Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas
A process for recovering sulfur from a hydrogen sulfide-bearing gas utilizes an aqueous reaction medium, a temperature of about 110-150° C., and a high enough pressure to maintain the aqueous reaction medium in a liquid state. The process reduces material and equipment costs and addresses the environmental disadvantages associated with known processes that rely on high boiling point organic solvents.
1. A process for removing sulfur from a hydrogen sulfide-containing gas, comprising the steps of:
supplying an aqueous solvent composed primarily of water into a reactor:
heating the aqueous solvent to a temperature of at least about 110° C. applying at least about 2 atmospheres of pressure to the reactor;
supplying sulfur dioxide into the reactor;
supplying a hydrogen sulfide-containing gas into the reactor;
chemically reacting the hydrogen sulfide with the sulfur dioxide to yield elemental sulfur, water and hydrogen sulfide-depleted gas;
recovering the elemental sulfur from the reactor; and
recovering the hydrogen sulfide-depleted gas from the reactor.
2. The process of claim 1 , wherein the aqueous solvent comprises at least about 75% by weight water.
3. The process of claim 1 , wherein the aqueous solvent comprises at least about 85% by weight water.
4. The process of claim 1 , wherein the aqueous solvent comprises at least about 95% by weight water.
5. The process of claim 1 , wherein the aqueous solvent is heated to a temperature of about 120° C. to about 150° C.
6. The process of claim 1 , wherein the pressure is at least about 10 atmospheres.
7. The process of claim 1 , wherein the pressure is at least about 20 to about 100 atmospheres.
8. The process of claim 1 , wherein the pressure is at least about 30 to about 80 atmospheres.
9. The process of claim 1 , further comprising the step of supplying a homogeneous catalyst into the reactor.
10. The process of claim 1 , further comprising the step of burning the elemental sulfur recovered from the reactor to yield sulfur dioxide.
11. The process of claim 1 , further comprising the step of cooling the hydrogen sulfide-depleted gas to remove solvent vapor.
12. The process of claim 1 , further comprising the step of removing sulfur dioxide from the hydrogen sulfide-depleted gas.
13. A process for removing sulfur from a hydrogen sulfide-containing gas, comprising the steps of:
providing a first elongated column reactor having inlets, outlets and an interior;
supplying an aqueous solvent composed primarily of water to one of the inlets;
heating the aqueous solvent to a temperature of at least about 115° C.;
applying at least about 10 atmospheres of pressure to the interior;
supplying sulfur dioxide to one of the inlets;
supplying a hydrogen sulfide-containing gas having a first hydrogen sulfide content to one of the inlets;
chemically reacting the sulfur dioxide with the hydrogen sulfide in the interior to yield elemental sulfur, water, and a hydrogen sulfide-depleted gas having a second hydrogen sulfide content;
removing the elemental sulfur from the interior through a first of the outlets; and
removing the hydrogen sulfide-depleted gas through a second of the outlets.
14. The process of claim 13 , wherein the aqueous solvent and hydrogen sulfide-containing gas are supplied to first and second of the outlets, respectively.
15. The process of claim 14 , wherein the sulfur dioxide is supplied to a third of the inlets.
16. The process of claim 13 , wherein the sulfur dioxide is supplied in a stoichiometric excess of an amount needed to chemically react with the hydrogen sulfide.
17. The process of claim 13 , further comprising the steps of:
providing a second elongated column having inlets, outlets and an interior;
supplying an aqueous solvent composed primarily of water to one of the inlets of the second elongated column;
heating the aqueous solvent supplied to the second elongated column to a temperature of at least about 115° C.;
applying at least about 10 atmospheres of pressure to the interior of the second elongated column;
supplying the hydrogen sulfide-depleted gas from the first elongated column to an inlet of the second elongated column, the hydrogen sulfide-depleted gas having the second hydrogen sulfide content;
chemically reacting the hydrogen sulfide from the hydrogen sulfide-depleted gas with sulfur dioxide in the second elongated column to yield elemental sulfur, water and second stage hydrogen sulfide-depleted gas;
removing the elemental sulfur through a first of the outlets in the second elongated column; and
removing the second stage hydrogen sulfide-depleted gas through a second of the outlets in the second elongated column.
18. The process of claim 17 , wherein the sulfur dioxide is supplied to the second elongated column as part of the hydrogen sulfide-depleted gas from the first elongated column.
19. The process of claim 17 , wherein at least some of the sulfur dioxide is supplied to the second elongated column from a source independent of the hydrogen sulfide-depleted gas from the first elongated column.
20. The process of claim 17 , wherein the second stage hydrogen sulfide-depleted gas has a lower sulfur dioxide content than the hydrogen sulfide-depleted gas.
21. A process of removing sulfur from a sulfur dioxide-containing gas, comprising the steps of
supplying an aqueous solvent containing at least about 80% by weight water into a reactor;
heating the aqueous solvent to a temperature of about 120° C. to about 150° C.;
applying about 30 to about 80 atmospheres of pressure to the reactor;
supplying sulfur dioxide into the reactor;
supplying a hydrogen sulfide-containing gas into the reactor;
chemically reacting the hydrogen sulfide with the sulfur dioxide to yield elemental sulfur, water, and hydrogen sulfide-depleted gas;
removing the elemental sulfur from the reactor;
removing the hydrogen sulfide-depleted gas from the reactor; and
removing excess water from the reactor.