二酸化イオウ 化学特性,用途語,生産方法
性質
1. 物理的特性
二酸化硫黄は、融点が-75.5℃、沸点が-10℃、液体時の比重が1.4です。二酸化硫黄は、水に溶けやすく、・・四塩化炭素・・・酢酸エーテル・に可溶です。二酸化硫黄には、酸化剤としても還元剤としても作用するという特徴があります。
2. その他の特徴
二酸化硫黄は、腐食性の強い有毒物質であり、緑青のように、各種の金属表面を腐食します。製錬所や石油・石炭等を燃料に使う工場の排煙などには、かなりの量の二酸化硫黄が含まれており、都市空気の汚染源や酸性雨の要因として注目されています。
解説
二酸化硫黄，ニサンカイオウ，亜硫酸ガス(sulfurous acid gas)は二酸化硫黄の気体の通俗名．天然には，火山ガス，鉱泉中に少量含まれている．工業的には，硫黄，硫化水素，黄鉄鉱FeS2などの金属硫化物の燃焼によって製造される．実験室では，市販のボンベ入り二酸化硫黄を使用するか，固体亜硫酸塩の硫酸分解，または銅と濃硫酸との熱時反応により発生させる．気体は無色．刺激臭があり有毒．液体は無色透明．固体は白色．密度1.46 g cm－3(－10 ℃，液体)，2.927 g dm－3(気体)．融点－75.48 ℃，沸点－10.02 ℃．水に易溶，アセトン，エタノール，四塩化炭素，ベンゼン，メタノール，酢酸，エーテル，クロロホルムに可溶．気体は折れ線形SO2分子からなり，S-O0.14308 nm．∠O-S-O119.32°．双極子モーメント1.59 D．
の反応速度は遅く，400～450 ℃ で白金または五酸化二バナジウムなどの触媒を用いないと，収率よく酸化されない．水が存在すれば，室温でも酸化される．二酸化硫黄は酸化剤としても還元剤としてもはたらく．硫化水素と反応し，硫黄と水とを生成する．二酸化硫黄の水溶液は亜硫酸H2SO3水溶液とよばれてきたが，H2SO3分子は水溶液中に存在せず，水和した二酸化硫黄分子が存在するのみである．液体二酸化硫黄は非水溶媒として多くの無機，有機化合物を溶かし，NMR(核磁気共鳴)の研究，合成などに用いられる．もっとも強い酸HSO3F-SbF5(super acid)の溶媒としても使われる．硫酸製造の原料，殺菌剤，殺虫剤，浮選，漂白剤，還元剤，農薬，医薬品，酸化防止剤などに用いられる．
用途
農業用くん蒸剤、殺虫剤、保存剤(果物及び野菜の防腐)、殺菌剤(食品加工,器具の消毒など)、漂白剤(製紙,繊維及び織物,麦わら,ゼラチン,グルー,てん菜糖)、パルプ工業(木材の処理)、粗皮のなめし、消毒剤、防腐剤、鉱油の精製(芳香族成分の溶剤抽出)非水化学溶媒、各種亜硫酸塩、その他化学薬品の製造、冶金
構造
二酸化硫黄は、C2v対称の折れ線形の構造をしています。分子軌道法の点から見ると、多くの電子対が結合に関与する超原子価化合物の一種であると言われていましたが、実際にはに似た比較的単純な結合構造であることが判明しています。硫黄と酸素の結合距離は約143pmで、折れ線構造のなす角度は約119°です。
製法
二酸化硫黄は、固体亜硫酸塩をで分解するといった方法や、と濃硫酸を熱反応させるという方法によって発生します。また、工業的には、硫黄・・黄鉄鉱等の金属硫化物を燃焼することで製造されています。セメント製造時には、無水硫酸カルシウムをコークスと加熱してを生成しますが、副生成物として二酸化硫黄が発生します。
効能
酸化防止剤
説明
Sulfur dioxide is a compound formed by the
combination of the elements sulfur and oxygen.
