Systems for removing carbon dioxide from a carbon dioxide containing gas, and related methods

A system for removing carbon dioxide from a carbon dioxide-containing gas, the system comprising:

• an absorber configured to absorb carbon dioxide from the carbon dioxide-containing gas with a non-aqueous solvent to form a carbon dioxide-lean gas, wherein the non-aqueous solvent comprises a nitrogenous base;
• a regenerator configured to remove the carbon dioxide from the non-aqueous solvent after the non-aqueous solvent is loaded with carbon dioxide;
• a water wash column configured to receive the carbon dioxide-lean gas from the absorber and to remove a first portion of the nitrogenous base from the carbon dioxide-lean gas to form a water washed gas;
• an acid wash column configured to facilitate contact between the water washed gas from the water wash column and a buffered acid solution to remove a second portion of the nitrogenous base from the carbon dioxide-lean gas to form an acid washed solution;
• and
• a separator configured to receive the acid washed solution from the acid wash column and to separate the second portion of the nitrogenous base from the acid washed solution, the separator including:
• a cyclone separator;
• or
• a solvent extraction separator configured to separate the second portion of the nitrogenous base from the acid washed solution using a solvent present in the non-aqueous solvent.