秸秆中钾元素对生物质成灰特性的影响研究

STUDY ON EFFECT OF KALIUM ELEMENT IN STRAW ON ASH CHARACTERISTICS OF BIOMASS

为研究秸秆中钾元素对生物质成灰特性的影响,利用马弗炉制取玉米秸秆灰样,采用扫描电镜(SEM)、能谱仪(EDS)及灰熔点测试仪对灰样进行分析,并分别研究K2CO3和KOH对灰熔融特性的影响。结果表明,由于生物质在燃烧过程中有机物的燃烧和挥发份的析出,及K元素在高温条件下易析出并主要以颗粒形式存在于灰的外表面,K元素具有可明显增加粘结性的特点,与Si、Ca氧化物粘结附着于灰表面形成孔洞;高温状态下K2CO3、KOH与酸性氧化物反应生成低熔点物质;分析可知钾(K)元素是影响灰熔点的重要因素,酸洗预处理可使灰熔点升高;当秸秆灰中K元素含量约为30%时,灰熔点达到最低值。

To study the effect of kalium element in straw on ash characteristics of biomass,the corn straw ash wasprepared in a muffle furnace,the ashes were analyzed by SEM,EDS and ash fusion point determination meter,and studythe effect of K2CO3 and KOH on ash fusion characteristic. The results showed that the combustion of organics andseparate out of volatiles results in the surface of ash generate holes,K element separate out at high temperature andconsist in outside surface in the shape of granule. K element increase cohesiveness and adhere to surface of ash with theoxide of Si and Ca. K2CO3 and KOH react with acidic oxide to form low-melting-point matter at high temperature,Kelement is important factor to influence ash fusion point,of the pretreatment acid-washing increases ash fusion point.When the content of K element in ash is 30%,ash fusion point is at a minimum. Moiety of K element volatilize duringcombustion process of biomass as the flue gas.