循环镁法烟气脱硫产物中硫酸镁(MgSO_4)的热解研究

Study on pyrolysis of magnesium sulfates produced in regenerative magnesia scrubbing fuel gas desulfurization (FGD) system

循环镁法烟气脱硫工艺是利用Mg(OH)2浆液吸收烟气中的SO2,脱硫副产物经过热解还原为MgO,再次制浆从而使之被循环利用。继讨论了MgSO3的最佳热解条件后,本文旨在进一步研究MgSO4的热解条件,以便寻找回收脱硫副产物的最佳条件。优化各个因素后得到MgSO4的最佳热解温度为850℃,热解时间为2h。热解产物通过X-衍射、柠檬酸法CAA法进行分析,得出该条件下MgSO4的分解率、产物MgO的纯度与反应活性最佳。

Magnesium hydroxide slurry was used for sulfur dioxide absorption in regenerative magnesia scrubbing fuel gas desulfurization （FGD） system. Magnesia was regenerated from desulfurization by-products through pyrolysis process and was applied in the system as resources recycling. Based on our former study on pyrolysis of Mg- SO3, this study focuses on discussions of pyrolysis condition of MgSO4 in order to find an appropriate recycling way of FGD by-products. An optimal magnesia yield was gained under a temperature of 850℃ and 2 h as pyrolysis time. Results of X-ray diffraction （XRD） and citric acid activity （CAA） also approved that the decomposition rate and the purity of recycled magnesia under the condition are superior.