higher boiling point fractions from the vapor so that the tower 9 would be relieved'of considerable work and, as a consequence, its capacity would be increased and closer fractionating would bethe result. If the wash oil from compartment 7 contains any low boiling fraction desired in the final condensation product (that going to tank A) it is run to the lower portion of the tower 9, or

the lower portion of tower 3down through lower boiling decks up through which hot vapors and steam are passing, and these low boiling fractions are thusdistilled out and pass on upthrou'ghthe 10 to be further fractionated, the vapors leaving tower 3 passing over to tower 9 through vapor pipe 43.

It is to be notedthat the. lower boiling deckslO' will also fractionate to the reflux coming down from the boiling decks 10 and which may contain some of the low boiling point fractions which are desired. in the final condensationproduct, the vapors fromY10' joining those from the vapor pipe 8. Final'-' ly, the residue in compartment 11 is thoroughly denuded of any low boiling point hydrocarbons and may be run through the cooler 16 to tank B from which it may be recirculated as a cooling medium in the analyzer, as wash oil in tower 3, as return oil to the still 1 if it is desired to crack it or distill it, or it may be pumped to storage for future disposal. This also applies to the residue coming from compartment 11'.

Furthermore, as previously described, wash oil may be run to tank C for recirculation, or may be run directly back through line 42 and valve 42' to the still for cracking and re-vaporization.

It is quite possible to obtain additional grades of oils as by adding compartments to tower 3, the outgoing wash oil and 'condensate may be run through an independent evaporating tower and for each tower two additional grades of oil will be obtained.

Furthermore I may circulate, as a wash oil, hydrocarbons containing specific boiling points which will be evaporated in the wash tower and will appear in the final condensation product going to tank A. As for instance if the natural vapor from st1ll 1 was devoid or lacking in certain boiling point fractions, and the resultant orfinal condensation product would be deficient in these fractions then a wash oil containlng those fractions 9 could be circulated through the wash tower and-they couldbe evaporated out and the vapors would join those from the still passing up the tower with the result that the deficient fraction would be added thereto and would appear in the final condensation. product precisely as if the orig inal vapor had contained them.

Furthermore the wash oil may be so reguboiling decks lated that the high boiling point oils be almost entirely eliminated from the vapors before entering the final column thereby making a narrower range of boiling pomts volatile hydrocarbons desired in thefinal condensation product going to tank A.

in the final condensation product by decreas-v ed or cold; connection 44 and valve 44' and connection 45 and valve .45 respectively may be connected to tower 9 at or near the top to increase the refluxing action or to add From the above description, it-will be readily seen that the apparatus has great flexibility and. a large capacity and close regulation, the wash "tower being utilized to 7 do the rougher work'of removing the undeof rectified before they enter the tower.

'sirable' hydrocarbons and the fractionating or vaporizing tower to 'complete the opera- .tion, and which it will dov to a more efiicient degree if the vapors arejpartially purified actual practice, I am enabled to obtain a finished gasoline as the final condensation product and one of excellent quality as to boiling points, color, odor,- etc., and also to obtain an increased yield recoverable from the crude. oil which in some cases may amount to 10% or more of the total'gasoline content. Furthermore, the high boiling point fractions withdrawn from compartments 11 and 11 are thoroughl denuded of r its ease of control, any grade of gasoline may.

an lin This fact indicates that the total gasoline content of the original crude oil, can by this apparatus be recovered in a single operation and in a single cut. Also, due to be produced at will consistent with the gasoline content of the crude oil undergoing distillation.

What I claim as new and desire to obtain by Letters Patent is 1. A process of fractionating hydrocarbons which comprises vaporizing the same,

"then washing and partially condensing the vapors with liquid hydrocarbons, then passing the residual vaporsv to a condensing tower and partially condensing them by using the- Wash oi'l andcondensates to further partially condense the vapors in said tower and finally condensing the ultimate residual vapors.

I 2. The process for the production of a mixture of hydrocarbons of predetermined boiling point range which comprises prelimipartially condensingthe vapors in a tower narily vaporizing mixed hydrocarbons, then passing the condensatesthrough a cooler and using the cooled condensates to partially condense the'residual vapors and finally con-.

densing the ultimate residual vapors.

3. A process for the production of commercial gasoline which comprises continuously vaporizing a mixture of hydrocarbons lowboiling fraction suita 1e for gasocontaining the gasoline fraction, subjecting the vapors to a partial condensing action in a condensing tower, cooling and using the condensates as a condensing medium, passing the residual vapors to a second condensing tower, again partially condensin them, using the cooled condensates from t e first tower to partially condense said residual vapors and finally condensing the ultimateresidual vapors to produce the gasoline.

