US2717857A - Method for manufacturing heating oil - Google Patents

Description

Sept# 13, 1955 s. o. BRoNsoN u ET AL 2,717,857

METHOD FOR MANUFACTURING HEATING OIL Filed Feb. 14, 1952 SQA/embers m a@ @7: om, me .ONQ Q A| L' AN d w. @LN Alm wnoN u www N@ A Q Kuqm n e e vm- MZON @q um? MQON A wrm w. @Q Bqwxc. o .rmaqo 2O qlru ww w w n@ 7m e m .Vgn J-O @(mv l mv n2 O @IJ N y All AI m All mmmh .0.039 92ml@ w .iO @z t wQoN n4 wzoN m AI .v n@ mzON @z zmhmmz a QEEOMQ a Juju zorEJlf doro A m, mi@

United States Patent Oiltice 2,717,857 METHOD FOR MANUFACTURING Stanley 0. Bronson II, Mountainside, Robert C. Morbeck, Fanwood, and Sumner B. Sweetser, Cranford, N. J., assignors to Esso Research and Engineering Company, a

corporation of Deaware Application February 14, 1952, Serial No. 271,556 4 Claims. (Cl. 196-35) HEATING GIL systems,

oil, and thermal or catalytic cracking of various petroleum oil fractions. Heretofore,

heating oil blends comprised a relatively large oils tend to cause clogging of filters, orices, or conduits associated with the burning systems in which they are employed.

'It is also known in the art that when a virgin heating oil In accordance catalytic cracked stocks are chari 2,7 32285? Patented sept. 1s, less oil from a relatively severe cracking operation in which case it treatment polymerizes many desirable constituents resulting in a loss 1n yield. Furthermore, the sludge is expensive and diflicult to handle.

tion D-396-48T for Fuel Oils (Grades o. 1 or 2).

Inspections of a typical heating oil blend are for example: Gravity, API 34.5 Distillation, A. S. T. M.:

Initial, B. P. F 363 10% F 438 50% F 504 90% F 583 Final, B P F 640 Flash, F 15s Color, Tag Robinson 15 Viscosity, SSU/ 100 F 34.7 Pour point, F 0 Sulfur', wt. per cent .37 Suspended sediment, mgs/IOO ml 1.0 YCarbon residue on 10% residuum, per cent .08 Corrosion, 1 hr. 212 F Pass Diesel index 48.2 Aniline point, F 140 The process of the present invention may be more fully understood by reference to the drawing illustrating one embodiment of the same. Referring specifically to the drawing, lation zone 1 by means of line 2. Temperature and pres- Normally this fraction is treated as for example sodium hydroxfor example, a thermal or a catalytic cracking process. However, the present invention is particularly directed toward the production of a high quality virgin-cracked heating oil blend wherein the cracking process comprises a catalytic cracking operation, as for example a fluid catalytic cracking operation.

A fluid catalytic cracking plant is composed of three sections: cracking, regeneration, and fractionation. The cracking reaction takes place continuously in one reactor at a temperature in the range from about 800 F. to l050 F. The spent catalyst is removed continuously for regeneration in a separate vessel, from which it is returned to the cracking vessel, which is at a pressure below about 200 lbs. usually below about 50 lbs. per sq. in. Continuity of flow of catalyst as well as of oil is thus accomplished, and the characteristic features of fixed-bed designs involving the intermittent shifting of reactors through cracking, purging, and regeneration cycles are eliminated.

Regenerated catalyst is withdrawn from the regenerator and ows by gravity down a standpipe, wherein a sufficiently high pressure head is built up on the catalyst to allow its injection into the fresh liquid oil stream. The

resulting mixture of oil and catalyst ows into the reacl tion vessel, in which gas velocity is intentionally low, so

that a high concentration of catalyst will result. The cracking that takes place results in carbon deposition on the cracked product oil vapors are withdrawn from the top of the reactor after passing through cyclone separators to free them of any entrained catalyst particles, while the spent catalyst is withdrawn from the bottom of the reactor and is iniected into a stream of undiluted air which carries the catalyst into the regeneration vessel. The products of combustion resulting from the regeneration of the catalyst leave the top of this vessel and pass through a series of cyclones where the bulk of the entrained catalyst is recovered. The regenerated catalyst is withdrawn from the bottom of the vessel to complete its cycle. The cracked products are removed from cracking zone 30 (overhead from the reactor) by means of line 'Z8 and introduced into a distillation zone 16. Temperature and pressure conditions in zone 16 are adjusted to remove overhead by means of line 17 normally gaseous constituents and to remove by means of line 18 hydrocarbon constituents boiling in the motor fuel boiling range. A fraction boiling above the heating oil boiling range is removed as a bottoms fraction by means of line 19. A fraction boiling in the heating oil boiling range is removed by means of line 20 and in accordance with the present invention may be caustic washed in zone 21. The fresh caustic or other treating agent is introduced by means of line 22 while the spent treating agent is removed by means of line 23. ent invention the caustic washed cracked heating oil is blended with the mild hydroned virgin heating oil.

