Methods for the removal of gaseous impurities from mixed gas streams

A method for the preparation of the D-M-O reactive solid containing alumina wherein D is potassium, M is manganese and O is oxygen, comprising the steps of:

• (a) dissolving potassium permanganate in water,
• (b) adding, to the potassium permanganate solution resulting from step (a), about 0.01 to about 0.20 mole of aluminum nitrate per mole of potassium permanganate in said solution,
• (c) drying the solution resulting from step (b) to a solid,
• (d) heating the resultant solid to temperatures between about 600.degree. C. to about 900.degree. C. under an inert atmosphere for about one-half hour,
• (e) cooling the solid resulting from step (d) to about room temperature, and
• (f) pressing the solid into cylindrical disks.

A method for the preparation of the D-M-O reactive solid containing alumina wherein D is potassium, M is iron, and O is oxygen, comprising the steps of:

• (a) adding ferric nitrate to melted potassium hydroxide in the ratio of one mole of ferric nitrate to about 8 to about 12 moles of melted potassium hydroxide,
• (b) adding, to the slurry resulting from step (a), about 0.01 to about 0.20 mole of aluminum nitrate per mole of ferric nitrate in said slurry,
• (c) heating the mixture resulting from step (b) to about 360.degree. C.,
• (d) cooling the mixture resulting from step (c) to about room temperature,
• (e) adding the mixture resulting from step (d) into an excess of cold 50% potassium hydroxide solution,
• (f) filtering the insoluble brown precipitate product,
• (g) washing the filtrate resulting from step (f) in about 1 molar potassium hydroxide solution while maintaining said solution at about 0.degree. C. to about 10.degree. C.,
• (h) refiltering the brown precipitate,
• (i) drying the solid resulting from step (h), and
• (j) pressing the solid into cylindrical disks.

A method for the preparation of the D-M-O reactive solid containing alumina wherein D is potassium, M is copper, and O is oxygen, comprising the steps of:

• (a) dissolving copper nitrate in water,
• (b) adding, to the copper nitrate solution resulting from step (a), about 0.01 to about 0.20 mole of aluminum nitrate per mole of copper nitrate in said solution,
• (c) adding 50% potassium hydroxide solution to the solution resulting from step (b) while stirring and chilling,
• (d) removing the supernatant liquid from the solution resulting from step (c),
• (e) drying the solid resulting from step (d), and
• (f) pressing the solid resulting from step (e) into cylindrical disks.

A method for recovering sulfur by converting hydrogen sulfide in a gas stream by direct oxidation of the hydrogen sulfide to elemental sulfur vapor comprising the steps of mixing said gas stream with gaseous oxygen present in an approximate stoichiometric amount for the direct conversion of hydrogen sulfide to elemental sulfur vapor;

• contacting said mixed gas stream at a temperature above about 300.degree. C. with a reactive solid of the general formula D-M-O wherein D is chosen from the alkali metals and alkaline earth metals;
• M represents a transition metal selected from the group consisting of manganese, copper, iron and groups VB, VIB, VIIB, VIII and IB of the Periodic Table;
• and O represents oxygen, to convert said hydrogen sulfide to elemental sulfur vapor by direct oxidation;
• and condensing said elemental sulfur vapor to thereby recover the same.

A method for recovering sulfur by converting hydrogen sulfide in a gas stream by direct oxidation of such hydrogen sulfide to elemental sulfur vapor comprising the steps of:

• (a) contacting said gas stream at a temperature above about 300.degree. C. with a reactive solid of the general formula D-M-O wherein D is chosen from the alkali metals or alkaline earth metals and M represents a transition metal selected from the group consisting of manganese, copper and iron, and groups IB, VB, VIB, VIIB, VIII of the Periodic Table;
• and O designates oxygen to convert said hydrogen sulfide to elemental sulfur vapor by direct oxidation;
• (b) condensing said elemental sulfur vapor;
• and
• (c) reoxidizing said reactive solid upon completion of step (a) by flowing an oxygen containing gas stream over the reactive solid at about atmospheric pressure for such a time and at such a temperature whereby oxygen in said gas stream reacts with said reactive solid to reoxidize the same.