アンモニア 化学特性,用途語,生産方法
外観
無色澄明の液体
溶解性
水、エタノール及びアセトンに混和する。
解説
液安ともいう。強いアンモニア臭を有する無色，流動性の液体。沸点－33.35℃，凝固点－77.7℃，臨界温度132.4℃，臨界圧112気圧，比重0.817(－79℃)，屈折率nD＝1.325(－15℃)，粘度0.2543センチポアズ(－33.5℃)(水の粘度は常温で約1センチポアズ)，誘電率22.7(－50℃)(水の誘電率は常温で約80)。ドライアイス‐メチルアルコールなどの冷媒を用いアンモニアNH3を液化して容易に得られる。
用途
化学原料 アンモニアは硝酸などの基礎化学品、硫安などチッソ肥料の原料となるため、工業的に極めて重要な物質である。 液化したアンモニアはバーチ還元の溶媒として使用される。
火力発電用燃料 前述のようにアンモニアは条件次第で燃焼し、燃やしても代表的な温暖化ガスである二酸化炭素が発生しない。このためアンモニアを火力発電用燃料として使う技術開発が行われている。
環境に有害な窒素酸化物の発生を抑制するために火力発電所のボイラーなどに設置される、選択触媒還元脱硝装置の還元剤として使用される。
用途
農業用の液体肥料、窒素質肥料、化学繊維。
合成
自然界では大気中に微量、天然水中にもアンモニアは少量存在しています。また、土壌中は肥料 (アンモニア含む) 、動植物の遺骸等に含まれた窒素有機物が分解生物によって、アンモニア態窒素に分解されて含まれています。
19世紀末期のヨーロッパでは、多くの研究者がアンモニアの合成に挑戦しました。不可能と思われていたアンモニア合成ですが、水素と窒素から直接アンモニアを合成するドイツ人ハーバーが実験室的に成功した研究をBASF 社のボッシュが1913年工業化しました。これが、ハーバー・ボッシュ法です。
現在、工業的なアンモニアの生産はハーバー・ボッシュ法によるものが一般的であり、触媒上で窒素と水素を加圧・高温環境下で反応させています。
効能
溶解剤, アンモニア原料
使用上の注意
不活性ガス封入
説明
Ammonia is a colorless, pungent-smelling gas that is one of the most important industrial inorganic chemicals. It is widely used in fertilizers, refrigerants, explosives, cleaning agents, and as a feedstock to produce numerous other chemicals. Ammonia ranks as one of the top 10 chemicals produced annually.
化学的特性
Ammonia is a colorless, strongly alkaline, and extremely soluble gas with a pungent, suffocating odor.
Strong ammonia solution occurs as a clear, colorless liquid having an exceedingly pungent, characteristic odor. It is lighter than air, and is formed as a result of the decomposition of most nitrogenous organic materials. The PhEur 6.0 states that concentrated ammonia solution contains not less than 25.0% and not more than 30.0% w/w of ammonia (NH3). The USP32– NF27 states that strong ammonia solution contains not less than 27.0% and not more than 31.0% w/w of ammonia (NH3).
Anhydrous ammonia, a major commercial chemical, is used in the manufacture of fertilizers, HN03, acrylonitrile, and other products, and as an electrolytic solvent.
物理的性質
Colorless gas with a penetrating, pungent, suffocating odor. An experimentally determined odor
threshold concentration of 45.8 ppm
v was reported by Leonardos et al. (1969). A detection odor
threshold concentration of 11.6 mg/m
3 (16.7 ppm
v) was experimentally determined by Nishida et
al. (1974).
来歴
During the Middle Ages ammonia was produced by the distillation of animal dung, hooves, and horn. Its preparation from horn gave it another name: spirit of hartshorn. Joseph Priestley (1733–1804) isolated ammonia in 1774 and called the compound alkaline air. The modern name ammonia was given to the compound in 1782 by the Swedish chemist Torbern Bergman (1735–1784). The exact chemical composition was determined by Claude-Louis Berthollet (1748–1822) in 1785. During the 19th century ammonia was obtained from the distillation of coal tar. The importance of nitrogen fertilizers in agriculture was established during the mid-1800s, and this coupled with the growth of the chemical industry provided incentive to find a method for fixing nitrogen.
使用
Ammonia is a large-tonnage industrial product and finds its major use in the manufacture of nitric acid and fertilizers. It is the most commonly used refrigerant, particularly for large industrial installations.
定義
ChEBI: An azane that consists of a single nitrogen atom covelently bonded to three hydrogen atoms.
調製方法
Ammonia is obtained commercially chiefly by synthesis from its
constituent elements, nitrogen and hydrogen, which are combined
under high pressure and temperature in the presence of a catalyst.
