Non-Aqueous Heat Transfer Fluid and Use Thereof

Abstract

A non-aqueous, reduced toxicity diol based heat transfer fluid is provided comprised of at least one diol that acts as an antidote for ethylene glycol poisoning, such as for example propylene glycol. The heat transfer fluid may also include corrosion inhibitors that are soluble in the diols used for the heat transfer fluid. The heat transfer fluid may be used as a coolant in internal combustion engines such as automobile engines.

1 - 29 . (canceled) 
   
   
       30 . A reduced toxicity, ethylene glycol and propylene glycol based, non-aqueous heat transfer fluid, which can be used as an engine coolant in environmental conditions ranging from ambient temperatures of −35° F. to +130° F., for use in a heat exchange system without any addition of water, said non-aqueous heat transfer fluid comprising:
 (a) ethylene glycol, wherein the ethylene glycol comprises between about 60 percent by weight to about 70 percent by weight of the total weight of the ethylene glycol and propylene glycol in the non-aqueous heat transfer fluid;   (b) propylene glycol, wherein the propylene glycol comprises between about 30 percent by weight and 40 percent by weight of the total weight of the ethylene glycol and the propylene glycol in the heat transfer fluid; and   (c) at least one corrosion inhibitor additive that is soluble in ethylene glycol and propylene glycol, wherein the heat transfer fluid contains no additives that require water to be present in the fluid to dissolve the additives or to otherwise enable the additives to function,   wherein the neat non-aqueous heat transfer fluid contains less than 0.5 percent by weight water.   
   
   
       31 . The non-aqueous heat transfer fluid of  claim 30 , wherein the corrosion inhibitor additive is selected from the group consisting of a molybdate salt, a nitrate salt and an azole. 
   
   
       32 . The heat transfer fluid of  claim 30 , wherein the ethylene glycol and propylene glycol comprise from about 85 percent by weight to about 99.85 percent by weight of the heat transfer fluid. 
   
   
       33 . The heat transfer fluid of  claim 30 , wherein the corrosion inhibitor is comprised of a molybdate salt in a concentration of between about 0.05 percent to about 5 percent by weight of the total weight of the heat transfer fluid. 
   
   
       34 . The heat transfer fluid of  claim 30 , wherein the corrosion inhibitor is comprised of a nitrate salt in a concentration of between about 0.05 percent to about 5 percent by weight of the total weight of the heat transfer fluid. 
   
   
       35 . The heat transfer fluid of  claim 30 , wherein the corrosion inhibitor is comprised of an azole in a concentration of between about 0.05 percent to about 5 percent by weight of the total weight of the heat transfer fluid. 
   
   
       36 . The heat transfer fluid of  claim 33 , wherein the molybdate salt is sodium molybdate. 
   
   
       37 . The heat transfer fluid of  claim 34 , wherein the nitrate salt is sodium nitrate. 
   
   
       38 . The heat transfer fluid of  claim 35 , wherein the azole is tolyltriazole. 
   
   
       39 . The heat transfer fluid of  claim 30 , wherein the corrosion inhibitor is comprised of at least one of (i) sodium molybdate in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the heat transfer fluid, (ii) sodium nitrate in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the heat transfer fluid, and (iii) tolyltriazole in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the heat transfer fluid. 
   
   
       40 . A method to reduce the toxicity of an ethylene glycol based, non-aqueous heat transfer fluid comprising the steps of:
 (a) providing an ethylene glycol based non-aqueous heat transfer fluid; and   (b) adding propylene glycol to the non-aqueous heat transfer fluid, wherein the ethylene glycol concentration of the resulting non-aqueous heat transfer fluid is about 70 percent by weight of the total weight of the ethylene glycol and the propylene glycol in the non-aqueous heat transfer fluid, and wherein the resulting non-aqueous heat transfer fluid contains less than 0.5 percent by weight water.   
   
   
       41 . The method of  claim 40 , further comprising the step of adding to the non-aqueous heat transfer fluid a corrosion inhibitor additive that is soluble in both ethylene glycol and propylene glycol, wherein the non-aqueous heat transfer fluid contains no additives that require water to be present in the fluid to dissolve the additives or to otherwise enable the additives to function. 
   
   
       42 . The method of  claim 41 , wherein the corrosion inhibitor is selected from the group consisting of a molybdate salt, a nitrate salt, and an azole. 
   
   
       43 . The method of  claim 40 , wherein the ethylene glycol and propylene glycol comprise from about 85 percent by weight to about 99.85 percent by weight of the non-aqueous heat transfer fluid. 
   
   
       44 . The method of  claim 42 , wherein the corrosion inhibitor comprises a molybdate salt in a concentration of between about 0.05 percent to about 5 percent of the weight of the non-aqueous heat transfer fluid. 
   
   
       45 . The method of  claim 42 , wherein the corrosion inhibitor comprises a nitrate salt in a concentration of between about 0.05 percent to about 5 percent of the weight of the non-aqueous heat transfer fluid. 
   
   
       46 . The method of  claim 42 , wherein the corrosion inhibitor comprises an azole in a concentration of between about 0.05 percent to about 5 percent of the weight of the heat transfer fluid. 
   
   
       47 . The method of  claim 44 , wherein the molybdate salt is sodium molybdate. 
   
   
       48 . The method of  claim 45 , wherein the nitrate salt is sodium nitrate. 
   
   
       49 . The method of  claim 46 , wherein the azole is tolyltriazole. 
   
   
       50 . The method of  claim 40 , wherein the corrosion inhibitor comprises at least one of (i) sodium molybdate in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the heat transfer fluid, (ii) sodium nitrate in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the heat transfer fluid, and (iii) tolyltriazole in a concentration between about 0.05 percent by weight to about 5 percent by weight of the total weight of the non-aqueous heat transfer fluid.