工業廢氣是大氣污染物的重要來源，工業廢氣的高效治理顯得非常重要，今天為大家介紹常見的六類工業廢氣的治理技術，再也不用為廢氣治理發愁了。

一、碳氫化合物的凈化

　　燃燒法

　　用燃燒方法銷毀有害氣體、蒸氣或煙塵，使其變為無害物質的過程，稱為燃燒凈化。燃燒凈化時所發生的化學作用主要是燃燒氧化作用及高溫下的熱分解。

　　目前在實際中使用的燃燒凈化方法有直接燃燒和熱力燃燒。對化工、噴漆、絕緣材料等行業的生產裝置中所排出的有機廢氣，廣泛采用了燃燒凈化的手段。

　　特點：用于凈化那些可燃的或在髙溫情況下可以分解的有害氣體，還可以用來消除惡臭，回收熱量。

　　催化燃燒法

　　即在催化劑作用下，使廢氣中的有害可燃組分氧化為CO2和H2O。由于絕大部分有機物均具有可燃燒性，因此催化燃燒法已成為凈化含碳氧化合物廢氣的有效手段之一。

　　目前催化燃燒法已應用于金屬印刷、絕緣材料、漆包線、煉焦、油漆、化工等多種行業中凈化有機廢氣。

　　特點：因廢氣溫度較高、有機物濃度較髙，對燃燒反應及熱量回收有利，具有較好的經濟效益，因此應用廣泛。

　　吸附法

　　作為凈化碳氫化合物廢氣的吸附劑有活性炭、硅膠、分子篩等，利用吸附劑對有機物進行吸附，其中應用泛、的吸附劑是活性炭。

　　特點：

　　①可以相當地凈化廢氣，即可進行深度凈化，特別是對于低濃度廢氣的凈化比用其他方法顯現出吏大的優勢；

　?、谠诓皇褂蒙罾?、髙壓等手段下，可以有效地回收有價值的有機物組分。

　　吸收法

　　在對碳氫化合物廢氣進行治理的方法中，吸收法的應用不如燃燒法、催化燃燒法、吸附等廣泛，特別是對使用有機溶劑的各種行業，如噴漆、絕緣材料、漆包線等的生產過程所排出的廢氣，還不能達到工業應用水平。

　　影響應用的主要問題是合適的吸收劑的選擇。

　　目前在石油煉制及石油化的生產及儲運中采用吸收法進行烴類氣體的回收利用。

　　冷凝法

　　利用物質在不同溫度下具有不同飽和蒸汽壓這一物理性質，采用降低系統溫度或提高系統壓力的方法，使處于蒸汽狀態的污染物冷凝并從廢氣中分離出來的過程。

　　特點：

　　冷凝凈化法適用范圍冷凝凈化法適于在下列情況下使用。

　　處理高濃度廢氣，特別是含有害物組分單純的廢氣；

　　作為燃燒與吸附凈化的預處理；特別是有害物含量較高時，可通過冷凝回收的方法減輕后續凈化裝置的操作負擔；

　　處理含有大量水蒸氣的高溫廢氣。

　　冷凝凈化法所需設備和操作條件比較簡單回收物質純度髙。

　　冷凝凈化法對廢氣的凈化程度受冷凝溫度的限制，要求凈化程度髙或處理低濃度廢氣時，需要將廢氣冷卻到很低的溫度，經濟上不合算。

二、含硫廢氣的凈制

　　該法是使用粉狀、粒狀吸收劑，吸附劑或催化劑去除廢氣中的80%。

　　優點：治理中無廢水、廢酸排出，減少了二次污染。

　　缺點：脫硫效率較低，設備廢大，操作要求髙。

       濕法脫硫

　　該法是采用液體吸收劑如水或械溶液洗涂含S02的煙氣，通過吸收去除其中的S02。由于使用不同的吸收劑可獲得不同的副產物而加以利用，因此濕法脫硫是各國研究最多的方法。

