Method of Limiting Chemical Degradation due to Nitrogen Dioxide Contamination

A method of limiting the chemical degradation of a hydrocarbonaceous liquid in service at bulk liquid temperatures of between 60 and 180° C., the degradation being initiated by nitration of the liquid resulting from contamination with nitrogen dioxide in service, comprising:

• preparing, or obtaining a freshly-prepared, hydrocarbonaceous liquid suitable for service at bulk liquid temperatures of between 60 and 180° C. and being free of aged components and nitrogen dioxide contamination;
• adding to said hydrocarbonaceous liquid, prior to service at bulk liquid temperatures of between 60 and 180° C., an ionic liquid and a detergent additive, wherein:
• the ionic liquid comprises:
• (i) one or more organic cations each comprising a central atom or ring system bearing the cationic charge and multiple pendant hydrocarbyl substituents, and
• (ii) one or more halogen-, sulfur- and boron-free organic anions each comprising one or more hydrocarbyl groups and one or more heteroatom-containing functional groups bearing a localised or delocalised anionic charge;
• and wherein the detergent additive comprises, as the active ingredient, one or more hydrocarbyl-substituted neutral or overbased metal salts;
• wherein the ionic liquid and detergent active ingredient are added in amounts that are co-operatively effective to thereafter inhibit the nitration of the hydrocarbonaceous liquid in service at bulk liquid temperatures of between 60 and 180° C., in the presence of nitrogen dioxide contamination;
• and
• putting said hydrocarbonaceous liquid into service, wherein the ionic liquid and detergent additive thereby limit the resulting chemical degradation of the liquid.

A method for the co-operative use of an ionic liquid and a detergent additive to limit the chemical degradation of a hydrocarbonaceous liquid in service at bulk liquid temperatures of between 60 and 180° C., the degradation being initiated by nitration of the hydrocarbonaceous liquid resulting from contamination with nitrogen dioxide during service, wherein the ionic liquid comprises:

• (i) one or more organic cations each comprising a central atom or ring system bearing the cationic charge and multiple pendant hydrocarbyl substituents, and
• (ii) one or more halogen-, sulfur- and boron-free organic anions each comprising one or more hydrocarbyl groups and one or more heteroatom-containing functional groups bearing a localised or delocalised anionic charge;
• and wherein the detergent additive comprises, as the active ingredient, one or more hydrocarbyl-substituted neutral or overbased metal salts;
• wherein the ionic liquid and detergent additive are added to the hydrocarbonaceous liquid free of aged components and nitrogen dioxide prior to service, and wherein the ionic liquid and detergent active ingredient thereafter inhibit the nitration of the hydrocarbonaceous liquid in service at bulk liquid temperatures of between 60 and 180° C. in the presence of nitrogen dioxide contamination.

A method to increase the efficacy of an ionic liquid additive comprising adding a detergent additive to a hydrocarbonaceous liquid containing an ionic liquid additive prior to service at bulk liquid temperatures of between 60 and 180° C. and exposure to nitrogen dioxide contamination, wherein the detergent additive comprises, as the active ingredient, one or more hydrocarbyl-substituted neutral or overbased metal salts, and the ionic liquid comprises:

• ionic liquid
• (i) one or more organic cations each comprising a central atom or ring system bearing the cationic charge and multiple pendant hydrocarbyl substituents, and
• (ii) one or more halogen-, sulfur- and boron-free organic anions each comprising one or more hydrocarbyl groups and one or more heteroatom-containing functional groups bearing a localised or delocalised anionic charge;
• wherein the efficacy of the ionic liquid additive for inhibiting the nitration of a hydrocarbonaceous liquid in service at bulk liquid temperatures of between 60 and 180° C. and resulting from contamination with nitrogen dioxide in service is increased.