Study on co-slurry and co-combustion characteristics of coal and modified-coal gasification fine slag

Abstract

In this study, hydrocarbon oil was used to modify coal gasification fine slag(CGFS) to improve its hydrophobic performance. The modified CGFS(MCGFS) was then mixed with coal to prepare MCGFS-coal water slurry(MCGFS-CWS), and the slurry’s flowability and combustion characteristics of MCGFS-CWS were investigated. XPS analysis and contact angle experiments revealed an increase in the non-polar groups on the surface of MCGFS, resulting in enhanced hydrophobicity with higher hydrocarbon oil content. The viscosity of MCGFS-CWS decreases as the amount of hydrocarbon oil increased, significantly improving its fluidity compared to CGFS-CWS. Under the conditions of this study, when the amount of hydrocarbon oil is 8%, the constant-viscosity concentration of MCGFS-CWS is 0.46% higher than that of CWS. Combustion characteristic studies revealed that the addition of CGFS increased the concentrations of alkali metals and alkaline earth metals in the slurry, promoting the catalytic combustion reaction. When the amount of hydrocarbon oil is large, the hydrocarbon oil in MCGFS ignites and burns at a lower temperature. The temperature released during the combustion of hydrocarbon oil is beneficial to promote the ignition of slurry and reduce the ignition temperature of MCGFS-CWS. These results demonstrate that hydrocarbon oil modification enhances the hydrophobicity of CGFS and reduces the ignition temperature of MCGFS-CWS.