Stabilised diesel fuel additive compositions
A diesel fuel composition containing metallic additives that are stabilized against phase separation. The diesel fuel contains a colloidally dispersed or solubilized metal catalyst compound, which can be used for diesel particulate trap regeneration and, as a stabilizer, 5-1,000 ppm (weight) of an oil-soluble or oil-dispersible organic compound having a lipophilic hydrocarbyl chain having attached directly thereto at least two contiguous polar head functional groups, i.e., the functional groups are separated by no more than three carbon atoms. The diesel fuel composition is particularly suitable for use with diesel engines fitted with a particulate trap for emissions control.
1. A diesel fuel composition comprising a diesel fuel, a colloidally dispersed or solubilised metal catalyst compound for diesel particulate trap regeneration and 10 to 1,000 ppm of an oil soluble or oil dispersible organic compound having a lipophilic hydrocarbyl chain having attached directly thereto at least two contiguous polar head functional groups, wherein the metal catalyst compound consists essentially of (a) one or more inorganic or organic compounds or complexes of sodium, manganese and platinum or (b) a mixture of inorganic or organic compounds or complexes of iron and one or more inorganic or organic compounds or complexes of sodium, manganese and platinum, and wherein at least one of the contiguous polar head groups of the organic compound is a carboxylic acid or carboxylate group, and the remainder are selected from carboxylic acid, carboxylate, ester or amide groups.
2. The composition of claim 1 wherein the metal catalyst compound comprises at least one iron oxide or an organic complex of iron.
3. The composition of claim 1 wherein the hydrocarbyl chain is a polyisobutenyl of Mn 200-4,000.
4. The composition of claim 1 wherein the remainder of the contiguous polar head groups of the organic compound are selected from carboxylic acid, carboxylate or ester groups.
5. The composition of claim 1 wherein at least one of the contiguous polar head groups is an ester of a primary or secondary alcohol having 1 to 22 carbon atoms, an ester of a polyoxyalkylene compound or a polyhydric alcohol having 2 to 5 hydroxyl groups.
6. The composition of claim further comprising a lubricity additive.
7. The composition of claim 1 further comprising a cold flow additive.
8. The composition of claim 1 further comprising a diesel detergent additive.
9. The composition of claim 1 wherein the metal catalyst compound comprises an iron oxide.
10. The composition of claim 1 wherein the diesel fuel contains 2000 ppm or less of sulphur.