Distillate fuel blends from fischer tropsch products with improved seal swell properties

• US 20050145540A1
• Filed: 02/15/2005
• Published: 07/07/2005
• Est. Priority Date: 10/19/2001
• Status: Active Grant

• Current Assignee: Sasol Technology Limited (Sasol Limited)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: O'Rear, Dennis J.
• Granted Patent: US 7,608,181 B2
• Time in Patent Office: Days
• US Class Current: 208/15
• CPC Class Codes: C10G 2/32 with the use of catalysts
• CPC Class Codes: C10G 2400/04 Diesel oil
• CPC Class Codes: C10L 1/08 for compression ignition
• CPC Class Codes: Y10S 208/95 Processing of "fischer-tropsch" crude

Abstract

The invention provides distillate fuel blend components with improved seal swell and lubricity properties obtained from Fischer Tropsch products. The blends contain a highly paraffinic distillate fuel component and distillate-boiling alkylcycloparaffins and/or distillate-boiling alkylaromatics. The invention further provides processes for obtaining such blends using the products of Fischer Tropsch processes. Finally, the invention provides methods for improving seal swell and lubricity properties for distillate fuels.

Claims

1. A distillate fuel blend with improved seal swell properties comprising:

a) at least one highly paraffinic distillate fuel component having a branching index of less than about 5, and a volume increase of less than about 0.2% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal; and

b) at least one component selected from the group consisting of alkylaromatics, alkylcycloparaffins and combinations thereof,

wherein the blend exhibits a volume increase of more than about 0.2% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal.

2. The distillate fuel blend according to claim 1 wherein the distillate fuel blend exhibits a volume increase of more than about 0.5% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal.

3. The distillate fuel blend according to claim 1 wherein the distillate fuel blend exhibits a volume increase of more than about 1.0% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal.

4. A distillate fuel blend component according to claim 1 wherein the alkylaromatics comprise alkylbenzenes.

5. A distillate fuel blend component according to claim 1 wherein the alkylcycloparaffins are selected from the group consisting of alkylcyclohexanes, alkylcyclopentanes, and mixtures thereof.

6. A distillate fuel blend component according to claim 1 further comprising an antioxidant selected from the group consisting of an alkylated phenol, a sulfur-containing component and combinations thereof, wherein when the antioxidant is a sulfur-containing component, the distillate fuel blend contains more than about 1 ppm sulfur.

7. A distillate fuel blend according to claim 1 which conforms to the specifications of either a diesel fuel or a jet fuel.

8. A distillate fuel blend according to claim 1 wherein the component selected from the group consisting of alkylaromatics, alkylcycloparaffins, and mixtures thereof is present in an amount of from about 1 wt % to about 25 wt %.

9. A distillate fuel blend according to claim 1 wherein the highly paraffinic distillate fuel component comprises more than about 70 wt. % paraffins.

10. A distillate fuel blend according to claim 1 wherein the blend has an improved lubricity according to ASTM D6078 of 225 grams or more.

11-35. -35. (canceled)

36. A distillate fuel blend with improved seal swell properties comprising:

a) at least one highly paraffinic distillate fuel component having a branching index of less than 5, and a volume increase of less than about 0.5% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal; and

b) at least one component selected from the group consisting of alkylaromatics, alkylcycloparaffins and combinations thereof,

wherein the blend exhibits a volume increase of more than about 0.5% when measured according to ASTM D 471 at 23±

2°

C. and for 70 hours when using a nitrile O-ring seal.

37. The distillate fuel blend according to claim 36 wherein the highly paraffinic distillate fuel has a branching index of less than about 4.

38. The distillate fuel blend according to claim 36 wherein the highly paraffinic distillate fuel has a branching index of less than about 3.

39. The distillate fuel blend according to claim 36 wherein the distillate fuel blend has an improved lubricity according to ASTM D6078 of 225 grams or more.