Process for the removal of highly concentrated carbon dioxide from high-pressure natural gas

摘要

This invention relates to a process for removing highly concentrated CO2 from high-pressure natural gas and recovering it in a high-pressure state. This process comprises the absorption step of bringing high-pressure natural gas having a CO2 partial pressure of 2 kg/cm2 or greater and a pressure of 30 kg/cm2 or greater into gas-liquid contact with a regenerated CO2-lean absorbing fluid comprising a CO2 absorbing fluid of which the difference in saturated CO2 absorption level between 40 DEG C. and 120 DEG C. is not less than 30 Nm3 per ton of solvent at a CO2 partial pressure of 2 kg/cm2, whereby highly concentrated CO2 present in the high-pressure natural gas is absorbed into the CO2-lean absorbing fluid to produce refined natural gas having a reduced CO2 content and a CO2-rich absorbing fluid; and the regeneration step of heating the CO2-rich absorbing fluid without depressurizing it, whereby high-pressure CO2 having a pressure of 10 kg/cm2 or greater is liberated and a CO2-lean absorbing fluid is regenerated and recycled for use in the absorption step.