US3097761A - Method and apparatus for dispensing motor fuel - Google Patents

Description

y 1963 J. F. DEMPSEY ETAL 3,097,761

METHOD AND APPARATUS FOR DISPENSING MOTOR FUEL Filed Dec. 19, 1957 2 Sheets-Sheet 1 A fi x1 8 z I z 1 J l O 1 o l g o, I I

I D I a I z 1 1 0 I, Z I E/ O O 0 O O O 9 l 7 Q 3 0 Octane Number llO Reform Reform Reform mu MEN TSA O NPM T M A ER. K mm m Mm Q B y 1963 J. F. DEMPSEY ETAL 3,097,761

METHOD AND APPARATUS FOR DISPENSING MOTOR FUEL Filed Dec. 19, 1957 2 Sheets-Sheet 2 v 4 mmmmmm O m m c v A C E QESZ m h-goo zobummom IOI o INVENTOR. Volume Percent Component A JAMES DEMPSEY BY FRANK R. SHUMAN,JR.

QMO- 5PM ATTORNEY United States Patent 3,097,761 METHOD AND APPARATUS FOR DISPENSING MOTOR FUEL James F. Dempsey, Claymont, Del., and Frank R. Shuman, Jr., Media, Pa., assignors to Sun Oil Company,

Philadelphia, Pa., a corporation of New Jersey Filed Dec. 19, 1957, Ser. No. 703,808 7 Claims. (Cl. 2221) This invention relates to the dispensing of a plurality of motor fuels of different octane rating at a service station for automobiles or other dispensing location.

In a prior art system for dispensing motor fuel, a plurality of, e.g. six, grades of motor fuel, each having different octane number, are dispensed at a single service station. The intermediate grades are formed by blending in ditferent proportions two motor fuel stocks whose octane numbers constitute the upper and lower limits respectively of the octane numbers obtainable in the system. This system has recognized important advantages, such as the provision of intermediate grades while eliminating separate transportation and storage facilities for those grades.

This system has however certain disadvantages which will appear from the following description and which are eliminated according to the invention while retaining in substantial measure the advantages of the prior art system.

The invention involves the use of three motor fuel stocks, each having different octane number, to produce a plurality of fuel grades each having different octane number. One of the grades is provided by either the intermediate octane stock, the highest octane stock or a blend of the two. Another grade, having lower octane number than that of the first-named grade, is provided by either the intermediate octane stock, the lowest octane stock, or a blend of the two. Any desired number of additional grades, constituting one of the stocks or a blend of the intermediate octane stock with one of the other two stocks, can also be dispensed. At least one of the grades is a blend of the intermediate octane stock with one of the other two stocks.

It has been proposed in the prior art to prepare at a dispensing location a blend of two or more fuels. Thus for example, three stoclcs each having different octane number may be blended and the resulting blend dispensed to the customer. But the proir :art has not suggested the use of three blending stocks to provide at least two gr-ades comprising one or more two-stock blends. Prior to the present invention, the benefits of such operation, as compared with prior art operation, were not recognized.

It would appear that the use of three stocks in a blending system would be detrimental, since transportation and storage facilities would have to be supplied for the third stock. This disadvantage is more than balanced however by the subsequently described advantages which are gained.

The invention will be further described with reference to the drawing. FIGURE 1 is a chart showing a typical relationship between manufacturing cost and octane number of motor fuel. FIGURE 2 is a schematic diagram illustrating manufacturing, transportation and dispensing according to one embodiment of the invention. FIGURE 3 is a schematic illustration of dispensing apparatus according to one embodiment of the invention. FIGURE 4 is a chart showing a typical blend-octane curve for blends of two fuels having different octane number.

Consider a system wherein the three stocks (A, C and E) have octane ratings of, say, 110, 100 and 90 respectively. As shown in FIGURE 1, the manufacturing cos-ts of these stocks are 100, 70 and 60 units respectively.

3,097,761 Patented July 16, 1963 "ice These figures [are indicative of relative magnitude only. The actual numbers in a given case would depend on the units used and other factors. The increment of cost between stocks A and C is greater than that between stocks C and B, because of the fact that, the higher the octane level, the greater the cost per octane number of further increasing the octane number.

