Process Optimization and Kinetic Modeling for Sucrose Acylation to Sucrose-6-acetate through the Dibutyltin Oxide Method

Sucrose-6-acetate (S-6-A) is an important intermediate in the industrial production process of sucralose. In this work, the synthesis and reaction kinetics for both the high-temperature and low-temperature processes of sucrose acylation to produce S-6-A via the dibutyltin oxide method were investigated. The influences of the molar ratios of both dibutyltin oxide (DBTO)/sucrose and acetic anhydride/sucrose, reaction time, and temperature on the yield of S-6-A were evaluated. Based on the reaction mechanism of the high-temperature process and the solubility characteristic of DBTO, the first-order pseudohomogeneous kinetic model was proposed, which fitted experimental data well in the temperature range of 360.15 to 370.65 K. In addition, the second-order pseudohomogeneous kinetic model was established for the low-temperature process, and the model fitting was in good agreement with experimental data in the temperature range of 274.15 to 296.15 K. The results indicate that the early stage cooling and reduction of reaction time can significantly enhance the yield of S-6-A in the low-temperature process. Hopefully, the kinetic models developed in this work can provide valuable insights into the process optimization of the acylation reaction, the design of the reactors, and the continuous process.