| 摘要 |
A method for preparing methylal is provided to prepare high purity methylal from formalin and methanol with high efficiency by using a reaction distillation apparatus equipped with a heterogeneous catalyst and a deaerating part. A method for preparing methylal comprises the steps of: (i) injecting formalin and methanol in the heterogeneous catalyst of a reaction distillation apparatus equipped with a purification part, a heterogeneous catalyst layer and a deaerating part; (ii) heating water and non-reacted material-containing mixture passing through the heterogeneous catalyst layer and a deaerating part, and circulating a gas-phase component to the lower part of the deaerating part and a liquid-phase component to the upper parts of the catalyst layer and the deaerating part; (iii) discharging a part of liquid-phase component; (iv) passing the gas-phase methylal through the purification part; and (v) condensing the gas-phase methylal, circulating a part of it to the upper part of the purification part and obtaining the rest as end products. |
