US2695223A - Furnace oils containing organic phosphorus compounds - Google Patents

Description

2,695,223 Patented Nov. 23, 1954 FURNACE OILS CONTAINING ORGANIC PHOSPHORUS COMPOUNDS John D. Bartleson, Cleveland, Ohio, aaaignor to The Stant odardmo Oil Company, Cleveland, Ohio, a corporation No Drawing. Application November 17, 1949, Serial No. 127,987

SClaims. can-'16 This invention relates to furnace oils containing a small amount of an oil dispersible orgariic phosphorus com- 625 F. for 3 hours, at atmospheric pressure in the preswill be apparent as details or embodiments of the in .rate of 3.3 cu. ft. per hour.

vention are set forth hereinafter. y

In order to facilitates clear understanding of the invention, the following specific embodiments are included. As a relnnmary or screening test, the effect of various agents or reducing the tendency toward the formation of a carbon residue of 'an SAE so1ventextracted mineral hydrocarbon oil was observed. In this test, two grams of the 011 sample is placed in a steel Petri dish, set in an electrically heated furnace and maintained at ence of air, and air is, passed over the Petri dish at the After the test, the carbon res1due 1s weighed. The following results are indicative of the improvement achieved with known organic phosphorus-compounds as additives:

TABLE I 011 min 5% Additive r Blank on C bon cductton ga Formula Resi duetn Carbon 3013M Weight Reslduein i Percent Weight g; 011mmwit di henl hen 1- c rs-oo 1. (1) p g ra t l' H0: so 101 (2) p fiaphosp 1 1 c H m 2 C'H'L 12.0 as

. E mfgu l hm lthloodors-(001111); 18.0 11.4 31

4 -tert-a mlo'o o1 =o 20.0

() g r p H11 o t )I 18.8 at I (lldhrzp PEQBYI- OeHrP(OO1H1)s 18.0 18.0 28 (o) 2.1 na ygwl- (cttaactmohho 20.0 m1 :4 ban 1- CQHIPO 00.11 18.7 1L ('0 phgmhongh. r 1): o 2:

pound having a boiling point of at least 400 F., and more particularly to a furnace oil containing an amount of the organic phosphorus compound to provide up to but not over 0.015 weight per cent of combined phosphorus to givea fuel oil composition of improved burning performance.

Furnace oils are often used in vaporizing pot type burners. In such a burner, the unvaporized oil is exposed to air, heat, and flame radiation for relatively long periods before the combustion occurs, and tends to form carbon deposits in the pot.

The art is confronted with the problem of providing furnace oils of improved burning performance, especial' ly catalytic or thermally cracked oils which are relatively poor in burning performance in vaporizing burners, especially as to the tendency to form carbon deposits.

As illustrative of furnace oils to which the invention is applicable, the following represent about the maxima and minima specifications:

Minimum flash point F-.. 100 Maximum pour point ,F 20 Maximum 10% point. F-.. 440 Maximum 90% point -e F 675 Minimum API gravity 26 Maximum SUS viscosity at 100 F 40 .standard model;(lvanhoe Model 2205 available from It contains a 10" The Perfection Stove Company). vaporizing pot type burner with gravity feed flow and has no forced draft. For convenience, the usual outer case was removed, and the burner assembly and oil flow control valve were supported on an angle iron frame to facilitate adjustments and change of burner pots. A cylindrical shield was provided in place of the outer case. The 'unit was connected to a 20 ft. stack, draft gauge connections, etc., in accordance with the U. S. Department of Commerce standards for testing vaporizing pot type space heaters. The'onIy draft control was the weighted It has been found, in accordance with the invention,

that adding a small amount of an oil dispersible organic phosphorus compound having a boiling point of at least 400 F. to the oil greatly improves its burning performance.

The objects achieved by the invention include the pro.- vision of furnace oils containing a small amount of an oil dispersible organic phosphorus compound having a boiling point of at least 400' F. and having improved buming performance characteristics; and other objects which butterfly T furnished with the burner.

The fuel tank is set above the; burner for gravity feed, mounted on a scale of suitable capacity calibrated to 0.01 lb.',"and connected with the constant level oil flow control valves of the burner by flexible plastic tubing (Tygon). This permits measuring the rate of fuel consumption by weight.

The burner is operated under low-fire conditions, since this accentuates thecarbonizing tendency of the furnace oil. In addition, a rather heavy low viscosity furnace oil is used, and this also accentuates the tendency toward carbonizing. After the test, the burner bowl is freed of oil, and the gain in weight due to the carbon deposit is de- 3 termined. The following specially prepared Pass-olefin reaction products were tested in this manner.