4. A process for the 'roduction of a mixture of hydrocarbons of predetermined boiling points which comprises volatilizing the hydrocarbons and passing the same through a wash towerto partially condense the by drocarbon vapors, cooling the condensates, passing the residual vapors to a second tower and using the cooled condensates to 'further partially condense the hydrocarbon vapors, 7

partially volatilizing the condensates in the second tower to mix the vapors with the said residual vapors and finally condensing the uncondensed hydrocarbon vapors. a

5. A process for the production of a mixture of hydrocarbons of predetermined boiling points which compr ses volatilizing the hydrocarbons, passing them through a wash tower, washing the Vapors with hydrocarbon oil to partially condense them, cooling the condensates including the washoil, passing the residual vaporsfrom the wash tower to a second tower, and there partially condensing them, utilizing the cooled wash oil to further partially condense the vapors in the second tower, reheating. the condensed hydrocarbons in the second tower to partially volatilize them and'mixing the vapors with the other uncondensed vapors therein and finally cooling the ultimate residual vapors to produce the mixture ofhydroc'arbon oil of the predetermined boiling points.

6. In combination, an oil still, a washing tower, a vapor pipe connecting 'said still tosaid tower below its top, means to cool the wash liquid and condensate, and a ump and connections to supply'the top 0 said tower with said'wash liquid,a fractionating tower, a vapor pipe leading from the wash tower to the fractionating towe an analyzer at the top of said fnactionating tower adapted to allow the condensate formed therein to flow back into the fractionating' column and the vapors to pass therethrough, a condenser for the vapors passing through the' analyzer and a pipe connecting the" top of the fractionating tower to the last mentioned condenser.

tower having a vapor chamber below its top and provided in its upper end with a scrubber, means to supply the washing tower with wash oil at its upper end, a vapor pipe leading from said stillto said chamber, a fractionating tower having spaced sets of boiling decks, a pipe leading from the top 7. In combination an oil still, a washing of the washing tower to the space between the sets of boiling decks of the fractionating tower, a pipe connectionbetween said cham ber in the washin tower and the s ace between the sets of oiling decks in t e fractionating tower, an analyzer at the top of the fractionating toweradapted to allow the condensate formed therein to flow back into the'fractionating column and the vapors to pass therethrough, a final condenser, and

a p pe leading from the fractionating tower to said final condenser.

- 8. In combination, an oil still, a washing tower having a vapor chamber below its top provided in its upper end with a scrubber,

means to supply the washing tower with wash oil at its up er end, a vapor pipe, lead- "ing from said sti l toisaid chamber,'a fractionating tower having spaced apart. boiling decks, a pipeleading from the top of the washing tower to the space between theboiling. decks in the fractionating tower, a pipe to supply oil vapors to thebottom of the analyzer at the top connection between said chamber in the washing tower and the space between the boiling decks in thefractionating tower, an of the fractionating tower adapted to allow the condensate formed therein to flow back into the 'fractionating column and the vapors to pass therethrough, afinal condenser, a pipe leading to said final condenser from the top of the fractionating tower, said washing tower having a chamber in the lower part thereof, and a vapor pipe leading from the last mentioned chamber to the space between the boiling decks in the fractionating tower.

9. In combination, a wash tower, means tower, a pump and pipe connections for supplying wash oil directly to the top of the tower, a fractionatiug tower and a pipe extending from the top of the wash tower to an intermediate point of the fractionating tower, an analyzer inthe top of the fractionating tower with pipe connections to said pump, and also to said scrubber, with valves in the ipe. lines leading to the anaconnected thereto, a fractionating tower conlyzer and to t e wash tower by manipulanected to the wash tower, a pump having connections to the fractionating tower and the top of the wash tower, said connections being supplied with valves whereby oil 'may be pumped directly into the top of the wash tower, and means for by-passing oil through the fractionating tower and thence into the wash tower.

- 12. In combination, a still, a wash tower connected thereto having a chamber there- 1 in, a fractionating tower, and connections from both the top and bottom of the wash tower chamber to the fractionating tower, I a pump and connections whereby oil may be circulated from asource of supply through the wash tower or through ot the wash tower and the fractionating tower. 13. In combination, an oil still, a' washing tower, a vapor pipe connecting said still to T said tower 'below its top, means to supply the top of said tower with wash oil, a frac:

tionating tower, a. vapor'pipe leading from i the top of the first tower to the fractionating tower intermediate its height, a conduit between said towers substantially level with the inlet to the fractionating towerfrom the first tower, an analyzer at the top of the fractionating, tower adapted to allow thecondensate formed therein to flow back into I the fractionating column and the vapors to pass therethrough, and a condenser having pipe connection with the top of the fractionating tower.

14. In combination, an oil still,a washing tower having a vapor chamber below its 1 top and provided in its upper end with a scrubber, means to supply the washing tower with wash oil at-its upper end, a vapor pipe.

leading from said still to said chamber, a

fractionating tower having spaced sets of boiling decks, a pipe-leading from the top vof the washin tower to the space between the sets of boiling decks in the fractionating tower, a pipe connection between said chamber in the washing tower and the space Y between the sets of boiling decks in the frac tionating tower, an analyzer in the top of the fractionating tower adapted to allow the condensate formed therein to flow back into the tractiona'ting column and the vapor to pass therethrough, a final condenser, a pipe I leading to said final condenser from-the top of the fractionating tower, and means to supply heat and steam to the fractionating v tower below the boiling decks.

' In testimony whereof I- hereunto aflix my signature.

I JOHNC. BLACK.

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