Antioxidant additive composition, a solution thereof, and a method for improving the storage stability of biodiesel fuel (variants)

Abstract

This invention relates to the petrochemical industry, in particular, to a method for improving the storage stability of biodiesel fuel via using an antioxidant additive. A method for improving the storage stability of biodiesel fuel, comprising addition of an alkylphenol-based antioxidant additive via providing an initial solution that contains 6 to 48 mass % of the alkylphenol-based composition comprised of, mass %: 2,6-di-tert-butyl-4-methylcyclohexanone—0.2-0.3; 2,6-di-tert-butylphenol—0.7-6.0; 2-sec-6-tert-butyl-p-cresol—1.5-5.0; 4,6-di-tert-butyl-o-cresol—3.0-8.0; 2,4-di-tert-butylphenol—0.3-0.5; 2,4-di-tert-butyl-6-dimethylaminomethylphenol—2.0-5.0; 4,4-methylene-bis(2,6-di-tert-butylphenol)—0.1-0.3; and 2,6-di-tert-butyl-4-methylphenol—to the balance, dissolved in biodiesel fuel; and adding the solution of the composition to the biodiesel fuel to reach a concentration of the composition of from 0.002 to 1.6 mass % based on the entire biodiesel fuel solution. The technical result consists of a considerable improvement of the storage stability of biodiesel fuel with a reduced amount of the antioxidant additive. The antioxidant additive used inhibits precipitation during the shelf life of biodiesel fuel for a longer period of time.

1 . An alkylphenol-based antioxidant additive composition for stabilizing biodiesel fuel which consist of, mass %:
 2,6-di-tert-butyl-4-methylcyclohexanone—0.2-0.3;   2,6-di-tert-butylphenol—0.7-6.0;   2-sec-6-tert-butyl-p-cresol—1.5-5.0;   4,6-di-tert-butyl-o-cresol—3.0-8.0;   2,4-di-tert-butylphenol—0.3-0.5;   2,4-di-tert-butyl-6-dimethylaminomethylphenol—2.0-5.0;   4,4-methylene-bis(2,6-di-tert-butylphenol)—0.1-0.3; and   2,6-di-tert-butyl-4-methylphenol—to the balance.   
     
     
         2 . A solution of an alkylphenol-based antioxidant additive composition for addition to biodiesel fuel comprising the alkylphenol-based antioxidant additive composition according to  claim 1  with a concentration of from 6 to 48 mass % in the biodiesel fuel. 
     
     
         3 . A method for improving the storage stability of biodiesel fuel comprising addition of an alkylphenol-based antioxidant additive, characterized in that the alkylphenol-based additive is the composition according to  claim 1 , a solution is provided containing from 6 to 48 mass % of said composition dissolved in biodiesel fuel, and the solution is added to the biodiesel fuel to reach a concentration of the composition of from 0.002 to 1.6 mass % based on the entire biodiesel fuel solution. 
     
     
         4 . A method for improving the storage stability of biodiesel fuel comprising addition of an alkylphenol-based antioxidant additive, characterized in that the antioxidant additive is added as a solution of the antioxidant additive composition according to  claim 2  to reach a concentration of the composition of from 0.002 to 1.6 mass % based on the entire biodiesel fuel solution.