US3282858A - Hydrocarbon fuel additive and hydrocarbon fuel - Google Patents

Description

United States Patent 3,282,858 HY DROCARBON FUEL ADDITIVE AND HYDROCARBON FUEL Richard W. Simmons, Bellingham, Wash, and Claude R. Usher, Burnaby, British Columbia, Canada, assignors to Feronol Chemicals Limited, Vancouver, British Columbia, Canada, a corporation of British Columbia, Canada No Drawing. Filed July 18, 1961, Ser. No. 126,830 1 Claim. (Cl. 252-428) This invention relates to an improved additive and catalyst for hydrocarbon fuels and improved hydrocarbon fuel.

An object of the present invention is the provision of an improved catalytic additive which may be added to any hydrocarbon fuel to produce a fuel having improved characteristics whether it is burned in a confined space, such as in a cylinder of an internal combustion engine, or in the open, such as in heating furnaces or boilers. The additive in the fuel results in more complete combustion, and a greater output of power, heat, light, etc. per unit of hydrocarbon than has heretofore been attained. In addition to this, the combustion of the treated fuel results in substantially less than in the past of the noxious and undesirable combustion products, e.g. hydrogen, unburned hydrocarbons, unburned contaminants of hydrocarbons, carbon monoxide, soot, carbon, smoke, etc. per unit of hydrocarbon.

Another object is the provision of an addition having a relatively high flash-point for the sake of safety.

Another object is the provision of a non-corrosive stable and low cost additive for improving hydrocarbon fuels.

A further object is the provision of a simple and nonhazardous process of manufacturing a fuel additive of potentially hazardous ingredients.

This invention is an improvement of that disclosed in United States Patent 2,506,539, dated May 2, 1950. The additive of the patent comprises an aromatic metal-free nitro compound such as picric acid, and an iron salt of an aromatic nitro acid such as ferrous picrate, dissolved in a solvent set out as methylated spirits and benzene. The patented additive has a dangerously low flash-point, is highly corrosive and unstable, and is costly and hazardous to produce. According to United States Federal Regulations, the hazardous additive could not be transported in glass containers, and yet its corrosive nature is such as to preclude storing it in steel containers. The fact that the flash-point of the additive disclosed by the said patent ranges from below 20 F. to around 40 F. precluded the use of the additive in United States ships.

Additives have been developed according to the present invention having a high enough flash point to be used in hydrocarbon fuels in these ships, and it has been found that the resulting fuel is particularly advantageous for use in diesel engines and oil-fired boilers which constitute the principal power sources for commercial marine shipping.

It has been found that the mere substitution of higher flash-point solvents does not successfully produce satisfactory additives. The causes of this phenomenon lie in the highly unstable nature of ferrous picrate, and in the peculiar solubility pattern of picric acid in organic solvents.

Referring to the instability of ferrous picrate, the effec- ICC tive combustion catalysis in the earlier invention depends upon the decomposition of this salt in the combustion chamber. Molecularly dispersed in the fuel, the ferrous picrate, upon decomposition, gives rise to extremely finely dispersed particles of iron which rapidly resonate between native iron and iron oxide as they enter reducing or oxidizing zones of the combustion. If the soluble ferrous picrate is oxidized during preparation or storage of the additive or its mixture with the fuel to any of the several oxides of iron, these precipitate as a coarse amorphous sludge. Even if these sludge particles were carried into the combustion chamber with the fuel flow, the amount of catalytic surface of these gross particles is negligible by comparison with the molecular dispersion described above.

A catalyst or additive according to the present inven' tion comprises an aromatic metal-free nitro compound and an iron salt of an aromatic nitro acid dissolved in a compatible solvent which does not contain oxidizing materials. The product may be further improved after the mixing by the addition of a suitable anti-oxidant or reducing substance. The additive is preferably a mixture of an aromatic nitro acid and a ferrous salt of an aromatic nitro acid, the ratio of salt to acid by weight in the mixture being within the range of from 1 to 10 down to 1 to 100, and a suitable mixture of solvents selected from the group comprising toluene, xylene, isopropyl alcohol, butanol, mineral oil, fusel oil, and aromatic petroleum fractions. In the preferred form of the invention, ferrous picrate and picric acid are used. The ratio of solvents to the catalytic mixture ranges from 30 to 1 up to 27 to 1. The anti-oxidant or reducing substance for protecting the product may be hydroquinone, nordihydroglutaric acid, N-butyl paraminophenol, N,N-di-secondary butyl-paraphenylenediamine, or any other compound or mixture which meets the requirements of protecting the active ingredients from oxidation for the same or longer period, is stable, is soluble in the solvent mixture, and has no other objectionable qualities as corrosiveness, toxicity, etc.