On a weight basis, the proportion of the elements is about I part sulfur to I part oxygen, or
more exactly, 50.05 percent to 49.95 percent,
respectively. At standard conditions of temperature and pressure, sulfur dioxide is a colorless gas with a characteristic pungent odor. It
may be cooled and compressed to a colorless
liquid, which, at one atmosphere pressure, boils
at 14°F (10.0°C) and freezes at -104.6°F (-75.9°C). Sulfur dioxide liquid is heavier than
water, and has a specific gravity of 1.436 at
32°F (0°C). As a gas, it is more than twice as
heavy as air; its relative density is 2.2638 at
atmospheric pressure and 32°F (0°C).
Sulfur dioxide is not flammable or explosive
in either the gaseous or liquid state. It is a relatively stable chemical. Temperatures above
3632°F (2000°C) are required to bring about
detectable decomposition of sulfur dioxide. Dry
sulfur dioxide (less than 100 ppm water) is not
corrosive to ordinary metals. However, in the
presence of even small amounts of water, sulfur
dioxide becomes corrosive to most metals, with
exceptions including lead, Type 316 stainless
steel, and certain alloys. Glass and certain plastics are also resistant to moist sulfur dioxide.
化学的特性
Sulfur dioxide,S02, also known as sulfurous acid anhydride,is a toxic, irritating, colorless gas. It is soluble in water, alcohol, and ether, and boils at -10 °C. Sulfur dioxide is used as a chemical intermediate, in artificial ice, in paper pulping,in ore refining,and as a solvent.
sulfur dioxide lewis structure
物理的性質
Colorless gas; pungent suffocating odor; gas density 2.927 g/L at 20°C; heavier than air, vapor density 2.263 (air=1); condenses to a colorless liquid at -10°C; density of liquid SO
2 1.434 g/mL; freezes at -72.7°C; critical temperature 157.65°C; critical pressure 77.78 atm; critical volume 122 cc/g; dielectric constant 17.27 at -16.5°C; dissolves in water forming sulfurous acid, solubility 22.97 g and 11.58 g/100mL water at 0° and 20°C, respectively, under atmospheric pressure; very soluble in acetone, methyl isobutyl ketone, acetic acid, and alcohol; soluble in sulfuric acid; liquid SO
2 slightly miscible in water.
天然物の起源
Reported found in orange juice, grapefruit juice, onion, boiled and cooked beef,starfruit and weinbrand brandy.
使用
Sulfur Dioxide is a preservative, being a gas that dissolves in water
to yield sulfurous acid. sulfite salts, such as sodium and potassium
sulfite, sodium and potassium bisulfite, and sodium and potassium
metabisulfite, yield free sulfurous acid at low ph. sulfur dioxide pre-
vents the discoloration of foods by combining with the sugars and
enzymes. it also inhibits bacterial growth. it is used in beverages,
cherries, wines, and fruits.
調製方法
Sulfur dioxide can be made by burning sulfur, or by roasting sulfide
ores such as pyrites, sphalerite, and cinnabar.
製造方法
Sulfur dioxide usually is prepared industrially by the burning in air or oxygen of sulfur or such compounds of sulfur as iron pyrite or copper pyrite. Large quantities of sulfur dioxide are formed in the combustion of sulfur-containing fuels. In the laboratory, the gas may be prepared by reducing sulfuric acid (H2SO4) to sulfurous acid (H2SO3), which decomposes into water and sulfur dioxide, or by treating sulfites (salts of sulfurous acid) with strong acids, such as hydrochloric acid, again forming sulfurous acid.
