H sub 2 S abatement with stabilized chelates in geothermal drilling

Patent · Tue Mar 17 04:00:00 EST 1992

OSTI ID:5246638

Bedell, S A

This patent describes a method for removing hydrogen sulfide from a gas stream. It comprises contacting a gas containing hydrogen sulfide with an aqueous chelating solution to form elemental sulfur, the solution comprising: ferric ions in a concentration of at least about 100 ppm; an aminocarboxylic acid chelating agent in an amount of at least an equivalent weight relative to the ferric ions; a buffering compound for maintaining a pH between about 4 and about 11; and a water-soluble inhibitor having a hydroxyl reaction rate constant of at least about 1 {times} 10{sup 9} dm{sup 3}mol{sup {minus}1}s{sup {minus}1} effective as a hydroxyl radical scavenger in an amount substantially in excess of an equivalent weight relative to the ferric ions, the inhibitor selected from the group consisting of iodide and bromide ions, nitrites, amino acids, aliphatic aldehydes, aryl sulfonic acids, and combinations thereof; wherein at least a portion of the ferric ions are reduced to ferrous ions; removing the sulfur from the solution; and oxidizing the ferric ions to regenerate the solution for reuse.

• Assignee: NOV; EDB-92-101909; NOV-92-028092
• Patent Number(s): US 5096691; A
• Application Number: PPN: US 7-295311
• OSTI ID: 5246638
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150600 -- Geothermal Energy-- Environmental Aspects
154000* -- Geothermal Energy-- Waste Management-- (1990-)
AIR POLLUTION ABATEMENT
CHALCOGENIDES
CHELATING AGENTS
CHEMICAL REACTION KINETICS
DRILLING
GASEOUS WASTES
GEOTHERMAL WELLS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
KINETICS
MANAGEMENT
PH VALUE
POLLUTION ABATEMENT
REACTION KINETICS
SULFIDES
SULFUR COMPOUNDS
WASTE MANAGEMENT
WASTES
WELL DRILLING
WELLS