Fuel composition and blend

Abstract

A fuel composition having reduced tendency to discoloration at high temperatures comprises kerosine and/or is a jet fuel, and also comprises a cyclic compound comprising m units of the formula 1 a. and n units of the formula (Ib) joined together to form a ring, wherein Y is a divalent bridging group which may be the same or different in each unit; R 0 is H or (C 1 -C 6 ) alkyl; R 5 is H or (C 1 -C 60 ) alkyl; and j is 1 or 2; R 3 is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group; each of R 1 , R 2 and R 4 , which may be the same or different, is hydroxyl, hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, with the proviso that at least one of R 1 , R 2 , R 4 is hydroxyl, and m+n is 4 to 20 , m is 1-8 and n is at least 3 and preferably either R 1 is hydroxyl and R 2 and R 4 are independently either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, or R 2 and R 1 are hydroxyl and R 1 is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and m+n is from 4 to 20, m is from 1 to 8 and n is at least 3.

1 . A fuel composition comprising a fuel, which comprises kerosine and/or is a jet fuel, and also comprising a cyclic compound comprising m units of the formula  1   a                     
       and n units of the formula (Ib)  
                 
 
       joined together to form a ring, 
 wherein Y is a divalent bridging group which may be the same or different in each unit;  
 R 0  is H or (C 1 -C 6 ) alkyl; R 5  is H or (C 1 -C 60 ) alkyl; and j is 1 or 2;  
 R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;  
 each of R 1 , R 2  and R 4 , which may be the same or different, is hydroxyl, hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, with the proviso that at least one of R 1 , R 2 , R 4  is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is at least 3.  
 
     
     
         2 . A composition according to    claim 1   , wherein the compound is a compound of the formula (I) with a ring structure.  
                   
       wherein Y 1  and Y 2  are as defined for Y.  
     
     
         3 . A composition according to    claim 1   , wherein either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, or R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl.  
     
     
         4 . A composition according to    claim 3    wherein R 1  is hydroxyl and R 2  and R 4  are hydrogen.  
     
     
         5 . A composition according to    claim 1   , wherein Y, Y 1  and Y 2  are of formula (CHR 8 ) d  wherein R 8  is hydrocarbyl of 1-6 carbons or hydrogen, and d is an integer of 1-4.  
     
     
         6 . A composition according to    claim 1   , wherein m is 1 and n is an integer of 5-10.  
     
     
         7 . A composition according to    claim 6    wherein m+n has the value of 6 or 8, or a mixture of compounds with m+n having the value of 6 and 8.  
     
     
         8 . A composition according to    claim 1   , wherein R 3  is a hydrocarbyl group of at least 8 carbon atoms.  
     
     
         9 . A composition according to    claim 8    wherein R 3  is an alkyl group of 8-20 carbons or is a polymeric hydrocarbyl group from polyisobutene.  
     
     
         10 . A composition according to    claim 1   , wherein R 5  is hydrogen, and R 0  (if present) is hydrogen.  
     
     
         11 . A composition according to    claim 1   , wherein the amount of cyclic compound is 5-1000 ppm (based on the weight of the composition).  
     
     
         12 . A composition according to    claim 1   , wherein the jet fuel is a Merox fuel.  
     
     
         13 . A composition according to    claim 1   , which also comprises a hydroxycarboxylic acid, different from said compound, and with at least one chain of at least 8 carbons.  
     
     
         14 . A composition according to    claim 13    wherein the hydroxy carboxylic acid is a beta hydroxy carboxylic acid.  
     
     
         15 . A composition according to    claim 14    wherein the hydroxy carboxylic acid is an N-substituted serine.  
     
     
         16 . A composition according to    claim 15    wherein the hydroxy carboxylic acid is a N-(polyisobutenyl succinyl)serine.  
     
     
         17 . A composition according to    claim 13   , wherein the cyclic compound and hydroxy carboxylic acid are present in a weight ratio of 30-85:70-15.  
     
     
         18 . A composition according to    claim 1   , wherein the fuel is a jet fuel.  
     
     
         19 . A blend for use in a liquid hydrocarbon fuel, comprising a cyclic compound as defined in    claim 1    and a hydroxy carboxylic acid as defined in    claim 13   .  
     
     
         20 . A method of thermally stabilising a fuel comprising kerosine or a fuel comprising a jet fuel which comprises mixing with said fuel a compound as defined in    claim 1   , or blend as claimed in    claim 19   .  
     
     
         21 . Use of a compound as defined in    claim 1    or blend as defined in    claim 19    to thermally stabilise a fuel comprising kerosine or a jet fuel.  
     
