Marine lubricating oil composite additive

Abstract

The present invention relates to a marine lubricating oil composite additive. Based on the total weight of the composite additive, said marine lubricating oil composite additive comprises: 25-45% sulfonate detergent with superhigh base number, 40-60% phenolate detergent with low base number, 0-8% dispersing agent, 0-4% antiwear agent, and 10-20% Group I base oil with high viscosity index which is selected from the group consisting of 400SN, 500SN and 600SN. The composite additive according to the present invention can satisfy the requirement of BOB system about the viscosity and base number, and can be blended with many system oils under a number of domestic and foreign brands so as to provide cylinder lubricating oils with different base numbers. The composite additive according to the present invention has good adaptability and excellent performances in terms of antiwear, antioxidization and high temperature detergency, which meet the requirement of marine engines about the performance of cylinder lubricating oils. Moreover, the composite additive according to the present invention is able to maintain good stability in the base oil of the system oil as well as good compatibility, and thus the lubricating performance of the cylinder lubricating oil will not be adversely affected.

1 . (canceled) 
     
     
         2 . An engine system, comprising:
 a system oil storage tank having a system oil outlet stream for providing a system oil;   an additive tank having an additive outlet stream for providing a composite additive comprising 25-45% sulfonate detergent with superhigh base number, 40-60% phenolate detergent with low base number, 0-8% dispersing agent, 0-4% antiwear agent, and 10-20% Group I base oil with high viscosity index which is selected from the group consisting of 400SN, 500SN and 600SN;   a blend on board device operably connected to the system oil outlet stream and the composite additive outlet stream and having a cylinder oil outlet stream, the blend on board device being operable to combine the system oil with the composite additive to form a cylinder oil having a predetermined base number;   a cylinder oil storage tank operably having an ejector outlet stream, the cylinder oil storage tank connected to the cylinder oil outlet stream and configured to retain receive the cylinder oil for a predetermined period of time; and   a main engine operably connected to a fuel oil inlet stream and the ejector outlet stream to receive the retained cylinder oil and intermix the fuel oil with the cylinder oil.   
     
     
         3 . The engine system of  claim 2 , wherein:
 the sulfonate detergent with superhigh base number is C 22 -C 30  linear alkyl benzene calcium sulphonate, wherein the base number thereof is 395-430 mgKOH/g;   the phenolate detergent with low base number is C 20 -C 25  alkyl sulfurized calcium phenolate, wherein the base number thereof is 240-265 mgKOH/g;   the dispersing agent is selected from the group consisting of mono-polyisobutylene succinimide, bis-polyisobutylene succinimide and multi-polyisobutylene succinimide;   the antiwear agent is zinc long-chain alkyl thiophosphate with the structure corresponding to the following formula,   
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , R 3  and R 4  are long-chain primary alkyl groups each comprising 12-18 carbon atoms, or R 1 , R 2 , R 3  and R 4  are long-chain secondary alkyl groups each comprising 12-16 carbon atoms. 
     
     
         4 . The engine system of  claim 2 , wherein the kinematic viscosity of said base oil is 8.5-11.5 cSt at 100° C. 
     
     
         5 . The engine system of  claim 2 , wherein the cylinder oil resulting from the combination of the system oil with the composite additive has a base number greater than or equal to 285 mgKOH/g. 
     
     
         6 . The engine system of  claim 2 , wherein the cylinder oil resulting from the combination of the system oil with the composite additive has a kinematic viscosity at 100° C. less than or equal to 95 mm 2 /s. 
     
     
         7 . A method for treating a marine cylinder oil comprising:
 blending a marine cylinder oil, in a shipborne Blender-on-Board system; with a composite additive comprising, based on the total weight of the composite additive:   25-45% sulfonate detergent with superhigh base number, 40-60% phenolate detergent with low base number, 0-8% dispersing agent, 0-4% antiwear agent, and 10-20% Group I base oil with high viscosity index which is selected from the group consisting of 400SN, 500SN and 600SN;   wherein:   the sulfonate detergent with superhigh base number is C 22 -C 30  linear alkyl benzene calcium sulphonate, wherein the base number thereof is 395-430 mgKOH/g;   the phenolate detergent with low base number is C 20 -C 25  alkyl sulfurized calcium phenolate, wherein the base number thereof is 240-265 mgKOH/g;   the dispersing agent is selected from the group consisting of mono-polyisobutylene succinimide, bis-polyisobutylene succinimide and multi-polyisobutylene succinimide;   the antiwear agent is zinc long-chain alkyl thiophosphate with the structure corresponding to the following formula,   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3  and R 4  are long-chain primary alkyl groups each comprising 12-18 carbon atoms, or R 1 , R 2 , R 3  and R 4  are long-chain secondary alkyl groups each comprising 12-16 carbon atoms.