Carbon dioxide liquefaction device

Abstract

The present invention is equipped with: a carbon dioxide liquefaction unit, which performs a heat exchange with a refrigerant (which is a portion of a cold heat source in the gaseous state that is used and manufactured in a cold heat source production plant), thereby liquefying carbon dioxide which has been separated and recovered from a gas containing carbon dioxide; and an energy recovery unit, which extracts energy and lowers the temperature of the gaseous refrigerant by expanding the gaseous refrigerant that has exchanged heat with the carbon dioxide in the carbon dioxide liquefaction unit. The energy recovery unit returns the gaseous refrigerant, the temperature of which has been lowered, to the cold heat source production plant.

1 . A carbon dioxide liquefaction device comprising:
 a carbon dioxide liquefaction unit which liquefies carbon dioxide separated and recovered from a gas containing carbon dioxide, by performing heat exchange with a portion of a cold heat source in a gaseous state, which is used and manufactured in a cold heat source production plant, as a refrigerant; and   an energy recovery unit which expands a gaseous refrigerant having performed heat exchange with the carbon dioxide in the carbon dioxide liquefaction unit, thereby extracting energy and at the same time, lowering a temperature of the gaseous refrigerant, wherein the energy recovery unit returns the gaseous refrigerant having a lowered temperature to the cold heat source production plant.   
     
     
         2 . The carbon dioxide liquefaction device according to  claim 1 , wherein the energy recovery unit lowers the temperature of the gaseous refrigerant to a temperature needed in order to use the gaseous refrigerant in the cold heat source production plant. 
     
     
         3 . The carbon dioxide liquefaction device according to  claim 1 , wherein the cold heat source production plant is provided with an air cryogenic separation unit which can separate raw material air into at least oxygen and nitrogen. 
     
     
         4 . The carbon dioxide liquefaction device according to  claim 3 , wherein the air cryogenic separation unit is provided with a heat exchange unit which performs heat exchange by using the gaseous refrigerant having a temperature lowered by the energy recovery unit. 
     
     
         5 . The carbon dioxide liquefaction device according to  claim 4 , wherein a plurality of sets of combinations of the energy recovery unit and the heat exchange unit are provided to be connected in series. 
     
     
         6 . The carbon dioxide liquefaction device according to  claim 2 , wherein the cold heat source production plant is provided with an air cryogenic separation unit which can separate raw material air into at least oxygen and nitrogen.