Corrosion inhibitors for FGD systems

Technical Report · Wed Apr 01 04:00:00 EST 1987

OSTI ID:6598653

Phull, B S; Lee, T S

Laboratory screening tests were conducted to evaluate the performance of seven corrosion inhibitors on the corrosion behavior of 1020 carbon steel, Type 316L stainless steel, alloy G-3 and Grade 2 titanium in a pilot flue gas desulfurization limestone scrubber. Replicate coupon and U-bend specimens of the three passive alloys were exposed in the absorber; and replicate specimens of all four materials were exposed in the outlet duct pre-reheat and post-reheat test zones. Linear polarization and potentiodynamic polarization tests were also performed on electrodes of all four materials in the slurry and in the outlet duct condensate environments. In the majority of cases, inhibitor was introduced into the slurry at the start of each test. Grade 2 titanium did not suffer any corrosion attack in any of the tests, either in the presence or absence of corrosion inhibitor. In the absorber, no inhibitor was completely effective in eliminating crevice corrosion, the predominant form of attack on alloy G-3 and 316L stainless steel. In the outlet duct pre-reheat zone, carbon steel suffered general corrosion; and alloy G-3 and 316L stainless steel suffered bold surface pitting and crevice corrosion under the coupon specimen mounting washers in the control tests. Only one inhibitor, a complex amine (Cronox 806), when added directly to the slurry appeared to provide complete inhibition in alloy G-3 in the outlet duct pre-reheat zone. Significant inhibition of corrosion of 316L stainless steel and alloy G-3 was observed in the outlet duct pre-reheat zone when a 1% solution of Na/sub 2/HPO/sub 4/ was injected continuously at a rate of 25 mL/min. Corrosion of all four materials was reduced significantly when subjected to reheat conditions. No stress corrosion cracking was observed on any of the materials in any test zone. 51 refs., 28 figs., 13 tabs.

• Research Organization: LaQue Center for Corrosion Technology, Inc., Wrightsville Beach, NC (USA); Electric Power Research Inst., Palo Alto, CA (USA)
• OSTI ID: 6598653
• Report Number(s): EPRI-CS-5157; ON: TI87920418
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200202* -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ACID PHOSPHATES
ALLOYS
AMINES
CARBON STEELS
CHEMICAL REACTIONS
CHEMISTRY
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COMPARATIVE EVALUATIONS
CORROSION
CORROSION INHIBITORS
CORROSION PROTECTION
CORROSION RESISTANT ALLOYS
CREVICE CORROSION
DESULFURIZATION
ECONOMIC ANALYSIS
ECONOMICS
ELECTROCHEMISTRY
ELEMENTS
EQUIPMENT
FLUE GAS
FOSSIL-FUEL POWER PLANTS
GASEOUS WASTES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
LIME-LIMESTONE WET SCRUBBING PROCESSES
MATERIALS
MATERIALS TESTING
METALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
PITTING CORROSION
POLLUTION CONTROL EQUIPMENT
POWER PLANTS
RECOMMENDATIONS
SCRUBBERS
SCRUBBING
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
STRESS CORROSION
TESTING
THERMAL POWER PLANTS
TITANIUM
TRANSITION ELEMENTS
WASTES