Ammonia solution is produced by dissolving ammonia gas in water.
イオン化
液体状のアンモニアをいう．比誘電率が大きく(25(－78 ℃))，電離性溶媒で
2NH3 NH4＋ ＋ NH2－
のように電離しているが，水よりは弱い電解質でイオン積[NH4＋][NH2－]は 10－22 mol2 dm－6(－33 ℃)．アルカリ金属を溶かして青色液となるが，これは金属のイオン化によって生じた電子が溶媒和電子となるためである．極性物質をよく溶解するが，水より電離度が小さいため，水よりは有機物をよく溶かす．液体アンモニア中ではアンモニウム塩はアンモノ酸，アミド化合物はアンモノ塩基となる．これらに対しては，水溶液中の酸塩基と同様，酸・塩基指示薬もそれぞれに対応して変色する．陽子親和力は水より大きいので塩基性の強い溶媒であり，水を還元するような強い還元剤も液体アンモニア中ではアンモニアを還元することはなく，強還元剤の還元反応を研究することができる．
一般的な説明
The product is a 0.4 M solution of ammonia in dioxane. Ammonia is a colorless gas with a characteristic strong odor. It is highly soluble in water, alcohol, chloroform and ether. It is extensively sold in the form of solution.1 Ammonia molecule is pyramidal in shape with nitrogen in the center and the three hydrogen atoms along the three vertices and the lone pair of electrons on the fourth vertex. Ammonia solution is commonly used as a base.
空気と水の反応
Soluble in water with evolution of heat. The amount of heat generated may be large.
反応プロフィール
AMMONIA is a base. Reacts exothermically with all acids. Violent reactions are possible. Readily combines with silver oxide or mercury to form compounds that explode on contact with halogens. When in contact with chlorates Ammonia forms explosive ammonium chlorate [Kirk-Othmer, 3rd ed., Vol. 2, 1978, p. 470]. Reacts violently or produces explosive products with fluorine, chlorine, bromine and iodine and some of the interhalogen compounds (bromine pentafluoride, chlorine trifluoride). Mixing of bleaching powder (hypochlorite solution) with ammonia solutions produces toxic/explosive ammonia trichloride vapors. Undergoes potentially violent or explosive reactions on contact with 1,2-dichloroethane (with liquid ammonia), boron halides, ethylene oxide (polymerization), perchlorates or strong oxidants (chromyl chloride, chromium trioxide, chromic acid, nitric acid, hydrogen peroxide, chlorates, fluorine, nitrogen oxide, liquid oxygen). Reacts with silver chloride, silver oxide, silver nitrate or silver azide to form the explosive silver nitride. May react with some heavy metal compounds (mercury, gold(III) chloride) to produce materials that may explode when dry. [Bretherick, 5th ed., 1995, p. 1553].
危険性
Inhalation of concentrated fumes may be
fatal. Moderate fire risk, explosive limits in air 16–
25%. Forms explosive compounds in contact with
silver or mercury. Eye damage and upper respiratory
tract irritant.
健康ハザード
Ammonia is intensely irritating to the eyes,nose, and respiratory tract. Toxic effectsinclude lachrymation, respiratory distress,chest pain, and pulmonary edema. A concentration of 10 ppm may be detected by odor;irritation of eyes and nose is perceptible atabout 200 ppm. A few minutes of exposureto 3000 ppm can be intolerable, causing seri ous blistering of the skin, lung edema, andasphyxia, leading to death. It is corrosive toskin because it reacts with moisture to formcaustic ammonium hydroxide. Long expo sure may result in destruction of tissues
LC50 value, inhalation (mice): 4200 ppm/hr.
火災危険
Mixing of ammonia with several chemicals can cause severe fire hazards and/or explosions. Ammonia in container may explode in heat of fire. Incompatible with many materials including silver and gold salts, halogens, alkali metals, nitrogen trichloride, potassium chlorate, chromyl chloride, oxygen halides, acid vapors, azides, ethylene oxide, picric acid and many other chemicals. Mixing with other chemicals and water. Hazardous polymerization may not occur.
燃焼性と爆発性
Ammonia vapor is slightly flammable (NFPA rating = 1) and ignites only with
difficulty. Ammonia forms explosive mixtures with air in the range 16 to 25%.
Water, carbon dioxide, or dry chemical extinguishers should be used for ammonia
fires.