毒性
二酸化硫黄は腐食性の強い有毒物質で，結膜炎を起こしたり，上気道をおかすために，せき，呼吸困難，胸痛などの症状を引き起こす．労働衛生上の許容濃度は5 ppm( ＝ 13 mg SO2/m3)である．植物では1 ppm 以下でも光合成が阻害されるため，大きな影響が出る．二酸化硫黄は空気中の酸素，水分，じんあいにより酸化されて硫酸になり，さらにその危険度を増す．また，緑青(ろくしょう)のように各種の金属表面を腐食する．大気中の二酸化硫黄の環境基準は，1日平均値が0.04 ppm 以下であり，かつ1時間値が0.1 ppm 以下であること，とされている．[CAS 7446-09-5][別用語参照]二酸化硫黄の微量分析，大気汚染
空気と水の反応
Dissolves in water to form sulfurous acid, a corrosive liquid. Moist Sulfur dioxide is very corrosive due to the slow formation of sulfuric acid [Handling Chemicals Safely 1980 p. 876].
反応プロフィール
Sulfur dioxide is acidic. Reacts exothermically with bases such as amines, amides, metal oxides, and hydroxides. Frequently used as a reducing agent although Sulfur dioxide is not a powerful one. Acts as a reducing bleach to decolorize many materials. Can act as an oxidizing agent. Supports combustion of powdered aluminum [Mellor 5:209-212 1946-47]. Reacts explosively with fluorine [Mellor 2:1 1946-47]. Supports burning of manganese [Mellor 12:187 1946-47]. Readily liquefied by compression. Contact between the liquid and water may result in vigorous or violent boiling and extremely rapid vaporization. If the water is hot an explosion may occur. Pressures may build to dangerous levels if the liquid contacts water in a closed container [Handling Chemicals Safely 1980]. Supports incandescent combustion of monocesium acetylide, monopotassium acetylide, cesium oxide, iron(II) oxide, tin oxide, and lead oxide [Mellor]. Ethylene oxide and SO2 can react violently in pyridine solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).
危険性
Toxic by inhalation, strong irritant to eyes
and mucous membranes, especially under pressure.
Dangerous air contaminant and constituent of smog.
Not permitted in meats and other sources of vitamin
B1. U.S. atmospheric standard 0.140 ppm. Pulmonary
function inhibitor and lower respiratory
tract irritant. Questionable carcinogen.
健康ハザード
Exposures to sulfur dioxide cause adverse health effects to users and occupational workers.
The gaseous sulfur dioxide is particularly irritating to the mucous membranes of the
upper respiratory tract. Chronic exposure to sulfur dioxide produces dryness of the throat,
cough, rhinitis, conjunctivitis, corneal burns, and corneal opacity. Acute exposure to high
concentrations of sulfur dioxide may also result in death due to asphyxia. By contrast,
chronic exposures to sulfur dioxide lead to nasopharyngitis, fatigue, and disturbances of
the pulmonary function. Animals exposed to chronic doses of sulfur dioxide have shown
thickening of the mucous layer in the trachea and also hypertrophy of goblet cells and
mucous glands resembling the pathology of chronic bronchitis. It has been found that
penetration of sulfur dioxide into the lungs is greater during mouth breathing than during
nose breathing. In fact, an increase in the fl ow rate of the gas would markedly increase the
penetration. Human subjects exposed for very brief periods to sulfur dioxide also showed
alterations in pulmonary mechanics. More information on the adverse effects of sulfur
dioxide and the manner of its potentiation in association with other chemicals may be
found in literature.
火災危険
Containers may explode in heat of fire or they may rupture and release irritating toxic Sulfur dioxide. Sulfur dioxide has explosive properties when Sulfur dioxide comes in contact with sodium hydride; potassium chlorate at elevated temperatures; ethanol; ether; zinc ethylsulfurinate at very cool temperatures (-15C); fluorine; chlorine trifluoride and chlorates. Sulfur dioxide will react with water or steam to produce toxic and corrosive fumes. When the liquid is heated Sulfur dioxide may release irritating, toxic Sulfur dioxide gas. Avoid ammonia, monocesium or monopotassium acetylide; dicesium monoxide; iron (II) oxide; tin oxide; lead (IV) oxide; chromium; manganese; molten sodium, powder aluminum and rubidium. Sulfur dioxide has explosive properties when Sulfur dioxide comes in contact with sodium hydride; potassium chlorate at elevated temperatures; ethanol; ether; zinc ethylsulfurinate at very cool temperatures (-15C); fluorine; chlorine trifluoride and chlorates. Sulfur dioxide will react with water or steam to produce toxic and corrosive fumes. Hazardous polymerization may not occur.
