A metallurgical coke replacement derived from torrefied wood chips pre-treated by wet oxidation

Abstract

We investigated the use of thermally treated wet oxidized biomass as feedstock to produce a metallurgical coke substitute and subjected the torrefied woodchip to wet oxidation at 80 °C for 30 min. To obtain a metallurgical coke substitute, the wet oxidized biomass was thermally treated at 900 °C at a heating rate of 10 °C/min under N2 atmosphere. Samples were characterised using different techniques. The proximate analysis revealed that the coke substitute had an ash yield of 4.3 wt%, compared to 16.1 wt% for metallurgical coke. The coke substitute had a lower sulphur content compared to metallurgical coke. The results for CO2 reactivity showed that the final reactivity of the prepared coke substitute was six times higher than that of the metallurgical coke. The lower sulphur content, lower ash yield and higher reactivity of the prepared coke compared to the industrial coke is advantageous in the steelmaking industry; these properties will increase blast furnace production and decrease environmental problems associated with the use of industrial coke.