Abstract:

Using a vertical tube furnace reactor combined with a low-pressure impactor particle collection device, the effects of corn stalk roasting mixed with ammonium dihydrogen phosphate (NH₄H₂PO₄) on the physical and chemical properties of roasted products and the emission of combustion particles in the fixed bed were studied. The results show that the corn stalk baking alone can effectively improve the quality of biomass, but also increase the emission of particulate matter. When baking at 300℃, PM₁, PM_1-2.5 and PM_2.5-10 increase by 76.5%, 194.8% and 170.2%, respectively. Studies have shown that the torrefied corn stalk with NH₄H₂PO₄ increased the ash content of solid products, but significantly reduced the O/C ratio of solid products and increased the ash-free heating value. In addition, blending NH₄H₂PO₄ can significantly increase the release rate of Cl during torrefaction and reduce the content of Cl in the solid product. Torrefaction with NH₄H₂PO₄ can effectively reduce the emission of particulate matter, especially PM₁, and the best effect is achieved when the mixing P/K molar ratio is 1, at this case, PM₁ reduces emissions by 28.8% compared to when no additive is added. Studies have shown that the introduction of NH₄H₂PO₄ in the biomass torrefaction can promote the removal of Cl and reduce the emission of fine particles in the subsequent combustion process.

Key words: NH₄H₂PO₄, corn stalk, torrefaction, particulate matter, emission characteristics

摘要：

使用立式管式炉反应器并结合低压撞击器颗粒物采集装置研究了玉米秆掺混磷酸二氢铵（NH₄H₂PO₄）烘焙对烘焙产物理化性质及固定床中燃烧颗粒物排放的影响。结果表明，玉米秆单独烘焙可有效提升生物质品质，但也提升了颗粒物排放。300℃烘焙时，PM₁、PM_1-2.5和PM_2.5-10分别增排76.5%、194.8%和170.2%。在烘焙过程掺混NH₄H₂PO₄可进一步提质，使得固体产物灰分有不同程度的增加，显著降低固体产物的O/C比，并提高样品的无灰基热值。此外，研究发现掺混NH₄H₂PO₄可显著提高烘焙过程Cl的释放率并降低固体产物中Cl的含量，有利于降低后续燃烧PM₁的排放。在掺混比例P/K摩尔比为1时减排效果最佳，此时PM₁相比无掺混时减排28.8%。结果表明在生物质烘焙过程引入NH₄H₂PO₄可以促进Cl的脱除并减少后续燃烧过程细颗粒物的排放，是一种有前景的生物质预处理手段。

关键词: 磷酸二氢铵, 玉米秆, 烘焙, 颗粒物, 排放特性