湿法烟气脱硫反应过程的实验研究

在石灰石/石膏湿法烟气脱硫中试台上,系统开展了浆液pH值、飞灰浓度、液气比、入口SO2浓度、烟气速度和氧化方式等对脱硫反应过程影响的实验研究。实验表明,脱硫效率随着石膏浆液pH值、液气比的升高而增加,且入口SO2浓度越高,液气比越低,影响效应越明显;脱硫效率随着烟气速度、烟气温度和入口SO2浓度的增加而下降;石膏浆液中飞灰含量对系统脱硫效率具有一定的促进作用:pH值>5.6,飞灰浸出液中Fe3+含量相对较低,Fe3+对脱硫反应过渡态催化氧化影响程度较轻,不同工况脱硫效率差别不大。pH值<5.6,飞灰浸出液中Fe3+含量随pH值降低而增大,增效效果逐渐显著;氧化方式对脱硫反应过程有明显的影响,强制氧化工艺的脱硫效率比自然氧化的高5%左右。

Experimental study on reaction process of wet flue gas desulfurization

In the limestone/gypsum wet flue gas desulfurization test rig, influencing factors such as pH value,liquid-gas ratio, SO₂ inlet concentration,gas temperature, gas velocity and oxidized form were studied. The results show that the desulfurization efficiency increases with elevating pH value and liquid-gas ratio. The effects of pH value and liquid-gas ratio on desulfurization efficiency are evident with higher SO₂ inlet concentration and lower liquid-gas ratio. Desulfurization efficiency decreases with increasing gas velocity, gas temperature and SO₂ inlet concentration. Ash in gypsum slurry can promote desulfurization: when pH>5.6, Fe³⁺ concentration in fly ash solution is relatively low, transition metal catalyzed oxidation of Fe³⁺ in fly ash solution plays a small role in the absorb of SO₂,desulfurization efficiency has no obvious distinction. when pH<5,Fe³⁺ concentration is growing with the decrease of pH value, ash has obvious influence on desulfurization efficiency. Oxidized form has obvious effect on desulphurization; the desulfurization efficiency of forced-oxidation is higher 5% than that of natural oxidations.