(JP8532370-X)      Prodn. of a carbonaceous absorbent (A) comprises: (a) halogenating a carbonised coal by contacting it with a halogen gas; (b) eliminating all or part of the halogen to give a porous carbonaceous material; and (c) micropore adjusting by contacting with a thermally decomposable hydrocarbon. Also claimed is a prodn. method for another carbonaceous absorbent (B) comprising performing activation treatment in place of the above step (c).    USE -   For prepn. of a carbonaceous absorbent having 9-14 cm3/g oxygen absorption (25 C, 1 atmos.) and 40-80 oxygen/nitrogen sepn. factor (claimed); for sepn. of CO2 and/or methane from a starting gas (claimed); for sepn. of nitrogen from air (claimed); for prodn. of hydrogen by removing CO2 from a methane-decompsn. gas; for prodn. of hydrogen by removing methane, etc., from coke oven gas; and for prodn. of CO2 by concentrating CO2 from a combustion discharge gas.    ADVANTAGE -   The absorbent (A) has remarkably improved oxygen absorption, and gives high nitrogen prodn. yield and decreased costs. The absorbent (B) has remarkably improved CO2 and methane absorption, and gives good sepn. of CO2 or methane from mixed gases.    (US5972834-A)      Prodn. of a carbonaceous absorbent (A) comprises: (a) halogenating a carbonised coal by contacting it with a halogen gas; (b) eliminating all or part of the halogen to give a porous carbonaceous material; and (c) micropore adjusting by contacting with a thermally decomposable hydrocarbon. Also claimed is a prodn. method for another carbonaceous absorbent (B) comprising performing activation treatment in place of the above step (c).    USE -   For prepn. of a carbonaceous absorbent having 9-14 cm3/g oxygen absorption (25 C, 1 atmos.) and 40-80 oxygen/nitrogen sepn. factor (claimed); for sepn. of CO2 and/or methane from a starting gas (claimed); for sepn. of nitrogen from air (claimed); for prodn. of hydrogen by removing CO2 from a methane-decompsn. gas; for prodn. of hydrogen by removing methane, etc., from coke oven gas; and for prodn. of CO2 by concentrating CO2 from a combustion discharge gas.    ADVANTAGE -   The absorbent (A) has remarkably improved oxygen absorption, and gives high nitrogen prodn. yield and decreased costs. The absorbent (B) has remarkably improved CO2 and methane absorption, and gives good sepn. of CO2 or methane from mixed gases.    (JP2995495-B2)      Prodn. of a carbonaceous absorbent (A) comprises: (a) halogenating a carbonised coal by contacting it with a halogen gas; (b) eliminating all or part of the halogen to give a porous carbonaceous material; and (c) micropore adjusting by contacting with a thermally decomposable hydrocarbon. Also claimed is a prodn. method for another carbonaceous absorbent (B) comprising performing activation treatment in place of the above step (c).    USE -   For prepn. of a carbonaceous absorbent having 9-14 cm3/g oxygen absorption (25 C, 1 atmos.) and 40-80 oxygen/nitrogen sepn. factor (claimed); for sepn. of CO2 and/or methane from a starting gas (claimed); for sepn. of nitrogen from air (claimed); for prodn. of hydrogen by removing CO2 from a methane-decompsn. gas; for prodn. of hydrogen by removing methane, etc., from coke oven gas; and for prodn. of CO2 by concentrating CO2 from a combustion discharge gas.    ADVANTAGE -   The absorbent (A) has remarkably improved oxygen absorption, and gives high nitrogen prodn. yield and decreased costs. The absorbent (B) has remarkably improved CO2 and methane absorption, and gives good sepn. of CO2 or methane from mixed gases.    (CN1156974-A)      Prodn. of a carbonaceous absorbent (A) comprises: (a) halogenating a carbonised coal by contacting it with a halogen gas; (b) eliminating all or part of the halogen to give a porous carbonaceous material; and (c) micropore adjusting by contacting with a thermally decomposable hydrocarbon. Also claimed is a prodn. method for another carbonaceous absorbent (B) comprising performing activation treatment in place of the above step (c).    USE -   For prepn. of a carbonaceous absorbent having 9-14 cm3/g oxygen absorption (25 C, 1 atmos.) and 40-80 oxygen/nitrogen sepn. factor (claimed); for sepn. of CO2 and/or methane from a starting gas (claimed); for sepn. of nitrogen from air (claimed); for prodn. of hydrogen by removing CO2 from a methane-decompsn. gas; for prodn. of hydrogen by removing methane, etc., from coke oven gas; and for prodn. of CO2 by concentrating CO2 from a combustion discharge gas.    ADVANTAGE -   The absorbent (A) has remarkably improved oxygen absorption, and gives high nitrogen prodn. yield and decreased costs. The absorbent (B) has remarkably improved CO2 and methane absorption, and gives good sepn. of CO2 or methane from mixed gases.