典型秸秆类生物质灰的特性研究

Investigation on the Ash Properties of Straw

生物质灰的特性对气化炉的参数设定及平稳运行有着重大的影响。以青岛周边的玉米秸秆为研究对象,结合XRD、XRF检测手段,对400~800℃下的灰样特性进行研究。结果表明:灰成分存在形式、灰分中矿物质转化以及灰的结渣程度与温度之间有明显的关联。玉米秸秆灰主要由K、Si、Cl等元素组成。随着温度的升高,K元素以KCl的形式逐渐变转化为KAlCl2O、KAlSO4等化合物。Si元素主要以SiO2的形式与碱金属元素形成了NaAl2Si5O14、K2Si2O5、K2O·Al2SO3·SiO2等低共熔的化合物。高温下KCl可形成团聚粘性颗粒,且灰中的硅酸盐熔融也可形成团聚颗粒沉积,这可能导致结渣严重。

The properties of straw ash is related to the process parameters setting and operation of gasifier.Corn stalk collected from Qingdao city was selected as raw material in this study.By combining the diagnostics systems of XRD and XRF,the properties of ash samples at 400~800℃ were investigated.The results show that the ash composition,mineral transformation and slagging degree of ash are closely related to temperature.Corn stalk ash is mainly composed of K,Si,Cl elements.With the increase of temperature,K element existing in the form of KCl gradually transforms into KAlCl2O and KAlSO4.Low eutectic compounds such as NaAl2Si5O14,K2Si2O5,and K2O·Al2SO3·SiO2 are formed by SiO2 and alkali metals.At high temperature,KCl can form agglomerated and viscous particles.In addition,silicate melting in ash can also form agglomerated particle deposition,which could potentially lead to serious slagging.