Use and method for reducing deposits in a diesel engine

Abstract

The use of a reaction product of (i) an alcohol and (ii) a dicarboxylic acid compound of formula (I): or an anhydride thereof; and/or of a polymer prepared from components (i) and (ii); as an additive in a diesel fuel composition to reduce the impact of deposits in an EGR system and/or the post combustion system of a diesel engine when combusting said diesel fuel composition.

1 . The use of a reaction product of (i) an alcohol and (ii) a dicarboxylic acid compound of formula (I): 
       
         
           
           
               
               
           
         
       
       or an anhydride thereof; and/or of a polymer prepared from components (i) and (ii); as an additive in a diesel fuel composition to reduce the impact of deposits in an EGR system and/or the post combustion system of a diesel engine when combusting said diesel fuel composition. 
     
     
         2 . A method of reducing the impact of deposits in an EGR system and/or the post combustion system of a diesel engine, the method comprising combusting in the engine a diesel fuel composition comprising as an additive a reaction product of (i) an alcohol and (ii) a dicarboxylic acid compound of formula (I): 
       
         
           
           
               
               
           
         
       
       or an anhydride thereof; and/or a polymer prepared from components (i) and (ii). 
     
     
         3 . The method of  claim 2 , which reduces the formation of deposits in the exhaust gas recirculation system of a diesel engine. 
     
     
         4 . The method of  claim 2 , which reduces the formation of deposits in the post combustion system of a diesel engine. 
     
     
         5 . The method of  claim 2 , wherein the dicarboxylic acid or anhydride thereof is selected from itaconic acid, itaconic anhydride, 2-methylene glutaric acid, 2-methylene glutaric anhydride, 2-methylene adipic acid, 2-methylene adipic anhydride and isomers and/or mixtures thereof. 
     
     
         6 . The method of  claim 2 , wherein the dicarboxylic acid is itaconic acid. 
     
     
         7 . The method of  claim 2 , wherein the alcohol is selected from:
 alkanols of formula CH 3 (CH 2 ) x OH or an isomer thereof wherein x is from 4 to 23;   alkenyl alcohols in which n is 0;   glycol ethers in which n is not 0.   
     
     
         8 . The method of  claim 2 , wherein the alcohol is selected from an
 an alcohol of formula R 1 OH wherein R 1  is a alkyl group having 8 to 30 carbon atoms;   an alcohol of formula R 1 OH wherein R 1  is an alkenyl group having 8 to 30 carbon atoms; and   an alcohol of formula H—(OR) n —OR 1  wherein n is from 1 to 24, R is ethylene, propylene or isopropylene, and R 1  is an unsubstituted alkyl group having 8 to 30, carbon atoms.   
     
     
         9 . The method of  claim 2 , wherein the alcohol is selected from hexanol, octanol, nonanol, decanol, dodecanol, tetradecanol, cetyl alcohol, stearyl alcohol, 2-ethyl-1-butanol, 2-ethyl-1-hexanol, 2-ethyl-1-heptanol, 2-propylheptanol, 2-ethyl-1-decanol, 2-hexyl-1-decanol, 2-octyl-1-decanol, 2-hexyl-1-dodecanol, 2-octyl-1-dodecanol, 2-decyl-1-tetradecanol, isotridecanol, cyclohexanol, cyclooctanol, benzyl alcohol, citronellol, oleyl alcohol, 9-decen-1-ol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, 5-hexen-1-ol, 6-methyl-5-hepten-2-ol, 1-octen-3-ol, trans-2-octen-1-ol, 10-undecen-1-ol and compounds of formula CH 3 (CH 2 ) x O(CH 2 CH(CH 3 )O) y H or an isomer thereof wherein x is from 10 to 15, and y is from 10 to 20. 
     
     
         10 . The method of  claim 2 , wherein the polycarboxylic acid compound and the alcohol are reacted in a molar ratio of from 2:1 to 1:2. 
     
     
         11 . The method of  claim 2 , wherein the additive is the direct reaction product of (i) an alcohol and (ii) a compound of formula (I) or an anhydride thereof. 
     
     
         12 . The method of  claim 2 , wherein the additive is a polymer prepared from components (i) and (ii). 
     
     
         13 . The method according to  claim 12 , wherein the additive is a polymer of formula (II): 
       
         
           
           
               
               
           
         
       
       wherein n is at least 2, x may be 0 or a positive integer, y may be 0 or a positive integer and each R is independently hydrogen or an optionally substituted hydrocarbyl group provided that at least 10% of all R groups are not hydrogen. 
     
     
         14 . The method according to  claim 13 , wherein the polymeric additive is prepared by polymerising the reaction product of a dicarboxylic acid of formula (I) and an alcohol. 
     
     
         15 . The method according to  claim 13 , wherein n is from 10 to 200. 
     
     
         16 . The method of  claim 2 , wherein the polymeric additive of formula (II) is the polymerised reaction product of itaconic acid or an anhydride thereof and 2-ethylhexanol wherein the polymer has a weight average molecular weight of from 2000 to 50000. 
     
     
         17 . The method of  claim 2 , wherein the additive is present in the fuel in an amount of from 10 to 200 ppm. 
     
     
         18 . The method of  claim 2 , wherein the exhaust gas recirculation system is a high pressure exhaust gas recirculation system, wherein the high pressure EGR system is either a stand-alone high pressure EGR system or is part of a hybrid or a dedicated EGR system. 
     
     
         19 . The method of  claim 2 , which reduces deposits in the post combustion system of a diesel engine having a pressure in excess of 1350 bar. 
     
     
         20 . The method of  claim 2 , which reduces the formation of deposits in a cooler of the EGR system, preferably by at least 10%. 
     
     
         21 . The method of  claim 2 , which reduces the formation of deposits on the turbocharger of the post combustion system. 
     
     
         22 . This method of  claim 2 , which reduces the formation of deposits on the diesel oxidation catalyst of the post combustion system. 
     
     
         23 . The method of  claim 2 , which reduces the formation of deposits on the diesel particulate filter of the post combustion system. 
     
     
         24 . The method of  claim 2 , which reduces the accumulation of soot in the diesel particulate filter. 
     
     
         25 . The method of  claim 2 , which reduces the formation of deposits on the selective catalytic reduction unit of the post combustion system. 
     
     
         26 . The method of  claim 2 , which reduces the formation of deposits on the ammonia oxidation catalyst of the post combustion system. 
     
     
         27 . The method of  claim 2 , which reduces the formation deposits on sensors within the post combustion system. 
     
     
         28 . The method of  claim 2 , which reduces the formation of deposits in one more components of the post combustion system by at least 5%. 
     
     
         29 . The method of  claim 2 , wherein the diesel engine is an off road engine, for example a marine, rail or stationary engine. 
     
     
         30 . The method of  claim 2 , 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 e.g. urea consumption; reduction in wear on all post combustion components (including but not limited to the turbo charger, oxidation catalyst, DPF, SCR CAT, sensors, and injectors within the post combustion system); increased longevity of exhaust components; and the protection of intake components downstream of the EGR.