脫硫脫硫方式按應(yīng)用階段可分為燃燒前、燃燒中、燃燒后三類，其中燃燒后煙氣脫硫（FGD）應(yīng)用最廣，按脫硫劑及產(chǎn)物干濕狀態(tài)又可分為濕法、半干法、干法，（炭素廠脫硫應(yīng)用最多的時(shí)濕法脫硫，少部分半干法脫硫）以下是詳細(xì)介紹:（最后有濕法脫硫工藝要素）

　　The desulfurization methods can be divided into three categories according to the application stage: pre combustion, during combustion, and post combustion. Among them, post combustion flue gas desulfurization (FGD) is the most widely used. According to the dry and wet state of the desulfurizer and product, it can be further divided into wet, semi dry, and dry methods. (Wet desulfurization is the most commonly used method for desulfurization in carbon plants, and a small part is semi dry desulfurization.) The following is a detailed introduction: (Finally, there are elements of wet desulfurization process)

　　燃燒前脫硫

　　Pre combustion desulfurization

　　燃燒前脫硫是通過對燃料預(yù)處理減少硫分，常用選煤與配煤技術(shù)。

　　Pre combustion desulfurization is achieved by reducing sulfur content through fuel pretreatment, commonly using coal selection and blending techniques.

　　a.利用物理方法（如重選、浮選）去除煤中無機(jī)硫（如黃鐵礦）

　　a. Using physical methods such as reselection and flotation to remove inorganic sulfur (such as pyrite) from coal

　　b.利用煤炭氣化后對合成氣脫硫（如低溫甲醇洗、聚乙二醇二甲醚法）

　　b. Using coal gasification for desulfurization of synthesis gas (such as low-temperature methanol washing, polyethylene glycol dimethyl ether method)

　　燃燒中脫硫

　　During combustion desulfurization

　　是在燃燒過程中加入脫硫劑固硫，常用爐內(nèi)噴鈣與循環(huán)流化床燃燒（CFBC），適合中小型鍋爐輔助脫硫。

　　It is to add desulfurizer to fix sulfur during the combustion process, commonly using furnace injection of calcium and circulating fluidized bed combustion (CFBC), suitable for assisting desulfurization in small and medium-sized boilers.

　　燃燒后脫硫（煙氣脫硫 FGD）

　　Post combustion desulfurization (flue gas desulfurization)

　　按干濕狀態(tài)分類：

　　Classified by dry and wet conditions:

　　干法脫硫（脫硫效率 60%-80%）；

　　Dry desulfurization (desulfurization efficiency 60% -80%);

　　半干法脫硫（脫硫效率 85%-95%）；

　　Semi dry desulfurization (desulfurization efficiency 85% -95%);

　　濕法脫硫（脫硫效率 95%-99%）。

　　Wet desulfurization (desulfurization efficiency 95% -99%).

　　干法脫硫（脫硫效率 60%-80%）

　　Dry desulfurization (desulfurization efficiency 60% -80%)

　　主要應(yīng)用：循環(huán)流化床（CFB）干法脫硫：將消石灰漿液噴入流化床，與煙氣中的SO2反應(yīng)；

　　Main applications: Circulating fluidized bed (CFB) dry desulfurization: spraying stone slurry liquid into the fluidized bed and reacting with SO2 in the flue gas;

　　SDS小蘇打干法脫硫：以碳酸氫鈉（NaHCO3）為脫硫劑，通過熱分解生成Na2CO3，再與SO2反應(yīng)：Na2CO3+SO2→Na2SO3+CO2。該法適應(yīng)性強(qiáng)（適用于高硫煙氣），常與中低溫SCR脫硝結(jié)合（SDS+SCR），實(shí)現(xiàn)SO2和NOx的超低排放。

　　SDS baking soda dry desulfurization: using sodium bicarbonate (NaHCO3) as the desulfurizer, Na2CO3 is generated through thermal decomposition, and then reacts with SO2: Na2CO3+SO2 → Na2SO3+CO2. This method has strong adaptability (applicable to high sulfur flue gas) and is often combined with medium and low temperature SCR denitrification (SDS+SCR) to achieve ultra-low emissions of SO2 and NOx.

　　半干法脫硫（脫硫效率85%-95%）

　　Semi dry desulfurization (desulfurization efficiency 85% -95%)

　　核心特征為“濕進(jìn)干出”：主要分為噴霧干燥法（SDA）、循環(huán)流化床法（CFB-FGD）、密相干塔法三類.