In accordance with the present invention the virgin heating oil removed by means of line 5 is, mildly hydrofined in hydrofining zone 8. It is essential in practicing the present invention that the hydrofming operation conducted on the virgin heating oil be a mild hydrofming operation, This is to be distinguished from conventional hydroning operations heretofore practiced in the art. Such hydroining operations have been employed at pressures from 200 to 500 lbs. per sq. in., at feed rates of .5 to 2.0 volumes of feed per volume of catalyst per hour. Relatively high rates of hydrogen recycle have been employed as for example, 2,000 to 4,000 standard cu. ft. per barrel in order to prevent carbonization of the catalyst. Likewise, very active catalysts have been used which are effective for P desulfurization. Under these conditions hydrogen consumption has generally been in the range of 150 to 600 standard cu. ft. per barrel of feed. This relatively high consumption of hydrogen in the past has made the process expensive to operate, so that its application in the past has In accordance with the presf paired the quality of the fuel.

been limited to the treatment of relatively high sulfur stocks which could not be desulfurized by any other available treating operation. The catalyst heretofore employed has been a cobalt molybdate supported on a carrier, as for example alumina.

Due to the fact that the sulfur content of heating oils is relatively low, since the cracking operation desulfurizes to a great extent, conventional hydroning operations have not been necessary in the processing of virgin heating oils. On the other hand, when conventional sweetening operations were employed in the processing of virgin heating oils for improving the carbon residue, these conventional operations were found entirely unsatisfactory, since they actually increased the carbon residue and further irn- On the other hand, when employing the mild hydroning process of the present invention, unexpected desirable results are secured with a higher quality blended fuel oil product.

The, mild hydroiining, conditions of the present invention may be secured by lowering the temperature, increasing the feed rate per volume of catalyst or by using a less active catalyst. In accordance with the present invention the temperatures used are in the range from about 400 to 700 F., preferably in the range from about 500 to 650 F. Pressures employed are in the range from 50 to 250 lbs. per sq. in., preferably in the range from about 100 to 200 lbs. per sq. in. The feed rates, in accordance with the present process, are in the range from about l-l6 volumes of liquid per volume of catalyst per hour. Preferred feed rates are in the range from 4l0 v./v./hr. The hydrogen in the gas to the hydroning unit may vary from 50 to 100%. This means that, for example dilute hydrogen from a hydroformer can be used in the hydroning process. A particularly desirable method of hydroning in accordance with the present process is to recycle appreciable quantities of hydrogen to the hydroning unit in order to completely prevent carbonization of the catalyst.

The catalyst utilized in the present operation may comprise known hydroning catalyst, as for example cobalt molybdate on a carrier as for example alumina, providing other operating conditions are adjusted to secure a mild hydroning process. The preferred catalyst, however, of the present invention comprises molybdenum oxide on a carrier preferably alumina. The amount of molybdenum oxide employed is about 5 to 13% by weight based upon the weight of the alumina. The catalyst is prepared by known methods, such as by impregnation of the alumina with a water-soluble molybdenum salt, followed by heating to convert this salt to molybdenum oxide, or by coprecipitation of aluminum and molybdenum hydroxides by addition of an ammoniacal solution of ammonium molybdate to an acid solution of an aluminum salt followed by water washing and by heating to convert to the oxides.

It is to be understood that the mild hydrofming conditions of the present invention are secured by the adjustment of the above named operating conditions. For instance, if a relatively high liquid feed rate is used as compared to the amount of catalyst present, the higher ternperature range may be employed. On the other hand, if a very active catalyst is used, it is desirable to use a relatively high feed rate or to use a relatively low ternperature. The mild hydrofining conditions of the present invention are measured by the amount of hydrogen consumption per barrel of oil feed. As pointed out heretofore in the art, conventional hydrofining operations utilized for the desulfurization of certain stocks are conducted under conditions whereby the hydrogen consumption ranges from 150 to 600 standard cu. ft. of hydrogen per barrel of oil. These operations used heretofore in the art secured a substantial sulfur reduction (50 to 90% In accordance with the present process, operating conditions are adjusted so that the hydrogen consumption in standard cu. ft. per barrel does not exceed 60 and is wir?,

preferably less than 40. Furthermore, the extent of the sulfur reduction when utilizing the mild hydroning conditons of the present invention does not exceed about 35% and preferably does not exceed about` 20%.`

The process of the present invention may bemmore fully understood by the following examples illustrating the same.

