The molecular formula of dichloromethane is CH2Cl2. Colorless transparent liquid with sexual smell. It is slightly soluble in water, soluble in ethanol and. It is a nonflammable solvent with low boiling point. It is often used to replace flammable petroleum ether, etc.

用處：

Use:

二氯甲烷具有溶解才能強和毒性低的優(yōu)點，大量用于制造電影膠片、聚碳酸酯，其他用作涂料溶劑、金屬脫脂劑，氣煙霧放射劑、聚氨酯發(fā)泡劑、脫模劑、脫漆劑。二氯甲烷為無色液體，在制藥工業(yè)中做反應(yīng)介質(zhì)，用于制備氨芐青霉素、羥芐青霉素和先鋒霉素等；還用作膠片生產(chǎn)中的溶劑、石油脫蠟溶劑、氣溶膠推進劑、有機合成萃取劑、聚氨酯等泡沫塑料生產(chǎn)用發(fā)泡劑和金屬清洗劑等。

It can be used as defoamer of polycarbonate, defoamer of film and film, and can be used as solvent of defoamer and defoamer of polycarbonate, film and film. Dichloromethane, a colorless liquid, is used as a reaction medium in the pharmaceutical industry for the preparation of ampicillin, benzylpenicillin and cephalosporin. It is also used as solvent, oil dewaxing solvent, aerosol propellant, organic synthesis extractant, polyurethane and other foaming agents and metal cleaning agents in film production.

二氯甲烷在主要用于膠片生產(chǎn)和醫(yī)藥范疇。其中用于膠片生產(chǎn)的生產(chǎn)量占總生產(chǎn)量的50%，醫(yī)面占總生產(chǎn)量的20%，清洗劑及化工行業(yè)生產(chǎn)量占總生產(chǎn)量的20%，其他方面占10%。二氯甲烷也用在工業(yè)制冷系統(tǒng)中用作載冷劑運用，但危害很大，與明火或灼熱的物體接觸時能產(chǎn)生劇毒的。遇濕潤空氣能水解生成微量的氯化氫，光照亦能促進水解而對金屬的腐蝕性加強。

Dichloromethane is mainly used in film production and medicine in China. Among them, 50% of the total production is used for film production, 20% for medical noodles, 20% for cleaning agent and chemical industry, and 10% for others. Dichloromethane is also used as a carrier refrigerant in industrial refrigeration system, but it is very harmful. It can produce highly toxic when contacting with open fire or hot objects. When wet air can hydrolyze to produce trace hydrogen chloride, light can also promote hydrolysis and strengthen the corrosion of metal.

二氯甲烷的應(yīng)急措施

Emergency measures for dichloromethane

二氯甲烷在運用過程中需求當(dāng)心慎重，由于它具有風(fēng)險特性，假如在運用過程中發(fā)作走漏，應(yīng)依據(jù)詳細狀況采取相應(yīng)的應(yīng)急措施，它都有哪些詳細措施呢？

Dichloromethane in the use process needs to be careful, because of its risk characteristics, if leakage occurs in the use process, corresponding emergency measures should be taken according to the detailed situation. What are the detailed measures?

1、切斷火源。2、盡可能切斷走漏源，避免流入下水道、排洪溝等性空間。3、疾速撤離走漏污染區(qū)人員區(qū)，并進行，嚴(yán)厲出入。4、倡議應(yīng)急處置人員戴自給正壓式呼吸器，穿防毒服。5、小量走漏：用砂土或其它不燃資料吸附或吸收。6、大量走漏：構(gòu)筑圍堤或挖坑收留，用泡沫掩蓋，降低蒸氣災(zāi)禍；用泵轉(zhuǎn)移槽車或?qū)Ｓ盟鸭鲀?nèi)，回收或運廢物處置場所處置。

1. Cut off the fire. 2. Cut off the leakage source as much as possible to avoid flowing into sewer, flood discharge ditch and other sexual space. 3. Quickly evacuate the personnel from the leakage contaminated area to the safe area, and strictly enter and exit. 4. It is suggested that emergency disposal personnel should wear self-contained positive pressure respirator and anti-virus clothing. 5. Small amount of leakage: adsorption or absorption with sand or other incombustible data. 6, a large number of leaks: build a dike or dig a hole to retain, cover with foam, reduce steam disaster; transfer the pump to the tank car or special collector, recover or transport to the disposal place of waste disposal.

二氯甲烷與明火或灼熱的物體接觸時能產(chǎn)生劇毒的，遇濕潤空氣能水解生成微量的氯化氫，釋放出的與氯化氫都具有毒性，所以在運用過程中要當(dāng)心當(dāng)心再當(dāng)心。

Dichloromethane and open fire or hot objects contact can produce highly toxic, when wet air can be hydrolyzed to produce a trace of hydrogen chloride, released and hydrogen chloride are toxic, so in the process of use, be careful and careful.

