Process for the removal of H.sub.2 S and adjustment of the H.sub.2 /CO ratio in gaseous streams containing hydrogen sulfide, carbon monoxide, and hydrogen

A process comprising

• (a) contacting a gaseous stream containing H.sub.2, CO, and H.sub.2 S with an H.sub.2 S-selective absorbent in an absorption zone and absorbing the bulk of the H.sub.2 S in said stream, producing a partially purified gas stream with water and containing a minor portion of H.sub.2 S;
• (b) contacting at least a portion of the partially purified gas stream with a water shift catalyst under conditions to react CO and water in a conversion zone, and converting CO and water to H.sub.2 and CO.sub.2, and producing a modified gas stream having increased ratio of H.sub.2 to CO and a minor portion of H.sub.2 S;
• (c) passing modified gas stream to a contacting zone and contacting modified gas stream with an aqueous reactant solution, the solution containing an effective amount of a reactant comprising oxidizing polyvalent metal ions or a polyvalent metal chelate of an acid having the formula ##STR5## wherein from two to four of the groups Y are selected from acetic and propionic acid groups;
• from zero to two of the groups Y are selected from 2-hydroxy ethyl, 2-hydroxy propyl, and ##STR6## wherein X is selected from acetic acid and propionic acid groups;
• and R is ethylene, propylene or isopropylene or alternatively cyclohexane or benzene where the two hydrogen atoms replaced by nitrogen atoms are in the 1,2 position;
• and mixtures thereof, and converting H.sub.2 S in said modified gas stream to sulfur and recovering a substantially sulfur-free gas modified stream having an increased ratio of H.sub.2 to CO.