Process for preparing a fuel additive and the additive

Abstract

The invention relates to a method for manufacturing a fuel additive and to the additive. It relates particularly to a lubricant additive that is highly suitable for use as an additive in connection with diesel engines. According to the method, saturated fatty acids with a high melting point are separated by cooling from a fatty-acid mixture, the said fraction of fatty acids with a high melting point being esterified and/or aminated to form a mixture of more than three esters and/or amines and the mixture thus obtained being re-mixed with that part of the original fatty-acid mixture from which the fatty acids with a high melting point were separated and the necessary amount of this last-mentioned mixture being mixed with fuel to form a lubricant. The separation of the saturated fatty acids with a high melting point takes place by passing the mixture through a cooling heat-transfer surface, to which the fatty acids adhere, and by removing the fatty acids from the surface by raising its temperature.

1 . A method for manufacturing fatty-acid compounds for use as a lubricant fuel additive, characterized in that saturated fatty acids with a high melting point are separated from a fatty-acid mixture by cooling, the fraction of the fatty acids with a high melting point is esterfied and/or aminated to form a mixture of more than three esters and/or amines and the mixture thus created is re-mixed with that part of the original fatty-acid mixture, from which the fatty acids with a high melting point were separated, and mixed with the necessary amount of this last-mentioned mixture to form a fuel lubricant.  
     
     
         2 . A method according to  claim 1 , characterized in that the fatty acids with a high melting point are separate from the fatty-acid mixture by passing the mixture through a cooling heat-transfer surface and that the fatty acids adhering to the cold surface are removed by raising its temperature.  
     
     
         3 . A method according to  claim 1 , characterized in that the fraction of saturated fatty acids with a high melting point is esterified using a mixture of several alcohols.  
     
     
         4 . A method according to  claim 3 , characterized in that the esterification takes place using fusel oil.  
     
     
         5 . A method according to  claim 4 , characterized in that the esterification takes place using a fusel oil in which there is water, the salts dissolved in which being removed by cooling the said fusel oil to a temperature of less than 0° C., particularly to a temperature of −10-−25° C. and removing the separated water phase.  
     
     
         6 . A method according to claims  4 , characterized in that the fusel oil is distilled prior to the esterification treatment.  
     
     
         7 . A method according to  claim 1 , characterized in that the fraction of fatty acids with a high melting point is aminated, particularly using diamines or amino-alcohols and/or lactarns.  
     
     
         8 . A method according to  claim 7 , characterized in that the amination takes place at a temperature of 130-150° C. and in the presence of an acid catalyst while mixing for at least 1 hour.  
     
     
         9 . A method according to  claim 7 , characterized in that the amination takes place using N,N-dialkylamines.  
     
     
         10 . A method according to any of the above claims, characterized in that the saturated fatty acids are treated by both esterification and amination, either together or separately, and that the products obtained are mixed with the unsaturated fatty acids that remain from the fatty-acid mixture, from which the saturated fatty acids were separated.  
     
     
         11 . A lubricant fuel additive comprising fatty-acid compounds, characterized in that it includes esterified and/or aminated saturated fatty acids with a high melting point and unsaturated fatty acids with a low melting point.  
     
     
         12 . An additive according to  claim 11 , characterized in that the additive contains esters of saturated fatty acids with a high melting point together with several alcohols.  
     
     
         13 . An additive according to  claim 11 , characterized in that the additive is formed of essentially the fatty acids of tall oil, the saturated fatty acids of which are esterified/aminated.