《液氨（liquid ammonia）.doc》由会员分享，可在线阅读，更多相关《液氨（liquid ammonia）.doc（10页珍藏版）》请在三一文库上搜索。
1、液氨（liquid ammonia）liquid ammoniaLiquid ammonia, also known as anhydrous ammonia, is a colorless liquid. Ammonia, as an important chemical raw material, is widely used for transportation and storage. Ammonia gas is usually obtained by pressurizing or cooling gaseous ammonia. Liquid ammonia is widely
2、used in industry, and it is corrosive and easy to volatilize. Therefore, the rate of chemical accidents is quite high.CatalogPhysical and chemical propertiesProduct usePacking&StoreageToxic treatment, toxicity and poisoning mechanismRoute of contact and symptoms of poisoningFirst-aid measuresPhysica
3、l and chemical properties of waste gas recoveryProduct usePacking&StoreageToxic treatment, toxicity and poisoning mechanismRoute of contact and symptoms of poisoningFirst-aid measuresWaste gas recoveryOpenbrief introductionThe English name Liquid ammonia (anhydrous ammonia) structure and molecular f
4、ormula NH3 production method, ammonia gas is compressed to produce liquid ammonia products. Product performance liquid ammonia is colorless liquid, has a strong pungent odor, easy to gasification into gas ammonia. The density of 0.617g/cm3; the boiling point is 33.5 C, below 77.7 C can become colorl
5、ess crystal has a stink.Edit the physical and chemical nature of this paragraphMolecular formula: NH3 ammonia gas relative density (air =1):0.59 molecular weight: 17.04 relative density of liquid ammonia (water =1):0.602824 (25 C) CAS number: 7664-41-7 flash point: 651.11 DEG C melting point (c):-77
6、.7 explosion limit: 16% 25% boiling point (c):-33.4 1% aqueous solution pH value: 11.7 kJ (ratio of heat kg K (4.609) ammonia liquid ammonia (gas) 2.179) vapor pressure: 882kPa (20 DEG C) of autoionization: 2NH3? NH4+ +NH2- NH4Cl is therefore in liquid ammonia acid, alkali is NaNH2Edit this paragrap
7、h for product useLiquid ammonia is mainly used in the production of nitric acid, urea and other chemical fertilizers, and can also be used as raw materials for pharmaceuticals and pesticides. liquid ammoniaIn the national defense industry, used in the manufacture of rockets, missiles, propellants. C
8、an be used as organic chemical products can also be used as a refrigerant ammoniated raw materials. Liquid ammonia can also be used for mercerizing of textiles. The lone electrons in the NH3 molecule tend to form coordination bonds with other molecules or ions, generating ammonia in various forms. S
9、uch as Ag (NH3), 2+, Cu (NH3), 42+, BF3, NH3 and so on, are NH3 coordination complexes. Liquid ammonia is a good solvent, because of the polarity of molecules and the presence of hydrogen bonds, liquid ammonia is very similar in many physical properties to water. Some active metals can replace hydro
10、gen and produce hydroxides from water, which is less easily replaced by hydrogen in liquid ammonia. But liquid ammonia can dissolve metals and form a blue solution. The metal liquid ammonia solution conducts electricity and decomposes slowly to give off hydrogen gas, which has a strong reducibility.
