【作者】 张会敏；

【导师】 张有贤；

【作者基本信息】 兰州大学 ， 环境科学， 2006， 硕士

【摘要】 烟气脱硫是控制酸雨和二氧化硫（SO₂）污染的主要技术手段,烟气脱硫的方法很多,但在其适用范围以及经济技术上各有缺陷。本文通过对国内外主要烟气脱硫技术的综合对比,发现利用柠檬酸钠回收烟气中SO₂的方法具有投资和运行费用低、工艺流程短、能有效回收SO₂、吸收剂可循环利用、无二次污染等优点。该方法在治理高浓度SO₂冶炼烟气中已有应用,但用于处理低浓度SO₂烟气的研究还较少。 本文针对低浓度SO₂烟气难以治理的问题,研究了柠檬酸钠法及其应用的可行性,并对脱硫过程中的各种影响因素进行了深入的理论和试验研究,揭示了柠檬酸钠吸收低浓度SO₂烟气的基本规律,确定了吸收、解吸过程的各种工艺参数,推导了液气比的具体计算方法,为该法的工业化设计提供了可靠的参考数据,对低浓度SO₂烟气的治理具有重要的现实意义。 试验结果表明,柠檬酸钠法具有较高的脱硫效率,出口烟气可以实现达标排放,而且回收的SO₂产品纯度均在90%以上,是一种值得推广的烟气脱硫技术。在实际运行中,吸收剂浓度、pH值、液气比、温度等参数对系统脱硫效率影响明显。考虑到吸收、解吸效率及运行成本,试验确定的主要工艺参数为:原始吸收液pH=4～5;柠檬酸浓度0.75～1.25mol/L;吸收温度控制在20～50℃:吸收塔吸收效率不小于98%;解吸率和液气比应根据烟气中SO₂浓度进行具体计算分析。更多还原

【Abstract】 Flue Gas Desulfurization（FGD） are the main technologies in the controlling of acid rain and sulfur dioxide, but still have their own disadvantages respectively in their applicable scope, economic benefit, or even the technology itself. This paper compares some of the main wet FGD technologies synthetically, and finds that the Sodium Citrate Process has many advantages such as low investment, low operation cost, short technical flow, can separate SO₂ effectively, the absorbent can be recycled, no secondary pollution, and so on. Sodium Citrate Process has been applied in high concentration SO₂ Flue Gas Desulfurization for many years, but little research has been carried out in that of low concentration.This paper aims at low concentration SO₂ flue gas, investigates the Sodium Citrate Process and its application feasibility, and carries out theoretical and experimental research on kinds of influential factors, finds the basic rule of sodium citrate absorbing SO₂ from low concentration flue gas, confirms the main parameters of absorption and desorption process, ratiocinates its own calculational methods of liquid gas ratio. All of these provide authentic reference data for the industrialization design, and have a concernful significance for the treatment of low concentration SO₂ flue gas.The result of experimentation indicates: the Sodium Citrate Process has quite higher desulfurization efficiency;the treated flue gas can satisfy the requirement of air standards;the production （gaseous SO₂） is quite pure, more than 90% by volume. Therefore, the Sodium Citrate Process is a new FGD technology worthy to be generalized. In practical running, the concentration of absorbent, pH value, liquid gas ratio and temperature all have significant influence on desulfurization efficiency. Considering absorption/desorption efficiency and the running cost, we confirm the following parameters: the pH value of original absorbent should between 4 and 5;the optimal concentration of citric acid is 0.75-1.25mol/L;temperature should be controled in 20⁵0 °C;absorption efficiency is more than 98%;desorption efficiency and liquid gas ratio should be calculated according to the SO₂ concentration in the flue gas.更多还原