　　The core feature is "wet in and dry out": it is mainly divided into three categories: spray drying (SDA), circulating fluidized bed (CFB-FGD), and dense coherent tower

　　霧干燥法（SDA）

　　Fog drying method (SDA)

　　通過旋轉(zhuǎn)霧化器將石灰漿（或消石灰漿）霧化成10-100μm的細(xì)小液滴，噴入反應(yīng)塔與300-500℃的煙氣充分混合。液滴中的水分迅速蒸發(fā)，脫硫劑與SO2反應(yīng)生成亞硫酸鈣（CaSO3），進(jìn)一步氧化為硫酸鈣（CaSO4），最終隨煙氣進(jìn)入除塵器收集。

　　By using a rotary atomizer, the lime slurry (or limestone slurry) is atomized into small droplets of 10-100 μ m, which are then sprayed into the reaction tower and thoroughly mixed with flue gas at 300-500 ℃. The water in the droplets evaporates rapidly, and the desulfurizer reacts with SO2 to produce calcium sulfite (CaSO3), which is further oxidized to calcium sulfate (CaSO4) and finally collected by the dust collector along with the flue gas.

　　循環(huán)流化床法（CFB-FGD）、

　　Circulating fluidized bed method (CFB-FGD)

　　流程：

　　process

　　吸收劑制備：

　　Preparation of absorbent:

　　采用消石灰（Ca(OH)2）作為脫硫劑（部分項(xiàng)目用石灰石粉（CaCO3）），通過石灰倉（存儲(chǔ)消石灰）→旋轉(zhuǎn)給料閥（控制給料量）→緩沖罐（穩(wěn)定料流）→噴料泵（加壓）輸送至吸收塔。

　　Using hydrated lime (Ca (OH) 2) as a desulfurizer (some projects use limestone powder (CaCO3)), it is transported to the absorption tower through a lime silo (storing hydrated lime), a rotary feeding valve (controlling the feeding amount), a buffer tank (stabilizing the material flow), and a spray pump (pressurization).

　　若采用石灰石粉，需先通過石灰石粉倉→粉倉旋轉(zhuǎn)給料閥→緩沖罐→噴料泵送至吸收塔。

　　If limestone powder is used, it needs to be first sent to the absorption tower through the limestone powder bin → powder bin rotary feeding valve → buffer tank → spray pump.

　　霧化噴射：

　　Atomization spray:

　　消石灰或石灰石粉通過噴槍（安裝在吸收塔底部文丘里管上方）噴入煙氣中，同時(shí)噴入霧化水（來自工藝水系統(tǒng)），使脫硫劑與煙氣充分混合。

　　Lime or limestone powder is sprayed into the flue gas through a spray gun (installed above the Venturi tube at the bottom of the absorption tower), and atomized water (from the process water system) is also sprayed to fully mix the desulfurizer with the flue gas.

　　作用：

　　Function:

　　消石灰（Ca(OH)2）與SO2反應(yīng)生成亞硫酸鈣（\text{CaSO}_3}），進(jìn)一步氧化為硫酸鈣（\text{CaSO}_4}，即石膏）；

　　Lime (Ca (OH) 2) reacts with SO2 to form calcium sulfite {CaSO}_3 }), further oxidized to calcium sulfate {CaSO}_4 }(i.e. gypsum);

　　霧化水的作用是降低煙氣溫度（通過蒸發(fā)吸熱），使反應(yīng)溫度維持在70-90℃（高于煙氣露點(diǎn)20℃以上，避免結(jié)露腐蝕），同時(shí)濕潤脫硫劑顆粒，增強(qiáng)反應(yīng)活性。

　　The function of atomized water is to reduce the temperature of flue gas (by absorbing heat through evaporation), maintain the reaction temperature at 70-90 ℃ (above the dew point of flue gas by more than 20 ℃ to avoid condensation corrosion), and wet the desulfurizer particles to enhance reaction activity.

　　濕法脫硫（脫硫效率 95%-99%）

　　Wet desulfurization (desulfurization efficiency 95% -99%)

　　原料主要有鈣法（石灰石、生石灰、電石渣）、氨法和鎂法脫硫。

　　The main raw materials include calcium desulfurization (limestone, quicklime, carbide slag), ammonia desulfurization, and magnesium desulfurization.

　　前面文章中有相關(guān)脫硫篇可查閱。

　　There are relevant desulfurization articles available for reference in the previous article.

