NOVELTY - System for chemical conversion of a biodiesel to an alkane composition comprises a first electrochemical reactor that reduces excess methanol (MeOH) in a biodiesel source material to yield a first composition comprising methyl esters of aliphatic carboxylic acids; a second electrochemical reactor that fragments the methyl esters of aliphatic carboxylic acids of the first composition by carbon-carbon double bond cleavage; and a third electrochemical reactor that hydrogenates the methyl esters of the second composition to yield a third composition comprising alkanes.    USE - The system or method is useful for chemical conversion of biodiesel to alkane composition (claimed).    ADVANTAGE - The invention provides a series of electrochemical processes carried out by directed electrochemical reactors for use in improving the quality of a biofuel, converting a biodiesel fuel to a fuel containing short chain alkanes, and converting the fatty acid methyl esters of a biodiesel fuel into a mixture of aliphatic hydrocarbons.    DETAILED DESCRIPTION - System for chemical conversion of a biodiesel to an alkane composition comprises a first electrochemical reactor that reduces excess methanol (MeOH) in a biodiesel source material to yield a first composition comprising methyl esters of aliphatic carboxylic acids; a second electrochemical reactor that fragments the methyl esters of aliphatic carboxylic acids of the first composition by carbon-carbon double bond cleavage to yield a second composition comprising short chain methyl esters of aliphatic carboxylic acids; and a third electrochemical reactor that hydrogenates the methyl esters of the second composition to yield a third composition comprising alkanes; system for chemical conversion of a biodiesel to an alkane composition comprising a first electrochemical reactor that fragments aliphatic chains of a biodiesel source material by carbon-carbon double bond cleavage to yield a first composition comprising short chain methyl esters of aliphatic carboxylic acids; and a second electrochemical reactor that performs a Kolbe reaction, where the aliphatic carboxylic acids of the first composition are decarboxylated to yield a second composition comprising alkanes; OR system for chemical conversion of a biodiesel to an alkane composition comprising a first electrochemical reactor that fragments aliphatic chains of a biodiesel source material by carbon-carbon double bond cleavage to yield a first composition comprising short chain methyl esters of aliphatic carboxylic acids; and a second electrochemical reactor that hydrogenates the methyl esters of the first composition to yield a second composition comprising alkanes. An INDEPENDENT CLAIM is a method for chemical conversion of biodiesel to alkane composition comprising providing a crude biodiesel composition, the biodiesel composition comprising fatty acid esters and methanol; reducing the amount of methanol in the biodiesel composition by electrochemical oxidation of methanol to carbon dioxide in a first electrochemical reactor; fragmenting fatty acid chains of the biodiesel composition in a second electrochemical reactor that cleaves the fatty acid chains at carbon-carbon double bonds to yield short chain fatty acids and aldehydes; and hydrogenating the short chain fatty acids and aldehydes in a third electrochemical reactor to yield a composition comprising alkanes; a method for chemical conversion of biodiesel to alkane composition, comprising providing a crude biodiesel composition, the biodiesel composition comprising fatty acid esters and methanol; fragmenting fatty acid chains in the biodiesel composition in a first electrochemical reactor that cleaves the fatty acid chains at carbon-carbon double bonds to yield short chain fatty acids and aldehydes; oxidizing the short chain aldehydes to short chain fatty acids; and performing a Kolbe reaction in a second electrochemical reactor, where the short chain fatty acids are decarboxylated to form alkanes; or a method for chemical conversion of biodiesel to alkane composition, comprising providing a crude biodiesel composition, the biodiesel composition comprising fatty acid esters and methanol; fragmenting fatty acid chains in the biodiesel composition in a first electrochemical reactor that cleaves the fatty acid chains at carbon-carbon double bonds to yield short chain fatty acids and aldehydes; and hydrogenating the short chain fatty acids and aldehydes in a second electrochemical reactor to form alkanes.