Process for stripping co2 from solutions of alkali metal carbonates

Process for stripping CO2 from solutions of alkali metal carbonates which have absorbed the same CO2, the method comprising:

• a vacuum regeneration in a first stripping column, in which steam is injected directly into a bottom portion of the first stripping column, said first stripping column being fed through a first duct with a solution that has absorbed the CO2, said first stripping column also includes an outlet duct of the regenerated solution;
• a heat transfer by the regenerated solution exiting the first stripping column, which, due to below atmospheric pressure in said first stripping column, is at a temperature such as to allow a heat exchange between a mixture of hot gases at a partial pressure of CO2 comprised between 0.05-0.25 bar, and the solution, through direct contact in a first exchanger;
• and
• a transport of heat from the first exchanger to the bottom of the first stripping column owing to said regenerated solution which, heated in the exchanger in direct contact, is sent back to the bottom of the first stripping column through a second duct and in which, being at a temperature higher than its boiling temperature at the pressure of the first stripping column, the regenerated solution undergoes a spontaneous flash which releases steam used for the regeneration of the solution itself.