Lubricating oil compositions for improved cleanliness in ammonia engines and methods of use thereof

Abstract

This invention relates to a lubricating oil composition for ammonia fueled internal combustion engines (AICE) including: a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof; b) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more); c) one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 2.5 to 12.0 wt. % of the composition, wherein the treat level of the lower molecular weight PIBSA-PAM is from 0.1 to 9.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 3.0 wt. %; and d) one or more overbased detergents selected from the group consisting of a metal salicylate, a metal carboxylate, a mixture of a metal salicylate and a metal sulfonate, a mixture of a metal carboxylate and a metal sulfonate, and combinations thereof, wherein the one or more overbased detergents have a Total Base Number (mgKOH/g) greater than or equal to 9 and less than or equal to 500 and deliver at least 5 mmol of total soap to the composition; and e) one or more zinc dialkyl dithiophosphate (ZDDP) compounds at from about 0.08 wt. % to about 2.0 wt. % of the lubricating oil composition. The lubricating oil composition has a total sulfated ash of less than or equal to 5.0 wt. %, and a total phosphorous level of less than or equal to 0.120 wt. %, and a viscosity of less than or equal to 25 cSt (KV100). The lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in a decrease in MCT performance rating of less than or equal to 4.0 merits. Also provided is a concentrate for use in a lubricating oil for an AICE and a method of improving engine cleanliness in an AICE.

What is claimed is: 
     
         1 . A lubricating oil composition for ammonia fueled internal combustion engines (AICE) comprising or resulting from the admixing of:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more);   c) one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol),   wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 2.5 to 12.0 wt. % of the composition, wherein the treat level of the lower molecular weight PIBSA-PAM is from 0.1 to 9.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 3.0 wt. %; and   d) one or more overbased detergents selected from the group consisting of a metal salicylate, a metal carboxylate, a mixture of a metal salicylate and a metal sulfonate, a mixture of a metal carboxylate and a metal sulfonate, or combinations thereof, wherein the one or more overbased detergents have a Total Base Number (mgKOH/g) greater than or equal to 9 and less than or equal to 500 and deliver at least 5 mmol of total soap to the composition; and   e) one or more zinc dialkyl dithiophosphate (ZDDP) compounds at from about 0.08 wt. % to about 2.0 wt. % of the lubricating oil composition;   wherein the lubricating oil composition having a total sulfated ash of less than or equal to 5.0 wt. %, and a total phosphorous level of less than or equal to 0.120 wt. %, and an overall viscosity of less than or equal to 25 cSt (KV100); and   wherein the lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in a MCT (GFC Lu 27-A-13) cleanliness merit rating change versus a comparable lubricating oil composition not exposed to ammonia contamination of less than or equal to 4.0 merits.   
     
     
         2 . The composition of  claim 1 , wherein the lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in an increase in kinematic viscosity (KV100) of less than or equal to 50%. 
     
     
         3 . The composition of  claim 1 , further including one or more corrosion inhibitors, rust inhibitors or combinations thereof at a treat rate of greater than or equal to 0.02 wt. % of the lubricating oil composition. 
     
     
         4 . The composition of  claim 3 , wherein the one or more corrosion and/or rust inhibitors are selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group, and combinations thereof. 
     
     
         5 . The composition of  claim 1 , wherein the metal of the one or more overbased metal detergents is selected from the group consisting of sodium, potassium, lithium, calcium, and magnesium. 
     
     
         6 . The composition of  claim 1 , wherein the optional higher molecular weight PIBSA-PAM is borated, the lower molecular weight PIBSA-PAM is borated or a combination thereof, and is/are included at a treat level to deliver from 20 ppm to 1000 ppm by weight of boron to the composition. 
     
     
         7 . The composition of  claim 1 , wherein the one or more overbased metal detergents includes a mixture of a calcium salicylate detergent and calcium sulfonate detergent that delivers to the composition a total soap of at least 10 mmol. 
     
     
         8 . The composition of  claim 1 , further including one or more of the following components: one or more friction modifiers; one or more antioxidants; one or more pour point depressants; one or more anti-foaming agents; one or more viscosity modifiers; one or more dispersants other than the higher molecular weight PIBSA-PAM and the lower molecular weight PIBSA-PAM; one or more inhibitors, one or more antirust agents; one or more seal swell agents; and/or one or more other anti-wear agents. 
     
     
         9 . The composition of  claim 1 , wherein the lubricating oil composition is used as a passenger vehicle lubricant, a commercial vehicle lubricant, or a marine vessel lubricant. 
     
