NOVELTY - Selectively separating hydrogen sulfide from a feed gas mixture comprising carbon dioxide and hydrogen sulfide, comprises: (a) contacting the feed gas mixture under sorption conditions with a non-aqueous sorbent comprising a basic non-protogenic nitrogenous compound; (b) sorbing the hydrogen sulfide into/onto the sorbent; (c) subjecting the sorbent to desorption conditions by which at least a portion of the sorbed hydrogen sulfide is desorbed; and (d) retrieving an hydrogen sulfide-rich product stream that has a higher mole% of hydrogen sulfide than the feed gas mixture.    USE - The process is useful for selectively separating hydrogen sulfide from a feed gas mixture comprising carbon dioxide and hydrogen sulfide.    DETAILED DESCRIPTION - Selectively separating hydrogen sulfide from a feed gas mixture comprising carbon dioxide and hydrogen sulfide, comprises: (a) contacting the feed gas mixture under sorption conditions with a non-aqueous sorbent comprising a basic non-protogenic nitrogenous compound which reacts with at least a portion of the hydrogen sulfide in the feed gas mixture; (b) sorbing the hydrogen sulfide into/onto the sorbent; (c) subjecting the sorbent to desorption conditions by which at least a portion of the sorbed hydrogen sulfide is desorbed; and (d) retrieving an hydrogen sulfide-rich product stream that has a higher mole% of hydrogen sulfide than the feed gas mixture. INDEPENDENT CLAIMS are included for:    (1) a cyclic process-1 for selectively separating hydrogen sulfide from a natural gas feed stream comprising hydrogen sulfide and carbon dioxide, comprising (i) contacting the natural gas feed stream under hydrogen sulfide sorption conditions with a non-aqueous sorbent comprising a basic non-protogenic nitrogenous compound, (ii) reacting at least a portion of the hydrogen sulfide in the natural gas feed stream with the sorbent so that the hydrogen sulfide is absorbed by the sorbent, (iii) retrieving a natural gas product stream, (iv) subjecting the sorbent containing the sorbed hydrogen sulfide to desorption conditions by which at least a portion of the hydrogen sulfide in the sorbent is desorbed from the sorbent, (v) retrieving a hydrogen sulfide rich product stream that has a higher mole% of hydrogen sulfide than the natural gas feed stream, (vi) passing at least a portion of the hydrogen sulfide-rich product stream to a Claus plant, and (vii) recovering sulfur from the hydrogen sulfide in the side stream, where the natural gas product stream has a lower content of hydrogen sulfide in mole% than the natural gas feed stream;    (2) a cyclic process-2 for separating hydrogen sulfide and carbon dioxide from a natural gas feed stream comprising hydrogen sulfide and carbon dioxide, from a producing formation, comprising the step (i) as above per se, (iia) reacting at least a portion of the hydrogen sulfide and carbon dioxide in the natural gas feed stream with the sorbent so that the hydrogen sulfide and the carbon dioxide are sorbed by the sorbent, the step (iii) as above per se, (iva) subjecting the sorbent containing the sorbed hydrogen sulfide and carbon dioxide to first desorption conditions by which a higher mole% of carbon dioxide is desorbed than hydrogen sulfide, (va) retrieving a carbon dioxide rich product stream that has a higher mole% of carbon dioxide than the natural gas feed stream, (via) subjecting the sorbent containing the sorbed hydrogen sulfide and carbon dioxide to second desorption conditions by which a higher mole% of hydrogen sulfide is desorbed than carbon dioxide, (viia) retrieving an hydrogen sulfide-rich product stream that has a higher mole% of hydrogen sulfide than the natural gas feed stream, and (viiia) re-injecting the side stream comprising carbon dioxide into the producing formation, where the natural gas product stream has a lower mole% of each hydrogen sulfide and carbon dioxide than the natural gas feed stream; and    (3) a cyclic process-3 for separating hydrogen sulfide and carbon dioxide from a feed gas stream comprising hydrogen sulfide and carbon dioxide, to produce a first product gas stream comprising hydrogen sulfide and a second product gas stream comprising carbon dioxide depleted in hydrogen sulfide, comprising the step (i) as above per se, (iib) reacting at least a portion of the hydrogen sulfide and the carbon dioxide in the feed gas stream with the sorbent so that the hydrogen sulfide and carbon dioxide are sorbed by the sorbent, (iiib) subjecting the sorbent containing the sorbed hydrogen sulfide and carbon dioxide to carbon dioxide desorption conditions by which a higher mole% of the carbon dioxide is desorbed than hydrogen sulfide, (ivb) retrieving a carbon dioxide rich product stream that has a higher mole% of carbon dioxide than the feed gas stream, (vb) subjecting the sorbent containing the absorbed hydrogen sulfide and carbon dioxide to hydrogen sulfide desorption conditions by which a higher mole% of hydrogen sulfide is desorbed than carbon dioxide, and (vib) retrieving an hydrogen sulfide rich product stream that has a higher mole% of hydrogen sulfide than the feed gas stream.