The modes of occurrence and emission of alkali metal of corn straw were studied at different pyrolysis temperature and all experiments were conducted on a horizontal tubular reactor. Experiment analysis included pyrolysis gases release measured with FTIR, alkali metal concentration analyzed with ICP-AES, existence form of AAEM with chemical fractionation analysis (CFA), microscopic structure of semi-char with SEM/ EDX, and type of alkali metal tested with XRD. The results showed that most of K in corn straw was inorganic K (91%). The major organic K was released during 300—600℃ with the main releasing compounds of inorganic K of KCl and K2SO4,etc. K migrated from inner to the surface of particle, leading to enrich K at the surface (700℃), and the content of K decreased with further increasing temperature. The release characteristics of K and Na were similar, however, the main transformation element was K. Due to the thermal stability of Ca and Mg, they were difficult to release during pyrolysis.%为了解高含K玉米秸秆在不同热解温度下碱金属的析出规律,建立了一维水平管式炉,利用FTIR、SEM-EDX、XRD等测试手段及化学分馏法对碱金属的释放规律及热解半焦中赋存形式进行深入实验研究.结果表明:K是玉米秸秆的主要碱金属元素,且91%的K以无机K的形式存在;300~600℃主要为有机K的分解、释放阶段,大于600℃主要为KCl、K2SO4等无机K分解、释放.K元素由颗粒内部向表面迁移,并在700℃出现表面K盐富集,继续升温富集程度降低;Na和K析出规律相似,Ca和Mg热稳定性强,热解过程多以稳定的化合物形式存在于热解半焦中,不易析出到气相.
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