Reaction kinetics of the production of polyoxymethylene dimethyl ethers from methanol and formaldehyde with acid cation exchange resin catalyst

The synthesis of polyoxymethylene dimethyl ethers (PODEn) from methanol and formaldehyde was studied in a fixed bed reactor over the strong acid cation exchange resin catalyst. First, the influence of operating parameters such as temperature and WHSV on reactions was investigated. The conversion of methanol and formaldehyde was improved by increasing temperature. Second, a kinetic equation was derived to estimate the reaction rate constant of methanol and formaldehyde towards PODE. The reaction rate and kinetic model with six PODEn-synthesis reactions was established. We used a fourth order Runge-Kutta method and quasi-Newton method to solve the kinetic equations. The values of apparent activation energies of the six reactions are between 38.58 and 43.68 kJ mol(-1). Ultimately, a mechanism was proposed to explain the results of apparent activation energy. The rate equations that were developed could predict the behavior of the synthesis of PODEn from methanol and formaldehyde reasonably well.