In FIGURE 2, an illustrative diagram is given, representing the differences in manufacture of the respective stocks. Stock E is obtained by subjecting straight run naphtha to reforming conditions in reformer 3 to pro- 1 duce a octane product. Stock C is obtained by subjecting straight run naphtha to reforming conditions in reformer 2 to produce a octane product. Stock A is obtained by subjecting straight run naphtha to reforming conditions in reformer '1 to produce a octane product. The reforming in this case may involve a series of processes for conversion of hydrocarbons to higher octane products. Any suitable known conditions can be emplyed in each reforming process. ferences in conditions to produce the differences in product octane rating can readily be chosen by a person skilled in the art. This feature is known in the art. The invention resides, not in reforming or otherwise converting hydrocarbons to different octane levels per se, but in dispensing in a particular 'manner the products thereby obtained.

Because of factors inherent in the nature of straight run petroleum hydrocarbons, it is more difiicult to increase their octane number by a second increment of 10 units, for example, than it is to increase their octane number by a first increment of 10' units. Therefore the unit cost is greater for the octane numb-er increments at higher octane level, and a 'curve ACE as in FIGURE l results.

Lines 10, 11 and 12 in FIGURE 2 are symbolic of the transportation of stoclcs A, C and E from a refining location or locations to a dispensing location. Any of the usual means of transportation, e.g. truck, ship, pipeline, etc. may be employed. At the dispensing location, the stocks are placed in separate containers, and at least one blend of two of the stocks is prepared for dispensing to motorists. For purpose of illustration, FIGURE 2 represents the blending of stocks A and C, for example in equal quantities, to produce grade B having about 1 05 octane, and the blending of stocks C and E, for example in equal quantities, to produce grade D having about 95 octane. The blends can be formed at any stage of the dispensing operation. They can be formed in storage tanks and dispensed through different pumps. They can be formed just prior to passage through the dispensing nozzle into the fuel tank of an automobile. They can be formed at any desired intermediate stage of the dispensing operation.

A preferred operation is to form the blends just prior to passage through the dispensing nozzle. In FIGURE 3, a dispensing nozzle 30, communicating with a valve 32, is schematically illustrated. A lever 34 is adapted to open and shut the valve 32 by hand pressure in the conventional manner. Communicating with the valve body are lines 36, 38 and 40 through which one or more of the stocks A, C and E is pumped by suitable conventional means not shown upon opening of valve 32. Prior to opening valve 32, the valves in lines 36, 38 and 40 are set in the proper manner to deliver the desired fuel. The valves in lines 36, 38 and 40 are preferably located as near as practicable to the valve 32. Any of the unblended components can be delivered by opening the valve in the line'delivering that component and closing the valves in the other two lines. Blend B can be delivered by opening the line 36 and line 38 valves and closing the line'40 valve, and delivering stocks A and C The difsimultaneously to valve 32 at equal rates controlled and metered by suitable means. Blend D can be delivered in similar manner with the line 38 and line 40 valves open and the line 36 valve closed.

Any suitable means can be employed to blend two stocks in controlled proportions just prior to passage through a dispensing nozzle. The particular such means employed do not constitute the invention, but rather the combination of such means with the other apparatus features and the dispensing by any such means of particular combinations of fuel stocks or blends.

It is not essential that all grades of fuel be dispensed through the same nozzle as shown in FIGURE 3, though this feature is preferred. If desired, each grade can be dispensed through a different nozzle. Alternatively; grades derived from two stocks, e.g. A and C, can be dispensed through one nozzle, and grades derived from two other stocks, e.g. C and E, can be dispensed through a second nozzle. The means for regulating the dispens ing and pricing, etc., in the case of each nozzle can be similar for example to those disclosed in E. T. Young United States application Serial No. 548,907, filed November 25, 1955, now Patent No. 2,977,970. Any other suitable means can be employed.

The advantages of manufacturing and transporting three rather than two motor fuel stocks are illustrated by the following table which shows, on the basis of the case above postulated, the cost of producing the various grades intermediate between 90 and 110 octane.

Two stocks Three stocks Octane Stock st;

Grade cost Grade 00st;

Composition Compositlon Average. 80 76 The saving in manufacturing cost obtained in the three stock system is usually greater even than that indicated by the average figures 80 and 76, since the volume of sales of the intermediate grades is usually greater than that of the terminal grades, and it is in the intermediate grades that the saving is obtained.

