Concepedia

Publication | Closed Access

Effect of gasifier environment on materials performance

20

Citations

0

References

1993

Year

Abstract

The main purpose of this paper is to review existing knowledge on metal alloy behaviour in contact with highly reducing syngas in coal gasification plants, presently close to commercialization. A secondary purpose is to compare laboratory and plant corrosion data. Present commercial practice indicates that most metal alloys will be used as heat exchangers to evaporate steam at 350–450°C. Smaller but significant future applications may be superheaters or hot-gas clean-up equipment exposed at 500–600°C. The alloys will probably be in contact with non-equilibrium gases quenched from much higher gasification temperatures in the range 1000–1500°C. Under these conditions the formation of chromia- rich protective oxide scales is rarely observed. The growth rate of less protective oxide/sulfide scales varies considerably with temperature, gas composition and alloy composition. For most applications, available Fe-Cr-Ni alloys can be found to provide adequate service life, provided carburization after long exposures can be avoided.