Influence of sulfation-enhancement salt additives on the corrosion behavior of materials in atmospheric fluidized-bed combustors

Technical Report · Tue Dec 01 04:00:00 EST 1981

OSTI ID:5529495

Chopra, O K; Smith, G W; Lenc, J F; Myles, K M; Johnson, I

Increased utilization of CaO can reduce the amount of limestone required for SO/sub 2/ retention in atmospheric fluidized-bed combustion (AFBC) systems. A recently developed method of improving the utilization involves treating the limestone with various salts, such as NaCl, CaCl/sub 2/, or Na/sub 2/CO/sub 3/. The present report provides information on the influence of these sulfation-enhancement salt additives on corrosion of candidate structural materials for AFBC systems. Four 100-h and two 1000-h corrosion test runs were conducted in a 152-mm-ID fluidized-bed coal combustor. In each run, three air-cooled corrosion probes and four uncooled corrosion coupon holders, each with seven specimens, were installed at various locations in the fluidized bed and freeboard sections of the combustor. The temperature of the corrosion specimens ranged from 400 to 850/sup 0/C. As controls, some of the runs were made without any salt additions. The results indicate that the presence of salt has no effect on the corrosion behavior of the various iron- and nickel-base alloys that were placed in the freeboard section of the combustor. Although the uncooled alloys within the fluidized bed do undergo oxidation/sulfidation corrosion, the addition of CaCl/sub 2/ does not further affect the corrosion rate; the addition of NaCl or Na/sub 2/CO/sub 3/ increases the corrosion rates for the high-nickel alloys, but not for the stainless steels. The observed corrosion rates for all of the alloys from within the fluidized bed containing approximately 2 mol % CaCl/sub 2/ or Na/sub 2/CO/sub 3/ are in good agreement with the rates reported in other similar studies without salt additions. The corrosion data and a metallographic evaluation of the corrosion specimens are presented.

• Research Organization: Argonne National Lab., IL (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5529495
• Report Number(s): ANL/CEN/FE-80-18; ON: DE82010204
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
42 ENGINEERING
421000* -- Engineering-- Combustion Systems
ADDITIVES
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE ROCKS
CARBONATES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COAL
COMBUSTORS
CORROSION
CORROSIVE EFFECTS
DATA
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
HALIDES
HALOGEN COMPOUNDS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
LIMESTONE
MATERIALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NUMERICAL DATA
OXYGEN COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SODIUM CARBONATES
SODIUM CHLORIDES
SODIUM COMPOUNDS