二氯甲烷尾氣回收的辦法

Recovery method of dichloromethane tail gas

由于二氯甲烷沸點低、易揮發(fā)，在被真空泵抽出的過程中會分發(fā)到空氣中，產(chǎn)生損失并傷害人體、污染環(huán)境。有什么更好的辦法來回收含有二氯甲烷的尾氣么？

Due to its low boiling point and volatile nature, dichloromethane will be distributed to the air in the process of being pumped out by vacuum pump, which will cause damage to human body and pollute the environment. Is there a better way to recover the tail gas containing dichloromethane?

1、吸收法

1. Absorption method

吸收法是將尾氣與吸收劑接觸,或采取噴淋、逆流等方式,在吸收塔內(nèi)完成,吸收液有柴油、DOP等高沸點溶劑，也可用添加助溶劑、凝聚劑的水。吸收法合適中高濃度(2g/m3以上)和中小排風(fēng)量(104m3/h以下)的管理,對低濃度、大風(fēng)量廢氣管理效率低。吸收法存在吸收液的后處置費事、會帶來二次污染和二次管理等問題。

The absorption method is to contact the tail gas with the absorbent, or spray or counter current in the absorption tower. The absorption liquid includes diesel oil, DOP and other high boiling point solvents, or water added with cosolvent and coagulant. The absorption method is suitable for the management of medium and high concentration (above 2G / m3) and medium and small exhaust air volume (below 104m3 / h), and has low management efficiency for low concentration and large air volume waste gas. There are some problems in the absorption method, such as the post disposal of absorption solution, secondary pollution and secondary management.

2、冷凝法

2. Condensation method

冷凝法是應(yīng)用二氯甲烷在不同溫度下的飽和蒸汽壓的不同，經(jīng)過降溫的辦法使氣體冷凝回收。其優(yōu)點是設(shè)備簡單、易操作。是只適用于高濃度的氣體。冷凝法普通只作為預(yù)處置辦法運用。

Condensation method is to use dichloromethane at different temperatures of saturated vapor pressure is different, through cooling method to condense gas recovery. It has the advantages of simple equipment and easy operation. It is only suitable for high concentration gas. Condensation method is usually used only as a pre-treatment method.

3、綜合法

3. Synthesis method

從應(yīng)用狀況來看，單一法較適于氣體量小、污染物濃度高的氣體，但關(guān)于目前國內(nèi)許多工藝過程產(chǎn)生的氣量大、低濃度的二氯甲烷廢氣來說，單一法的凈化管理工藝主要存在2個:一是凈化設(shè)備運轉(zhuǎn)耗能與高運轉(zhuǎn)費用問題在此條件下較為突出，本錢和費用較高；二是有些工藝存在效率不高和二次污染問題,處置效果也不能令人稱心,從而影響了工藝的大面積推行和應(yīng)用。目前，在制藥生產(chǎn)中,將兩種或兩種以上單一法進行分離，用于二氣甲烷尾氣的回收。

From the application situation, the single method is more suitable for the gas with small amount of gas and high concentration of pollutants. However, there are two main problems in the purification and management process of single method for dichloromethane waste gas with large gas volume and low concentration produced by many domestic processes: first, the problems of energy consumption and high operation cost of purification equipment operation are more prominent under this condition, and the cost and cost are higher; second, the waste gas generated by many domestic processes is high Some processes have the problems of low efficiency and secondary pollution, and the disposal effect is not satisfactory, which affects the large-scale implementation and application of the process. At present, in pharmaceutical production, two or more single methods are used for the recovery of methane tail gas.

4、吸附法

4. Adsorption method

吸附法是用活性炭對二氯甲烷尾氣進行吸附凈化，特別對低濃度尾氣的吸附,是好的辦法。該辦法的吸附較好,吸附后的用水蒸氣進行脫附,冷凝回收。吸附回收法合適處置的是高濃度(2g/m3以上)單組份,而關(guān)于多組份及易溶于水的溶劑用該法處置后需進行后續(xù)精餾。用該辦法處置后的尾氣能到達排放規(guī)范,對環(huán)境管理有較大的意義。

Adsorption method is to use activated carbon to adsorb and purify dichloromethane tail gas, especially for low concentration tail gas. The adsorption of this method is better, and the water vapor after adsorption is desorbed and condensed for recovery. High concentration (above 2G / m3) single component is suitable to be disposed by adsorption recovery method, while the multi-component and water-soluble solvents need to be further rectified after being disposed by this method. The tail gas treated by this method can reach the emission standard, which is of great significance to environmental management.

平常我們在對二氯甲烷尾氣進行回收處置的時分，應(yīng)該加強氣體自身的回收開展作用，做好整體處置及運用，從而到達加強運用效果的作用。

In general, when we recycle and dispose of dichloromethane tail gas, we should strengthen the recovery and development of the gas itself, do a good job in the overall treatment and application, so as to achieve the effect of strengthening the use.