CARBON MONOXIDE FROM LEAN GASES.

This paper describes the Cosorb process that can economically recover carbon monoxide from gas streams (including waste gases) at low pressure and ambient temperature. Not only is it effective on relatively rich gas mixtures coming from processes such as hydrocarbon reforming or partial oxidation; it can also cope with waste streams that contain nitrogen, such as basic-oxygen-furnace (BOF) gases, blast-furnace off-gases, and tail gas from carbon-black plants. The Cosorb process relies on selective absorption of CO by forming a chemical complex with cuprous aluminum tetrachloride (CuAlCl//4) in a toluene solvent. Most other components in the gas stream, such as nitrogen, hydrogen, carbon dioxide, oxygen and methane, are only slightly soluble and are not complexed. However, the feed gas must be free of water, hydrogen sulfide and sulfur dioxide because these compounds poison the solvent mixture. Details of the process as well as a scheme of a plant are included.