EXAMPLE I Comparison of Sweeteniny Methfods on West Temas V In various operations` the virgin heating oil was/hyfl droned using a cobalt molybdatc on alumina catalyst wherein the concentration of the cobalt molybdate wasabout to 15% by weight based upon the alumina. In other operations the catalyst comprised molybdenum oxide on alumina wherein the concentration of the molybdenum oxide by weight based upon the alumina was in the range of about 8 to 10%.

The data presented above demonstrate the fact that a satisfactory reduction in copper number, which is indicative of mercaptan content, can be secured by mildly hydroiining the virgin fraction. The data further-show that when the hydrofined virgin oil was mixed with a cracked oil which had been treated only by caustic washing, a product with a satisfactorily low carbon residue was obtained. While satisfactory results can be rgn Heating OfiZ 1 0peration A B C D E F G Air Hypo- Hydm Sweetening Method Feed Doctor Pbs/S Caustic @mmm Unisol lining MN Inspections on sweetened Prod.:

Copper No g 82 1 1 22 18 10 1 g Carbon Residue (10% Residuum). 0.03 0. 0S 0.12 0 05 0. 20 0.03 0. 02 Carbon Residue of /50 Blends of sweetened Virgin Heating Oil and Cracked Heating Oil 2:

Actual Value. 0. 36 0. 35 0. 18 0. 2O 0. 15 0. l2 Expected Valu 0A 14 0. 16 0, 12 0. 13 0. 12 0. 11

2 Cracked heating oil was a blend of th 1 West Texas virgin heating oil had a boiling range of B30-660 F. and a sulfur content of 0.65 wt. percent.

mal and catalytic stocks with a boiling range of 355- F. It was er treated only by caustic washing and had a carbon residue of 0.20 wt. percent and a sulfur content o 1.17 wt.

percent.

From the above (operation G) it is apparent that'the hydroiining-sweetening process of the present invention produces processes.

The equivalent treating procedures used in the above operations are summarized as follows:

results far superior to equivalent sweetening A1" rearing4 p obtained with cobalt molybdate catalyst, operatedat 600 F. and 8 to A16 v./v.hr., the preferred operating conditions include the use of the M003 on Al catalyst at 600 F. with a feed rate of 4 to 16 v./v./hr. Satisfactory o'perlation can also be obtained at 500i F. with either catalyst at lower feed rates.

rocedures p Process Doctor PbS-s Air-Caustic Hypochlorite Unisol Prewash 0.5% of 15 B. Caustic... 0.5% of 15 B. Caustic... 0.5% of 15 B. Caustic... 0.5% of 15 B. Caustic... 0.50% tt l5 B.

aus 1c. Treating Agent Doctor sol Phs-S Caustic, 48 B. Hypochlorite sol Unisol sol Composition su1fur,45 mg./100 mL... Pigs, s,1 15 B. Caus- 10 g./l. Sodium Hypopass. Water Wash followed by Paper Filtration.

The hydroning conditions for various operations are as shown in the following table:

Hydrofining West Texas light virgin heating oil 50/50 ona'on and 48 B. Caustic.

chlori g./l. free NaOH. 2% 11% 3 10% treats.2 Ailr lilown for 30 In Viulent Agitation for 20 2 ecs. Water Wash followed by Water Wash followed by Water Wash fol- Paper Filtration. Paper Filtration.

lowed by Paper Filtration. Ds/lb. of 15 B. caustic, 41 mg. s/100 rnl. of caustic, 10 vol. percent treat. 2 Under N2.

As discussed, severe hydrofning for desulfurizing oil products is known in the art. The process has generally 1 Column. A B C D E V F PbS/s Process Feed Hydroning 2 sweetening Feed Rate, V./V./Hr 1 4 8 16 Product Inspections:

Copper No 0 1 4 21 1 Total Sulfur- 0. 04 0.36 0. 46 0. 55 0. 64 Carbon Residue, Wt. 0. 04 0.01 0.00 0.00 0.13 Carbon Residue on Blen of- 62% sweetened Virgin Actual 0 05 0. 04 0.42 38% of Catalytic Heating Oil 3 Expected.. 0 03 0. 03 0.11

Light virgin heating oil had a boiling range of B25-530 F.

rate of 1,000 s. C.

