脱硫剂通常是指从燃料、原料或其他材料中去除游离硫或硫化物的药剂。在污染物的控制和处理中,主要指用于去除废气中硫氧化物的药剂。脱硫剂的选择直接取决于工艺流程。一种工艺可以使用一种或两种脱硫剂。有些工艺可以回收部分脱硫剂,然后补充。在选择之前,我们应该充分了解脱硫剂的具体类型?现在让我们向您介绍一下。
Desulfurizer usually refers to the agent that removes free sulfur or sulfide from fuel, raw material or other materials. In the control and treatment of pollutants, it mainly refers to the agent used to remove sulfur oxides in waste gas. The selection of desulfurizer directly depends on the process flow. One or two desulfurizers can be used for one process. Some processes can recover some desulfurizers and then supplement them. Before selection, we should fully understand the specific type of desulfurizer? Now let's introduce it to you.
1、钙基脱硫剂
1. Calcium-based desulfurizer
钙基脱硫剂广泛应用于脱硫。常见的钙基脱硫剂包括石灰、熟石灰、电石渣、石灰石和白云石,也可以从富含钙的工业废物和原料中获得。钙基脱硫剂具有来源广、原料易得、成本低、脱硫效率高等优点,被广泛应用于烟气脱硫技术和燃烧过程脱硫技术中。固硫产品在1100℃以下具有良好的耐高温分解性能。
Calcium-based desulfurizers are widely used in desulfurization. Common calcium-based desulfurizers include lime, hydrated lime, carbide slag, limestone and dolomite, and can also be obtained from industrial wastes and raw materials rich in calcium. Calcium-based desulfurizer is widely used in flue gas desulfurization technology and combustion process desulfurization technology due to its advantages of wide source, easy availability of raw materials, low cost and high desulfurization efficiency. The sulfur fixation product has good high-temperature decomposition resistance below 1100 ℃.
不同的钙基脱硫剂具有不同的脱硫效果。在炉内喷钙脱硫中,在相同钙硫比下,石灰石的脱硫效率较低,熟石灰的脱硫效率较高。这是因为当Cao水合为Ca(OH)2时,其比表面积会增加,孔径分布会更好,而Ca(OH)2的热分解温度很低,分解为Cao时,其比表面积会增加,从而提高脱硫效率。
Different calcium-based desulfurizers have different desulfurization effects. In the process of calcium injection desulfurization in the furnace, the desulfurization efficiency of limestone is lower and that of hydrated lime is higher under the same calcium sulfur ratio. This is because when CaO is hydrated to Ca (OH) 2, its specific surface area will increase and the pore size distribution will be better, while the thermal decomposition temperature of Ca (OH) 2 is very low. When decomposed to CaO, its specific surface area will increase, thus improving the desulfurization efficiency.
1、Cao基钙脱硫剂
1. Cao-based calcium desulfurizer
许多企业使用的早期Cao基脱硫剂主要是由约90%的石灰和5%~10%的萤石组成的混合脱硫剂。在活性石灰中加入萤石和铝可以显著提高脱硫效果。石灰是一种容易获得的原料,原料充足,价格低廉。但石灰基脱硫剂用量大,渣量大,处理周期长。它还反映了铁水温度较高时的高脱硫率。
The early Cao-based desulfurizer used by many enterprises is mainly a mixed desulfurizer composed of about 90% lime and 5%~10% fluorite. Adding fluorite and aluminum to active lime can significantly improve the desulfurization effect. Lime is an easily available raw material with sufficient raw materials and low price. However, the amount of lime based desulfurizer is large, the amount of slag is large, and the treatment cycle is long. It also reflects the high desulfurization rate when the hot metal temperature is high.
2、CaC2基钙脱硫剂
2. CaC2-based calcium desulfurizer
电石(CaC2)具有很强的脱硫能力。研究表明,铁水温度为1350℃时,电石粉脱硫反应的平衡常数较高。电石、干煤粉、镁或氧化钙在工业中被广泛使用。然而,电石容易与空气中的水分反应生成乙炔气体,乙炔气体易燃易爆。因此,电石加工、运输、储存和使用过程中对安全措施的要求很高,造成加工困难。不能满足深度脱硫的要求。
Calcium carbide (CaC2) has strong desulfurization ability. The results show that the equilibrium constant of calcium carbide desulfurization reaction is higher when the temperature of molten iron is 1350 ℃. Calcium carbide, dry pulverized coal, magnesium or calcium oxide are widely used in industry. However, calcium carbide is easy to react with water in the air to generate acetylene gas, which is flammable and explosive. Therefore, the requirements for safety measures in the process of carbide processing, transportation, storage and use are very high, resulting in processing difficulties. It cannot meet the requirements of deep desulfurization.
