n-Butyl acrylate (n-BA), one
of the important chemicals in the resin industry, can be synthesized
by esterification of acrylic acid (AA) and n-butanol
(BuOH). Owing to the thermodynamic immiscibility of n-BA and water, reactive extraction is promising to intensify the
esterification with a suitable solvent (e.g., ionic liquid, IL) through
in situ shifting of the reaction equilibrium toward n-BA. Herein, a typical Brønsted acidic IL 1-butyl-3-methylimidazolium
hydrogen sulfate ([BMIm][HSO4]) was employed to intensify
the esterification process. The liquid–liquid equilibrium (LLE)
of ternary systems {AA or BuOH + n-BA + [BMIm][HSO4]} and a quinary system {AA + BuOH + n-BA
+ water + [BMIm][HSO4]} was investigated at atmospheric
pressure and temperatures T = 313.15, 333.15, and
353.15 K and T = 333.15, 343.15, and 353.15 K, respectively.
According to experimental results, the solute distribution coefficient
and solvent selectivity were tested to verify the thermodynamic feasibility
of [BMIm][HSO4] as a catalyst and an extractant for n-BA formation. In addition, the NRTL model was adopted
to correlate the experimental data, and the binary interaction parameters
for the esterification system were fitted.