Shuai Guo

Ash fusion characteristics during co-gasification of biomass and petroleum coke

In this study, the effect of biomass ash on petroleum coke ash fusibility was investigated at a reducing atmosphere. Some analytical methods, such as ash fusion temperatures (AFTs) analysis, X-ray diffraction (XRD), FactSage and scanning electron microscopy (SEM), were applied to determine the characteristics of ash fusion and transformation of mineral matters. The results indicated that AFTs were closely associated with ash mineral compositions. It was found that the formations of high melting point calcium silicate, vanadium trioxide and coulsonite resulted in the high AFTs of Yanqing petroleum coke (YQ). When blending with certain proportional pine sawdust (PS), corn stalk (CS), the AFTs of mixture could be decreased significantly. For PS addition, the formations of low-melting point calcium vanadium oxide should be responsible for the reduction of AFTs, whereas for CS addition the reason was ascribed to the formation of low-melting point leucite and the disappearance of high-melting V2O3.

Influence of coal ash on potassium retention and ash melting characteristics during gasification of corn stalk coke

This study experimentally investigated the potassium fixation ability and ash fusion characteristics during the gasification of corn stalk coke blended with coal ash in CO2 atmosphere. The ash samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). FactSage was also employed to calculate the components and quantities of solid and liquid phase. The results show that the ratio of potassium retained in the biomass ash decreases with the increase in the gasification temperature. In addition, the retention ratio increases with more coal ash added. The improvement of potassium retention ratio is due to the reaction of potassium with alumina/silica to form the solid/slag phase of the potassium aluminosilicates. On the other hand, the ash fusion temperatures of the blended ash are increased by adding the coal ash, compared with the biomass ash. The study confirms that coal ash is a potential additive for not only fixing potassium, but also increasing the ash fusion temperatures of easy-to-slagging biomass.