Title:
Fuel oil
United States Patent 2230642


Abstract:
The present invention relates to fuel oils having improved combustion characteristics. The invention especially relates to heavy or residual fuel oils, the combustion properties of which are improved by the incorporation of addition agents selected from the class of oil-soluble metallic soaps....



Inventors:
Fischer, Herbert G. M.
Hulse, Stewart H.
Application Number:
US22473138A
Publication Date:
02/04/1941
Filing Date:
08/13/1938
Assignee:
STANDARD OIL DEV CO
Primary Class:
International Classes:
C10L1/14; C10L1/18; C10L1/20
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Description:

The present invention relates to fuel oils having improved combustion characteristics. The invention especially relates to heavy or residual fuel oils, the combustion properties of which are improved by the incorporation of addition agents selected from the class of oil-soluble metallic soaps. The invention especially relates to improved fuels having A. P. I. gravities in the range from 1° to 15° and having furol viscosities at 122* F. in the range from 25 to 300.

It is well known in the art to prepare various commercial fuel oils, the inspections of which vary widely. These fuels are secured from various crudes and are processed In a manner to secure a desired fuel for a particular use. For example, it is well known in the art to prepare heavy fuel oils, as for example, bunker fuels or residual fuels having gravities in the range from 1° to 15* A. P. I. and furol viscosities of from 25 to 300 seconds at 1220 F. These heavy or residual fuels are usually burned with commercial burners in boilers or other fired apparatus, as for example, in stationary and marine boilers.

These fuels have not been entirely satisfactory due to the fact that considerable care must be exercised in order to insure complete combustion of the fuel. When incomplete combustion occurs, small particles of solid unburned carbonaceous material may pass through the flame and be deposited on the surfaces of the boilers or apparatus, or may be carried by the gaseous products of combustion to the atmosphere.

Some fuels, particularly the heavy fuels, as for example, bunker fuels or residual fuels, are worse offenders in this respect than others. For example, it has been noted that when fuels of this character are employed in Scotch marine boilers, the percentage of unburned carbonaceous material is at times unduly high. This is very objectionable, since heating value is lost due to the incomplete combustion of the fuel, thus increasing the cost of the particular operation. It is also very objectionable since these unburned carbonaceous materials accumulate on heating surfaces and render the same inefficient. Furthermore, when this situation exists, it is likely that the unburied carbonaceous materials will be carried out through the stack and will deposit in the surrounding area with deleterious results.

The present invention is directed to improved fuel oil compositions which may be readily burned without the formation of undue unburned carbonaceous materials. The improved fuels of the present invention are secured by adding to a aK fuel a small quantity of an addition agent selected from the class of oil-soluble metallic soaps.

The preferred soaps are the naphthenates, as for example, sodium, cadmium, manganese, calcium and zinc naphthenate. Cobalt naphthenate and iron naphthenate have been found to be particularly effective. Although the naphthenates are preferred, other oil-soluble soaps, as for example, the oleates and stearates of these metals, are also effective. The chlorinated fatty soaps, as for example, calcium chlorinated stear- I0 ate are also suitable. The preferred soaps are those which will not raise the viscosity of the fuel oil and which will not degrade any of the other properties.

These addition agents may be added at any time prior to combustion and in any concentration desirable, depending upon the particular type of fuel oil being used and also depending upon the conditions under which the fuel oil is to be burned. In general, it is preferred to add from 0.1% to 3% by weight of the oil-soluble soap.

For example, when utilizing lead or iron naphthenates in bunker or residual fuels, it is preferred to add from about 0.2% to 2%. In general, the weight of the metal added should range from about .02% to .1%, preferably from about .05% to .1%.

Although the addition agents of the present invention may be added to any fuel oil, they are especially adapted for use in conjunction with residual or bunker fuels. These fuels have gravities in the range from 10 to 150 A. P. I. and furol viscosities at 122" F. in the range from 25 seconds to 300 seconds.

In order to more fully illustrate the present invention, the following example is given.

Example 1 An unblended fuel oil having a gravity of 110 A. P. I. and a furol viscosity of about 100 seconds at 122* F. was fired in a commercial boiler, using a commercial pressure atomizing burner in a manner to maintain the following conditions: Viscosity at atomizer--.... 150 seconds Saybolt Universal. Pressure at atomizer ..--.- 125 lbs. per sq. in.

Excess air--.---------- 25% Rate of heat liberation--. 45,000 B. t. u. per hr. cu. ft. of combustion chamber. A measured quantity of fuel was burned and the deposition of unburned carbonaceous material formed on the heating surfaces was collected and weighed. Samples of the stack gases were withdrawn through a sampling line, the velocity 65 in which was maintained equal to that in the stack so that the material being carried up the stack could be collected in a filter and weighed.

Blended fuels containing various addition agents were burned under identical conditions with the following results: Unblended fuel......

+Zino naphthenate..

+Lead naphthenate_ +-Copper naphthenate.....-----. . 20 +Manganese naphthenate........

+Cobalt naphthenate..h.. .te--.. +Iron naphthenate_ Weight percent naph. thenate added Weight percent metal added as naphthenate Unburned carbonace.

dus material (In percent of that formed when burning unblended fuel) Stack Percent 62.6 68.0 46.8 45.7 38.4 32.6 29.5 Total (inc.

tubes) Percent 100.0 94.3 83.8 79.5 68.0 67.4 62.6 amount of unburned combustion material was decreased by 10% to 40%.

The present invention is not to be limited by any theory or mode of operation, but only by the following claims in which it is desired to 8 claim all novelty insofar as the prior art permits.

We claim: 1. A liquid fuel oil composition adapted to be burned by means of oil burners at substantially atmospheric pressure having improved combustion characteristics, comprising a heavy fuel oil substantially free of suspended solid particles, having a gravity in the range from about 10 to 15* A. P. I. and containing from about 0.1% to 3% of an addition agent selected from the class of 1I oil-soluble naphthenates of the group consisting of iron, cobalt, and manganese naphthenates.

2. A liquid fuel oil composition adapted to be burned by means of oil burners at substantially atmospheric pressure having improved combustion properties, comprising a heavy fuel oil substantially free of suspended solid particles, having a gravity in the range from about 10 to 15° A. P. I. and containing from about 0.5% to 3% of iron naphthenate. 21 HERBERT G. M. FISCHER.

STEWART H. HULSE.

2. From the above data it may be readily seen that the fuel compositions of the present invention were considerably improved in that the