沼氣濕法和干法脫硫是目前2大主要脫硫方法,他們之間的區(qū)別主要是通過以下幾個方面來實現(xiàn):干法脫硫與濕法脫硫的區(qū)別濕法和干法脫硫是目前2大主要脫硫方法,他們之間的區(qū)別主要是通過以下幾個方面來實現(xiàn)。
Wet and dry desulfurization of biogas are the two main desulfurization methods at present. The difference between them is mainly realized through the following aspects: the difference between dry desulfurization and wet desulfurization. Wet and dry desulfurization are the two main desulfurization methods at present. The difference between them is mainly realized through the following aspects.
一、干法沼氣脫硫
1、 Dry biogas desulfurization
干法沼氣脫硫是指應(yīng)用粉狀或粒狀吸收劑、吸附劑或催化劑來脫除煙氣中的SO2。它的優(yōu)點是工藝過程簡單,無污水、污酸處理問題,能耗低,特別是凈化后煙氣溫度較高,有利于煙囪排氣擴散,不會產(chǎn)生“白煙”現(xiàn)象,凈化后的煙氣不需要二次加熱,腐蝕性小;其缺點是脫硫效率較低,設(shè)備龐大、投資大、占地面積大,操作技術(shù)要求高。主要的方法有:
Dry biogas desulfurization refers to the application of powdered or granular absorbent, adsorbent or catalyst to remove SO2 from flue gas. It has the advantages of simple process, no sewage and acid treatment problems, low energy consumption, especially the high temperature of the purified flue gas, which is conducive to the exhaust diffusion of the chimney and will not produce the phenomenon of "white smoke", and the purified flue gas does not need secondary heating and is less corrosive; Its disadvantages are low desulfurization efficiency, huge equipment, large investment, large floor area and high operation technical requirements. The main methods are:
吸著劑噴射法按所用吸著劑不同分為鈣基和鈉基工藝,吸著劑可以干態(tài),濕潤態(tài)或漿液,噴入部位可以為爐膛、省煤器和煙道。鈣硫比為2時,干法工藝的脫硫效率達50%~70%,鈣的利用率達50%,這種方法較適合老電廠改造,因為在電廠排煙流程中不需增加任何設(shè)備就能達到脫硫目的。
The sorbent injection method is divided into calcium based and sodium based processes according to the sorbent used. The sorbent can be dry, wet or slurry, and the injection part can be furnace, economizer and flue. When the calcium sulfur ratio is 2, the desulfurization efficiency of dry process is 50% ~ 70% and the utilization rate of calcium is 50%. This method is more suitable for the transformation of old power plants, because the desulfurization purpose can be achieved without adding any equipment in the smoke exhaust process of power plants.
接觸氧化法此法與工業(yè)制酸法一樣,是以硅石為載體,以五氧化二釩或硫酸鉀為催化劑,使SO2氧化成SO3。SO3與水汽作用形成硫酸或與氨作用生成(NH4)2SO4。此法是高溫操作,所需費用高,但由于技術(shù)上較為成熟,目前國內(nèi)外對高濃度煙氣的治理多采用此法。
Contact oxidation method this method is the same as the industrial acid making method. It uses silica as the carrier and vanadium pentoxide or potassium sulfate as the catalyst to oxidize SO2 into SO3. SO3 reacts with water vapor to form sulfuric acid or with ammonia to form (NH4) 2SO4. This method is a high-temperature operation and requires high cost. However, due to its relatively mature technology, this method is mostly used for the treatment of high concentration flue gas at home and abroad.
電子束輻照法本法的工藝技術(shù)簡單,它是利用高能電子束的光化學(xué)反應(yīng),用氨作為吸收劑。煙氣通過輻照反應(yīng)器,經(jīng)輻照后,產(chǎn)生了大量的氫氧基和氧原子,煙氣中二氧化硫和氮氧化物形成硫酸和硝酸,繼而與添加物氨反應(yīng)生成硫酸銨、硝酸銨等混合物,作為農(nóng)用肥料。
Electron beam irradiation method the process technology of this method is simple. It uses the photochemical reaction of high-energy electron beam and ammonia as absorbent. The flue gas passes through the irradiation reactor. After irradiation, a large number of hydroxyl groups and oxygen atoms are produced. Sulfur dioxide and nitrogen oxides in the flue gas form sulfuric acid and nitric acid, and then react with the additive ammonia to form ammonium sulfate, ammonium nitrate and other mixtures as agricultural fertilizer.
