PRODUCTION OF GASEOUS CARBON DIOXIDE USING WASTE GAS CONTAINING GASEOUS CARBON DIOXIDE

摘要

PURPOSE:To separate and recover high purity CO2 from waste gas contg. CO2 by absorbing and capturing the CO2 in an absorbing liq. cooled to an extremely low temp. with liquefied natural gas. CONSTITUTION:Waste gas 19 contg. CO2 such as combustion gas is cooled with sea water 21 in a precooler 20, passed through a dehydration tower 22 and a deodorization tower 6, introduced into a heat exchanger 1, and cooled to about -80 deg.C. The cooled gas is fed to an absorption tower 2 provided with a cooler 3 contg. ''Freon'' cooled to -120 deg.C with LNG13, and the gas is brought into contact with a spray of ethanol cooled to -80 deg.C. Most of the CO2 in the waste gas is captured by absorption and separated from the waste gas. The ethanol contg. absorbed CO2 is fed to a stripper 5, and the CO2 is released by heating the ethanol with the heat of waste gas passing through the stripper 5. The released CO2 is liquefied with a liquefier 7 and stored in a tank 8 as liquefied CO2.