     
         22 . A cyclic compound comprising m units of the formula Ia.  
                   
       and n units of the formula (Ib)  
                 
 
       joined together to form a ring, 
 wherein Y is a divalent bridging group which may be the same or different in each unit;  
 R 0  is H, a C 1 -C 6  alkyl or a metal or ammonium cation;  
 R 5  is H or a C 1 -C 60  alkyl; and  
 j is 1 or 2;  
 R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;  
 each of R 1 , R 2  and R 4 , which may be the same or different, is hydroxyl, hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, with the proviso that at least one of R 1 , R 2 , R 4  is hydroxyl, and  
 m+n is 4 to 20, m is 1-8 and n is at least 3; and  
 with the proviso that at least one of the conditions a) to e) below is satisfied: 
 (a) the cyclic compound comprises at least one formula (Ia) unit in the form of a carboxylate anion,  
 (b) the cyclic compound comprises at least one formula (Ia) unit in the form of an alkaline earth metal or alkali metal carboxylate salt,  
 (c) the cyclic compound comprises at least 2 units of formula (Ia)  
 (d) the cyclic compound comprises an m+n value of 5 to 11, and  
 (e) the cyclic compound is in the substantial absence of linear species comprising formula (Ia) and (Ib) units and/or or the substantial absence of compounds of the formula (IIa) and (IIb) below:  
                 
 
 
 
     
     
         23 . A compound as claimed in    claim 22   , which comprises at least 2 of (a), (b), (c), (d) and (e).  
     
     
         24 . A compound as claimed in    claim 23   , which comprises (c) and at least one of (a), (b), (d) and (e).  
     
     
         25 . A compound as claimed in    claim 22   , which comprises at least three of (a), (b) (c), (d) and (e).  
     
     
         26 . A compound as claimed in    claim 25   , which comprises (c), (d) and at least one of (a), (b) and (e).  
     
     
         27 . A compound as claimed in    claim 22   , wherein 
 m is 2, and    n is 6.    
     
     
         28 . A compound as claimed in    claim 22   , wherein at least one of COOR 0  groups is in the form of an alkali metal salt, preferably, a lithium, sodium or potassium salt.  
     
     
         29 . A compound as claimed in    claim 28   , wherein at least one of the COOR 0  groups is in the form of a potassium salt.  
     
     
         30 . A compound as claimed in    claim 22   , which is a 1-salix[8]arene comprising six dodecyl substituted phenolic units, and two salicylic acid unit joined by methylene bridges.  
     
     
         31 . A compound as claimed in    claim 30   , which is in the form of its dipotassium salt.  
     
     
         32 . A fuel composition or lubricating composition comprising a compound as claimed in    claim 22   .  
     
     
         33 . Use of a compound as claimed in    claim 22    as an additive for improving the thermal stability of a fuel composition or lubricating oil composition.  
     
     
         34 . A method of purifying a mixture, 
 said mixture comprising an oil Product, at least one additive and water;    wherein:    said oil Product is a liquid fuel oil composition or lubricating oil composition,    at least part of the water is in the form of a dispersion of water in said Product, and    said additive is a cyclic compounds comprising m units of the formula Ia  
                 
   and n units of the formula (Ib)  
                 
   joined together to form a ring,    wherein each of Y and y 2  is a divalent bridging group which may be the same or different in each unit;    R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,    R  5  is H or (C 1 -C 60 ) alkyl;    j is 1 or 2;    R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;    either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or    R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and    m+n is from 4 to 20, m is from 1 to 8 and n is at least 3;    said method comprising: 
 providing said mixture,  
 coalescing at least part of said water in said dispersion into separable droplets of water,  
 and separating said droplet water from an oil phase comprising the oil Product and Additive of reduced non-dissolved water content.  
   
     
     
         35 . A method as claimed in    claim 34   , wherein said oil phase is substantially free of non-dissolved water.  
     
     
         36 . A method as claimed in    claim 34   , wherein the oil Product is a hydrocarbon fuel, especially aviation fuel.  
     
     
         37 . A method as claimed in    claim 34   , wherein the oil Product is a blend of a first oil product comprising a fuel oil composition or lubricating oil composition and said Additive, and a second oil product comprising a fuel oil composition or lubricating oil composition, which may be the same or different to the hydrocarbon fuel of the first oil product, 
 each of the first and second oil products being contaminated with water or susceptible to contamination with water.    
     