Example 8 Pass-MOTOR POLYMER REACTION PRODUCT A commercially desirable olefin is so-called "motor lyrner or reduced motor polymer. Motor polymer rs usually made from C3 and C4 olefins by non-selective polymerization, e. g., with a phosphorus acid type catalyst. A polymer gasoline fraction may be removed therefrom by fractional distillation to the 250' F. cut point, and the residue is known as reduced motor polymer." The reduced motor polymer may contain small amounts of materials lighter than the trimer. Its average molecular weight is about 145 and it preferably contains a major amount of olefins boiling below 600' F. The olefins used should be of a suficiently high molecular weight to give a final product having the desired oil dispersibility. In general, olefins having from about 6 to about 25 carbon atoms in the molecule are preferred. The reaction may be carried out in the presence or absence of air or water, or in an atmosphere of inert or non-deleterious gas, such as nitrogen 01' Has. It may also be carried out under pressure, e. g., the pressure generated when the reaction is carried out in a closed vessel. The yield is very high. Generally the amount of sulfide is chosen so that all of it will react at the temperature selected and the reaction is continued until it is consumed. The olefin or mixture of olefin may be reacted with the phosphorus pentasulfide in weight ratios from 0.25 to 0.75 mol of the phosphorus pentasulfide per mol of olefin. Generally the ratio is 0.5210.

As anexample, 60 lbs. of reduced motor polymer, 22.8 lbs. of phosphorus pentasulfide and 2.4 lbs. of water were mixed and heated in a closed vessel. The temperature reached 350 F. in one hour and it was maintained at this temperature, with agitation, for 3 hours. The reaction mass was then filtered hot from a sludge amounting to about 10%. This filtrate is referred to hereinafter as the Example 8 additive.

Example 9 P S -CYCLOHEENE REACTION PRODUCT A mixture'of 60 grams of recrystallized phosphorus pentasulfide and 761 grams of cyclohexene was refluxed or 108 hours at 81 C. Hydrogen sulfide evolved continuously during the reaction. The unreactedphosphorus sulfide was filtered out, and the filtrate was evaporated under reduced pressure at room temperature until crystallization began. After chilling overnight at C., the crystalline product was filtered out. After rinsing the product with cold cyclohexene, the yield was found to be 38 grams of a material whose melting point was 113 to 115 C. The product was a colorless, crystalline, hygroscopic solid of molecular formula CrsHraPzSt. The probable structure as favored by evidence is:

When the additive of Example 4 is used in a highly cracked catalytic furnace oil and tested under the same conditions, the carbon residue is reduced to 69 grams from 91 grams for the oil without the additive.

These reductions in carbon residue are very significant especially since they are achieved with a very small amount of the additive; the results can be reproduced substantially accurately e. g., a repetition of the blank showed 94 grams of carbon residue and a 0.94 ratio.

It is important that the amount of the additive be very small, generally not over 0.05% by weight of the organic phosphorus compound, and any amount may be used which is sufficient to improve the burning characteristics.

aryl, alkaryl, aralkyl; or corresponding compounds wherein the carbon chain is interrupted by a non-metallic element, such as 0 or S.

A. Phosphines R Q R 1 such as: triphenylpho hine CsHs 3P. B. Phosphinates Sp such as: dicresyl phenylphosphinate, CsH5'P(OC'IHr):|.

C. Phosphonates on such as: di-phenyl phenylphosphonate,

CsHs-PO- (OCsI-Ish. D. Esters of phosphoric acid such as: trioctyl ho hate: 0P OCgH; phatidic acid p SP and Phoswhere R is (CnHsaCOOhCsI-Ie.

E. Thiophosphonates such as: diphenyl phenylphosphonate, 5

CsHs'PS-(OCsI-lsh.

F. Thiometaphosphates t 5 8 a Bg- -Rs such as: dicyclohexene thiometaphosphate,

CsHs-PS-Sa-PS-CsHs.

This group of compounds, besides containing phosphorus, contains carbon, hydrogen and oxygen and/or It is appreciated that certain phosphines have been suggested as additives for oils for use in diesel type engines, the amount of additive being in the range of 0.1 to 5.0%. This is much higher than used in the pot burner furnace oils in accordance with the present inventron, which 0118 are burned at atmospheric pressure. It 1s believed that the performance of the additive in the furnace Oll composition of the invention is different than the performance of an additive in a diesel oil which is ignited under high compression conditions. It has been indicated in the literature that triaryl phosphines are not effective to decrease the ignition delay period of such an oil in a diesel engine. When the additive of Example 4 of the invention was incorporated in a catalytic gas oil type furnace oil at a concentration of 0.10 weight per cent,

the oil smoked very objectionably and in addition deposited soot on the walls of the burner bowl.

