Patent ID: 8641791
Filing Date: 2014-02-04
Classification: C10L

Abstract:
1. A method of supplying iron to a particulate trap of a diesel engine exhaust in a form suitable for promoting trap regeneration, the method comprising the following steps: a. adding a particulate trap regenerating additive comprising a colloid consisting of iron oxide particles dispersed in a carrier fluid, dispersing means within the colloid being one or more carboxylic acid compounds to a diesel fuel, in an amount which provides an iron concentration within the fuel sufficient to promote trap regeneration of a particulate trap, wherein the iron oxide in the particulate trap regenerating additive is the only oxide added to the diesel fuel; b. combusting the diesel fuel composition resulting from step a. in a diesel engine equipped with a particulate trap in its exhaust system; and c. within the particulate trap, thereafter collecting iron-containing compounds resulting from combustion, in association with at least some of carbonaceous particulate matter emitted by the engine; wherein said carboxylic acid compounds include at least one hydrocarbyl-substituted dicarboxylic acid containing between 8 and 200 carbon atoms, and wherein any additional carboxylic acid compounds within the colloid are either hydrocarbyl-substituted dicarboxylic acids containing between 8 and 200 carbon atoms, or aliphatic monocarboxylic acids containing between 8 and 20 carbon atoms, or mixtures thereof; and wherein the weight ratio of carboxylic acid(s) to iron in the colloid (measured as the total weight of acid compound(s) to weight of elemental iron contained within the iron oxide particles) is in the range of from about 1.5:1 to about 1:2.