　　最后給大家分享我們最常用的石灰石-石膏脫硫法的關(guān)鍵環(huán)節(jié)技術(shù)：

　　Finally, we would like to share with you the key technical steps of our most commonly used limestone gypsum desulfurization method:

　　核心反應(yīng)：

　　Core reaction:

　　吸收階段：SO? + H?O → H?SO?

　　Absorption stage: SO?+H? O → H?SO?

　　H?SO? ? H? + HSO??

　　H?SO?  ? H? + HSO??

　　CaCO? + 2H? → Ca?? + CO?↑ + H?O

　　CaCO?  + 2H? → Ca??  + CO?↑ + H?O

　　氧化階段：2HSO?? + O? → 2SO??? + 2H?

　　Oxidation stage: 2HSO??  + O? → 2SO???  + 2H?

　　結(jié)晶階段：Ca?? + SO??? + 2H?O → CaSO?·2H?O↓

　　Crystallization stage: Ca??  + SO???  + 2H?O → CaSO? ·2H?O↓

　　原料：粒度250目90%，鈣純度>75%,越高越好。

　　Raw materials: particle size of 250 mesh, 90%, calcium purity>75%, the higher the better.

　　塔液位：硫含量高的化，不宜過低，要有充分的量循環(huán)反應(yīng)；

　　Tower liquid level: For those with high sulfur content, it should not be too low and there should be sufficient circulating reaction;

　　漿液溫度：控制35-65℃（不是煙氣溫度）；

　　Slurry temperature: Control 35-65 ℃ (not flue gas temperature);

　　液氣比：15-30 L/m?（硫含量越高，液氣比需越大），計(jì)算方法：煙氣流量100000m?，循環(huán)泵4臺(tái)流量1200m?/h，則液氣比L/G=1200*4*1000/200000=24

　　Liquid to gas ratio: 15-30 L/m? The higher the sulfur content, the greater the liquid to gas ratio required. Calculation method: If the flue gas flow rate is 100000m ? and the flow rate of four circulating pumps is 1200m ?/h, then the liquid to gas ratio L/G=1200 * 4 * 1000/20000=24

　　吸收塔pH值：5.0-5.8（最佳反應(yīng)區(qū)間），pH＜5.0會(huì)導(dǎo)致吸收能力下降，pH＞6.0易引發(fā)Ca結(jié)垢

　　Absorption tower pH value: 5.0-5.8 (optimal reaction range). pH<5.0 will lead to a decrease in absorption capacity, while pH>6.0 is prone to Ca scaling

　　吸收塔密度：1.08-1.15g/cm?；

　　Absorption tower density: 1.08-1.15g/cm?;

　　石膏含水率：10-15%（真空皮帶脫水后）

　　Gypsum moisture content: 10-15% (after vacuum belt dehydration)

　　氧化風(fēng)：（可以選擇空氣懸浮風(fēng)機(jī)比較好用），如果是環(huán)形母管 + 多根支管（DN25~DN50）+ 多孔噴頭的可以少一些，3-5個(gè)單點(diǎn)吹入的需要多些。

　　Oxidation air: (air suspension fan can be chosen for better use). If it is a circular main pipe+multiple branch pipes (DN25~DN50)+porous nozzles, there can be fewer, and more need to be blown into 3-5 single points.

　　噴淋：漿液噴淋覆蓋率至少達(dá)到150%以上，錯(cuò)層分布，可以選擇雙噴頭。

　　Spray: The coverage rate of slurry spray should reach at least 150%, with staggered distribution, and dual nozzles can be selected.

　　濾布：200-300目，日常沖洗，定期更換；

　　Filter cloth: 200-300 mesh, daily flushing, regular replacement;

　　旋流器壓力：0.15-0.25mpa

　　Cyclone pressure: 0.15-0.25mpa

　　脫水機(jī)沖洗水壓力：（作用：濾布沖洗水、真空盒密封）>0.4mpa；

　　Dehydration machine flushing water pressure: (function: filter cloth flushing water, vacuum box sealing)>0.4mpa;

　　脫水機(jī)真空：>0.04mpa

　　Dehydration machine vacuum:>0.04mpa

　　可以適當(dāng)使用增效劑和消泡劑

　　Enhancers and defoamers can be used appropriately

　　脫硫的穩(wěn)定運(yùn)行和石膏穩(wěn)定脫干，也是系統(tǒng)調(diào)整和細(xì)節(jié)把控，大家有什么問題可以具體交流。

　　The stable operation of desulfurization and the stable dehydration of gypsum are also system adjustments and detail control. If you have any questions, please communicate them in detail.