　　優點：濕法脫硫所用設備較簡單，操作容易，脫硫效率較高。

　　缺點：脫硫后煙氣溫度較低，于煙囪排煙擴散不利。

三、含H2S廢氣的凈制

       干法脫硫

　　干法是利用的還原性和可燃性，以固體氧化劑或吸附劑來脫硫，或者直接使之燃燒。干法脫硫是以氧氣使H2S氧化成硫或硫氧化物的一種方法，也可稱為干式氧化法。

　　常用的有改進的克勞斯法、氧化鐵法、活性碳吸附法、氧化鋅法和卡太蘇耳法。

　　所用的脫硫劑、催化劑有活性炭、氧化鐵、氧化鋅、二氧化錳及鋁礬土，此外還有分子篩、離子交換樹脂等。一般可回收硫、二氧化硫、硫酸和硫酸鹽。

　　吸收劑有甲醇、碳酸丙烯酯、聚乙二醇二甲醚等，不僅能脫除硫化氫，氧硫化碳、二硫化碳等，溶液可以再生，并將硫化氫回收，而且也能選擇性地吸收二氧化碳。

　　化學吸收法

　　常用的有氨水催化法及改良蒽醌二磺酸法（砷堿法因溶液有毒已較少采用）。

四、NOx廢氣的凈制

　　煙氣脫硝

　　在煙氣凈化技術上控制NOx排放，目前主要方法有選擇性非催化還原SNCR、選擇性催化還原SCR、低氮燃燒技術和電子束照射法、臭氧氧化法、吸附法、氧化吸收法等。其中，選擇性非催化還原SNCR、選擇性催化還原SCR，低氮燃燒，臭氧氧化法等技術已商業化。

五、含鹵素廢氣的凈制

　　1、含氟廢氣的凈制

　　該法是以粉狀的吸附劑吸附廢氣中的氟化物。該凈化方法首先是煙氣與吸附劑的接觸，完成吸附過程;二是煙氣與吸附劑分開。該過程都是在吸附設備中完成的。

　　特點：凈化效率高、工藝簡單、沒有水的二次污染，也不受各種氣候的影響，但凈化設備的體積較大。

　　吸收法

　　該法是用水、減性溶液或某些鹽類溶液來吸收含氟廢氣中的氟化物，從而達到凈化回收的目的，同時還可以得到副產品氟硅酸、冰晶石、氟硅酸鈉及氟硅脲等。

　    水法吸收和堿吸收法是常用的兩種方法。

　　特點：凈化工藝過程可以連續操作和回收各種氟化物，凈化效率高、效果好；其缺點是會造成二次污染，在寒冷地區還需保溫措施。

　　稀釋法

　　是向含氟氣體的廠房送新鮮空氣或將含氟廢氣向高空排放進行自然稀釋。這種方法一般不采用。

　　2、含氯廢氣的凈制

　　含氯廢氣的治理主要是通過濕法來凈化，一般是采用化學中和法、氧化還原法等過程對廢氣進行吸收，作到綜合利用。

　　堿液中和法

　　即以堿液作為吸收液對氯氣進行吸收，常用的吸收劑有氫氧化鈉溶液、碳酸鈣溶液、石灰乳溶液等。

　　或氯化亞鐵吸收法

　　該方法以氯化亞鐵或作為吸收劑，據氧化還原反應性質對氯氣進行回收與凈化。其工藝設備可采用填料塔，并以廢鐵屑作填料，生產的三氯化鐵可作為防水劑，三價鐵可被鐵屑還原，再次參與吸收反應。

　　特點：該方法設備簡單，操作容易，廢鐵屑來源豐富，技術合理；但反應速度比中和法要慢，效率較低。

　　吸收法

　　當氯氣濃度大于1%時，可采用為吸收劑，其設備可采用噴淋或填充塔，在吸收塔內將氯的吸收液通過加熱或吹脫解吸回收的氯氣可再次使用。

　　水吸收法

　　當氯氣濃度＜1%時，有時可用水通過噴淋塔來吸收氯氣，其效果不如堿性中和法好。用水蒸氣加熱解吸時可回收氯氣，如國內的一些氯堿廠在“氯水"解吸時用蒸氣或熱交換方法回收氯氣。

　　此外，還有用硅膠、活性炭、離子交換樹脂等進行吸附的方法，但因成本太高或是技術還不十分成熟而沒有得到廣泛的應用。

六、廢氣的凈制

　　水吸收法

　　處理主要采用水吸收法。水吸收法是基于氣體易溶于水的原理常常采用水直接吸收氣體。當所得溶液達到一定濃度時，經凈化濃縮可得到副產品鹽酸。

　　同時，處理廢氣還有堿液吸收法，聯合吸收法以及冷凝法。

Industrial emissions is an important source of atmospheric pollutants, efficient treatment of industrial waste gas is very important today to introduce common governance six industrial gas technology, no longer have to worry about gas treatment.

