Corrosion of refractory materials in fluidised bed gasification of alkali rich fuels

Abstract

Gasification of renewable fuels is not common practice due to the high costs of technologies and the absence of reliably working refractories. Refractory degradation is of such high significance that improved refractory durability was ranked first by industry experts in a list of 20 research and development areas related to the economic viability of gasification. Therefore, for improvement of the reliability and durability of refractory linings, this work is dealing with the corrosion resistance of nine commercial refractories to a variety of emissions from potential fuels. The refractories were exposed to a gasifier-like, water vapour and alkali rich atmosphere. Exposures with a duration of 250 h produced corrosion effects that were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. Furthermore, thermodynamic calculations were included to further explain the equilibrium chemistry. The results show that extremely low silica refractories are promising candidates for gasifier utilisation.

Corrosion of Polycrystalline Wool by Na₂CO₃ Vapor

“…The corrosion of metals and refractories by alkaline vapor is a severe problem in the kiln. 7,8) In addition, when biomass fuels, which utilize renewable energy sources, are burned in various furnaces, corrosion vapor is formed due to the fuel alkalinity, 9,10) which attacks refractories in the furnace. Recently, ceramics containing Na and/or K have been widely studied as lead-free electronic ceramics for environmental protection, and there are major concerns about the effects of alkaline vapors on refractories in the furnace.…”

Thermodynamic Study of the Corrosion of Refractories by Sodium Carbonate

“…Many researchers used scanning electron microscopy (SEM), energy dispersive X-ray detection (EDX), and X-ray diffractometry (XRD) to study the erosion of different kind of refractory materials by alkali metal carbonates [21,22,23,24,25,26,27,28]. The corrosion mechanism of refractory materials by sodium salts is studied from the viewpoint of slag and sedimentt; the anti-sodium corrosion performance of different types of refractory materials is compared, and the best material is selected.…”

Corrosion of laser joined silicon carbide in gasification environment

“…The samples were exposed to a gasifier-like atmosphere at temperatures between 800uC and 900uC for the time period of 250 h. Corrosion effects after exposure were analysed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Recently, the corrosion behaviour of ceramic filter candle materials and several refractory materials was investigated under similar conditions, 22,23 which can also indicate suitable glass filler systems.…”