When from 0.01 to 0.08% by weight of the above mixture is added to a hydrocarbon fuel, the characteristics and quality of that fuel are greatly improved, as are the results attained by the use of such fuel.

A good additive comprises a mixture of 1 part by weight of ferrous picrate and 32 parts by weight of picric acid dissolved in from 930 parts to 980 parts of a nonoxidizing solvent mixture.

The following examples illustrate the extent and advantages of this invention.

EXAMPLE I A series of embodiments of ferrous picrate-picric acid mixtures (1:32 ratio) were made with various solvent mixtures. Table 1 shows the results. In all cases there were added 1.03 grams of the catalytic mixture to 29.6 milliliters of the solvent mixture. The components of the solvent mixtures are described as percentages by volume of the particular mixture. After each component is shown its flash-point in parentheses. Column 4 is the flash-point of the final mixture. Column 5 shows the stability of the ferrous picrate in the mixture (as the percentage of added ferrous iron remaining in solution after 24 hours); while Column 6 reports the solubility of picric acid in the mixture as percentage dissolved.

Table I Col. 1 Col. 2 Col. 3 Col. 4 Col. 5 Col. 6

Aromatic Solvent Aliphatic Solvent Alcohol Flash Percent of Percent of Point, Ferrous Picric F. Pierate Acid Toluene 80% (40 F.) Isopropyl (53 F.) 100 100 Xylene 80% (88 F.) do 53 100 100 Xylene 40% (88 F.) Mineral Oil 40% (200 F.) .-do 50 90 100 Xylene (88 F.) Mineral Oil 45% (200 F. lsopropyl 10% (53 F.) 54 90 Solvent A 90% (114 F do 40 100 Solvent A (114 F.) Butanol 20% F.) 90 40 Solvent B 87.5% (290'F.) Fusel Oil 12.5% (112 F.) 114 100 100 Solvent B 94% Butanol 6% (90 F.) 140 100 100 1 Solvent A is a 2 Solvent B is a EXAMPLE II 1.03 grams of a mixture of ferrous picrate and picric acid were dissolved in 6 ml. of warm denatured alcohol (methylated spirits). This solution was added to 23.6 ml. of benzene. The resultant mixture was poured into a tin-plated 4-ounce rectangular can, the cap screwed on, and the can maintained at 80 F. After three days the can was badly corroded and the product leaked through the seams.

EXAMPLE III 2.06 grams of a mixture of ferrous picrate and picric acid were dissolved in 12 ml. of warm anhydrous isopropyl alcohol and this solution added to 47.2 ml. of toluene. The resultant mixture was divided into two equal portions. The first of these (A) was run into a can as in Example 11. The second portion (B) was dried by shaking it with dry silica gel. After drying, this portion was also sealed into a can. After two weeks storage the first can was corroded and leaking, while the second can showed no evidence of corrosion.

EXAMPLE IV 32 grams of wet picric acid (10% water content) were mixed with 840 ml. of Pacific base oil (Solvent B of Table I). With vigorous stirring, the picric acid was dissolved, and the water dropped out as a heavy separate phase. ml. of fusel oil, containing 8% water, were used to dissolve 1 gram of ferrous picrate. This mixture was stirred into the solution of picric acid in the base oil. Because of the (Water repellency of the base oil and the hydrocarbon polarity of the fusel oil, the water dissolved in the fusel oil was coacerbated out of the resultant mixture. 11.6 ml. of water were recovered after the mixture was decanted off. A minimal treatment with silica n aromatic solvent of Kauri-Butanol value of 73 92% aromatic base oil distilling over the range from 502 F. to 700 F.

gel completed the dehydration of the mixture, and it was found to be non-corrosive.

EXAMPLE V In view of the highly hazardous nature of dry ferrous picrate, a novel process of preparation and safe handling of this salt has been devised. According to an example of this process, 3,300 grams of ferrous sulfate (copperas) are dissolved in 4 liters of hot water (70 0.). 1,240 grams of anhydrous sodium carbonate are dissolve-d in 4 liters of hot water, and the two solutions mixed. The mixture is stirred and the precipitated ferrous carbonate is settled out. The relatively clear aqueous layer is decanted oif and the precipitate is washed with four more 4-1iter portions of hot water. After washing with water, the precipitate is washed with three 3-liter portions of denatured alcohol. The final volume after the last wash is made up to 12 liters with alcohol and the mixture is treated with 10 grams of hydroquinone. The suspension is warmed on a water bath to 70 C. and 5,400 grams of picric acid are added. The whole is stirred and allowed to react for several hours until the evolution of carbon dioxide is completed. It is then cooled. The alcohol is poured oif the crystals of ferrous picrate, and these are taken up in 188 gallons of fusel oil. Meanwhile, 212 kg. of wet picric acid have been dissolved in 1,320 gallons of Pacific base oil. The fusel oil solution of ferrous picrate is pumped into this solution, which is agitated for one hour. Following an overnight settling, the water is drawn off the bottom of the mixing tank, one hundred pounds of coarse silica gel are stirred into the mixture and allowed to settle. The final product is ready for packaging in drums or cans.

