Method and composition for asphaltene dispersion
Provided is a method of dispersing asphaltenes to inhibit asphaltene precipitation and/or deposition in a hydrocarbon. The method includes adding to the hydrocarbon an asphaltene dispersing agent which is an ester of a mono-carboxylic fatty acid and a sugar. The sugar has at least 4 hydroxyl groups. In addition, more than one of the hydroxyl groups on the sugar are reacted with the mono-carboxylic fatty acid to form the ester.
1. A method of dispersing asphaltenes to inhibit asphaltene precipitation and/or deposition in a hydrocarbon, the method comprising adding to the hydrocarbon an asphaltene dispersing agent which is an ester of a mono-carboxylic fatty acid and a sugar;
wherein the sugar comprises at least 4 hydroxyl groups; and
wherein more than one of the hydroxyl groups on the sugar are reacted with the mono-carboxylic fatty acid to form the ester.
2. A method according to claim 1 wherein at least one of the hydroxyl groups on the sugar remains unreacted in the ester.
3. A method according to claim 1 wherein on average, at most 75% of the hydroxyl groups on the sugar are reacted with the fatty acid to form the ester.
4. A method according to claim 1 wherein the sugar is a disaccharide.
5. A method according to claim 1 wherein the sugar is sucrose.
6. A method according to claim 1 wherein the fatty acid comprises at least 10 wt % polyunsaturated species.
7. A method according to claim 1 wherein the fatty acid is derived from soybean oil.
8. The method according to claim 1 wherein the ester has an asphaltene dispersing value of at least 60% at a concentration of 50 ppm in the hydrocarbon.