NOVELTY - The method involves regenerating metal in-which the metal is oxidized using oxygen from air. A non-chelating amine is regenerated by heating liquid solution that comprises a physical solvent, the non-chelating amine, the metal, chelating ligand and a stabilizer, where gas stream comprises natural gas and includes pressure of 30-200 bar. Carbon-di-oxide is liberated from the physical solvent by decreasing the pressure above the liquid solution prior to the regeneration of non-chelating amine, where the liquid solution includes a pH of 7-13.    USE - Method for absorbing carbon-di-oxide and hydrogen sulfide from a methane for use as fossil energy source for vehicle or electricity generator.    ADVANTAGE - The method enables connecting first flash vessel in series to second flash vessel to reduce pressure of enriched solution in an efficient manner. The method enables combining absorption of carbon-di-oxide and hydrogen sulfide and conversion of hydrogen sulfide in one single process with the liquid solution, thus providing a more effective and efficient purification process for natural gas that requires lower investment and lower maintenance costs in an efficient manner.    DETAILED DESCRIPTION - The stabilizer is selected from a group consisting of thiodiglycolic acid, 3,3- thiodipropionic acid, sodium thiocyanate, sodium dithionite, ammonium thiosulfate, sodium thiosulfate, diethylhydroxylamine, thiourea, thiosemicarbazide, bisulphite, sodium benzoate, para-toluenesulfonic acid, potassium iodide, potassium bromide, potassium chloride, 2-propanol, 1- butanol, ethylene glycol, sodium formate, sucrose, sorbitol, nitrites, amino acids, aliphatic aldehydes and aryl sulfonic acids. The chelating ligand is selected from a group consisting of nitrilotriacetic acid, hydroxyethyl ethylenediamine triacetic acid, pentetic acid, triethanolamine, N-methyliminodiacetic acid and etidronic acid. The physical solvent is water. The non-chelating amine is an amino acid. The amino acid is selected from a group consisting of taurine, glycine, alanine, asparagine, glutamine, lysine, histidine, derivatives of N-methylglycine and N-methylalanine and sodium or potassium salt. The non-chelating amine is a non-chelating amine e.g. monoethanolamine and 2 piperidine ethanol. An INDEPENDENT CLAIM is also included for an apparatus for purifying a gas stream.    DESCRIPTION OF DRAWING(S) - The drawing shows a graph representing relation between carbon-di-oxide partial pressure and concentration of carbon-di-oxide that is absorbed in a solvent.    Concentration of carbon-di-oxide (C)    Partial carbon-di-oxide pressure (P)