2、钠基脱硫剂
2. Sodium based desulfurizer
钠基化合物用作湿法洗涤工艺(Na2CO3)和炉内喷射和管道喷射(NaHCO3)工艺中的脱硫剂。特别是广泛应用于小型电厂和工业锅炉。该工艺投资少,脱硫效果好。当ca/s=1.4~2.2时,脱硫率可达70%,脱硝率可达10%~20%。碱分解的熔融氧化钠具有很强的腐蚀性,氧化钠的挥发污染环境。纯碱脱硫产生的炉渣具有良好的流动性,很难去除炉渣。苏打水的价格也相对较高。因此,纯碱作为脱硫剂已十分少见。
Sodium compounds are used as desulfurizers in wet scrubbing process (Na2CO3) and furnace injection and pipeline injection (NaHCO3) processes. Especially widely used in small power plants and industrial boilers. The process has low investment and good desulfurization effect. When ca/s=1.4~2.2, the desulfurization rate can reach 70%, and the denitration rate can reach 10%~20%. The molten sodium oxide decomposed by alkali is highly corrosive, and the volatilization of sodium oxide pollutes the environment. The slag produced by soda ash desulfurization has good fluidity and is difficult to remove. The price of soda water is also relatively high. Therefore, it is very rare to use soda ash as desulfurizer.
使用钠基脱硫剂存在的问题是脱硫剂来源困难;脱硫产品中的钠盐易溶于水,对灰场水体造成污染;在干喷过程中,钠基脱硫剂将no转化为No3,导致排烟颜色变黄,影响电厂形象。
The problem of using sodium based desulfurizer is that the source of desulfurizer is difficult; The sodium salt in the desulfurization product is easily soluble in water, causing pollution to the water body of the ash yard; In the process of dry injection, sodium based desulfurizer converts no into No3, which causes the color of smoke to turn yellow and affects the image of the power plant.
脱硫催化剂
Desulfurization catalyst
3、氨基脱硫剂
3. Amino desulfurizer
在电子束辐照脱硫工艺和氨洗工艺中,氨通常以氨水或氨水的形式用作脱硫剂。氨基脱硫剂的活性很好,所以用量比其他脱硫剂少。氨基脱硫剂脱硫过程的副产物是硫酸铵,可用作农业肥料。当氨用作脱硫剂时,应注意氨的高价;无需准备,但需要特殊的运输、储存、计量和输送设备;氨泄漏会引起异味、中毒等环境问题;过量的氨注入可能会形成白烟排放
In electron beam irradiation desulfurization process and ammonia washing process, ammonia is usually used as desulfurizer in the form of ammonia water or ammonia water. Amino desulfurizer has good activity, so its dosage is less than other desulfurizers. Ammonium sulfate is the by-product of the desulfurization process of amino desulfurizer, which can be used as agricultural fertilizer. When ammonia is used as desulfurizer, attention should be paid to the high price of ammonia; No preparation is required, but special transportation, storage, metering and conveying equipment are required; Ammonia leakage will cause environmental problems such as odor and poisoning; Excessive ammonia injection may cause white smoke emission
4、镁基脱硫剂
4. Mg-based desulfurizer
镁基脱硫基团包括MgO、Mg(OH)2等。氧化镁(轻烧氧化镁)和氢氧化镁因其缓冲性能强(pH值高达9)、活性和吸附能力强、使用安全可靠、无腐蚀性,在环境领域得到广泛应用。1350℃下镁与硫的反应平衡常数不如电石和石灰脱硫的平衡常数高。然而,镁和硫具有很高的亲和力,反应区的动力学条件非常好。反应迅速且非常强烈。镁与硫在铁水中反应生成的MGS熔点高(2000℃),密度低(2.82g/cm3),易结渣。然而,镁具有很高的活性,因此必须将其作为脱硫剂进行钝化。
Mg-based desulfurization groups include MgO, Mg (OH) 2, etc. Magnesium oxide (light burned magnesium oxide) and magnesium hydroxide are widely used in the environmental field because of their strong buffering performance (pH value up to 9), strong activity and adsorption capacity, safe and reliable use, and non-corrosive. The reaction equilibrium constant of magnesium and sulfur at 1350 ℃ is not as high as that of calcium carbide and lime desulfurization. However, magnesium and sulfur have a high affinity, and the kinetic conditions in the reaction zone are very good. The reaction is rapid and very strong. The MGS produced by the reaction of magnesium and sulfur in molten iron has high melting point (2000 ℃), low density (2.82g/cm3) and is easy to slag. However, magnesium has high activity, so it must be passivated as desulfurizer.
