Effect of hydrodynamic parameters on the oxidative desulphurisation of low rank coal

Abstract

In this paper, the desulphurisation of high sulphur low-rank coal is proposed as a raw material for pulverised coal injection technology. Therefore, the influence of oxidant linear velocity and the size of the coal grain was investigated in a fluidised bed. The hydrodynamic parameters of the fluidised bed including: porosity, Sherwood criterion (diffusion Nusselt number), and mass transfer coefficient (external surface) were calculated. Furthermore, the study examined the effects of intensity and efficiency on the desulphurised coal properties; organic matter, ash, and volatile matter contents. The key changes during the conversion of pyritic sulphur and coal organic matter were subsequently examined. The results showed that the sulphur content (Std 3.16 wt%) of the low-rank coal, was transformed to (Std ≤ 1.5 wt%) after desulfurization. Other enhanced properties were: Vdaf ≤ 38.0 wt%; Ad ≤ 10.0 wt%, now suitable for pulverised coal injection technology.