A hydrocarbon purification

Combustion

Combustion method to destroy harmful gases, vapors or dust, it becomes harmless substances in the process, called combustion purification. Chemical reaction that occurs when combustion purification mainly thermal combustion oxidation and high temperature decomposition.

Currently combustion purification methods used in practice have a direct combustion and heat of combustion. Chemical, paint, insulation materials and other industries in the production unit of organic waste discharged, a widely used means of combustion purification.

Features: for purifying harmful gas or in the case of Gao temperature can break those flammable, can also be used to eliminate odor, heat recovery.

Catalytic combustion

That is in the catalyst, the exhaust gas harmful combustible components are completely oxidized to CO2 and H2O. Since most organic compounds have can burn, therefore the catalytic combustion has become one of the effective means to purify exhaust gases containing carbon and oxygen compounds.

Currently catalytic combustion method has been applied to the metal printing, insulation materials, wire, coke, paint, chemical and other industries in the organic waste gas purification.

Features: Due to the higher exhaust gas temperature, concentration of organic matter than the Gao, the combustion reaction and heat recovery favorable, with good economic and therefore the most widely used.

Adsorption

As the exhaust gas purifying hydrocarbon adsorbent activated carbon, silica gel, molecular sieve, using an adsorbent for adsorption of organic matter, including the most widely used, the best effect is activated carbon adsorbent.

Features:

① can be quite thoroughly purify exhaust gas, deep purification can be carried out, especially for the low-concentration exhaust gas purification using other methods show Officials large odds ratio;

② without the use of deep cold, under pressure of Gao and other means to effectively recover valuable organic components.

Absorption

On hydrocarbons in the exhaust gas treatment method, absorption method of application is better combustion, catalytic combustion, adsorption and so widely, particularly on the use of organic solvents in a variety of industries, such as painting, insulation materials, wire and other production processes the exhaust gas, it can not fully meet the level of industrial application.

The main issues affecting the application of suitable absorbent choice.

Currently recycling hydrocarbon gas absorption method using the oil refining and petrochemical production and storage and transportation.

Condensation method

The use of material having different saturation vapor pressure at different temperatures, the physical properties, the use of lower system temperature or pressure of the system to improve the ways in which the condensed contaminants in the vapor state and separated from the exhaust gas process.

Features:

Condensate purification method scope condensate purification method is suitable for use in the following cases.

Treatment of high concentration waste gas, particularly those containing harmful components of exhaust gas alone;

As a pretreatment of the combustion and adsorption clarifier; especially when high content of harmful substances, can reduce the operational burden of the subsequent purification by means of condensation recovery method;

Processing of high temperature exhaust gas containing a large amount of water vapor.

Condensate purification method required equipment and operating conditions are relatively simple purity of recovered material Gao.

Condensate purification method for purifying exhaust gas is limited by the degree of condensation temperature required degree of purification or treatment Gao low concentration waste gas, the waste gas needs to be cooled to very low temperatures, economically viable.

Second, the net sulfur exhaust system

This method is the use of powdered, granular absorbents, adsorbents or catalyst removal in the exhaust gas of 80%.

Advantages: No waste water treatment, waste acid discharge, reduce the secondary pollution.

Disadvantages: desulfurization efficiency is low, large waste facilities, operating requirements Gao.

Wet desulfurization

The method is the use of a liquid absorbent, such as water or mechanical wash coat solution containing S02 flue gas by absorption to remove one of the S02. Due to the use of different absorbent obtain different by-products and take advantage of, so wet desulphurization was the most national research method.

Advantages: wet desulfurization equipment used is relatively simple, easy to operate, high desulfurization efficiency.

Disadvantages: low temperature flue gas desulfurization, chimney smoke diffusion in the negative.

Third, the exhaust gases containing H2S net system

Dry desulfurization

Dry method is the use of combustible and reducing to an oxidizing agent or a solid adsorbent desulfurization, or simply to make it burn. Dry desulfurization make H2S is oxidized to sulfur oxygen or sulfur oxides a method, also known as dry oxidation method.