11、 For example, the liquid ammonia solution of sodium: the reason why the metallic liquid ammonia solution is blue in color and that it can conduct electricity and is strongly reductive is due to the formation of ammonia electrons in the solution. For example sodium dissolved in liquid ammonia in lost
12、 valence electron produces its positive ions: ammonia is heated to 800 to 850 DEG C, on nickel catalyst, ammonia decomposition, can obtain hydrogen nitrogen mixed gas containing 75%H2 and 25%N2. The gas produced by this method is a good protective gas and can be widely used in the semiconductor indu
13、stry, metallurgical industry, and other industrial and scientific research that needs to protect the atmosphere.Edit this section packing, storage and transportationLiquid ammonia is a category 2.3 poisonous gas. It is filled by cylinder or tank car. Filling cylinders or tanks shall comply with the
14、liquid ammonia tank issued by the state Labour BureauRegulations on safety supervision of gas cylinders and regulations for the safety technical supervision of stationary pressure vessels. Allowable weight filling factor is 0.52kg/L. Cylinders and tanks for liquid ammonia shipments must comply with
15、the transport rules of dangerous goods formulated by the Ministry of communications of the Peoples Republic of China, and shall be prohibited from heating during transit. The cylinder must have safety cap, bottle external rubber ring or rope dressing, prevent the intense impact and vibration. Liquid
16、 ammonia cylinders should be stored in warehouses or shed platforms. In case of open storage, tents should be covered to prevent direct sunlight. Mainly by rail and road transport.Edit this paragraph poisoning disposalToxicity and toxicity mechanismLiquid ammonia, human mouth TDLo:0.15 ml/kg liquid
17、ammonia, human inhalation of LCLo:5000, ppm/5m ammonia into the human body will hinder the three carboxylic acid cycle, reducing the role of cytochrome oxidase. Causing increased brain ammonia, can produce neurotoxic effects. High concentration of ammonia can cause tissue dissolution and necrosis.Ro
18、ute of contact and symptoms of poisoningliquid ammonia1. inhalation is the main route of contact. Ammonia irritation is a reliable, harmful concentration alarm signal. However, due to olfactory fatigue, after long-term exposure to low concentration of ammonia will be difficult to detect. (1) mild in
19、halation of ammonia poisoning, manifested in rhinitis, pharyngitis, bronchitis, bronchitis.Patients with pharyngeal pain, cough, sputum or hemoptysis, chest tightness and chest pain. (2) the occurrence of acute inhalation of ammonia poisoning is caused by accidents, such as pipe rupture and valve ru
20、pture. The main symptoms of acute ammonia poisoning are respiratory tract mucous membrane irritation and burn. The symptoms vary according to ammonia concentration, duration of inhalation, and personal feelings. (3) severe inhalation poisoning can cause laryngeal edema, subglottic stenosis and respi
21、ratory tract mucosal abscission, which can cause tracheal obstruction and asphyxia. Inhalation of high concentrations can directly affect pulmonary capillary permeability and cause pulmonary edema. 2. skin and eye contact with low concentrations of ammonia, eye and wet skin can quickly stimulate. Ex
22、posure to high concentrations of ammonia in moist skin or eyes can cause severe chemical burns. Skin contact can cause severe pain and burns, and coffee coloration can occur. By the corrosion rubbery and weak, the depth of tissue damage can occur. High concentrations of vapors are irritating to the
23、eyes, causing pain and burns, causing obvious inflammation, and may cause edema, epithelial tissue destruction, corneal opacity, and inflammation of the iris. Mild cases are usually mild, severe cases may last for a long time, and persistent complications such as persistent edema, scarring, permanen
24、t opacities, bulging eyes, cataracts, eyelid and eyeball adhesions, and blindness are present. Repeated or persistent exposure to ammonia can cause conjunctivitis.First-aid measures1. remove pollution. If the patient is only exposed to ammonia and has no skin or eye irritation, there is no need to r
25、emove the pollution. If the contact is liquid ammonia and the clothes have been contaminated, clothes should be removed and placed in a double plastic bag. Liquid ammonia accidentIf you have eye contact or eye irritation, rinse with plenty of water or saline for more than 20 minutes. Such as eyelid
26、spasm in flushing, should slowly into 1 2 drops 0.4% oxybuprocaine, to fully wash. If the patient wears contact lenses and is easy to remove and does not damage the eyes, contact lenses should be removed. Rinse the skin and hair with contact with plenty of water for more than 15 minutes. Protect you
