典型煤灰组分与热解产物相互作用的研究

Study on the Interactions Between Typical Coal Ash Components and Pyrolysis Products

以CaSO_(4)、Fe_(2)O_(3)作为煤灰典型组分,开展典型煤灰组分与热解产物(热解气、半焦)相互作用的实验研究,并针对一些新反应、新结论利用HSC进行热力学验证.结果表明,热解温度范围内热解还原气(H_(2)、CO)与CaSO_(4)或Fe_(2)O_(3)发生氧化还原反应,降低了H_(2)和CO浓度,升高了CO_(2)浓度.半焦与CaSO_(4)或Fe_(2)O_(3)混合物在高温下逸出大量CO和CO_(2).结合热力学分析,可以推断固体碳基还原剂被CaSO_(4)或Fe_(2)O_(3)大量氧化成CO和CO_(2),且随着温度的升高,气体产物中CO比例逐渐增加,而CO_(2)比例一直下降.此外,实验及热力学研究均证明Fe_(2)O_(3)氧化活性高于CaSO_(4),Fe_(2)O_(3)优先与还原性气体或者固体发生氧化还原反应.

In order to clarify the mechanism of coal pyrolysis with ash as the heat carrier,thermodynamic(HSC)and experimental study on the interactions between typical ash components(CaSO_(4)and Fe_(2)O_(3))and pyrolysis products(H_(2),CO,CH 4 and char)are carried out.The results show that the pyrolytic reducing gas(H_(2),CO)reacts with CaSO_(4)or Fe_(2)O_(3)in the pyrolysis temperature range,leading to the decrease in H_(2)and CO concentration but increase in CO_(2)concentration.Char is oxidized by CaSO_(4)or Fe_(2)O_(3)into CO and CO_(2),and the dominant gaseous products are CO_(2)at low temperature and CO at high temperature.In addition,thermodynamic and experimental results show that compared with CaSO_(4),and Fe_(2)O_(3)has higher reactivity,preferentially reacting with pyrolytic gas or char.