Intensified Co-Oligomerization of Propylene Oxide and Carbon Dioxide in a Continuous Heat Exchanger Loop Reactor at Elevated Pressures

We herein report the development of the continuous co-oligomerization of propylene oxide and carbon dioxide to yield high quality polyether carbonate polyols with oligomeric molecular weights (MWs), narrow and monomodal molecular weight distributions (MWDs), and strict OH end group functionality under intensified reaction conditions. A 0.4 L shell-and-tube heat exchanger loop reactor with static CSE-XR mixers was the flow setup of choice for this novel process. The exothermic statistical oligomerization was performed in bulk while CO2 pressures of up to 100 bar were applied. A parameter study was performed for this propoxylation process: STYs of up to 1.5 kg·L–1·h–1 were realized and the synthesis of more than 75 kg valuable material was demonstrated on a mini-plant rig.