Absorbing solution, method and device for absorbing CO2 or H2S or both

A removing apparatus which removes at least one of CO2 and H2S that are present in a gas, the removing apparatus comprising:

• an absorber that receives the gas and causes the gas to come into contact with an absorbing-solution whereby at least one of CO2 and H2S is absorbed by the absorbing-solution;
• and
• a regenerator that regenerates the absorbing-solution which has absorbed at least one of CO2 and H2S by removing any one of CO2 and H2S or both from the absorbing-solution, and that supplies the absorbing-solution from which at least one of CO2 and H2S has been removed to the absorber,
• wherein the absorbing-solution includes a secondary-amine composite absorbent which is a mixture of a secondary monoamine and a secondary diamine and a tertiary monoamine that is added to the secondary-amine composite absorbent, wherein the tertiary monoamine concentration with respect to the mixture of secondary monoamine and secondary diamine is set to 1 to 20 weight percent.

A method of removing apparatus to remove at least one of CO2 and H2S that are present in a gas, the method comprising:

• causing the gas to come into contact with an absorbing-solution whereby at least one of CO2 and H2S is absorbed by the absorbing-solution;
• and
• regenerating the absorbing-solution that absorbed any one of CO2 and H2S by removing at least one of CO2 and H2S from the absorbing-solution,
• wherein the causing step includes causing the gas to come into contact with an absorbing-solution that is regenerated in the regenerating step, and
• wherein the absorbing-solution includes a secondary-amine composite absorbent which is a mixture of a secondary monoamine and a secondary diamine, and 1 to 20 weight-percent, based on the weight of said secondary-amine composite absorbent, of a tertiary monoamine that is added to the secondary-amine composite absorbent.