Method of reducing the impact of deposits in a post combustion system of a diesel engine
A method of reducing the impact of deposits in a post combustion system of a diesel engine. The method comprises combusting in the engine a diesel fuel composition comprising as additives: (a) one or more quaternary ammonium salts; and (b) one or more compounds which are a product of a Mannich reaction between an (b1) aldehyde, (b2) an amine and (b3) an optionally substituted phenol. The method may be particularly effective when combusting a diesel fuel composition comprising renewable diesel.
1 . A method of reducing the impact of deposits in a post combustion system of a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising as additives:
(a) one or more quaternary ammonium salts; and
(b) one or more compounds which are a product of a Mannich reaction between an (b1) aldehyde, (b2) an amine and (b3) an optionally substituted phenol, wherein the diesel fuel composition comprises at least 25 vol % of renewable diesel;
wherein the post combustion system of the diesel engine comprises a diesel particulate filter; and
wherein the method comprises reducing the formation of deposits in the diesel particulate filter.
2 . The method of claim 1 , wherein the diesel fuel composition is a biodiesel 100% derived from renewable sources.
3 . The method of claim 2 , wherein the diesel fuel composition is neat hydrotreated triglyceride oil.
4 . The method of claim 1 , wherein additive (a) is one or more quaternised reaction product of (a1) a hydrocarbyl-substituted acylating agent and (a2) a compound comprising at least one tertiary amine group and a primary amine, secondary amine or alcohol group.
5 . The method of claim 4 , wherein (a1) is a polyisobutylene-substituted succinic anhydride having a PIB molecular weight (Mn) of 700 to 1300.
6 . The method of claim 4 , wherein (a2) is N,N-dimethylaminopropylamine, N,N-diethylaminopropylamine or N,N-dimethylamino ethylamine.
7 . The method of claim 1 , wherein additive (a) comprises a quaternary ammonium salt formed by reacting methyl salicylate, dimethyl oxalate or propylene oxide (optionally in combination with an acid) with the reaction product of (a1) a polyisobutylene-substituted succinic anhydride having a PIB molecular weight (Mn) of 700 to 1300 and (a2) dimethylaminopropylamine.
8 . The method of claim 1 , wherein additive (b) is one or more reaction products of (b1) formaldehyde, (b2) polyethylene polyamine and (b3) a para-substituted monoalkyl phenol.
9 . The method of claim 8 , wherein additive (b) is one or more reaction products of (b1) formaldehyde, (b2) ethylene diamine and (b3) dodecyl phenol.
10 . The method of claim 1 , wherein additive (b) is formed by reacting (b1), (b2) and (b3), in a molar ratio of 1.1-5 parts (b1) to 1 part (b2) to 1.1-2 parts (b3).
11 . The method of claim 1 , wherein the diesel fuel composition further comprises, as an additive, (c) at least one reaction product of a carboxylic acid-derived acylating agent and an amine.
12 . The method of claim 11 , wherein additive (c) comprises the reaction product of (c1) a polyisobutene-substituted succinic acid or succinic anhydride and (c2) a polyethylene polyamine selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethylene-heptamine and mixtures and isomers thereof; wherein the polyisobutene substituent has a number average molecular weight of between 500 and 2000.
13 . The method of claim 1 , wherein the diesel fuel composition comprises from 1 to 1000 ppm of (a) and from 1 to 1000 ppm of (b).
14 . The method of claim 11 , wherein the diesel fuel composition comprises from 1 to 1000 ppm of (c).
15 . The method of claim 1 , which reduces the accumulation of soot in a diesel particulate filter.
16 . The method of claim 1 , which reduces the formation of deposits on a turbocharger of the post combustion system.
17 . The method of claim 1 , which reduces the formation of deposits on a diesel oxidation catalyst of the post combustion system.
18 . The method of claim 1 , which reduces the formation of deposits on a selective catalytic reduction unit of the post combustion system.
19 . The method of claim 1 , which reduces the formation of deposits on an ammonia oxidation catalyst of the post combustion system.
20 . The method of claim 1 , which reduces the formation of deposits on sensors within the post combustion system.
21 . The method of claim 1 , which reduces the formation of deposits in one more components of the post combustion system by at least 5%.
22 . The method of claim 1 , which increases the interval between regenerations of a diesel particulate filter by at least 30 minutes.
23 . The method of claim 1 , wherein the diesel engine is an off-road engine, a rail, or stationary engine.
24 . The method of claim 1 , which provides one or more benefits selected from: an increase in power generation; an increase in torque; an increase in fuel economy; a reduction in emissions; a reduction in combustion chamber deposits; an acceleration improvement; driveability improvements; a reduction in cold start issues; lower soot formation; mitigation of lubricant degradation and/or performance loss; a reduction in diesel exhaust fluid and consumption; reduction in wear on all post combustion components; increased longevity of exhaust components; an increase in the maintenance period for the engine and/or post combustion components; the protection of intake components downstream of the EGR, throttles and the intake manifold; a reduction in fuel consumption; and an increase in vehicle range.