Abstract: The steam-gasification reaction characteristics of coal and petroleumcoke (PC)were studied in the drop tube furnace (DTF). The effects of various factors such as types of carbonaceous material, gasification temperature (1100-1400 ℃) and mass ratio of steam to char (0.4:1, 0.6:1 and 1:1 separately) on gasification gas or solid products were investigated. The results showed that for all carbonaceous materials studied, H₂ content exhibited the largest part of gasification gaseous products and CH₄ had the smallest part. For the two petroleum cokes, CO₂ content was higher than CO, which was similar to Zun-yi char.When the steam/char ratio was constant, the carbon conversion of both Shen-fu and PC chars increased with increasing temperature. When the gasification temperature was constant, the carbon conversions of all char samples increased with increasing steam/char ratio. For all the steam/char ratios, compared to water gas shift reaction, char-H₂O and char-CO₂ reaction were further from the thermodynamic equilibrium due to a much lower char gasification rate than that of water gas shift reaction rate. Therefore, kinetic effects may play a more important role in a char gasification step than thermodynamic effects when the gasification reaction of char was held in DTF. The calculating method for the equilibrium shift in this studywill be aworth reference for analysis of the gaseous components in industrial gasifier. The reactivity of residual cokes decreased and the crystal layer (L₀₀₂/d₀₀₂) numbers of residual cokes increased with increasing gasification temperature. Therefore, L₀₀₂/d₀₀₂, the carbon crystallite structure parameter, can be used to evaluate the reactivity of residual cokes.

Key words: Drop tube furnace, Steam/char ratio, Thermodynamic equilibrium, Reactivity

摘要： The steam-gasification reaction characteristics of coal and petroleumcoke (PC)were studied in the drop tube furnace (DTF). The effects of various factors such as types of carbonaceous material, gasification temperature (1100-1400 ℃) and mass ratio of steam to char (0.4:1, 0.6:1 and 1:1 separately) on gasification gas or solid products were investigated. The results showed that for all carbonaceous materials studied, H₂ content exhibited the largest part of gasification gaseous products and CH₄ had the smallest part. For the two petroleum cokes, CO₂ content was higher than CO, which was similar to Zun-yi char.When the steam/char ratio was constant, the carbon conversion of both Shen-fu and PC chars increased with increasing temperature. When the gasification temperature was constant, the carbon conversions of all char samples increased with increasing steam/char ratio. For all the steam/char ratios, compared to water gas shift reaction, char-H₂O and char-CO₂ reaction were further from the thermodynamic equilibrium due to a much lower char gasification rate than that of water gas shift reaction rate. Therefore, kinetic effects may play a more important role in a char gasification step than thermodynamic effects when the gasification reaction of char was held in DTF. The calculating method for the equilibrium shift in this studywill be aworth reference for analysis of the gaseous components in industrial gasifier. The reactivity of residual cokes decreased and the crystal layer (L₀₀₂/d₀₀₂) numbers of residual cokes increased with increasing gasification temperature. Therefore, L₀₀₂/d₀₀₂, the carbon crystallite structure parameter, can be used to evaluate the reactivity of residual cokes.

关键词: Drop tube furnace, Steam/char ratio, Thermodynamic equilibrium, Reactivity