Utilization of semi-dry sintering flue gas desulfurized ash for SO2 generation during sulfuric acid production using boiling furnace
Utilization of semi-dry sintering flue gas desulfurized ash for SO2 generation during sulfuric acid production using boiling furnace
复制标题
DOI：
10.1016/j.cej.2017.06.180
复制
发表时间：
2017-11
影响因子：
15.1
通讯作者：
Jian-an Zhou;Ding Bin;Chao-bo Tang;Jian-bo Xie;Bao Wang;Hua Zhang;Ni Hongwei
中科院分区：
文献类型：
--
作者：
Jian-an Zhou;Ding Bin;Chao-bo Tang;Jian-bo Xie;Bao Wang;Hua Zhang;Ni Hongwei
为有效解决钢铁企业半干法烧结烟气脱硫灰（SSFGDA）的资源化问题，提出了在硫酸生产过程中，将脱硫灰加入沸腾炉制取SO2的新工艺。采用热力学和模拟计算方法，对灰中CaSO 3的高温特性进行了初步研究。采用Kissinger法、Achar模型和Coats-Redfer模型，得到了煤灰中CaSO 3的分解动力学方程。通过热重分析（TGA）和落管炉（DTF）实验进一步研究了煤灰中CaSO 3的分解特性。结果表明，在温度低于400 °C时，游离水损失，Ca（OH）2分解，而在约460 °C时，部分CaSO 3被氧化。在680 °C以上，CaCO 3开始分解，分解过程在790 °C终止。剩余的CaSO 3在约810 °C下继续分解。CaSO 3分解的活化能为261.45 ± 77.93 kJ/mol，指前因子ln（A/s−1）= 26.13 ± 7.29，动力学方程为dα/dt= 2.19 × 1011× exp（−3.11 × 104/T）。压力、温度和氧含量是影响灰中CaSO 3分解的关键因素。较低的压力和氧含量以及较高的温度可以促进CaSO 3的分解，并且可以在实际的硫酸加工厂中实现。因此，本研究对沸腾炉制酸过程中添加脱硫灰制备SO2的可行性进行了初步的考察和验证。
To effectively solve the problem of reutilizing semi-dry sintering flue gas desulfurized ash (SSFGDA) from steel plants, a new technology is proposed in this paper in which ash is added to a boiling furnace to obtain SO2during sulfuric acid production. Using thermodynamics and simulation calculations, the high-temperature characteristics of CaSO3in the ash were preliminarily investigated. By using Kissinger method and the models of Achar and Coats-Redfer, the decomposition kinetics equation of CaSO3in the ash were obtained. The decomposition characteristics of CaSO3in the ash were further investigated by thermogravimetric analysis (TGA) and drop tube furnace (DTF) experiments. The results show that at temperatures below 400 °C, free water is lost and Ca(OH)2decomposes, whereas at approximately 460 °C, part of the CaSO3is oxidized. Above 680 °C, CaCO3begins to decompose, with the decomposition process terminating at 790 °C. The remaining CaSO3continues to decompose at approximately 810 °C. The activation energy of CaSO3decomposition is 261.45 ± 77.93 kJ/mol; the pre-exponential factor is expressed as ln(A/s−1) = 26.13 ± 7.29, and the kinetics equation is dα/dt= 2.19 × 1011× exp(−3.11 × 104/T). Pressure, temperature and oxygen content are the key factors affecting the decomposition of CaSO3in the ash. A lower pressure and oxygen content and a higher temperature can facilitate the decomposition of CaSO3and can be achieved in actual sulfuric acid processing plants. Therefore, in this study, the feasibility of preparing SO2by adding desulfurized ash during the production of sulfuric acid using a boiling furnace was preliminarily examined and verified.