Evaluation of ammonia fixation components in actual refinery sour waters

Book · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6119032

Ammonia fixation is a term used to describe the occurrence of ammonia in stripped sour waters (SSW) that is resistant to removal by means of additional steam. Samples of refinery SSW were analyzed for organic components, oxidized sulfur compounds, and heavy metals to determine the cause of ammonia fixation during stripping. The heavy metals levels measured were too low to be causes of fixation. However, acidic materials were identified that would cause fixation. These acids included thiosulfuric acid, thiocyanic acid, and weak organic acids. In some SSW, ammonia is synthesized during analysis, resulting in an apparent nonstrippable residual ammonia. Analytical difficulties were encountered in measuring cyanides, ammonia, and sulfides in sour waters. The cyanide measurements often showed free cyanide values exceeding total cyanides. Ammonia measurements yielded high apparent values in some sour waters because ammonia was synthesized during the analysis. Measurement of low sulfide concentrations was hampered by an unknown component in sour water that interfered with the methylene blue test for sulfide. This interference could not be eliminated by sample dilution. The sulfide test also gave highly variable results even when interferences were not a factor. The amount of ammonia fixation that will occur with a particular sour water can be predicted by a potentiometric titration. Fixation can also be predicted by batch stripping using nitrogen gas until the pH of the stripped water reaches 6.

• OSTI ID: 6119032
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020800* -- Petroleum-- Waste Management
AMINES
AMMONIA
AZINES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHLORIDES
CHLORINE COMPOUNDS
CRYOGENIC FLUIDS
CYANIDES
DRUGS
ELEMENTS
EVALUATION
FLUIDS
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
LIQUID WASTES
METHYLENE BLUE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PETROLEUM REFINERIES
PH VALUE
PHASE TRANSFORMATIONS
PHENOTHIAZINES
POTENTIOMETRY
QUALITATIVE CHEMICAL ANALYSIS
SOLIDIFICATION
STEAM
SULFIDES
SULFUR COMPOUNDS
THIOCYANIC ACID
TITRATION
WASTE WATER
WASTES
WATER