Reactive Extraction of Nicotinic Acid with Tri-n-Octylamine (TOA) Dissolved in Different Diluents

The production of nicotinic acid and nicotinamide can be intensified by enzymatic conversion of 3-cyanopyridine. This fermentation process requires an economic and efficient separation method to compete with the synthetic process. In the present study, equilibrium data for the extraction of nicotinic acid using TOA dissolved in different diluents such as toluene and butyl acetate and n-dodecane are presented. Different parameters like distribution coefficient, degree of extraction, loading ratio, and equilibrium complexation constants were determined. The highest strength of the complex solvation is found for toluene with a maximum loading ratio (Z = 0.154) followed by butyl acetate (Z = 0.121) and dodecane promoting probably (1,1) acid-TOA complex formation. An optimization procedure (differential evolution algorithm) is used for the determination of the equilibrium extraction constant (KE) and the number of reacting acid molecules (m) per TOA molecule through mass action law modeling approach (Chemodel). Introduction Nicotinic acid (3-pyridine carboxylic acid) widely used in food, pharmaceutical and biochemical industries is an important chemical. Due to ecological problems and complicate the synthesis methods, the chemical route for nicotinic acid production will become unattractive in the future. In recent years, the application of enzymes to organic chemical processing has attracted the attention of researchers. Nitrilases enzymes are gaining popularity as biocatalysts for the mild and selective hydrolysis of nitriles. The production of nicotinic acid and nicotinamide can be