Thanks for your answer. In order to remove CO2 in the propylene unit we increased the steam and reduces the pressure in the deetanizer tower. It seems do not remove the CO2 enough. This tower remove the lighter streams on the top (ethane, CO2, etc) and the bottom have propane/propylene, but it seems do not remove enough the CO2. The propane/propylene stream in the tower bottom still have 2-3 ppm of CO2 and produces propylene with CO2. How can I improve this tower to remove more CO2 ?