Kinetics of esterification of succinic anhydride with methanol by homogeneous catalysis

Article abstract of DOI:10.1002/kin.550261006

Kinetic data on the esterification of succinic anhydride with methanol catalyzed by sulfuric acid have been obtained using a stirred batch reactor. In addition to get a precise ascertainment of the parameters the esterification of monomethyl succinate with methanol has been studied separately. Several experiments have been carried out with different initial molar ratios and different amounts of sulfuric acid at various temperatures. The conversion to dimethyl succinate at 30-65°C follows a first-order rate expression with respect to each component. A theoretical rate equation is derived by the following reaction mechanism: (1) succinic anhydride is protonated by sulfuric acid to form a reaction intermediate, (2) irreversible esterification to monomethyl succinate, (3) protonation of the monoester, and (4) the esterification to dimethyl succinate proceeds reversibly. The resultant kinetic equation fitted the experimental data quite well and is given by the expression: dc_CH(3)OH÷dt = c_H(2)SO(4) [ - 4.344 × 10⁸e^-65239/RT c_C(4)H(4)O(3)c_CH(3)OH - 2.457 × 10⁶e^-57732/RT c_C(5)H(8)O(4)c_CH(3)OH + 229e^-34361/RT c_{C(6)H(10)O(4)}c_H(2)O]