study represents a mathematical procedure for the kinetic analysis of naphthalene sulfonation using sulfuric acid at molar ratios ranging from 0.7 to 1.5 and reaction temperatures from 115 to 180-degrees-C. The overall sulfonation comprises many consecutive, parallel, and reversible reactions. Representative samples of the reaction mixture are analyzed by high-performance liquid chromatography for quantitative evaluation of the sulfonic acid isomers produced and by alkalimetric determination of acidity. The model suggested includes the concentration of the five components in the reaction mixture, considering five reactions. The kinetic parameters for these reactions are estimated for ''best fit'' of the experimental data by the weighted least squares method based on minimizing the deviation between measured data and those calculated according to the model. This model describes fairly well the process kinetic through the evaluated parameters. It is observed from the results that, with respect to the yield of the target (beta-sulfonic acid), the optimum reaction temperature is 170-degrees-C for equimolar acid to naphthalene ratio.

Sulfonation reaction of naphthalene with 98% sulfuric acid is investigated at temperature range from 115-degrees-C to 180-degrees-C for different time intervals and different molar reactants ratio. Naphthalene sulfonic-acids (NSA) are produced through naphthalene sulfonation with 98% sulfuric acid. The technique of liquid chromatography is used for the individual analysis of sulfonic-acid (SA) isomers (alpha-, beta- and di-) resulting at the operating sulfonation conditions. The isomers resolution is achieved on a stainless steel column packed with octylsilica material (Silasorb C-8, 10 mum), using methanol as mobile phase containing sodium sulfate. Maximum naphthalene conversion (96%) is obtained after two hours at 170-degrees-C and 1.1 sulfuric acid to naphthalene molar ratio. Also, maximum yield of beta-naphthalene sulfonic acid isomer (94%) is achieved at the same above conditions.