EXAMPLE VI A furnace used to heat the boiler of a large hot water heating system was placed under test. The furnace, using bunker fuel oil, was checked for maximum efficiency, and readings taken regarding its operation and condition. Product B of Example III was then introduced into the fuel system at the rate of one gallon of catalyst solution to 1,600 gallons of fuel, and the furnace again tested and examined at intervals. The following comparative data were obtained. No adjustments were made on the furnace during the test period.

Before Catalyst Catalyst Used (cleaned one Burner week before Adjusted test) 1 week 2 weeks Maximum Stack Temperature.

Flue Gas Carbon Dioxide Carbon Monoxide Oxygen Soot removed after 1 week- Soot removed after 2 weeks Soot on heat exchanger inch 10 lbs Under inch Higher stack temperatures normally indicate dirty heat exchanger surfaces. The increase in stack temperature accompanied by cleaner conditions in the heat exchanger and combustion chamber examined; results below; 150,000 miles on engine at this ovenhaul.

areas indicates more heat was obtained from the fuel. Carbon Cmbqn Milesper In addition, use of the catalyst in the fuel permitted fur- 5 gioxide, gx gen MOllOXlde TFJ .S.1tGhal. t-her furnace adjustments after the tests were completed cent gg which gave an additional increase in efiiciency. The operator stated that the burner started more quickly and Catalyst Not used 19 days:

i h e Idle 0.8 18.8 more quietly The burner flame tested g t 1' and Hamhmmem 12 18.8 Showed 11111011 10 Full load, Uphil 2.4 15.8

5. Catalyst Used 7 Days: EXAMPLE v11 Idle $12 fi 3.6 14.6 A furnace in a boiler used mainly to heat water for 0 8 19 2 industrial processes was placed under test and examined. 1.2 19.0 Product B of Example III was then added at the rate of one gallon to 1,500 gallons of fuel, which was bunker fuel, and the furnace tested and examined periodically, Without the catalyst, the exhaust pipe showed a buildup with data and observations as below. No furnace adof carbon deposits. With the catalyst these were reduced justments were made during the test period. 20 to the verge of disappearance within the time of this test.

Before Catalyst 2 days Catalyst Used 8 days 14 days Deposits Heavy soot and gummy de- No soot or gummy matter. Clear of soot, etc. White Clear of soot, etc., nearly posits at front end of fire- White deposits same. deposits clearing. clear of white deposits. box. Heavy white deposits on firebox surfaces and boiler metal. Filrcbox front during Too hot for hand. Hot. Cool enough for hand Cool enough for hand.

urrung. Ignition by diesel igniter 3-4 seconds and noisy 1 second, quiet At once, quiet At once, quiet. Burner Nozzle Cleaied every 2-3 hours of Small amount or carbon-- No cleaning No cleaning.

02.! on. Flue Heavy soot Half soot loose No soot Clean. Smoke Light, grey Light, white Light, white Light, white. Flue gas:

00 5.6-- 5.8- 10.0- 10.0. 0 1.0s 12.4- 6.4-- 6.3. 00 p.p.m 200 20a 10 5. Exposure meter reading at 6.7 6.7-. 7.0- 7 Plus.

firebox. Frequency of blowing soot Twice/week No blowing. No soot.

from tubes. xS)ome soft scale. half metal are.

EXAMPLE VIII Carbon Carbon Miles per Dioxide, Oxygen, Monoxide U.S. Gal. Percent Percent p .p.m. Fuel this period 1. Before Catalyst:

Idle 0. 8 l9. 4 1, 500 Half Throttle 2. 0 17.8 1, 200 Full Load, Uphill 9.2 7. 2 1,000 4. 67 2. Catalyst Used 18 days:

Idle 1. 8 18. 4 250 Half Throttle 2. 0 18.0 250 Full Load, Uphill 6.0 12.6 250 4.13 3. Catalyst Used 27 days: 70

Idle 1. 4 18. 6 200 Half Throttle. 2. 4 17. 8 150 Full Load, Uphill 3. 4 15.8 100 4.

At this point one head removed, pistons removed, injectors 75 The exhaust gave off substantial dark smoke and unpleasant fumes without the catalyst in the fuel. With the catalyst the exhaust smoke became light and the fumes mild.

