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 having a lower concentration of carbon dioxide than the carbon dioxide-containing gas, wherein the non-aqueous solvent comprises a nitrogenous base;
• an acid wash column configured to remove the nitrogenous base entrained in the carbon dioxide-lean gas with sulfuric acid to form an acid washed solution including the sulfuric acid and the nitrogenous base and an acid washed gas having a lower concentration of the nitrogenous base than the carbon dioxide-lean gas;
• and
• a packed bed including calcium hydroxide configured to increase a pH of the acid washed solution.

A method of removing carbon dioxide from a carbon dioxide-containing gas, the method comprising:

• absorbing carbon dioxide from the carbon dioxide-containing gas in an absorber with a nitrogenous base to form a loaded absorbent including the carbon dioxide and a carbon dioxide-lean gas including entrained nitrogenous base;
• removing the nitrogenous base from the carbon dioxide-lean gas with an acid wash solution to form an acid washed solution including the nitrogenous base and a cleaned gas having a lower concentration of the nitrogenous base than the carbon dioxide-lean gas;
• and
• passing the acid washed solution through a packed bed including calcium hydroxide to deprotonate the nitrogenous base in the acid washed solution.