In actual refinery practice, high octane motor fuels are produced by a plurality of processes such as reforming, alkylation, cracking, etc. Straight run hydrocarbons are often subjected to a plurality of processes designed to increase octane rating. The motor fuels which are marketed are often blends of products of different processes. Anti-knock additives such as tetraethyl lead are usually employed. Yet, however complex the preparation may be, the principle illustrated in FIGURES 1 and 2 generally applies. From the standpoint of manufacturing cost, it is more advantageous to produce a product having given octane number by conducting a process which gives that product directly than to conduct a process of the same general type, which gives a product having higher octane number, and blend back with a low octane stock. Therefore it is more advantageous to obtain the stock C for example by blending refinery streams having octane number relatively close to 100 octane, e.g. in the range from 95 to 105 octane, than by blending refinery streams having a wider spread in octane number and corresponding relatively closely to the stocks A and E.

The saving in manufacturing cost obtained in going from two stocks to three is illustrated in FIGURE 1 by the difference in cost of 100 octane fuel between point C for the three-stock system and point C' for the two-stock system. The point C is on the dashed line AC'E which is the cost-octane line for grades obtained by blending stocks A and E, assuming that octane numbers of blends are additive. This assumption will be further discussed subsequently. In going from three stocks to four or five, the magnitude of the saving is illustrated by the difference in cost of and 105 octane fuels between points D and B for the five-stock system for example and points D and B for the three-stock system. Points B and D are on the dashed lines CBA and EDC respectively, which are the approximate cost-octane lines for grades obtained by blending stocks C and A on the one hand and stocks E and C on the other. It is seen that the magnitude of the saving is much less in going from three stocks to larger numbers of stocks than in going from two stocks to three stocks. Therefore, the additional transportation and storage facilities required for more than three stocks are not justified.

It is essential that at least one blend of two fuel stocks be dispensed at the dispensing location. Otherwise the close matching of octane rating of the fuel with octane requirements of individual automobiles cannot be obtained. The rapid increase in octane requirement of automobiles has increased the range of octane requirements of the automobiles in use and made it impossible to obtain close matching with three fuel grades or less.

The excessive manufacturing costs of a two fuel blending system are made particularly high when the necessary octane spread between the two blending stocks is increased. Such increase is characteristic of motor fuels at the present time. The highest octane component, which is needed as such only in very small quantities, if at all, must be produced in large quantities for a two-stock blending system, since it is a component of every blend, even down to the next to the lowest octane grade. The three-stock system eliminates this undesirable feature in large measure, since it permits omitting the highest octane component from numerous grades. For example, in the illustrative operation described previously, the highest octane component A is a component of only two of the five grades.

In the preceding discussion, it was assumed that octane numbers blend linearly. This assumption is usually only approximately true. An actual blend-octane curve representing an average of many determinations is shown in FIGURE 4. The solid line AHE is a plot of actual octane numbers obtained by blending 105 octane component A with about 94 octane component E in various proportions. The octane numbers of stocks A and E in FIGURE 4 do not correspond exactly with those of stocks A and E in FIGURE 1, but FIGURE 4 illustrates a principle which applies to stocks A and E in both figures. The dashed line AHE in FIGURE 4 is a stranght line illustrating the linear assumption. The graph shows that an inter unediate octane blend, e.g. a octane blend, requires more of component A, and consequently costs more, than would be expected on the linear assumption. Application of this fact to FIGURE 1 would result in changing the line ACE in that figure to provide a slight convexupward curvature. This would increase the distance between points on that line and points on line ACE, and therefore increase the advantage of operation according to the invention.

There are indications in the prior art that, in some cases involving the blending of 80 octane fuel for example with a lower octane fuel, opposite curvature to that in FIGURE 4, i.e. convex upward instead of concave upward curvature, characterizes the actual blend-octanecurve. Even in such cases, the curvature is usually not sufficiently great to bring, when applied to FIGURE 1, the line ACE down to the line ACE or below. Therefore, an advantage still results from operation according to the invention in such cases. However, the advantages of the invention are greater when the relationship shown in FIGURE 4, which seems to be typical of blends having octane number of at least 90, exists.