At the time of engine examination noted above, the injectors were clean, piston domes bright on exhaust port side and a small amount of carbon on intake side, ring grooves clean, valves showed slight crescent-shaped deposits of hard carbon which were clearly the small residue from larger pro-existing coatings.

The improved combustion resulting 'from use of the catalyst was noted just before an engine overhaul and just after an engine overhaul, as evidenced in each case by the reduced carbon monoxide content of the exhaust gases, by the increased mileage per unit of fuel, by the amount and appearance of the exhaust smoke and by the removal of carbon deposits in the exhaust pipes which were laid there while no catalyst was in use. These improvements are evidenced under all work loads and engine speeds.

EXAMPLE IX A gasoline engine, used as the prime mover in a 1957 Ford Fairlane 500 (8 cylinder engine) was given exhaust gas analysis without use of the catalyst in the fuel. The catalyst, Product B of Example III was added to the fuel in the ratio of 1 gallon of catalyst mixture to 1,600 gallons of fuel, and the exhaust gases were again analyzed after about 2,000 miles of operation using fuel containing the catalyst. No adjustments were made to the engine during this period. A further partial analysis was made after 22 Weeks of operation with the catalyst in the fuel, again with no adjustment. 1

The testresults are summarized below.

Carbon Oxygen, Carbon Dioxide, Percent Monoxide, Percent Percent Before Catalyst: 1

Idle 10.9 5.1 3.0 Accelerating 12. 6 12. 8 1. 6 Decelerating 8. 9 15. 2 2. 1 Half Thrttle 13. 4 1. 6 5. 2 With Catalyst 2,000 M Idle 9.8 4. 2 0.15 Accelerating 9. 8 3. 2 0. 2 Decelerating. 7. 0 7. O 0. 1 Half Throttle 11. 0 3.0 0. 25 With Catalyst 22 weeks: Id1e 11. 6 3. 4 0. 7

The considerable reduction of carbon monoxide under all engine speeds While using the oalalyst mixture is very marked, and continues to show in large degree even after a period when the engine could be expected to have drifted off the optimum adjustments found at the start of the tests.

EXAMPLE X introduced into the fuel, in the ratio of one gallon ofcatalyst mixture to 1,500 gallons of fuel. The flame height was maintained at the same height, and with no other change, other light sources excluded and the "light meter read again at intervals of one-quarter hour for one hour.

With a constant flame height above the metal Wickholder edge of 28 millimeters, at a distance of six inches from the lamp edge, the light meter read 11-foot candles Under the same conditions, but using 4.)

without catalyst. catalyst, the meter read 13 /2 foot-candles during the test period. This indicates an increase in flame brightness of 22% under these conditions of operation and measurement.

EXAMPLE XI The same wick lantern used in Example X was operated using domestic furnace fuel, heavier and much less highly refined than kerosene, and much cheaper. Without the catalyst, the flame was low and very smoky. Addition of the catalyst mixture in the ratio of one gallon Olf catalyst mixture to 1,500 gallons of fuel .gave burning conditions which permitted much higher flame height with no increase in smoking, and consequently much improved light production. Flame height increase was of the order of 100% over the untreated fuel.

What We claim as our invention is:

An improved process for the manufacture of a liquid hydrocarbon fuel catalyst comprising the steps of dissolving one part of copperas in water, adding a solution of 0.35 part of sodium carbonate in water, mixing, washing the precipitated solids in water and in alcohol, treating the resultant alcoholic suspenion with hydroquinone (0.1 part) and 1.69 parts of wet picric acid, crystallizing the reaction product, dissolving it in 179 parts of fusel oil, mixing this solution with 1,280 parts of a non-oxidizing hydrocarbon solvent whose flash point exceeds 80 F. and whose aromatic content exceeds 70% and in which 60.5

' parts of 'wet picric acid have been dissolved, drawing oif the water which drops out, and treating the mixture with 13 parts of silica gel. 1

References Cited by the Examiner UNITED STATES PATENTS 2,461,972 2/ 1949 Fischer 44-75 X 2,506,539 5/1950 Boardman 44-74 X 2,700,612 1/ 1955 Chenicek 4474 X 2,797,152 6/1957 Hughes et a1. 44-75 X y FOREIGN PATENTS 484,094 6/ 1952 Canada. 697,730 9/ 1953 Great Britain.

OTHER REFERENCES Silberrad et al.: Trans. Chem. Soc. Pt. 1, p. 475 (1908).

DANIEL E. WYMAN, Primary Examiner.

M. WEINBLATT, Y. M. HARRIS,

Assistant Examiners.