二、濕法沼氣脫硫
2、 Wet biogas desulfurization
濕法沼氣脫硫是指應(yīng)用液體吸收劑(如水或堿性溶液等)洗滌煙氣脫除煙氣中的SO2。它的優(yōu)點是脫硫效率高,設(shè)備小、投資省、操作較容易、容易控制以及占地面積小;而缺點是易造成二次污染,存在廢水后處理問題,能耗高,特別是洗滌后煙氣的溫度低,不利于煙囪排氣的擴散,易產(chǎn)生“白煙”,需要二次加熱,腐蝕嚴(yán)重等。主要的方法有:
Wet biogas desulfurization refers to the application of liquid absorbent (such as water or alkaline solution) to wash the flue gas to remove SO2 in the flue gas. It has the advantages of high desulfurization efficiency, small equipment, low investment, easy operation, easy control and small floor area; The disadvantage is that it is easy to cause secondary pollution, there are problems of wastewater post-treatment, high energy consumption, especially the low temperature of flue gas after washing, which is not conducive to the diffusion of chimney exhaust, easy to produce "white smoke", need secondary heating, serious corrosion and so on. The main methods are:
石灰石-石膏法該工藝是利用石灰石/石灰石漿液洗滌煙道氣,使之與SO2反應(yīng),生成亞硫酸鈣(CaSO3),經(jīng)分離的亞硫酸鈣可以拋棄,也可以通入空氣強制氧化和加入一些添加劑,以石膏形式進行回收。為了減輕SO2洗滌設(shè)備的負(fù)荷,先要將煙道氣除塵,然后再進入除塵設(shè)備與吸收液發(fā)生反應(yīng)。石灰/石灰石-石膏法技術(shù)比較成熟,吸收劑價廉易得,運行可靠,應(yīng)用廣,脫硫效率可達90%以上。
Limestone gypsum method this process uses limestone / limestone slurry to wash flue gas and react with SO2 to produce calcium sulfite (CaSO3). The separated calcium sulfite can be discarded, or it can be forced to oxidize with air and add some additives to recover in the form of gypsum. In order to reduce the load of SO2 washing equipment, the flue gas must be dedusted first, and then enter the dedusting equipment to react with the absorption liquid. The technology of lime / limestone gypsum method is relatively mature, the absorbent is cheap and easy to obtain, the operation is reliable, the application is the widest, and the desulfurization efficiency can reach more than 90%.
鈉法此法是用氫氧化鈉、碳酸鈉、或亞硫酸鈉溶液為吸收劑吸收煙氣中的SO2,因該法具有對SO2吸收速度快,管路和設(shè)備不易堵塞等優(yōu)點,所以應(yīng)用比較廣泛,吸收液可以經(jīng)無害化處理后棄去或適當(dāng)方法處理后獲得副產(chǎn)品NaSO3晶體、石膏、硫酸等。
Sodium method this method uses sodium hydroxide, sodium carbonate or sodium sulfite solution as absorbent to absorb SO2 in flue gas. Because this method has the advantages of fast SO2 absorption speed and difficult blockage of pipelines and equipment, it is widely used. The absorption solution can be discarded after harmless treatment or treated by appropriate methods to obtain by-products NaSO3 crystal, gypsum, sulfuric acid, etc.
磷銨復(fù)肥法該法是利用天磷礦石和氨為原料,在煙氣脫硫過程中副產(chǎn)品為磷銨復(fù)合肥料,工藝流程主要包括四個過程,即:活炭脫硫并制得稀硫酸;稀硫酸萃取磷礦制得稀硫酸溶液;磷酸和氨的中和液[(NH4)2HPO4]二級脫硫;料漿濃縮干燥制磷銨復(fù)肥。脫硫效率為95%以上。
Ammonium phosphate compound fertilizer method this method uses tianphosphorus ore and ammonia as raw materials, and the by-product in the process of flue gas desulfurization is ammonium phosphate compound fertilizer. The process flow mainly includes four processes: desulfurization with live carbon and preparation of dilute sulfuric acid; Dilute sulfuric acid solution is prepared by extracting phosphate rock with dilute sulfuric acid; Secondary desulfurization of Neutralization Solution [(NH4) 2HPO4] of phosphoric acid and ammonia; The slurry is concentrated and dried to produce ammonium phosphate compound fertilizer. The desulfurization efficiency is more than 95%.
The above is a detailed introduction to wet desulfurization, which I hope will be helpful to you If you have any questions, please contact us We will provide service for you with our attitude http://www.fengkecheng.cn