Gasification reactivities of metallurgical cokes with carbon dioxide, steam and their mixtures

Abstract

Gasification reactivities of cokes with carbon dioxide, steam and their mixtures at 1200 °C were investigated, using seven single cokes made in a laboratory furnace from single coals of different properties, and also one commercial coke. The reactivity with steam was significantly higher than that with carbon dioxide. The reactivities of the mixture increased proportionally with increasing steam content above 10%; however, the reactivity below 10% steam content was smaller than that with pure carbon dioxide, the minimum reactivity being observed at a steam content of 2–4%. The reactivities of the compounds corresponding to optical texture were determined by analysing the coke microscopically before and after gasification. In general, except for one coke, the inert texture was the most reactive. Increasing size of the optical unit decreased the gasification reactivity, fibrous and leaflet textures were the least reactive. Gasification with steam developed pores within the inner region of the coke, whereas carbon dioxide reacted with the coke at or near the surface, producing a relatively smooth surface. Some proposals are suggested for better coke production.