27、r eyes and skin when you rinse your skin and hair. 2. the patient should be removed immediately from the contaminated area, and the patient will be resuscitated by a three step (airway, breathing, circulation): airway: the airway should not be obstructed by the tongue or foreign body. Breathing: che
28、ck whether the patient is breathing, such as no breathing, you can use a pocket mask and so on to provide ventilation, circulation: check pulse, if there is no pulse, cardiopulmonary resuscitation should be performed. 3., the initial treatment of ammonia poisoning, no special antidote, should suppor
29、t treatment. If the contact concentration is 500ppm, and the emergence of eye irritation and pulmonary edema symptoms, it is recommended to take the following measures: first, spray 5 times (dexamethasone with metered dose inhaler), then spray two times every 5 minutes, until arriving at the hospita
30、l emergency room now. If the contact concentration is 1500ppm, should establish intravenous access, and intravenous injection of 1.0g Kakip Nixonn Ron (methylprednisolone) or the same dose of steroids. (Note: in clinical controlled studies, the role of corticosteroids has not been demonstrated. For
31、ammonia inhalation, humidified air or oxygen should be given. If you have hypoxia symptoms, you should give humidified oxygen. If respiratory distress is concerned, endotracheal intubation should be considered. When the patients condition cannot be intubated, a loop cartilage incision should be perf
32、ormed if the condition permits. For patients with bronchospasm, you can give bronchodilator sprays, such as Uncle Ding Chuanning. For example, skin contact with ammonia can cause chemical burns, which can be treated by heat burns: proper rehydration, analgesics, maintenance of body temperature, and
33、the use of disinfectant pads or cleaning sheets. If the skin contact with high pressure liquid ammonia, pay attention to frostbite.Edit this paragraph exhaust gas recoveryThe liquid ammonia finishing process of waste gas is discharged, the composition of water vapor, air and ammonia, ammonia is harm
34、ful gas, the health effects of environmental pollution, to reduce emissions, strengthen the recovery, on the one hand can reduce the cost, on the other hand can protect the environment. Liquid ammonia alarmThe recovery of ammonia absorption method, the gas discharged from the liquid ammonia treatmen
35、t machine, through the pipeline to the washing tower recovery device (absorber), mix with air in the water absorption tower of ammonia into ammonia, at this time the air is clean and discharged outside the tower, and then the ammonia and water separation by distillation, ammonia is distillation and
36、absorption of ammonia into ammonia by rectification, the concentrated ammonia, then the ammonia concentration through the compressor pressure and condensed into liquid ammonia storage tank, and input. In the ammonia recovery unit, the top of the washing tower has an exhaust port, and the ammonia con
37、tent in the exhaust gas should be controlled, which is lower than the environmental protection requirements. The ammonia recovery system created by Chengjiang textile machinery factory and Nanjing chemical industry university is a method of combining absorption and compression. In January 2000 of th
38、at year, experts from the China Textile Machinery Association organized on-the-spot investigation,Agreed that the ammonia recycling system is successful, the recovery system is the creative use of low pressure absorption, low temperature, low pressure distillation in water, condensing the three low
39、pressure technology, which can simplify equipment and save energy, the law is in operation at low temperature and low pressure, high safety factor, but also conducive to reduce maintenance power. There are washing tower (absorption tower), distillation tower, compressor, condenser, liquid ammonia st
40、orage tank. Ammonia monitoring and alarm in the process of using liquid ammonia leak to alarm, leakage of liquid ammonia produced by Baoji kaiteli electronics company cut off the alarm and automatic filling liquid ammonia alarm device in line with the National Technical Supervision and inspection de
41、partments requirements. Liquid ammonia pressure, because the critical temperature of ammonia is 132.4 degrees, lower than this temperature, as long as the appropriate pressure can be liquefied. At normal temperatures, the atmosphere is liquefied at about 78 atmospheres to liquefy ammonia into liquid ammonia. But the actual use temperature may not be normal at room temperature. Our country requires that the design should be no less than 50 degrees Celsius saturated vapor pressure. The design pressure for liquid ammonia containers should be 2.16MPa