燃焼性と爆発性
Sulfur dioxide is a noncombustible substance (NFPA rating = 0).
取扱いおよび保管上の注意
取扱い及び保管上の注意は、下記の通りです。
- 保管容器は、換気の良い40℃以下の場所で保管する。
- 使用後は、容器のバルブを完全に閉め、口金キャップとを付ける。
- 水分があると、やスチールなど多くの金属を侵すため、接触を避ける。
- 液状ではプラスチックやゴムを侵すため、接触を避ける。
- 屋外や換気の良い区域のみで使用する。
- 使用時は保護手袋、保護眼鏡を着用する。
- 取扱い後はよく手を洗浄する。
- 皮膚に付着した場合は、石鹸と水で洗い流す。
- 眼に入った場合は、水で数分間注意深く洗う。
- 蒸気は呼吸器を刺激し、咳や気管支炎などを引き起こすので、吸入を避ける。
使用用途
1. 食品添加物
二酸化硫黄は、抗菌作用をもつ性質を活かし、酒やドライフルーツの保存料、漂白剤、酸化防止剤として利用されています。
2. 溶媒
液体の二酸化硫黄は、非水溶媒として、多くの無機化合物や有機化合物を溶かすため、核磁気共鳴の研究や各種の合成などに用いられています。
3. 漂白剤
二酸化硫黄は、強い還元作用をもっているため、パルプ等の漂白剤・殺菌剤などにも利用されています。
4. その他
二酸化硫黄は、その他にも、硫酸や等を製造する際の原料として使用されています。殺虫剤や還元剤、農薬、医薬品、石油精製などにも用いられています。
法規情報
二酸化硫黄は、労働安全衛生法では名称等を通知すべき危険物及び有害物に、労働基準法では疾病化学物質にそれぞれ指定されており、取り扱いには注意が必要です。
応用例（製薬）
Sulfur dioxide is used as an antioxidant for pharmaceutical
injections. It is also used as a preservative and antioxidant in the
food and cosmetics industries.
材料の用途
Service conditions must be defined to properly
specifY materials of construction for handling
sulfur dioxide. It is customary, however, to use
carbon steel for dry sulfur dioxide at ambient
temperatures. Reference should be made to the
latest edition of the ASME Code, Section VIlI,
Division I for vessels, and to the latest edition of ANSI/ASME 831.3, Chemical Plant and
Petroleum Refinery Piping for piping specifications.
Moist sulfur dioxide is corrosive to carbon
steel; therefore, other materials of construction
have to be considered in this case. A source of
data on the corrosivity of sulfur dioxide to various materials is the Corrosion Data Survey,
published by the National Association of Corrosion Engineers; suppliers of liquid sulfur dioxide are another source.
安全性プロファイル
A poison gas. Experimental reproductive effects. Human mutation data reported. Human systemic effects by inhalation: pulmonary vascular resistance, respiratory depression, and other pulmonary changes. Questionable carcinogen with experimental tumorigenic and teratogenic data. It chiefly affects the upper respiratory tract and the bronchi. It may cause edema of the lungs or glottis, and can produce respiratory paralysis. A corrosive irritant to eyes, skin, and mucous membranes. This material is so irritating that it provides its own warning of toxic concentration. Levels of 400-500 ppm are immediately dangerous to life. Its toxicity is comparable to that of hydrogen chloride. However, less than fatal concentration can be borne for fair periods of time with no apparent permanent damage. It is a common air contaminant. A nonflammable gas. It reacts violently with acrolein, Al, CsHC2, Cs2O, chlorates, ClF3, Cr, FeO, F2, Mn, KHC2, KClO3, Rb2C2, Na, Na2C2, SNOx diaminolithiumacetylene carbide. Will react with water or steam to produce toxic and corrosive fumes. Incompatible with halogens or interhalogens, lithium nitrate, metal acetylides, metal oxides, metals, polymeric tubing, potassium chlorate, sodium hydride.
