For separating carbon dioxide (CO2) from a gas stream, a substantially moisture free gas stream is produced using a first temperature swing adsorption (TSA), a first pressure swing adsorption (PSA), a first vacuum swing adsorption (VSA), membrane separation, a first absorption, or any combination thereof. CO2 is captured from the substantially moisture free gas stream and substantially dry CO2 depleted stream is produced using a second TSA, a second PSA, a second VSA, or a second absorption with a non-aqueous solvent with or without a chemical reaction. Adsorbents and/or absorbents used during moisture removal are regenerated using the substantially dry CO2 depleted stream. Purifying a gas stream containing CO2 and impurities includes producing a stream substantially depleted of moisture and impurities using a physical or reactive adsorbent, thermally regenerating the adsorbent to produce a stream substantially enriched in impurities, and removing impurities from the stream substantially enriched in impurities.