     
         38 . A method of transporting a first oil Product and a second oil Product separately along the same line, each oil Product being contaminated with water or susceptible to contamination with water, said method comprising: 
 sequentially, in any order, passing along the line:    i) a first oil Product comprising an Additive which is a cyclic compounds comprising m units of the formula Ia  
                 
   and n units of the formula (Ib)  
                 
   joined together to form a ring,    wherein each of Y and Y 2  is a divalent bridging group which may be the same or different in each unit;    R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,    R 5  is H or (C 1 -C 60 ) alkyl;    j is 1 or 2;    R 3 is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;    either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or    R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and    m+n is from 4 to 20, m is from 1 to 8 and n is at least 3; and    ii) a second oil Product; and thereafter,    coalescing any water present in said oil Products in dispersal form, to produce droplets of water;    separating said droplets of water from said oil Products to leave an oil Product(s) of reduced water content, especially substantially free of non-dissolved water, and preferably with substantially no interface e.g. less than 10% (based on the total value of separated water and interface).    
     
     
         39 . A method of increasing the lifetime of a coalescer for coalescing water present in a water dispersion in an oil Product, 
 said method comprising introducing into the coalescer a mixture comprising said oil Product, at least one Additive and water;    wherein: 
 said at least one Additive is a cyclic compounds comprising m units of the formula Ia  
                 
 
 and n units of the formula (Ib)  
                 
 
 joined together to form a ring,  
   wherein each of Y and y 2  is a divalent bridging group which may be the same or different in each unit;    R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,    R 5  is H or (C 1 -C 60 ) alkyl;    j is 1 or 2;    R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;    either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or    R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and    m+n is from 4 to 20, m is from 1 to 8 and n is at least 3.    
     
     
         40 . Use (a) of an Additive which is a cyclic compounds comprising m units of the formula Ia  
                   
       and n units of the formula (Ib)  
                 
 
       joined together to form a ring, 
 wherein each of Y and y 2  is a divalent bridging group which may be the same or different in each unit;  
 R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,  
 R 5  is H or (C 1 -C 60 ) alkyl;  
 j is 1 or2;  
 R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;  
 either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or  
 R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and  
 m+n is from 4 to 20, m is from 1 to 8 and n is at least 3;  
 for improving the thermal stability of a liquid oil Product, and rendering the stabilised oil Product substantially water immiscible or substantially non-emulsifiable with water.  
 
     
     
         41 . Use of an Additive which is a cyclic compounds comprising m units ofthe formula Ia  
                   
       and n units of the formula (Ib)  
                 
 
       wherein each of Y and y 2  is a divalent bridging group which may be the same or different in each unit; 
 R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,  
 R 5  is H or (C 1 -C 60 ) alkyl;  
 j is 1 or2;  
 R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;  
 either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or  
 R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and  
 m+n is from 4 to 20, m is from 1 to 8 and n is at least 3;  
 for improving the thermal stability of a liquid oil Product, without substantially affecting its interfacial tension (e.g. by less than 20% of the value of the oil Product without the Additive).  
 
     
     
         42 . Use of an Additive which is a cyclic compounds comprising m units of the formula Ia  
                   
       and n units of the formula (Ib)  
                 
 
       joined together to form a ring, 
 wherein each of Y and Y 2  is a divalent bridging group which may be the same or different in each unit;  
 R 0  is H or (C 1 -C 6 ) alkyl or is a metal cation,  
 R 5  is H or (C 1 -C 60 ) alkyl;  
 j is 1 or2;  
 R 3  is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group;  
 either R 1  is hydroxyl and R 2  and R 4  are independently either hydrogen, hydrocarbyl or heterosubstituted hydrocarbyl, or  
 R 2  and R 4  are hydroxyl and R 1  is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and  
 m+n is from 4 to 20, m is from 1 to 8 and n is at least 3;  
 for improving the thermal stability of a liquid oil Product, while enabling it also to pass the single element test as defined as in the current edition of API 1581 (Specification and Clarification procedures for Aviation Jet Fuel Filter/Separators).  
 
     
     
         43 . A method as claimed in    claim 34   , wherein said Additive is characterized in that at least one of the conditions a) to e) below is satisfied: 
 (a) the cyclic compound comprises at least one formula (Ia) unit in the form of a carboxylate anion,    (b) the cyclic compound comprises at least one formula (Ia) unit in the form of an alkaline earth metal or alkali metal carboxylate salt,    (c) the cyclic compound comprises at least 2 units of formula (Ia)    (d) the cyclic compound comprises an m+n value of 5 to 11, and    (e) the cyclic compound is in the substantial absence of linear species comprising formula (Ia) and (Ib) units and/or or the substantial absence of compounds of the formula (Ia) and (Ib) below: