亚硫酸钠的抗氧化本征动力学

Intrinsic kinetics study of sodium sulfite oxidation inhibition

为了提高干法一体化脱硫脱硝技术的竞争性,将燃煤烟气硫硝过程产生的高浓度SO_2资源化制备高附加值的亚硫酸钠,用inhibition power(IP)量化评价了不同抗氧化剂的抗氧化效果,发现在制备亚硫酸钠时加入抗坏血酸具有较高的抗氧化性能,研究了Na_2SO_3浓度、抗坏血酸浓度、温度、pH值及其他组分(如CO_3^(2-)、Hg^(2+)等)对氧化速率的影响,系统研究了其抗氧化本征动力学。结果表明:相比于其他抗氧化剂,在抗坏血酸作用下亚硫酸钠的氧化出现了长达90 min的诱导期,其IP值为7.54×10~8,远高于其他抗氧化剂;低pH值时,抗氧化效果较好;CO_3^(2-)和Hg^(2+)均会减弱抗氧化效果。

In order to improve the competitiveness of the dry-integrated desulfurization and denitrification technology,high-concentration SO_2 generated from sulfur and flue gas from coal-fired flue gas was utilized to prepare high-value added sodium sulfite.Kinetic model was used to evaluate the inhibiting effect of different inhibitors valued by Inhibition Power（IP）.It was found that the stronger oxidation inhibition effect was brought by adding ascorbic acid during sodium sulfite preparation process.Effects of different factors,including sodium sulfite concentration,ascorbic acid concentration,reaction temperature,pH value,carbonate ions and mercury ions,on sodium sulfite oxidation rate was investigated.The results show that ascorbic acid is a powerful inhibitor. The induction time lasts 90 minutes during the oxidation process in the presence of ascorbic acid and its IP is 7.54×10~8,higher than other inhibitors.Lower p H is benefit to the oxidation inhibition and carbonate ions and mercury ions can weaken the inhibiting effect.