安全性
Sulfur dioxide is used in food and pharmaceutical products.
However, in large amounts, sulfur dioxide gas is highly irritant to
the eyes, skin, and mucous membranes. Inhalation can lead to
severe irritation of the respiratory tract. Direct contact with the
liquid form may cause frostbite. Sulfur dioxide and sulfites may also
cause allergic reactions and asthma.
職業ばく露
Sulfur dioxide is used in the manufacture of sodium sulfite, sulfuric acid; sulfuryl chloride; thionyl chloride; organic sulfonates; disinfectants, fumigants, glass, wine, ice, industrial and edible protein; and vapor pressure thermometers. It is also used in the bleaching of beet sugar, flour, fruit, gelatin, glue, grain, oil, straw, textiles, wicker ware; wood pulp; and wool; in the tanning of leather; in brewing and preserving; and in the refrigeration industry. Exposure may also occur in various other industrial processes as it is a by-product of ore smelting, coal and fuel oil combustion; paper manufacturing and petroleum refining.
発がん性
Sulfur dioxide may act as a cancer promoter. The mortality of
arsenic smelter workers was higher when they had also been
exposed to sulfur dioxide. In addition, rats exposed to
3.5 or 10 ppm of sulfur dioxide developed squamous cell
carcinomas from inhalation of benzo[a]pyrene, but neither compound alone produced carcinomas under the conditions
of this experiment.
貯蔵
Sulfur dioxide is noncorrosive and stable when dry. It is usually
stored under pressure in cylinders, and should be kept in a cool, dry,
well-ventilated area, away from flammable materials.
輸送方法
UN1079 Sulfur dioxide, Hazard Class: 2.3; Labels: 2.3-Poisonous gas, 8-Corrosive material, Inhalation Hazard Zone C. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner
純化方法
Dry it by bubbling through conc H2SO4 and by passage over P2O5, then through a glass-wool plug. Freeze it with liquid air and pump it to a high vacuum to remove dissolved gases. It is easily liquefied by compression (2.5atmospheres at 15o), or by passing it through a glass spiral column in a freezing mixture of ice and salt. It is a colourless liquid with a density of 1.434 at 0o, which on rapid evaporation forms a snow white solid. It could be used as a solvent in certain reactions. HARMFUL SUFFOCATING VAPOURS.
不和合性
Sulfur dioxide reacts vigorously with strong alkalis and oxidizing
agents. The moist gas corrodes most metals. Sulfur dioxide is
incompatible with chlorates, fluorine, interhalogens, powdered
metals, metal oxides, metal acetylides, sodium hydroxide, and
diethyl zinc. It is also incompatible with thiamine and gelatin.
廃棄物の処理
Return refillable compressed gas cylinders to supplier. Pass into soda ash solution, then add calcium hypochlorite; neutralize and flush to sewer with water (A-38).
予防処置
Occupational workers should be careful at workplaces because exposure to sulfur dioxide
occurs from breathing it in the air. It affects the lungs and at high levels may result in burning
of the nose and throat, breathing diffi culties, and severe airway obstructions.
規制状況(Regulatory Status)
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (IV infusions;
injection solutions). Included in the Canadian List of Acceptable
Non-medicinal Ingredients.
二酸化イオウ 上流と下流の製品情報
原材料
準備製品