Buchheiser Simon, Deutschmann Max Philipp, Rhein Frank, Allmang Amanda, Fedoryk Michal, Stelzner Björn, Harth Stefan, Trimis Dimosthenis, Nirschl Hermann
Process Machines, Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
Combustion Technology, Engler-Bunte-Institute, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
Materials (Basel). 2023 Feb 28;16(5):2009. doi: 10.3390/ma16052009.
The combustion of metal fuels as energy carriers in a closed-cycle carbon-free process is a promising approach for reducing CO emissions in the energy sector. For a possible large-scale implementation, the influence of process conditions on particle properties and vice versa has to be well understood. In this study, the influence of different fuel-air equivalence ratios on particle morphology, size and degree of oxidation in an iron-air model burner is investigated by means of small- and wide-angle X-ray scattering, laser diffraction analysis and electron microscopy. The results show a decrease in median particle size and an increase in the degree of oxidation for leaner combustion conditions. The difference of 1.94 μm in median particle size between lean and rich conditions is twentyfold greater than the expected amount and can be connected to an increased intensity of microexplosions and nanoparticle formation for oxygen-rich atmospheres. Furthermore, the influence of the process conditions on the fuel usage efficiency is investigated, yielding efficiencies of up to 0.93. Furthermore, by choosing a suitable particle size range of 1 to 10 μm, the amount of residual iron content can be minimized. The results emphasize that particle size plays a key role in optimizing this process for the future.
在无碳闭环过程中燃烧金属燃料作为能量载体，是减少能源部门二氧化碳排放的一种很有前景的方法。对于可能的大规模实施，必须充分了解工艺条件对颗粒特性的影响，反之亦然。在本研究中，通过小角和广角X射线散射、激光衍射分析和电子显微镜，研究了铁-空气模型燃烧器中不同燃料-空气当量比对颗粒形态、尺寸和氧化程度的影响。结果表明，在更稀薄的燃烧条件下，颗粒中位径减小，氧化程度增加。贫燃和富燃条件下颗粒中位径相差1.94μm，比预期值大20倍，这可能与富氧气氛中微爆炸和纳米颗粒形成强度增加有关。此外，还研究了工艺条件对燃料使用效率的影响，效率高达0.93。此外，通过选择1至10μm的合适颗粒尺寸范围，可以将残余铁含量降至最低。结果强调，颗粒尺寸在优化该工艺未来应用方面起着关键作用。
