CONDENSATION-ABSORPTION HYBRID TOWER FOR SIMULTANEOUS WATER VAPOR CONDENSING AND AMMONIA SCRUBBING

摘要

An apparatus for separating and recovering carbon dioxide simply and efficiently is provided to recover high purity carbon dioxide, use a minimum amount of water, and scrub ammonia at a low temperature by exhausting carbon dioxide only from a mixture of carbon dioxide, water vapor and ammonia gas from an upper part of a carbon dioxide stripping tower, washing ammonia gas with water, and condensing water vapor, thereby injecting the condensed water vapor again into the stripping tower. An apparatus for producing high purity carbon dioxide from a mixed gas containing carbon dioxide comprises: a first absorption tower(101) for optionally absorbing carbon dioxide from waste gas using ammonia water; a stripping tower(103) for stripping carbon dioxide from ammonia water containing carbon dioxide; a third absorption tower(106) for absorbing ammonia gas contained in the stripped carbon dioxide using water; a second absorption tower(105) for removing ammonia contained in waste gas(114) from the top of the first absorption tower using water and sending ammonia-containing water to the third absorption tower; a first heat exchanger(102) for exchanging heat between carbon dioxide-containing ammonia water from the first absorption tower and recirculating ammonia water from the stripping tower; a concentration tower(107) for recirculating ammonia-containing water to the second absorption tower while recirculating the concentrated ammonia water to the stripping tower after concentrating some of ammonia water from the stripping tower; and a second heat exchanger(110) for exchanging heat between water discharged from the concentration tower and carbon dioxide-containing ammonia water discharged from the first heat exchanger, wherein the third absorption tower is a condensation-absorption hybrid tower for exhausting carbon dioxide only from a mixture of carbon dioxide, water vapor and ammonia gas exhausted from the top of the stripping tower, washing ammonia gas with water, and condensing water vapor to inject the condensed water vapor into the stripping tower again.