     
         10 . A method of improving engine cleanliness in an ammonia fueled internal combustion engine (AICE) comprising:
 i) providing to the ammonia fueled internal combustion engine a lubricating oil composition comprising or resulting from the admixing of:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof; 
 b) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more); 
 c) one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 2.5 to 12.0 wt. % of the composition, wherein the treat level of the lower molecular weight PIBSA-PAM is from 0.1 to 9.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 3.0 wt. %; and 
 d) one or more overbased detergents selected from the group consisting of a metal salicylate, a metal carboxylate, a mixture of a metal salicylate and a metal sulfonate, a mixture of a metal carboxylate and a metal sulfonate, and combinations thereof, wherein the one or more overbased detergents have a Total Base Number (mgKOH/g) greater than or equal to 9 and less than or equal to 500 and deliver at least 5 mmol of total soap to the composition; and 
 e) one or more zinc dialkyl dithiophosphate (ZDDP) compounds at from about 0.08 wt. % to about 2.0 wt. % of the lubricating oil composition; 
 wherein the lubricating oil composition having a total sulfated ash of less than or equal to 5.0 wt. %, and a total phosphorous level of less than or equal to 0.120 wt. %, and an overall viscosity of less than or equal to 25 cSt (KV100); and 
   ii) providing a fuel comprising ammonia to the ammonia fueled internal combustion engine; and   iii) combusting the fuel in the ammonia fueled internal combustion engine; and
 wherein the lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in a MCT (GFC Lu 27-A-13) cleanliness merit rating change versus a comparable lubricating oil composition not exposed to ammonia contamination of less than or equal to 4.0 merits. 
   
     
     
         11 . The method of  claim 10 , wherein the lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in an increase in kinematic viscosity (KV100) of less than or equal to 50%. 
     
     
         12 . The method of  claim 10 , further including one or more corrosion inhibitors, rust inhibitors or combinations thereof at a treat rate of greater than or equal to 0.02 wt. % of the lubricating oil composition. 
     
     
         13 . The method of  claim 12 , wherein the one or more corrosion and/or rust inhibitors are selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group, and combinations thereof. 
     
     
         14 . The method of  claim 10 , wherein the metal of the one or more overbased metal detergents is selected from the group consisting of sodium, potassium, lithium, calcium, and magnesium. 
     
     
         15 . The method of  claim 10 , wherein the optional higher molecular weight PIBSA-PAM is borated, the lower molecular weight PIBSA-PAM is borated or a combination thereof, and is/are included at a treat level to deliver from 20 ppm to 1000 ppm by weight of boron to the composition. 
     
     
         16 . The method of  claim 10 , wherein the one or more overbased metal detergents includes a mixture of a calcium salicylate detergent and a calcium sulfonate detergent that delivers to the composition a total soap of at least 10 mmol. 
     
     
         17 . The method of  claim 10 , further including one or more of the following components: one or more friction modifiers; one or more antioxidants; one or more pour point depressants; one or more anti-foaming agents; one or more viscosity modifiers; one or more dispersants other than the higher molecular weight PIBSA-PAM and the lower molecular weight PIBSA-PAM; one or more inhibitors, one or more antirust agents; one or more seal swell agents; and/or one or more other anti-wear agents. 
     
     
         18 . The method of  claim 10 , wherein the lubricating oil composition is used as a passenger vehicle lubricant, a commercial vehicle lubricant, or a marine vessel lubricant. 
     
     
         19 . A concentrate comprising or resulting from the admixing of:
 from 1 to less than or equal to 50 wt. % of one or more base oils;   from 2 to 40 wt. % of one or more overbased detergents selected from the group consisting of a metal salicylate, a metal carboxylate, a mixture of a metal salicylate and a metal sulfonate, a mixture of a metal carboxylate and a metal sulfonate and combinations thereof, wherein the one or more overbased detergents have a Total Base Number (mgKOH/g) greater than or equal to 9 and less than or equal to 500 and deliver at least 5 mmol of total soap to the composition;   from 2 to 40 wt. % of optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more), and one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), and   from 2 to 20 wt. % of one or more zinc hydrocarbyl diphosphate compounds, wherein the one or more zinc hydrocarbyl diphosphate compounds include hydrocarbyl groups derived from one or more primary alcohols, one or more secondary alcohols or a combination of primary and secondary alcohols.   
     
     
         20 . The concentrate of  claim 19 , further including from 0.10 to 10 wt. % of one or more corrosion inhibitors, rust inhibitors or combinations thereof selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group and combinations thereof. 
     
     
         21 . The concentrate of  claim 19 , further comprising combining the concentrate with a base oil to form a lubricating oil composition comprising:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more);   c) one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 2.5 to 12.0 wt. % of the composition, wherein the treat level of the lower molecular weight PIBSA-PAM is from 0.1 to 9.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 3.0 wt. %; and   d) one or more overbased detergents selected from the group consisting of a metal salicylate, a metal carboxylate, a mixture of a metal salicylate and a metal sulfonate, a mixture of a metal carboxylate and a metal sulfonate, and combinations thereof, wherein the one or more overbased detergents have a Total Base Number (mgKOH/g) greater than or equal to 9 and less than or equal to 500 and deliver at least 5 mmol of total soap to the composition; and   e) one or more zinc dialkyl dithiophosphate (ZDDP) compounds at from about 0.08 wt. % to about 2.0 wt. % of the lubricating oil composition;   wherein the lubricating oil composition having a total sulfated ash of less than or equal to 5.0 wt. %, and a total phosphorous level of less than or equal to 0.120 wt. %, and an overall viscosity of less than or equal to 25 cSt (KV100); and   wherein the lubricating oil composition upon exposure to ammonia contamination per the NOx-Ammonia exposure protocol results in a MCT (GFC Lu 27-A-13) cleanliness merit rating change versus a comparable lubricating oil composition not exposed to ammonia contamination of less than or equal to 4.0 merits.