镁不仅可以用单一脱硫剂脱硫,还可以用镁基复合脱硫剂脱硫。镁基脱硫剂中使用的镁粉也需要钝化处理。该镁粉采用铣刀切割或喷涂方法制成,直径0.15~1.2mm,w(mg)=90%,其余为钝化层。流动性处理过的氧化钙粉末与镁粉混合,以确保密相输送顺畅。镁石灰复合脱硫剂的脱硫反应机理如下:由于添加了石灰,氧化钙粉包裹和分散了镁粉,使其均匀分布在铁水中,不仅扩大了反应面积,而且减缓了镁的气化速度,提高了镁的利用率;Cao可以作为络合物的核心来进行μm)聚合,可以加速夹杂物的上浮,不断降低反射区的硫浓度,提高脱硫速度,有利于快速深度脱硫的要求。
Magnesium can be desulfurized not only with a single desulfurizer, but also with magnesium-based composite desulfurizer. The magnesium powder used in magnesium-based desulfurizer also needs passivation treatment. The magnesium powder is made by milling cutter cutting or spraying, with a diameter of 0.15~1.2mm, w (mg)=90%, and the rest is the passivation layer. The fluidity treated calcium oxide powder is mixed with magnesium powder to ensure smooth transportation of the phase. The desulfurization reaction mechanism of magnesium-lime composite desulfurizer is as follows: due to the addition of lime, calcium oxide powder wraps and disperses magnesium powder, making it evenly distributed in molten iron, which not only expands the reaction area, but also slows down the gasification rate of magnesium and improves the utilization rate of magnesium; Cao can be used as the core of complex μ m) Polymerization can accelerate the floating of inclusions, continuously reduce the sulfur concentration in the reflection zone, and improve the desulfurization speed, which is conducive to the requirements of rapid and deep desulfurization.
镁脱硫具有技术、经济合理、维护检修方便、连续运行安全可靠、无石膏结垢、副产硫酸镁或回收利用、无污染排放等优点。由于镁脱硫剂在技术和经济上的优势以及研究开发的深入,镁脱硫剂的应用越来越广泛。
Magnesium desulfurization has the advantages of advanced technology, reasonable economy, convenient maintenance and repair, safe and reliable continuous operation, no gypsum scaling, by-product magnesium sulfate or recycling, no pollution discharge, etc. Due to the technical and economic advantages of magnesium desulfurizer and the in-depth research and development, the application of magnesium desulfurizer is more and more extensive.
5、工业废物作为脱硫剂
5. Industrial waste as desulfurizer
主要有两种废物可以起到脱硫作用。一种是电石渣、白泥、石灰渣等钙基工业废物,另一种是碱土工业废物,如钢渣、冶金废物、化学废物等,对脱硫有一定的催化作用。1000~1100℃时,白泥和电石渣的固硫率较高,1000℃时,白泥的固硫率高达84.5%,甚至高于Cao。然而,当温度上升到1200~1300℃时,白泥和电石渣的固硫率迅速下降,即白泥和电石渣在低温下具有较高的固硫效果。
There are mainly two kinds of wastes that can play a role in desulfurization. One is calcium-based industrial waste such as calcium carbide slag, white mud and lime slag, and the other is alkaline earth industrial waste, such as steel slag, metallurgical waste and chemical waste, which has a certain catalytic effect on desulfurization. At 1000~1100 ℃, the sulfur fixation rate of white mud and carbide slag is higher, and at 1000 ℃, the sulfur fixation rate of white mud is as high as 84.5%, even higher than that of CaO. However, when the temperature rises to 1200~1300 ℃, the sulfur fixation rate of white mud and carbide slag decreases rapidly, that is, white mud and carbide slag have high sulfur fixation effect at low temperature.
The above is a detailed introduction about wet desulfurization, which I hope will help you. If you have any questions, please contact us. We will provide you with our service https://www.hneee.net