The smoking tendency was tested in accordance with accepted procedures by withdrawing smoke by means of a tube inserted in the stack, cooling the smoke to about room temperature, and then drawing the cool smoke through a 20 mm. diameter area of a 25 mm. filter disc of Harshaw grade E filter paper held in a special connection. The smoke was drawn through the disc at a fixed rate for one minute, using a vacuum of 25" of mercury to regulate the flow. The filter disc was removed and then rated visually using a set of standards ranging from 0 (white) to (black). In such a test, oil containing 0.1% of the Example 4 additive showed a smoke rating of 9.0, which is objectionably high. The amount of the additive should not be over an amount to provide 0.015% combined phosphorus in the furnace 011 composition, in order that the smoking of the furnace 0% under these severe conditions will not be objectiona le.

In addition the walls of the burner bowl were visually evaluated for cleanliness or absence of soot or carbon deposit. The rating is expressed by comparison, with a set of standards running from A (good) to E (bad). In the above test with the furnace oil containing 0.1% of the additive of Example 4 the rating was E. This indicates that this amount of additive is too high. In such a test, the furnace oil containing 0.01% of the additives of Examples 4, 8 or 9, showed ratings of A. Comparable results are obtained with the other additives of the invention, providing the amount of the additive does not provide over 0.015% of combined phosphorus in the furnace oil.

The organic phosphorus compounds used in accordance with the invention are freeof metal atoms. Generally the compounds contain carbon hydrogen and phosphorus, and in addition may contain oxygen, sulfur or chlorine.

The foregoing description is for illustrative purposes only, and the invention is subject to modification or variation within the scope of the appended claims.

The expression consisting essentially of as used in the claims is intended to mean that the ingredients recited therein are the essential ingredients, and such expression is not intended to exclude from the composition other ingredients in such amounts as would not render the composition unsuitable for burning, but is intended to exclude ingredients which counteract or vitiate the efiect of the oil-dispersible organic phosphorus compound on carbon deposits.

I claim:

1. A composition consisting essentially of a cracked furnace oil of viscosity suitable for burning in a vaporizing pot-type burner and having a normal tendency to form a carbon deposit in the pot of the burner, in combination with an amount of an oil dispersible organic phosphorus compound free of metal atoms and having a boiling point of at least 400 F., said compound being selected from the group consisting of phosphines, phosphinates, phosphonates, phosphoric acid esters, thiophosphonates and thiometaphosphates to provide not over 0.015 weight per cent of combined phosphorus in the oil, whereby the presence of said phosphorus compound improves the burning performance of the oil and minimizes the carbon deposit due to the cracked characteristic of the oil.

2. A composition consisting essentially of cracked furnace oil of viscosity suitable for a vaporizing pot type burner and having a normal tendency to form a carbon deposit in the pot of the burner and an amount of an oildispersible tri-p-tert-amyl-phenylphosphate free of metal atoms and having a boiling point of at least 400 F. to provide not over 0.015 weight per cent of combined phosphorus in the oil whereby the burning performance of the oil is improved and deposition of carbon due to the cracked characteristic of the oil is minimized.

3. A composition consisting essentially of cracked furnace oil of viscosity suitable for a vaporizing pot type burner and having a normal tendency to form a carbon deposit in the pot of the burner and an amount of an oil-dispers'ible phosphorus pentasulfide-cyclohexene reaction product free of metal atoms and having a boiling point of at least 400 F. to provide not over 0.015 weight per cent of combined phosphorus in the oil whereby the burning performance of the oil is improved and deposition of carbon due to the cracked characteristic of the oil is minimized.

References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. A COMPOSITION CONSISTING ESSENTIALLY OF A CRACKED FURNACE OIL OF VISCOSITY SUITABLE FOR BURNING IN A VAPORIZING POT-TYPE BURNER AND HAVING A NORMAL TENDENCY TO FORM A CARBON DEPOSIT IN THE POT OF THE BURNER, IN COMBINATION WITH AN AMOUNT OF AN OIL DISPERSABLE ORGANIC PHOSPHORUS COMPOUND FREE OF METAL ATOMS AND HAVING A BOILING POINT OF AT LEAST 400* F., SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF PHOSPHINES, PHOSPHINATES, PHOSPHONATES, PHOSPHORIC ACID ESTERS, THIOPHINATES AND THIOMETAPHOSPHATES TO PROVIDE NOT OVER 0.015 WEIGHT PER CENT OF COMBINED PHOSPHORUS IN THE OIL, WHEREBY THE PRESENCE OF SAID PHOSPHORUS COMPOUND IMPROVES THE BURNING PERFORMANCE OF THE OIL AND MINIMIZES THE CARBON DEPOSIT TO THE CRACKED CHARACTERISTIC OF THE OIL.