Regeneration of liquid redox systems using Thiobacillus ferrooxidans
AssigneeGas Research Institute
InventorCharanjit Rai
Life of this patent
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Abstract
In the removal of hydrogen sulfide from a gas stream by use of a liquid catalyst containing ferric ions, the ferric ions of the liquid catalyst are converted to ferrous ions. Regeneration of the ferric ions can be accomplished by bubbling air through the liquid catalyst. A significant decrease in regeneration time for transforming the ferrous ions back to the original ferric ion state can occur when a culture of Thiobacillus ferrooxidans bacteria is introduced to the liquid catalyst. Optimization indicates a pH range between 6.0 and 9.0, a temperature between 20.degree. C. and 45.degree. C. and a cell concentration of 12.5.times.10.sup.8 cells per liter.
Claims23
A process for removal of hydrogen sulfide from a gas, the process comprising:
- introducing a first gas stream containing hydrogen sulfide into a liquid catalyst comprising ferric ions, thereby causing oxidation of said first gas stream containing hydrogen sulfide;
- maintaining said liquid catalyst at a pH of about 7.0 to 10.0, said first gas stream being in contact with said liquid catalyst;
- said oxidation converting said liquid catalyst ferric ions to ferrous ions thereby causing formation of elemental sulfur;
- maintaining in said neutral or alkaline liquid catalyst a culture of Thiobacillus ferrooxidans bacteria;
- contacting a second gas stream containing oxygen molecules with said liquid catalyst;
- and
- wherein said second gas stream regenerates said ferrous ions to ferric ions.
A process for batch removal of hydrogen sulfide from a gas stream, the process comprising:
- introducing a first gas stream containing hydrogen sulfide into a liquid catalyst comprising ferric ions capable of oxidizing said hydrogen sulfide into elemental sulfur thereby causing oxidation of said first gas stream containing hydrogen sulfide, said liquid catalyst further comprising a culture of Thiobacillus ferrooxidans bacteria;
- maintaining said liquid catalyst at a pH of about 7.0 to 10.0;
- said oxidation converting said liquid catalyst ferric ions to ferrous ions thereby causing formation of elemental sulfur;
- introducing a second gas stream containing oxygen molecules into said liquid catalyst;
- and
- said second gas stream oxidizing said ferrous ions to ferric ions.
A process for continuous removal of hydrogen sulfide from a gas stream, the process comprising:
- introducing a first gas stream containing hydrogen sulfide into a liquid catalyst comprising ferric ions capable of oxidizing said hydrogen sulfide to elemental sulfur thereby causing oxidation of said first gas stream containing hydrogen sulfide;
- maintaining in said liquid catalyst a culture of Thiobacillus ferrooxidans bacteria;
- maintaining said liquid catalyst at a pH of about 7.0 to 10.0;
- said oxidation converting said liquid catalyst ferric ions to ferrous ions thereby causing formation of elemental sulfur;
- introducing a second gas stream containing oxygen molecules into said liquid catalyst simultaneously with said first gas stream;
- and
- said second gas stream oxidizing said ferrous ions to ferric ions.
Dependencies are inferred from the claim text.