The advantages according to the invention are obtained,

not only when dispensing fuels A, B, C, D and E as shown in FIGURE 1 for example, but aiso when dispensing various other combinations of fuels derived from the three stocks A, C and E. Examples of such combinations are the following: the two-grade combination B and D; the three-grade combination B, C and D; the threegrade combination B, D and E; the four-grade combination B, C, D and G; the five-grade combination F, B, C, D and G; the two-grade combination G and B; the two-grade combination F and G; etc. The grade G is a blend of stocks C and E containing a greater proportion of stock E than in blend D. The grade F is a blend of stocks A and C containing a greater proportion of stock A than in blend B.

Equal volume blends are preferred according to the invent-ion, but other proportions can be used. A person skilled in the art can readily determine suitable proportions for obtaining a desired octane number from available blending stocks.

Preferably the difference in octane number between stocks A and E is at least 6 units, more preferably at least 12 units. Preferably the difference in octane number between stock C and either of stocks A and E is at least 2 units, more preferably at least 4 units.

The invention claimed is:

1. Process for dispensing motor fuel which comprises: supplying motor fuel to a dispensing zone in two separate streams having different octane numbers; blending said streams in continuous flow to obtain a blend; directly dispensing the blend in continuous flow from the dispensing zone; subsequently supplying motor fuel to the dispensing zone in a third stream having octane number outside the range between the octane numbers of the first two streams; dispensing a fuel containing the third stream from the dispensing zone; the three streams constituting the sole supply of motor fuel to the dispensing zone; maintaining the dispensing zone closed to the stream having the highest octane number of the three streams 'whenever the stream having the lowest octane number of the three streams is supplied to the dispensing zone; and maintaining the dispensing zone closed to the stream having the lowest octane number of the three streams whenever the stream having the highest octane number of the three streams is supplied to the dispensing zone.

2. Process according to claim 1 wherein the third stream has octane number above the octane numbers of the first two streams.

3. Process according to claim 1 wherein the third stream has octane number below the octane numbers of the first two streams.

4. Process according to claim 1 wherein the third stream is dispensed alone.

5. Process according to claim 1 wherein the third stream is dispensed in a blend with that one of the first two streams which has octane number closest to the octane number of the third stream.

6. Process for dispensing motor fuel which comprises: placing in a separate container each of three motor fuels having different octane number; supplying motor fuel to a first dispensing zone in two separate streams supplied respectively from the container holding the fuel with the highest octane number of the three fuels and from the container holding the fuel having the intermediate octane number of the three fuels; blending the two streams in continuous flow to obtain a blend; directly dispensing the blend in continuous flow from the first dispensing zone, the two streams constituting the sole supply of motor fuel to the first dispensing zone; supplying motor fuel to a second dispensing zone in two separate streams supplied respectively from the container holding the fuel having the lowest octane number of the three fuels and from the container holding the fuel having the intermediate octane number of the three fuels; blending the latter two streams in continuous flow to obtain a blend; directly dispensing the resulting blend in continuous flow from the second dispensing zone, the latter two streams constituting the sole supply of motor fuel to the second dispensing zone.

7. Apparatus for dispensing motor fuel which comprises three conduits in parallel, all communicating with a valve housing, flow rate controlling means communicating with each of said conduits and adapted to deliver a metered quantity of liquid through each conduit, a valve in each of said conduits directly upstream from said housing, a dispensing nozzle directly downstream from said housing, and valve means in said housing adapted to permit liquid flow from said conduits into said nozzle when open and to prevent such flow when closed.

Holmes May 5, 1936 Ortner June 18, 1957

Claims (1)

1. PROCESS FOR DISPENSING MOTOR FUEL WHICH COMPRISES: SUPPLYING MOTOR FUEL TO A DESPENSING ZONE IN TWO SEPARATE STREAMS HAVING DIFFICULT OCTANE NUMBERS, BLENDING SAID STREAMS IN CONTINUOUS FLOW TO OBTAIN A BLEND; DIRECTLY DISPENSING THE BLEND IN CONTINUOUS FLOW FROM THE DISPENING ZONE; SUBSEQUENTLY SUPPLYING MOTOR FUEL TO THE DISPENSING ZONE IN A THIRD STREAM HAVING OCTANE NUMBER OUTSIDE THE RANGE BETWEEN THE OCTANE NUMBERS OF THE FIRST TWO STREAM; DISPENDING A FUEL CONTAINING THE THIRD

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