文献名： Synergetic combustion behavior of aluminum and coal addition in hybrid iron-methane-air premixed flames

作者 ： Li Yueh-Heng ^a ， Stalline Pangestu ^a ， Aris Purwanto ^a ， Chen Chih-Ting ^ab

^a Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan, ROC

^b Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA

摘要： This study investigated the combustion behaviors of pure iron and mixed particles, particularly iron–aluminum and iron–coal mixtures, doped into methane (CH ₄ )–air premixed flames . The mechanically mixed particles were prepared with a weight ratio of 1:1. Thermogravimetric analysis revealed that the Fe particles and the Fe–coal mixture underwent oxidation in similar regions of relatively low temperatures; the Fe ‒ Al mixture underwen t a multistage oxidation process . A conical CH ₄ –air premixed flame—with the CH ₄ –air equivalence ratio maintained at the stoichiometric value—was doped with micron-sized solid fuels at various feed rates. Increasing the particle feed rate appeared to alter the flame front characteristics. The interdependency  between solid fuels and the CH ₄ –air premixed flame was investigated with respect to flame temperatures, gas emissions, and metal oxide  products. Particle microexplosions occurred in the Fe–coal combustion. Regarding the mechanism underlying the microexplosions, we hypothesized that the bubbles inside the Fe particles may have contained dissolved O ₂ , N ₂ , and CO; the dissolved CO may have generated iron carbonyl (Fe(CO) ₅ ). Coalescence , repeated bubbling, and bubble expansion processes led to the expansion of iron oxides  with hollow shells. The rapid increase in inner pressure and explosive internal combustion  caused by the ripening and flammability of the (Fe(CO) ₅ )/O ₂  bubbles engendered the microexplosions. CO was added to the Fe flame to validate this hypothesis.

关键词： Metal fuels， Particle microexplosion ， Coalescence ， Hybrid combustion ， Iron carbonyl