高温下煤焦气化反应特性(Ⅰ)灰分熔融对煤焦气化反应的影响

CHARACTERISTICS OF COAL CHAR GASIFICATION AT HIGH TEMPERATURE (Ⅰ) THE EFFECT OF ASH FUSION ON COAL CHAR GASIFICATION

在900～1500℃灰分的熔融温度范围内和常压下,研究了煤焦与二氧化碳的气化反应。实验研究发现,活化能随气化过程而变化,除反应初期外,气化反应严重受内扩散过程的影响。高温下的煤焦气化存在一个特性温度,在该温度下,反应中、后期气化速率显著降低,其影响范围在特性温度上下约200～300℃。特性温度与煤种及灰分性质等因素有关,一般低于其相应灰分的软化点温度。

Coal char gasification with CO2 was studied in the 900-1500℃ temperature range of ash fusion under normal pressure. It was found that the activation energy changed with the gasification process. Except for the initial stage of reaction, gasification was affected seriously by internal diffusion. There was a characteristic temperature in coal char gasification at a high temperature, where the gasification rate was significantly reduced in the intermediate and final stages of reaction. Its effect covered about 200-300℃ around the characteristic temperature, its value was related to many factors, such as the kind of coal, the properties of ash etc., generally lower than the ash softening temperature.