3 The catalytically cracked heating oil had a boiling range of 42o/650 F. It was treated only by caustic washing before use and had a carbon residue of 0.08% and sulfur content of about 1.3 wt. percent.

been used on high sulfur stocks. It has now been found, however, that mild hydrofining is useful for treating products which require no reduction in sulfur, other than mercaptan sulfur which is the type contributing to bad odor in heating oils. The present invention is concerned with an application of hydrofining to this type of operation.

The hydroiined virgin constituents, after removal from the hydroiining zone may be further rened or treated as desired.

For example, it may be desirable to remove small traces of dissolved HzS which constituents may be removed either by steam stripping or by caustic washing. If caustic washing is utilized, a caustic solution having a strength from 2-l0% sodium hydroxide may be ernployed.

In accordance with the present process, a virgin heating oil is sweetened by hydroning under relatively mild conditions whereby mercaptan sulfur in the oil is converted to hydrogen sulde, which is separated from the oil by conventional means. The virgin heating oil is then blended with cracked heating oil components which have been treated only by caustic washing to obtain a heating oil blend which is satisfactory with respect to requirements for carbon residue, as well as other inspections for heating oil. This is to be contrasted with other sweetening methods where considerably more severe conditions would of necessity have to be utilized on the cracked stock than if the virgin oil were not hydroned as described in accordance with the present operation.

What is claimed is:

1. A process for improving the quality of virgin heating oil which comprises subjecting virgin heating oil constituents to a temperature in the range of 400 to 700'F., and pressure in the range of 50 to 250 pounds per square inch in the presence of extraneously generated hydrogen and a hydroning catalyst comprising molybdenum oxide on a carrier at feed rates in the range of l to 16 v./v./hr. so that there is a consumption of hydrogen not in excess of about 60 standard cubic feet per barrel and so that the sulfur reduction does not exceed about 2. The process dened by claim 1 in which the said hydrogen consumption does not exceed about standard cubic feet of hydrogen per barrel, and the said sulfur reduction does not exceed about 20%.

3. A process for the preparation of a high quality heating oil blend comprising virgin fractions and cracked fractions, which comprises segregating virgin hydrocarbon constituents boiling in the heating oil boiling range and cracked hydrocarbon constituents boiling in the heating oil boiling range, subjecting said virgin constituents to a temperature in the range of 400" to 700 F., and pressure in the range of to 250 pounds per square inch in the presence of extraneously generated hydrogen and a catalyst consisting of cobalt molybdate on a carrier at feed rates in the range of l to 16 v./v.hr. so that there is a consumption of hydrogen not in excess of about standard cubic feet per barrel and so that the sulfur reduction does not exceed about 35%, and thereafter blending said treated virgin constituents with said cracked constituents to produce a high quality heating oil blend.

4. The process defined by claim 3 wherein said cracked hydrocarbon constituents are caustic treated prior to the said blending.

References Cited in the lile of this patent UNITED STATES PATENTS 2,347,515 Shmidl Apr. 25, 1944 2,547,380V Fleck Apr. 3, 1951 2,574,447 Porter Nov. 6, 1951 2,574,448 Docksey et al Nov. 6, 1951 2,577,823 Stine Dec. 11, 1951 2,592,383 Blatz Apr. 8, 1952 FOREIGN PATENTS 456,764 Italy Apr. 21, 1950 989,481 France May 23, 1951

Claims (1)

1. A PROCESS FOR IMPROVING THE QUALITY OF VIRGIN HEATING OIL WHICH COMPRISES SUBJECTING VIRGIN HEATING OIL CONSTITUENTS TO A TEMPERTURE IN THE RANGE OF 400* TO 700* F., AND PRESSURE IN THE RANGE OF 50 TO 250 POUNDS PER SQUARE INCH IN THE PRESENCE OF EXTRANEOUSLY GENERATED HYDROGEN AND A HYDROFINING CATALYST COMPRISING MOLYBDENUM OXIDE ON A CARRIER AT FEED RATES IN THE RANGE OF 1 TO 16 V./V./HR. SO THAT THERE IS A CONSUMPTION OF HYDROGEN NOT IN EXCESSES OF ABOUT 60 STANDARD CUBIC FEET PER BARREL AND SO THAT THE SULFUR REDUCTION DOES NOT EXCEED ABOUT 35%.

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