US3835022A - Arctic diesel fuel - Google Patents

Abstract

KEROSENE AND NAPHTHENIC PETROLEUM OIL FRACTIONS ARE BLENDED TO PROVIDE AN ARCTIC DIESEL FUEL HAVING A CLOUD POINT OF AT LEAST AS LOW AS -45*F., A POUR POINT OF AT LEAST AS LOW AS-50*F., A CETANE INDEX OF AT LEAST 40 AND A DISTILLATION END POINT OF AT LEAST 625*F.

Description

United States Patent 3,835,022 ARCTIC DIESEL FUEL James A. Frayer, Pittsburgh, and Harry C. Staulfer,

Cheswick, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa. No Drawing. Filed Jan. 16, 1973, Ser. No. 324,147 Int. Cl. Cl 1/08 US. Cl. 208-- 3 Claims ABSTRACT OF THE DISCLOSURE Kerosene and naphthenic petroleum oil fractions are blended to provide an arctic diesel fuel having a cloud point of at least as low as ---45 F., a pour point of at least as low as 50 F., a cetane index of at least 40 and a distillation end point of at least 625 F.

BACKGROUND OF THE INVENTION Standard refinery processes for the conversion of paraffinic or paraflinic-asphaltic crude oils into more valuable hydrocarbon fractions normally comprise fractionating or distilling the crude to recover separate streams of light gases, gasoline, kerosene, diesel oil, gas oil, and residual topped crude. The diesel oil fractions obtained from such processes normally have pour points above 10 F. and

distillation end points in the range of 600 to 650 F. Although acceptable as fuels for diesel engines in many geographical areas, it is evident that such fuels would not be acceptable in arctic regions or other geographical locations where diesel engines are operated in temperatures which are below the pour point of the diesel fuel.

To lower the pour point of these diesel oils, it is customary to blend kerosene with the diesel oil fraction. Parafiinic kerosene fractions will have substantially lower pour points than the higher distillation range diesel oil fraction with the precise pour point dependent upon the distillation range of the -kerosene. For example, a kerosene fraction having an end point of 500 F. can be expected to have a pour point of about --50 F. In the preparation of an arctic diesel fuel having a pour point of at least as low as 50 F., it is evident that a blend of the kerosene and a diesel oil fraction described above to obtain the desired pour point would necessarily require that the blended product contain nearly 100 percent kerosene.

In addition to low cloud and pour points, arctic diesel fuels desirably are such that the distillation end point (as determined by ASTM D86) should be at least 625 F., and preferably in the range of 625 to 650 F. If a diesel fuel composition was prepared by blending a kerosene fraction with a diesel oil fraction as described in the above paragraph, the distillation end point of the blend would be substantially below 625 F.

Accordingly, an object of the invention is to provide an improved diesel fuel composition having a pour point substantially below the pour point of conventional paraffinic diesel oil fractions.

Another object of the invention is to provide a diesel fuel having a cloud point at least as low as 45 F., a pour point of at least as low as 50 F. and a distillation end point of at least 625 F.

Other objects, advantages and features of the invention will be readily apparent to those skilled in the art from the following description and appended claims.

3,835,022 Patented Sept. 10, 1974 INVENTION A diesel fuel composition having a cloud point at least as low as 45" F., a pour point of at least as low as 50 F. and a distillation end point of at least 625 F. is obtained by preparing a blend comprising from 5 to 15 volume percent of a naphthenic petroleum oil and a kerosene.

DESCRIPTION OF THE INVENTION In the preparation of diesel fuels for consumption in diesel engines there are specifications, in addition to cloud, pour, and distillation end point characteristic discussed above, which are employed to define a suitable arctic diesel fuel. For purposes of this invention, the term arctic diesel fuel as employed herein refers to a diesel fuel which has the following specifications:

Pour point (ASTM 97), F., Maximum 50 Cloud point (ASTM D2500), F., Maximum 45 Cetane index (D613), Minimum 40 Distillation end point, F., Minimum 625 In preparing the novel diesel fuel compositions of this invention, a petroleum naphthenic oil fraction, as hereafter described, is blended with a substantially paraffinic kerosene fraction. The kerosene which can be obtained from crude oil fraction by conventional distillation process will have a distillation range as determined by ASTM D86 from about 310 F. to about 535 F. and a flash point (as determined by ASTM D93) of at least 120 F. The cloud and pour point of the described paraffinic kerosene fraction will range from -40 F. to 50 F. and -45 F. to 60 F., respectively.

The naphthenic petroleum oil employed in preparing the novel blended compositions of this invention can be obtained from crude oil by conventional distillation process known in the art. The naphthenic compound should be comprised of at least 95 percent naphthenes in the saturate fraction and have a distillation range from about 525 to about 800 F. The cloud and pour points of the naphthenic component will generally be lower than F.

A suitable method for obtaining the highly naphthenic blend component of this invention can comprise fractionating a naphthenic crude oil to obtain a fraction having the above-described distillation range which shall have a paraflinic content of less than 5 volume percent. The naphthenic component can then be passed over hydrogenation catalyst in a conventional process where it is treated to improve its thermal stability and effect removal of sulfur compounds, nitrogen and other impurities if desired.

The kerosene and naphthenic petroleum oil components are blended together so as to form a diesel fuel composition containing from 5 to 15 percent by volume of the naphthenic component. The product blend will normally have a cloud point .55 F. or below and a pour point of 60 F. or below. The distillation end point of the distillate will normally range from 625 to 650 F. with the cetane index being at least 45.0.

The following example is presented to illustrate the objects and advantages of the invention. It is not intended, however, to limit the invention to the specific embodiments presented therein.

EXAMPLE An arctic diesel fuel composition was prepared 7 blending kerosene and 10 percent by volume of a petro- The petroleum naphthenic oil employed in blend contained 100 percent naphthenes in the saturate fraction and had the following properties:

Gravity, API 25.6 Cloud Point, F --65 Pour Point, F- 65 Cetane Index 47.2 Distillation, F.:

Overhead Point End Point 768 10% 5 64 601 639 70% 658 90% 691 The diesel fuel product blend had the following properties:

Gravity, API 41.4 Cloud Point, F. Pour Point, F. Cetane Index 46.0

Distillation, F.: V

Overhead Point .ILL; ll IILIJIIIIII HT End Point 633 Although the invention has been described with reference to specific embodiments, references, and details, various modifications and changes will be apparent to one skilled in the art-andtare contemplated to be embraced in the invention.

We claim: 7

1. Anarctic diesel fuel composition comprising a blend of a substantially paraflinic kerosene with from.5 to 15 volume percent of a naphthenic petroleum oil comprised of at least naphthenes in the saturate fraction and having a distillation range from about 525 to about 2. The composition of Claim .1 wherein thexconcentration-of the naphthen'ic petroleum oil is about 10 percent by volume.

3. The composition of'Claiml wherein the distillation range of the keroseneisjn therangeirom about 330 F.

to about 500 F. Y

References Cited UNITED STATESFPATENIQ 3,522,169 7/1970 Ireland 3,620,961 11/1971 Ireland OTHER REFEREfiCEs Nelson: Petroleum Refinery Engineerin ff I I 1958, pp. 56 to 58, .156 .and .158 to 161,,pub ."Mc.G r,av v Hill Inc., N.Y., .N.Y. e

HERBERT LEVINE, Primaiy mate,