Method for capturing co2 from a flue gas from a district heating plant

A method for capturing CO2 from a flue gas from a district heating plant fired on a carbonaceous fuel, where the flue gas is compressed and thereafter cooled before the flue gas is introduced into an absorber, where the flue gas is brought in countercurrent flow to an aqueous CO2 absorbent solution introduced into the absorber, to give a lean flue gas that is withdrawn from the absorber, reheated against incoming compressed flue gas, and thereafter expanded and released into the atmosphere, where the rich absorbent having absorbed CO2 is collected at the bottom of the absorber, withdrawn therefrom and introduced into a regenerator in which the CO2 rich absorbent is stripped to release CO2 by countercurrent flow to steam to give a lean absorbent, withdrawing the stripped, or lean absorbent from the bottom of the regenerator and introduction of the lean absorbent into the absorber, and withdrawing of the CO2 stripped of the absorbent and steam from the regenerator for further treatment and export for deposition of the CO2, wherein the flow of lean absorbent is split in two, a first flow which is introduced at the top of an absorbent packing in the absorber, and a second flow which is introduced at the top of a cooler packing at the top of the absorber for cooling and drying of the lean flue gas before being reheated against incoming compressed flue gas, and thereafter expanded and released into the surrounding, and wherein the second absorbent flow is cooled against a heat fluid received from the district heating plant and wherein the thus heated heat fluid is led back to the district heating plant.

A plant for capturing CO2 from a flue gas from a district heating plant fired on a carbonaceous fuel comprising a flue gas pipe for introduction of the flue gas into a flue gas compressor operated by a driver, a compressed flue gas pipe for introducing the compressed flue gas into a heat exchange unit wherein the compressed flue gas is cooled against a CO2 lean flue gas, a cooled flue gas pipe for withdrawing the cooled flue gas and introduction thereof into absorber column below packed section, a lean absorbent pipe for introduction of lean absorbent at the top of the packed section, a lean flue gas pipe connected to the top of the absorbent column for leading the lean flue gas from the absorber column to the heat exchange unit to be heated against the compressed flue gas, a heated lean flue gas pipe for leading the heated lean flue gas from the heat exchange unit into a lean flue gas expander, an expanded lean flue gas pipe for releasing the lean flue gas into the surroundings, a rich absorbent pipe for leading rich absorbent collected at the bottom of the absorber and introduction thereof into a desorber column at the top of packed stripper section, steam pipes for introduction of steam into the desorber column below the packed stripper section, a CO2 withdrawal pipe arranged to withdraw CO2 from the top of the desorber column for further treatment and disposal, and a lean absorbent pipe for leading lean absorbent collected at the bottom of the desorber column and introduction thereof into the absorber column, wherein a side draw pipe is arranged to withdraw a part of the lean absorbent in the lean absorbent pipe, introduce the withdrawn absorbent into the cooling water heat exchanger for cooling thereof against heat medium received from the district heating plant in a heat medium pipe, where a heat medium return pipe is arranged to return the thus heated heat medium to the district heating plant, and a cooling medium introduction pipe for leading the cooled lean absorbent from the heat exchanger and introduction thereof at the top of a cooler packing at the top of the absorber.