Abstract Study on selenium (Se) transformation during coal combustion will facilitate the development of emission–control technologies. A fixed–bed reactor was used to conduct pyrolysis and combustion experiments involving three types of coal at 600–1000 °C. In an inert atmosphere, the release ratios of Se increased slowly as temperature increased, varying between 56% and 74% for different coals at 1000 °C. All forms of Se in coal were thermally unstable and the conversion of Se in other forms into residual and organic–bound Se occurred. In an oxidizing atmosphere, the release ratios of Se differed significantly for different coals at low temperatures, but approached 100% at 1000 °C. Each form of Se in coal was released in different ratios. The water–soluble and ion–exchangeable Se, and carbonate– and oxide–bound Se were produced in the solid products. The oxidizing atmosphere was more conducive to the release of Se because the sulfide– and organic–bound Se was fully oxidized. Se could be converted into water–soluble and ion–exchangeable form and released less in Ca–rich coal. Sulfur (S) prohibited Ca from adsorbing Se by forming CaSO4, promoting the release of Se in S–rich coal.

中文翻译：

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煤热转化过程中硒的转化：大气和无机物含量的影响

摘要 煤燃烧过程中硒（Se）转化的研究将促进排放控制技术的发展。固定床反应器用于在 600-1000 °C 下进行涉及三种煤的热解和燃烧实验。在惰性气氛中，Se 的释放率随着温度的升高而缓慢增加，在 1000 °C 时，不同煤的 Se 释放率在 56% 到 74% 之间变化。煤中所有形式的硒都是热不稳定的，其他形式的硒会转化为残留的和有机结合的硒。在氧化性气氛中，低温下不同煤种Se的释放率差异显着，但在1000°C时接近100%。煤中每种形式的硒以不同的比例释放。水溶性和离子交换性硒，在固体产品中产生碳酸盐和氧化物结合的硒。由于硫化物和有机结合的硒被完全氧化，氧化气氛更有利于硒的释放。硒可以转化为水溶性和离子交换形式，并且在富钙煤中释放较少。硫 (S) 通过形成 CaSO4 阻止 Ca 吸附 Se，促进 Se 在富 S 煤中的释放。