Commonly used to improve the Claus process, iron oxide method, activated carbon adsorption, zinc oxide and chi too Su ear method.

The desulfurization agent used, catalysts are activated carbon, iron oxide, zinc oxide, manganese dioxide and bauxite, in addition to molecular sieves, ion exchange resins and the like. Usually recoverable sulfur, sulfur dioxide, sulfuric acid and sulfates.

Absorbents, methanol, propylene carbonate, polyethylene glycol dimethyl ether, etc., not only to remove hydrogen sulfide, carbonyl sulfide, carbon disulfide, the solution can be regenerated and recycled hydrogen sulfide, but also capable of selectively removing carbon dioxide .

Chemical absorption

Commonly used ammonia catalytic anthraquinone disulfonic acid and Improvement Act (arsenic soda solution because toxic has been less used).

Fourth, the net made NOx exhaust gas

Flue gas denitrification

In the flue gas purification technology to control NOx emissions, the main method of selective non-catalytic reduction SNCR, selective catalytic reduction SCR, low NOx combustion technology and electron beam irradiation, ozone oxidation, adsorption, absorption oxidation method. Wherein the selective non-catalytic reduction SNCR, selective catalytic reduction SCR, low NOx combustion, ozone oxidation technology has been commercialized.

Fifth, the halogen-containing exhaust gases net system

1, net made of fluorine gas

The method is based on powdered adsorbent exhaust gas fluoride. The flue gas purification method first contact with the adsorbent, the adsorption process is completed; the second is separated from the flue gas with the adsorbent. This process is done in the adsorption device.

Features: high purification efficiency, simple process, no secondary pollution of water, is not affected by all kinds of weather, but the larger the volume of purification equipment.

Absorption

The law is water, some subtractive solution or salt solution to absorb fluoride fluorine-containing exhaust gas, so as to achieve the purpose of purification and recovery, but also can be a by-product fluosilicic acid, cryolite, sodium fluoride and silicon fluoride urea or the like.

Water absorption and alkali absorption method is commonly used in two ways.

Features: purification process can be operated continuously and recycling of fluorides, high purification efficiency, good effect; the drawback is cause secondary pollution, insulation measures needed in cold areas.

Dilution

Fresh air is sent to a gas containing fluorine or fluorine-containing gas plant to high-altitude emissions for natural dilution. This method is generally not used.

2, net made of chlorine gas

Chlorine gas governance mainly through wet to purify, is generally used in the chemical process and method, redox method of gas absorption, utilization done.

Lye and law

Namely lye as the absorbing liquid to absorb chlorine, sodium hydroxide solution commonly used absorbent, sodium carbonate solution, lime solution and the like.

Ferrous sulfate or ferrous chloride absorption method

In this method, ferrous chloride or ferrous sulfate as an absorbent, according to the nature of the redox reaction of chlorine gas is recovered and purified. Its process equipment can be packed towers, and scrap iron as a filler, the production of ferric chloride can be used as a waterproofing agent, ferric iron can be reduced again to participate in the absorption reactions.

Features: This method is simple equipment, easy to operate, a rich source of scrap iron, technically sound; but the reaction rate is slower than the neutralization method, less efficient.

CTC Absorption Spectrometry

When the chlorine concentration is greater than 1%, it can be used as absorbent carbon tetrachloride, which can be spray equipment or packed column, in the absorber absorbing liquid chlorine by heating or stripping desorption recycling of chlorine can be used again.

Water Absorption Spectrometry

When the chlorine concentration of <1%, sometimes by spraying water tower to absorb chlorine, are less effective than alkaline and good law. Recyclable chlorine by heating the desorption of water vapor, such as some domestic chlor-alkali plants in the "chlorine" desorption-recovery steam or heat exchange process chlorine.

In addition, there were adsorption method using silica gel, activated carbon, ion exchange resin, but the cost is too high or the technology is not very mature and has not been widely used.

Sixth, the net hydrogen chloride gas

Water Absorption Spectrometry

Mainly deal with hydrogen chloride water absorption. Water absorption principle is soluble in water-based gas is often used water directly absorb hydrogen chloride gas. When the resulting hydrogen chloride solution reaches a certain concentration, purified and concentrated hydrochloric acid by-product can be obtained.

At the same time, the process of hydrogen chloride gas as well as alkali absorption method, combined with absorption and condensation.