Method to condense and recover carbon dioxide (CO2) from CO2 containing gas streams

A method to cool and condense a CO2 containing gas stream to recover CO2, comprising the steps of:

• providing more than one heat exchanger, the more than one heat exchanger comprising at least one water condensing heat exchanger and at least one CO2 condensing heat exchanger, each heat exchanger having a first flow path for passage of a first fluid and a second flow path for passage of a second fluid;
• passing an uncompressed CO2 containing gas stream along the first flow path of the water condensing heat exchanger to cool and condense water vapor in the CO2 containing gas stream, and through a separator to separate condensed water from the CO2 containing gas stream;
• cooling coolant water in a chiller that is powered by heat in the CO2 containing gas stream;
• compressing the CO2 containing gas stream exiting the separator and then cryogenically cooling the CO2 containing gas stream in the at least one CO2 condensing heat exchanger, the at least one CO2 condensing heat exchanger condensing at least a portion of the CO2 in the CO2 containing gas stream, and
• separating the condensed CO2 from the cooled CO2 containing gas stream in a CO2 separator;
• passing the cooled CO2 containing gas stream from the CO2 separator along the second flow path of at least one heat exchanger to cool the CO2 containing gas stream in the first flow path;
• passing the cooled coolant water from the chiller along the second flow path of at least one heat exchanger to cool the CO2 containing gas stream in the first flow path;
• generating a natural gas stream at a temperature and pressure suitable for distribution in a distribution natural gas line from a Liquid Natural Gas (LNG) stream by:
• firstly, pressurizing the LNG stream in a liquid pump;
• secondly, heating the pressurized LNG stream in stages by passing the pressurized LNG stream through the second flow path of the at least one CO2 condensing heat exchanger and at least one additional heat exchanger to generate the natural gas stream;
• and
• thirdly, passing the natural gas stream through a gas expander to depressurize and cool the natural gas stream to a pressure and temperature suitable for distribution, the natural gas stream being expanded by the gas expander without being consumed, the gas expander being capable of generating power from expanding natural gas before discharging the natural gas stream into the distribution natural gas line for downstream consumption.