生物质中矿物质在气化条件下的演变行为研究  

Evolution behaviors of mineral matters in biomass under gasification conditions

作　　者：曹琴[1] 黄胜[1] 吴诗勇[1] 吴幼青[1] 高晋生[1] 

机构地区：[1]华东理工大学资源与环境工程学院煤气化及能源化工教育部重点实验室,上海200237

出　　处：《燃料化学学报》2016年第6期668-673,共6页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21506060)资助~~

摘　　要：以稻秸秆和玉米秸秆为原料,考察了弱还原性气氛以及550-1 300℃生物质中矿物质的变化,并采用Fact Sage软件对生物质中矿物质在高温下的演变行为进行了模拟。结果表明,生物质灰中Na和K元素的存在形式相对稳定,部分以气态氯化物的形式挥发出去,部分存在于低熔点硅酸盐或硫酸盐中;Si元素与Ca、Fe、Mg和Al四种元素形成的硅酸盐的变化形式较多,主要形成辉石[(Ca,Mg,Fe)_2Si_2O_6]、橄榄石[(Ca,Mg,Fe)_2SiO_4]和黄长石[Ca_2(Al,Mg)(Si,Al)SiO_7]三类物质,随着温度的升高,部分辉石会转化为橄榄石与黄长石,此三类物质相互作用易形成熔点较低的共熔体而导致矿物质的熔融。方石英和莫来石[Al_6Si_2O_(13)]是导致稻秸秆流动温度高于玉米秸秆的主要原因,莫来石最终转化为斜铁辉石[FeSiO_3]、铁尖晶石[FeAl_2O_4]和钙长石[CaAl_2Si_2O_8]等熔点较低的矿物质。The composition and reaction of mineral matters in rice strawand corn stalk were investigated in weak reducing atmosphere at temperature range of 550- 1 300 ℃.The Fact Sage was also used to simulate the evolution behaviors of mineral matters under high temperatures.The results showthat the existing form of Na and K in biomass is relatively stable,including volatilized chlorides,silicates and sulphates with a lower melting point.The silicates made up of Si,Ca,Mg,Fe and Al have various forms,mainly including pyroxene[（ Ca,Mg,Fe）_2Si_2O_6],olivine [（ Ca,Mg,Fe）_2SiO_4] and melilite [Ca_2（ Al,Mg）（Si,Al）SiO_7].Pyroxene is transformed into olivine and melilite with the increasing of temperature.The interaction of the three kinds of materials could result in the generation of eutectics which could lead to the melting of mineral matters in biomass.The formation of cristobalite and mullite [Al_6Si_2O_（13）]leads to a higher flowtemperature of rice strawash than corn stalk ash, the mullite ultimately is transformed into lowmelting point materials like clinoferrosilite[FeSiO_3],iron spinel[FeAl_2O_4]and anorthite[CaAl_2Si_2O_8].

关 键 词：生物质 矿物质 熔融特征温度 XRD FactSage 

分 类 号：TQ53[化学工程—煤化学工程]