使用用途
1. 肥料
最も一般的なアンモニアの使用用途は化学肥料です。世界で生産されたアンモニアのうち、約8割は肥料として消費されます。残り2割は工業用として、化学製品の基礎材料に使用されています。
世界の人口増加を支えてきた食糧増産技術ですが、中でもアンモニアを原料とする窒素化合物を使った化学肥料は農業に大きく貢献しました。現在も世界の人口は増え続けています。食料確保の必要性から、農産物肥料としてのアンモニアの重要性は今後も変わらないと考えられます。
2. 燃料アンモニア
近年、地球温暖化対策への新たな取り組みの一つとして、アンモニアを燃料エネルギーとして利用する研究が注目されています。アンモニアは燃焼時に、を排出しないカーボンフリー物質であるためです。現在、技術開発が進んでいるのが、石炭火力発電のボイラーにアンモニアを混ぜて燃焼させる「火力混焼」です。将来的には、エネルギー源をすべてアンモニアとする専焼発電を視野に入れた技術開発が進められています。
3. エネルギーキャリア
二酸化炭素の排出量を減らすために、水素をエネルギーとして使用するものも増えてきています。大量輸送が難しい水素を別の材料に変換したものを「水素キャリア」と呼びます。
輸送媒体として水素分子 (H) を含むアンモニア (NH3) が役立つ可能性が高いです。アンモニアは前述したように、肥料用途を中心に世界で輸出入が行われていることから、輸送の既存技術は確立しています。
輸送後、触媒の存在下で熱分解によって再び水素に戻し、などに利用する使い方とアンモニアのまま燃料にしてしまう使い方が考えられています。
化学性质
常温常圧では，強い刺激臭のある色のガスであり，人体に有毒な可燃性ガスである。常圧での沸点は?33.4℃で，空気中での爆発範囲は15.5?28％（l atm，常温）であり，酸素中での爆発範囲は13.5?82％である。水溶液中では水酸化アンモニウムになり，弱塩基性を呈し金属塩水溶液から金属水酸化物を沈殿する。
応用例（製薬）
Ammonia solution is typically not used undiluted in pharmaceutical
applications. Generally, it is used as a buffering agent or to adjust
the pH of solutions. Most commonly, ammonia solution (the
concentrated form) is used to produce more dilute ammonia
solutions.
Therapeutically, dilute ammonia solution is used as a reflex
stimulant in ‘smelling salts’, as a rubefacient, and as a counterirritant
to neutralize insect bites or stings.
工業用途
Ammonia (NH3) is an alkaline gas with a sharp, penetrating odor. Reacting nitrogen and
hydrogen under pressure, in the presence of a catalyst, produces ammonia. Gaseous
ammonia is flammable in air at concentrations of 15–28% by volume. Anhydrous liquid
ammonia is a colorless liquid with a strong odor. Ammonia, because of its unique
chemical properties to metal ions, is primarily used in hydrometallurgical processing.
In the mineral processing industry, ammonia is rarely used as a pH regulator. There was
only one operating plant in the world that used ammonia as a pH regulator in treatment
of a copper/zinc ore.
材料の用途
Most common metals are not affected by dry
ammonia. However, when combined with water
vapor, ammonia will attack copper, zinc, or
alloys containing copper as a major alloying
element. Therefore, these materials should not
be used in contact with ammonia. Certain hightensile-
strength steel have developed stresscorrosion
cracking in ammonia service, but such
cracking can be prevented by the use of 0.2 percent
water by weight in the ammonia as an inhibitor.
Ammonia storage tanks and their valves
and fittings are usually made of steel.
安全性
Ingestion of strong solutions of ammonia is very harmful and causes
severe pain in the mouth, throat, and gastrointestinal tract as well as
severe local edema with cough, vomiting, and shock. Burns to the
esophagus and stomach may result in perforation. Inhalation of the
vapor causes sneezing, coughing, and, in high concentration,
pulmonary edema. Asphyxia has been reported. The vapor is
irritant to the eyes. Strong solutions are harmful when applied to the
conjunctiva and mucous membranes. Topical application of even
dilute ammonia solutions, used to treat insect bites, has caused
burns, particularly when used with a subsequent dressing.
When used as an excipient, ammonia solution is generally
present in a formulation in a highly diluted form.
職業ばく露
Ammonia is used as a nitrogen source
for many nitrogen-containing compounds. It is used in the
production of ammonium sulfate and ammonium nitrate for
fertilizers; and in the manufacture of nitric acid, soda; synthetic
urea, synthetic fibers; dyes; and plastics. It is also
utilized as a refrigerant and in the petroleum refining and
chemical industries. It is used in the production of
many drugs and pesticides. Other sources of occupational
exposure include the silvering of mirrors, gluemaking, tanning
of leather; and around nitriding furnaces. Ammonia is
produced as a by-product in coal distillation and by the
action of steam on calcium cyanamide, and from the
decomposition of nitrogenous materials.
