This paper studied the effect of high temperature (up to 1873K) and separated combustion mode (volatile combustion and char combustion are separated) on SO₂ release characteristics during pulverized coal combustion under O₂/CO₂ atmosphere. Coal combustion experiments were conducted at different combustion environment temperatures utilizing a high temperature fixed-bed setup. The results show that as temperature rises, the SO₂ release curve is transformed from a single-peak process to a double-peak process. In separated combustion, temperature has little effect on the volatile-SO₂ (SO₂ released during volatile combustion) but brings about a significant effect on char-SO₂ (SO₂ released during char combustion). Char-SO₂ release amount and the ratio of it to fuel-SO₂ release amount (total SO₂ released during coal combustion) increase with temperature rising. The increase of temperature leads to a dramatic decreasing of sulphur mass fixed in the ash and causes SO₂ release amount to rise when temperature is lower than 1573 K. Separated combustion causes a higher SO₂ release amount than coupled combustion (the same as conventional combustion, volatile combustion and char combustion are simultaneous). Thermochemistry equilibrium composition calculation results show that alkali metals and alkaline-earth metals are significant in sulphur retention. CaSO₄ and Na₂SO₄ are the main sulphates at high temperatures.

本文研究了高温（高达1873K）和分离燃烧模式（挥发性燃烧和焦炭分离）对O ₂ / CO ₂气氛下煤粉燃烧过程中SO ₂释放特性的影响。利用高温固定床装置在不同的燃烧环境温度下进行了煤燃烧实验。结果表明，随着温度的升高，SO ₂释放曲线从单峰过程转变为双峰过程。在分离的燃烧，温度对挥发性-SO影响不大₂（SO ₂挥发性的燃烧过程中释放的），但带来了对char-SO一个显著效果₂（在焦炭燃烧过程中释放出SO ₂）。随着温度升高，Char-SO ₂释放量及其与燃料-SO ₂释放量的比（燃煤过程中释放的总SO ₂）增加。温度的升高导致烟灰中固定的硫质量急剧下降，并在温度低于1573 K时导致SO ₂释放量增加。单独燃烧比耦合燃烧产生更高的SO ₂释放量（与常规燃烧相同） ，挥发燃烧和焦炭燃烧是同时发生的）。热化学平衡组成计算结果表明，碱金属和碱土金属的硫截留率显着。硫酸钙₄和Na ₂ SO ₄是高温下的主要硫酸盐。