Shell-and-Tube Reactor for Synthesizing Polycarbonate Polyether Polyols

A shell-and-tube reactor for synthesizing polycarbonate polyether polyols, comprising a reaction tube, comprising:

• a carbon dioxide-epoxide heat transfer unit disposed at an upper portion of the reaction tube for reducing the temperature of the materials;
• a solid-liquid mixing unit disposed within the reaction tube and located below the carbon dioxide-epoxide heat transfer unit;
• a circulation control unit configured to drive the circulation and flow of materials within the reaction tube;
• a temperature control unit configured to regulate the temperature within the reaction tube;
• and
• a pressure control unit configured to regulate the internal pressure of the reaction tube;
• wherein the circulation control unit, temperature control unit, and pressure control unit cooperate to control the entire reaction process, wherein:
• after one-time feeding of the epoxide, chain transfer agent, and catalyst into the reaction tube, the circulation control unit delivers materials from the solid-liquid mixing unit to the carbon dioxide-epoxide heat transfer unit, and after the material temperature is reduced, returns it to the solid-liquid mixing unit;
• by adjusting the circulation rate via the circulation control unit and further adjusting the temperature and pressure control units, the temperature of the material in the upper portion of the reaction tube is maintained lower than that in the lower portion, the temperature difference between the middle and lower portions does not exceed 5° C., and the material temperature along the flow direction increases gradually;
• wherein the length-to-diameter ratio (L:d) of the reaction tube is less than 50.