概要
アンモニアとは、窒素 (N) 原子1つと水素 (H) 原子3つの無機化合物です。
強い刺激臭が特徴の物質で、アンモニア臭は動物性食品に多くみられます。動物性食品にはタンパク質や遊離アミノ酸等、窒素化合物が大部分を占めるためです。これらが微生物によって腐敗し、分解されることでアンモニアが発生し、臭いとして現れます。
アンモニアは、常温常圧において無色の気体として安定しています。加圧・冷却により容易に液化し、液化したものは液安もしくは液化アンモニアと呼ばれます。
水によく溶ける物質であるため、アンモニア水の状態でも使用される場合が多いです。アンモニア水はアルカリ性を示し、 分析試薬として使用されます。他にも、衣類の染み抜き、虫刺されの際の中和剤として外用薬にも使用されています。
特徴
アンモニア分子は窒素原子を頂点とし、3つの水素原子が底辺を形成していているのが特徴です。窒素原子と水素原子はそれぞれ結合し、3次元の三角錐形の配置をとります。
三角錐形の理想的結合核は、四面体形の電子対幾何構造に基づきますが、単結合よりも孤立電子対の方が大きな空間の領域を占有するため、理想的な角度からずれます。このため、結合角は正四面体の109.5°ではなく結合核107°です。
環境運命予測
Chemical/Physical. Reacts violently with acetaldehyde, ethylene oxide, ethylene dichloride
(Patnaik, 1992).
Reacts with acids forming water soluble ammonium salts.
貯蔵
On exposure to the air, ammonia solution rapidly loses ammonia.
Ammonia solution should be stored in a well-closed container,
protected from the air, in a cool, dry place. The storage temperature
should not exceed 208℃.
合成方法
合成ガス圧縮機を出たガスは循環ガス圧縮機からのアンモニアを含んだ未反応ガスと混合され，次に?5??20℃までアンモニア冷凍機により冷却され，製品アンモニアの凝縮分離と微量のCO，CO2や水分を除去する。
輸送方法
Shipped in tank cars, tank trucks, barges, and
steel cylinders. Labeling and restrictions vary with concentration: NA1005 Ammonia, anhydrous, Hazard
Class: 2.2; Labels: 2.2-Nonflammable compressed gas,
Domestic (U.S.), Inhalation Hazard (Special Provision 13).
UN1005 Ammonia, anhydrous, Hazard Class: 2.3; Labels:
2.3-Poison Gas, 8-Corrosive material International,
Inhalation Hazard Zone D. UN2672 Ammonia solutions,
relative density between 0.880 and 0.957 @ 15 C in water,
with .10 % but NOT . 35 % ammonia, Hazard class: 8;
Labels: 8-Corrosive material. UN2073 Ammonia solution,
relative density less than 0.880 @ 15 C in water, with .
35% but NOT . 50% ammonia, Hazard Class: 2.2;
Labels: 2.2-Nonflammable compressed gas. Note: Also
used for Ammonium hydroxide, CAS1336-21-6, Record
A:0110.
純化方法
Dry the liquid, and store it, with sodium in a steel cylinder, then distil and condense it by means of liquid air, the non-condensable gases being pumped off. In order to obtain liquid NH3 from a cylinder, turn the cylinder upside-down (i.e. with the valve at the bottom, use a metal stand to secure it in this position) and lead a plastic tube from the tap to a measuring cylinder placed in an efficient fume cupboard which is kept running. Turn the tap on and allow the ammonia to be released. At first, gas and liquid will splatter out (make sure that the plastic tube is secure), but soon the liquid will drip into the measuring cylinder. The high latent heat of evaporation will cool the ammonia so that the liquid will remain cool and not boil vigorously. If the ammonia is required dry, the necessary precautions should be taken, i.e. the gas is allowed to flow through tubes packed with coarse CaO pellets. AMMONIA (gas, liquid or aqueous solution) is very irritating and should not be inhaled in any quantity as it can lead to olfactory paralysis (temporary or permanent).
不和合性
Ammonia solution reacts vigorously with sulfuric acid or other
strong mineral acids and the reaction generates considerable heat;
the mixture boils.
廃棄物の処理
Dilute with water, neutralize
with HCl and discharge to sewer. Recovery is an option to
disposal which should be considered for paper manufacture,
textile treating, fertilizer manufacture and chemical process
wastes.
規制状況(Regulatory Status)
Included in the FDA Inactive Ingredients Database (oral suspensions,
topical preparations). Included in nonparenteral medicines
licensed in the UK. Included in the Canadian List of Acceptable
Non-medicinal Ingredients.
参考文献
J.S. Solis, G. Hefter, P.M. May, Australian J. Chem., 48, 1283 (1995), DOI: 10.1071/CH9951283.
アンモニア 上流と下流の製品情報
原材料
準備製品